ORCID Profile
0000-0002-9884-3852
Current Organisation
University of South Australia
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Publisher: Informa UK Limited
Date: 04-2010
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-2014
Publisher: Springer Science and Business Media LLC
Date: 25-04-2015
Publisher: MDPI AG
Date: 06-01-2014
DOI: 10.3390/RS6010580
Publisher: Springer Science and Business Media LLC
Date: 12-02-2015
DOI: 10.1007/S10661-014-4202-Y
Abstract: From data collected monthly at 26 monitoring cross sections in the Wei River in the Shaanxi Region of China during the period 2008-2012, the temporal pollution characteristics of heavy metals (Hg, Cd, Cr(VI), Pb, and As) were analyzed based on a heavy metal pollution index (HPI). The monthly HPI values of the five heavy metals in the river fluctuated greatly in 2008 and then declined gradually with time. This general trend of reduction in HPI appears not to have a seasonal variation and most likely resulted from the continued improvement in heavy metal pollution control strategies implemented by local environmental agencies combined with a significant improvement in wastewater treatment capacities. Among the five heavy metals, Cd and Pb were below 0.1 and 3 μg L(-1), respectively, at all the s ling points in the studied areas in the year 2012. The detection rates of As, Hg, and Cr(VI) were in the order of Hg > Cr(VI) > As. Hg, Cr(VI), and As exceeded, in a month of the dry season in 2012, the standard limits for category III surface waters according to the China Environment Quality Standards for Surface Water (CEQSSW). Based on the assessment using the HPI method, the pollution status of these heavy metals in water of the Wei River in the Shaanxi Region was generally at an acceptable level, but exhibited distinctive characteristics between the main stream river and tributaries. Most of the tributaries were more seriously polluted than the main river. A health risk assessment was conducted based on the Human Health Risk Assessment (HHRA) method recommended by the United States Environmental Protection Agency (USEPA). Apart from As, the health risk for the five heavy metals in the region were at acceptable levels for drinking water sources (hazard quotient (HQ) < 1, carcinogenic risk (CR) ranged from 10(-4)-10(-6)) according to the Risk Assessment Guidance for Superfund (RAGS), USEPA. Arsenic was identified as the most important pollutant of concern among the five heavy metals both its values of the HQ and CR indicated potentially adverse health risks for the local population.
Publisher: Elsevier BV
Date: 09-2009
Publisher: Springer International Publishing
Date: 2021
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.SCITOTENV.2014.01.014
Abstract: Green roofs as one of the components of water-sensitive urban design have become widely used in recent years. This paper describes performance monitoring of four prototype-scale experimental green roofs in a northern suburb of Adelaide, South Australia, undertaken over a 1-year period. Four species of indigenous Australian ground cover and grass species comprising Carpobrotus rossii, Lomandra longifolia 'Tanika,' Dianella caerula 'Breeze' and Myoporum parvifolium were planted in extensive and intensive green roof configurations using two different growing media. The first medium consisted of crushed brick, scoria, coir fibre and composted organics while the second comprised scoria, composted pine bark and hydro-cell flakes. Plant growth indices including vertical and horizontal growth rate, leaf succulence, shoot and root biomasses, water use efficiency and irrigation regimes were studied during a 12-month period. The results showed that the succulent species, C. rossii, can best tolerate the hot, dry summer conditions of South Australia, and this species showed a 100% survival rate and had the maximum horizontal growth rate, leaf succulence, shoot biomass and water use efficiency. All of the plants in the intensive green roofs with the crushed brick mix media survived during the term of this study. It was shown that stormwater can be used as a source of irrigation water for green roofs during 8 months of the year in Adelaide. However, supplementary irrigation is required for some of the plants over a full annual cycle.
Publisher: ACM
Date: 02-12-2014
Publisher: Elsevier BV
Date: 04-2019
Publisher: Unpublished
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 03-2014
Publisher: Elsevier
Date: 2020
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.JENVMAN.2022.114472
Abstract: Porous concrete is increasingly being used as a more sustainable surfacing alternative to asphalt and other impermeable materials. This is because, not only does it provide source control of stormwater, but it also has the potential to help mitigate the urban heat island effect through the process of evaporative cooling. This experimental investigation examines how evaporation from these systems is affected by the availability of water within the porous concrete and the influence this has on the surrounding environment, particularly in terms of air temperature and humidity. The effect of a dual layer porous concrete on evaporation rates is also assessed, which is important because the dual layer system is a relatively new development that is now being used in many parts of the world. It was found that both evaporation rate and evaporative cooling were strongly influenced by water availability near the upper surface of the porous concrete and under these conditions significant air temperature reductions can be achieved. It was also found that having a dual layered porous concrete system did not have a considerable effect on evaporation rates in this study, probably because of the relatively large thickness of the upper layer.
Publisher: Thomas Telford Ltd.
Date: 25-09-2023
Abstract: Urease enzymes from plants are directly utilised in enzyme induced calcite precipitation (EICP) to catalyse calcium carbonate (CaCO 3 ) precipitation between soil particles to improve their strength and stiffness. EICP does not require microbial culture and may be applicable for finer soils due to their smaller size. However, most studies on EICP utilise purified urease enzymes, which are often rare, expensive and limited to food-grade beans or seeds, making the technique less cost-effective. To find alternative and cheaper sources, crude urease extracts from erse plant species, particularly weeds and Australian native plants, were obtained, identified and characterised using a series of in vitro experiments. All selected plant species contain a considerable amount of urease enzyme, exhibiting different urease activity and CaCO 3 precipitation. EICP treatment by different crude extracts showed different levels of hydraulic conductivity, unconfined compressive strength (UCS), wind and raindrop erosion resistance. However, the crude extract from an Australian weed, matured Paddy melon seeds (M-PMS), had the highest specific activity of 8997U/mg and was further used for EICP treatment of six different soil types. The UCS of treated soils was influenced by the soil types. For similar CaCO 3 content, the strength and stiffness of the EICP-treated specimens were significantly influenced by the confining stress and degree of saturation in undrained triaxial conditions. Also, the mass loss, strength and average CaCO 3 decreased with increasing cycles of wetting-drying, freezing-thawing and elevated temperature. When compared with purified urease enzyme, M-PMS produced comparable strength and durability resistance for the treated s les.
Publisher: Oxford University Press (OUP)
Date: 03-11-2015
DOI: 10.1093/JAC/DKV366
Abstract: The objective of this study was to develop a real-time PCR method for specific detection of the gonococcal GyrA amino acid 91 locus directly in clinical s les so as to predict Neisseria gonorrhoeae ciprofloxacin susceptibility. The real-time PCR assay, GyrA91-PCR, was designed using two probes, one for detection of the WT S91 sequence and the other for detection of the S91F alteration. The performance of the assay was initially assessed using characterized N. gonorrhoeae isolates (n = 70), a panel of commensal Neisseria and Moraxella species (n = 55 isolates) and clinical s les providing negative results by a commercial N. gonorrhoeae nucleic acid lification test (NAAT) method (n = 171). The GyrA91-PCR was then applied directly to N. gonorrhoeae NAAT-positive clinical s les (n = 210) from the year 2014 for which corresponding N. gonorrhoeae isolates with susceptibility results were also available. The GyrA91-PCR accurately characterized the GyrA 91 locus of all 70 N. gonorrhoeae isolates (sensitivity = 100%, 95% CI = 94.9%-100%), whereas all non-gonococcal isolates and N. gonorrhoeae NAAT-negative clinical s les gave negative results by the GyrA91-PCR (specificity = 100%, 95% CI = 98.4%-100%). When applied to the 210 N. gonorrhoeae NAAT-positive clinical s les, the GyrA91-PCR successfully characterized 195 s les (92.9%, 95% CI = 88.5%-95.9%). When compared with the corresponding bacterial culture results, positivity by the GyrA91-PCR WT probe correctly predicted N. gonorrhoeae susceptibility to ciprofloxacin in 161 of 162 (99.4%, 95% CI = 96.6%-99.9%) s les. The use of a PCR assay for detection of mutation in gyrA applied directly to clinical s les can predict ciprofloxacin susceptibility in N. gonorrhoeae.
Publisher: American Society of Civil Engineers
Date: 21-03-2019
Publisher: Thomas Telford Ltd.
Date: 10-2012
Abstract: Both wet and dry detention basins are commonly used for the treatment of road runoff. The basin investigated in this study was located on the eastern side of the southern expressway in Adelaide, Australia. Event mean pollutant concentrations (EMCs) and total pollutant loads were determined for the basin inflows and outflows. The water quality parameters tested included pH, conductivity, total suspended solids, total dissolved solids (TDS), total Kjeldahl nitrogen, total phosphorous, total hydrocarbons, cadmium, chromium, copper, lead, zinc and nickel. Six critical events were s led in this manner during the course of the investigation. Total pollutant loads passing through as basin inflow were determined over the six monitored events. Comparison of basin inflow and outflow quality demonstrated that the average load reductions varied from as little as 18% for TDS up to 77% for total phosphorous and lead. While copper concentrations at the basin inflow were detected in four out of the six events, no detectable concentrations were found in the outflows. The average reductions for lead and zinc were more than 50% on more than 80% of occasions.
Publisher: Elsevier BV
Date: 05-2022
Publisher: MDPI AG
Date: 15-04-2019
DOI: 10.3390/W11040783
Abstract: This paper presents a monitoring-based investigation of rainwater collection systems using economic performance indicators in a group of households with nonconventional end-uses for rainwater that are not traditionally associated with rainwater supply. The monitored data for five household rainwater tank systems were analysed in two stages. For the first stage, the data was empirically analysed to develop a method to predict effective roof catchment areas. For the second stage, the effective roof catchment areas, together with roof area connection percentages, were analysed against different types of water demands in in idual households. The in idual systems were investigated for yield capacities, costs and water security using a modified Roof Runoff Harvesting Systems average annual yield model based on daily water balance procedures. The Life Cycle Costing analysis of the systems using the model was based on the Capital Recovery Method by taking into consideration the capital costs as well as ongoing costs for maintenance, replacement and operation of the systems. The analysis established the optimal sizing requirements for the studied rainwater tanks and their corresponding roof area connectivity.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.SCITOTENV.2017.01.130
Abstract: This research addresses the question as to whether or not the Normalised Difference Vegetation Index (NDVI) is scale invariant (i.e. constant over spatial aggregation) for pure pixels of urban vegetation. It has been long recognized that there are issues related to the modifiable areal unit problem (MAUP) pertaining to indices such as NDVI and images at varying spatial resolutions. These issues are relevant to using NDVI values in spatial analyses. We compare two different methods of calculation of a mean NDVI: 1) using pixel values of NDVI within feature/object boundaries and 2) first calculating the mean red and mean near-infrared across all feature pixels and then calculating NDVI. We explore the nature and magnitude of these differences for images taken from two sensors, a 1.24m resolution WorldView-3 and a 0.1m resolution digital aerial image. We apply these methods over an urban park located in the Adelaide Parklands of South Australia. We demonstrate that the MAUP is not an issue for calculation of NDVI within a sensor for pure urban vegetation pixels. This may prove useful for future rule-based monitoring of the ecosystem functioning of green infrastructure.
Publisher: Thomas Telford Ltd.
Date: 06-2009
Abstract: This paper investigates the ‘effective life’ (or useful lifespan) of permeable pavement installations subject to sediment loadings. The broad aims of this study, which included both laboratory and field work components, were to improve understanding of the long-term pavement hydraulic conductivity, to assess the effective life of permeable pavements and to quantify the degree of sediment trapping and associated pollutant retention. Three types of permeable pavement were investigated. For each type the effects of pavement cleaning were also investigated. Over a simulated 35 years of sediment loading conducted in the laboratory, the results showed reductions of 59–75% in hydraulic conductivity with an average sediment retention of 94%. Suspended sediment concentrations measured at the outflow of the laboratory test beds did not show any significant difference between pavers that were subjected to cleaning and those that were not. For the field studies presented in this paper, hydraulic conductivities were very high in locations where permeable pavements are subjected to small to moderate sediment loads. At other locations with high coarse sediment and organic sediment loads, hydraulic conductivity tests indicated that clogging occurred at a rapid rate, particularly where runoff flowing onto the pavement was concentrated.
Publisher: Copernicus GmbH
Date: 26-07-2013
DOI: 10.5194/NHESSD-1-3577-2013
Abstract: Abstract. Combination of reduction in the frequency, duration and magnitude of natural floods, rising saline water-table in floodplains and excessive evapotranspiration have led to an irrigation-induced groundwater mound forced the naturally saline groundwater onto the floodplain in the Lower River Murray. It is during the attenuation phase of floods that these large salt accumulations are likely to be mobilised and will discharge into the river. The Independent Audit Group for Salinity highlighted this as the most significant risk in the Murray–Darling Basin. South Australian government and catchment management authorities have developed salt interception schemes (SIS). This is to pump the highly saline groundwater from the floodplain aquifer to evaporation basins in order to reduce the hydraulic gradient that drives the regional saline groundwater towards the River Murray. This paper investigates the interactions between a river (River Murray in South Australia) and a saline semi-arid floodplain (Clarks Floodplain) significantly influenced by groundwater lowering (Bookpurnong SIS). Results confirm that groundwater extraction maintain a lower water-table and more fresh river water flux to the saline floodplain aquifer. In term of salinity, this may lead to less amount of solute stored in the floodplain aquifer. This occurs through two mechanisms extracting some of the solute mass from the system and changing the floodplain groundwater regime from a losing to gaining one. Finally, it is shown that groundwater extraction is able to remove some amount of solute stored in the unsaturated zone and mitigate the floodplain salinity risk.
Publisher: IWA Publishing
Date: 13-10-2014
DOI: 10.2166/WCC.2014.031
Abstract: The main objective of this study was to investigate the statistical characteristics of point rainfall and the novelty of the work was the development of a hybrid probability distribution that can model the full spectrum of daily rainfall in the Onkaparinga catchment in South Australia. Daily rainfall data from 1960 to 2010 at 13 rainfall stations were considered. Spatial dependency among the rainfall maxima was assessed using madograms. Relatively strong and significant autocorrelation coefficients were observed for rainfall depths at finer (daily and monthly) temporal resolutions. The performance of different distribution models was examined considering their ability to regenerate various statistics such as standard deviation, skewness, frequency distribution, percentiles and extreme values. Model efficiency statistics of modelled percentiles of daily rainfall were found to be useful for optimum threshold selection in a hybrid of the gamma and generalized Pareto distributions. The hybrid and the mixed exponential distributions were found to be more efficient than any single distribution (Weibull, gamma and exponential) for simulating the full range of daily rainfall across the catchment. The outcomes from this study will assist water engineers and hydrologists to understand the spatial and temporal characteristics of point rainfall in the Onkaparinga catchment and will hopefully contribute to the improvement of rainfall modelling and downscaling techniques.
Publisher: Elsevier BV
Date: 09-2015
Publisher: IWA Publishing
Date: 1995
Publisher: Wiley
Date: 07-11-2011
Publisher: Thomas Telford Ltd.
Date: 07-2011
DOI: 10.1680/WAMA.2011.164.7.361
Abstract: The harvesting, storage and reuse of stormwater from permeable pavement reservoirs provides an opportunity to alleviate water shortages in urban areas. Reservoirs may be filled with a range of basecourse aggregate materials that provide structural support to the pavement. The materials have the potential to affect the quality of stored water. This research investigated changes in water quality when water was stored in two types of basecourse aggregate. Synthetic stormwater was placed in permeable pavement reservoir models filled with dolomite aggregate or quartzite aggregate or control reservoirs with no aggregate. The influence of residence time was investigated by monitoring stored water quality for up to 144 h. Conductivity and pH increased in both aggregate-filled reservoirs. Total suspended solids and turbidity also increased in the aggregate-filled reservoirs, before falling to levels significantly lower than the control reservoirs. Levels of phosphorous and organic nitrogen were significantly lower in the aggregate-filled reservoirs after 144 h. Total zinc, copper and lead were reduced by 94–99% in the aggregate-filled reservoirs compared with the controls after 144 h storage.
Publisher: Elsevier BV
Date: 08-2015
Publisher: Copernicus GmbH
Date: 10-04-2013
DOI: 10.5194/HESSD-10-4597-2013
Abstract: Abstract. The wide variability of hydrological losses in catchments is due to multiple variables that affect the rainfall-runoff process. Accurate estimation of hydrological losses is required for making vital decisions in design applications that are based on design rainfall models and rainfall-runoff models. Using representative single values of losses, despite their wide variability, is common practice, especially in Australian studies. This practice leads to issues such as over or under estimation of design floods. Probability distributions can be used as a better representation of losses. In particular, using joint probability approaches (JPA), probability distributions can be incorporated into hydrological loss parameters in design models. However, lack of understanding of loss distributions limits the benefit of using JPA. The aim of this paper is to identify a probability distribution function that can successfully describe hydrological losses in South Australian (SA) catchments. This paper describes suitable parametric and non-parametric distributions that can successfully describe observed loss data. The goodness-of-fit of the fitted distributions and quantification of the errors associated with quantile estimation are also discussed a two-parameter Gamma distribution was identified as one that successfully described initial loss (IL) data of the selected catchments. Also, a non-parametric standardised distribution of losses that describes both IL and continuing loss (CL) data were identified. The results obtained for the non-parametric methods were compared with similar studies carried out in other parts of Australia and a remarkable degree of consistency was observed. The results will be helpful in improving design flood applications.
Publisher: Elsevier BV
Date: 10-2015
DOI: 10.1016/J.SCITOTENV.2015.05.024
Abstract: A generalized linear model was fitted to stochastically downscaled multi-site daily rainfall projections from CMIP5 General Circulation Models (GCMs) for the Onkaparinga catchment in South Australia to assess future changes to hydrologically relevant metrics. For this purpose three GCMs, two multi-model ensembles (one by averaging the predictors of GCMs and the other by regressing the predictors of GCMs against reanalysis datasets) and two scenarios (RCP4.5 and RCP8.5) were considered. The downscaling model was able to reasonably reproduce the observed historical rainfall statistics when the model was driven by NCEP reanalysis datasets. Significant bias was observed in the rainfall when downscaled from historical outputs of GCMs. Bias was corrected using the Frequency Adapted Quantile Mapping technique. Future changes in rainfall were computed from the bias corrected downscaled rainfall forced by GCM outputs for the period 2041-2060 and these were then compared to the base period 1961-2000. The results show that annual and seasonal rainfalls are likely to significantly decrease for all models and scenarios in the future. The number of dry days and maximum consecutive dry days will increase whereas the number of wet days and maximum consecutive wet days will decrease. Future changes of daily rainfall occurrence sequences combined with a reduction in rainfall amounts will lead to a drier catchment, thereby reducing the runoff potential. Because this is a catchment that is a significant source of Adelaide's water supply, irrigation water and water for maintaining environmental flows, an effective climate change adaptation strategy is needed in order to face future potential water shortages.
Publisher: Thomas Telford Ltd
Date: 2010
Publisher: Elsevier
Date: 2013
Publisher: MDPI AG
Date: 07-08-2014
DOI: 10.3390/W6082339
Publisher: Elsevier BV
Date: 11-2021
Publisher: MDPI AG
Date: 09-08-2018
DOI: 10.3390/SU10082826
Abstract: More well-maintained green spaces leading toward sustainable, smart green cities mean that alternative water resources (e.g., wastewater) are needed to fulfill the water demand of urban greenery. These alternative resources may introduce some environmental hazards, such as salt leaching through wastewater irrigation. Despite the necessity of salinity monitoring and management in urban green spaces, most attention has been on agricultural fields. This study was defined to investigate the capability and feasibility of monitoring and predicting soil salinity using proximal sensing and remote sensing approaches. The innovation of the study lies in the fact that it is one of the first research studies to investigate soil salinity in heterogeneous urban vegetation with two approaches: proximal sensing salinity mapping using Electromagnetic-induction Meter (EM38) surveys and remote sensing using the high-resolution multispectral image of WorldView3. The possible spectral band combinations that form spectral indices were calculated using remote sensing techniques. The results from the EM38 survey were validated by testing soil s les in the laboratory. These findings were compared to remote sensing-based soil salinity indicators to examine their competence on mapping and predicting spatial variation of soil salinity in urban greenery. Several regression models were fitted the mixed effect modeling was selected as the most appropriate to analyze data, as it takes into account the systematic observation-specific unobserved heterogeneity. Our results showed that Soil Adjusted Vegetation Index (SAVI) was the only salinity index that could be considered for predicting soil salinity in urban greenery using high-resolution images, yet further investigation is recommended.
Publisher: Wiley
Date: 22-04-2019
DOI: 10.1002/MET.1783
Publisher: Copernicus GmbH
Date: 14-05-2013
DOI: 10.5194/HESSD-10-5975-2013
Abstract: Abstract. Spatial and temporal variations in statistical characteristics of point rainfall are important for rainfall modelling. The main objective of this study was to investigate the statistical characteristics of point rainfall and to identify a probability distribution that can model the full spectrum of daily rainfall in the Onkaparinga catchment in South Australia. Daily rainfall data from 1960 to 2010 at thirteen rainfall stations were considered. Statistical moments and autocorrelation coefficients were estimated for rainfall depths at different temporal resolutions. The heterogeneity of monthly rainfall was tested using the Precipitation Concentration Index (PCI). Interannual variability of annual and seasonal PCI was observed. The catchment was characterized by unstable monthly rainfall with PCIs of more than 10 for all rainfall stations. Relatively strong and significant autocorrelation coefficients were observed for rainfall depths at finer (daily and monthly) temporal resolutions. The performance of different distribution models was examined considering their ability to regenerate various statistics such as standard deviation, skewness, frequency distribution, percentiles and extreme values. Model efficiency statistics of modelled percentiles of daily rainfall were found to be useful for optimum threshold selection in the hybrid distributions. A hybrid of the gamma and generalized pareto (GP) distributions was found to be more efficient than any single distribution (Weibull, gamma and exponential) for modelling the full range of daily rainfall across the catchment. In addition to this, a hybrid of the Weibull and GP distributions was also proposed. The outcomes from this study will assist water engineers and hydrologists to understand the spatial and temporal characteristics of point rainfall in the Onkaparinga catchment and will hopefully contribute to the improvement of rainfall modelling and downscaling techniques.
Publisher: Copernicus GmbH
Date: 15-11-2013
DOI: 10.5194/HESS-17-4541-2013
Abstract: Abstract. Accurate estimation of hydrological losses is required for making vital decisions in design applications that are based on design rainfall models and rainfall–runoff models. The use of representative single values of hydrological losses, despite their wide variability, is common practice, especially in Australian studies. This practice leads to issues such as over or under estimation of design floods. The probability distribution method is potentially a better technique to describe losses. However, a lack of understanding of how losses are distributed can limit the use of this technique. This paper aims to identify a probability distribution function that can successfully describe hydrological losses of a catchment of interest. The paper explains the systematic process of identifying probability distribution functions, the problems faced during the distribution fitting process and a new generalised method to test the adequacy of fitted distributions. The goodness-of-fit of the fitted distributions are examined using the Anderson–Darling test and the Q–Q plot method and the errors associated with quantile estimation are quantified by estimating the bias and mean square error (MSE). A two-parameter gamma distribution was identified as one that successfully describes initial loss (IL) data for the selected catchments. Further, non-parametric standardised distributions that describe both IL and continuing loss data are also identified. This paper will provide a significant contribution to the Australian Rainfall and Runoff (ARR) guidelines that are currently being updated, by improving understanding of hydrological losses in South Australian catchments. More importantly, this study provides new knowledge on how IL in a catchment is characterised.
Publisher: Copernicus GmbH
Date: 11-2013
DOI: 10.5194/HESS-17-4339-2013
Abstract: Abstract. Deep percolation enhancement from recycled wastewater irrigation may contribute to salt accumulation and water table elevation that can ultimately cause soil and ground water degradation. Variation of drainage rate and solute leaching were investigated in an urban park containing heterogeneous landscape plants that were irrigated with recycled wastewater. Field monitoring was undertaken at Veale Gardens in the Adelaide Parklands, Australia. Based on landscape variation in Veale Gardens, two landscape zones were defined: one being largely covered with turf grasses with few trees and shrubs (MG) with the second zone being mostly trees and shrubs with intermittent turf grasses (MT). Experiments were performed on two zero-tension lysimeters placed horizontally 100 cm below ground to monitor the variation of volume and quality indicators of drained water for four seasons. The outcomes showed a significant variation of drainage quantity and quality in the MT and MG zones. The low vegetation cover in the MG zone resulted in more drained water than in the high vegetation cover (MT zone). In both zones, more drainage water was collected in winter than in other seasons. This is in spite of the input water showing a maximum rate in summer. The seasonal salinities measured in the two lysimeters showed very similar trends with the lowest salinity rate in autumn with the levels increasing through winter and spring. Chemical analyses of leachate solute and salt loading indicated no impact from using recycled wastewater.
Publisher: Elsevier BV
Date: 11-2015
Publisher: Canadian Center of Science and Education
Date: 13-08-2013
DOI: 10.5539/EP.V2N4P10
Publisher: Elsevier BV
Date: 09-2016
Publisher: Elsevier BV
Date: 02-2010
Publisher: Informa UK Limited
Date: 15-12-2014
Publisher: IWA Publishing
Date: 02-2007
DOI: 10.2166/WST.2007.111
Abstract: Innovative Water Sensitive Urban Design (WSUD) systems are being investigated at three locations to the north and south of Sydney, Australia. These systems contain porous concrete pipes that are designed so that stormwater exfiltrates through the permeable walls of the pipes into the surrounding substrate media material. The porous pipes and media material treat the passing stormwater. The primary aim of the overall project is to develop a model to describe the treatment effectiveness of confined WSUD systems. This paper focuses on the system located at the Weathertex Industrial Site, Heatherbrae. Due to wood processing operations that occur at this site, it is recognised that the surface runoff will carry a heavy organics loading. Granulated Activated Carbon (GAC) is recognised for its ability to reduce the concentration of dissolved organics present in both wastewater and stormwater. GAC was therefore chosen as a filtration medium to be investigated at this site. To maximise the effectiveness of the GAC, extensive laboratory batch studies were undertaken prior to the field system being constructed to determine the optimum GAC/sand ratio. The purpose of the experimental work was to assess the dissolved organic removal potential through sorption of various concentrations of GAC. The aim of this paper is to describe these laboratory experiments and discuss how they related to the field system. Through these experiments it was determined that a sand/GAC ratio of 25:1 was ideal for the media material at the Heatherbrae site.
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/EN12131
Abstract: Environmental context In 2009, at the end of the longest drought period ever recorded in Australia, a major dust storm blanketed the cities of Sydney and Brisbane for more than 24 h. The source of the dust was inner New South Wales and South Australia, where large scale open-cut mining occurs together with agricultural practices. We report results of extensive mineralogical and chemical analyses of the dust, and discuss their significance in terms of the dust origins and potential human health risks. Abstract In a 24-h period from 23 to 24 September 2009, a dust storm passed over Sydney, Australia that produced a red sky and reduced the visibility to a few metres. It was Sydney’s worst dust storm since 1942. During this period, the PM10 (particles measuring 10 μm or less) value jumped from 50 to 11 800 µg m–3. The dust storm was s led and its mineralogical and organic contents were analysed. Four major particle sizes (0.6, 4.5, 9.3 and 20 µm) were observed in the dust. A multimodal particle distribution indicated a long range of dust transport. Mineralogical analysis showed that the particles were mainly composed of crustal elemental oxides of Al and Si. The ratio of Al/Si was 0.39 and the organic content was 10.6 %, which was found to be enriched with humic-type substances. The high Al/Si ratio ( .3) indicated that the dust originated from desert land whereas the high organic content indicated that the particles were also derived from eroded agricultural land. A fluorescence spectroscopic study on the organic matter at excitation and emission wavelengths of 245–265 and 330–350 nm indicated that biohazardous substances were unlikely to be present in the dust.
Publisher: Emerald
Date: 15-11-2011
DOI: 10.1108/02644401111178992
Abstract: Porous concrete is a mixture of open‐graded coarse aggregate, water and cement. It is also occasionally referred to as no‐fines concrete or pervious concrete. Due to its high infiltration capacity, it is viewed as an environmentally sustainable paving material for use in urban drainage systems since it can lead to reduced flooding and to the possibilities of stormwater harvesting and reuse. However, the high porosity is due in the main part to the lack of fine aggregate particles used in the manufacture of porous concrete. The purpose of this paper is to present a numerical method to understand more fully the structural properties of porous concrete. This method will provide a useful tool for engineers to design with confidence higher strength porous concrete systems. In the method, porous concrete is modelled using a discrete element method (DEM). The mechanical behaviour of a porous concrete s le subjected to compressive and tensile forces is estimated using two‐dimensional Particle Flow Code (PFC2D). Three numerical ex les are given to verify the model. A comprehensive set of micro‐parameters particularly suitable for porous concrete is proposed. The accuracy and effectiveness of simulation are confirmed by comparison with experimental results and empirical equations. The experimental investigations for porous concrete described in this paper have been designed and conducted by the authors. In addition, the type of two dimensional PFC analysis presented has rarely been used to model porous concrete strength characteristics and from the results presented in this paper, this analysis technique has good potential for predicting its mechanical properties.
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 12-2018
Publisher: Wiley
Date: 11-11-2013
Publisher: American Society of Civil Engineers
Date: 16-05-2016
Publisher: Elsevier BV
Date: 08-2014
DOI: 10.1016/J.SCITOTENV.2014.05.040
Abstract: Living roofs are an emerging green infrastructure technology that can potentially be used to ameliorate both climate change and urban heat island effects. There is not much information regarding the design of green roofs for dry climates and so the aim of this study was to develop low maintenance and unfertilized green roofs for a dry climate. This paper describes the effects of four important elements of green roofs namely slope, depth, growing media and plant species and their possible interactions in terms of plant growth responses in a dry climate. Sixteen medium-scale green roofs were set up and monitored during a one year period. This experiment consisted of twelve vegetated platforms and four non-vegetated platforms as controls. The design for the experiment was a split-split-plot design in which the factors Slope (1° and 25°) and Depth (100mm, 300 mm) were randomized to the platforms (main plots). Root depth and volume, average height of plants, final dry biomass and ground cover, relative growth rate, final dry shoot-root ratio, water use efficiency and leaf succulence were studied during a twelve month period. The results showed little growth of the plants in media type A, whilst the growth was significant in both media types B and C. On average, a 90% survival rate of plants was observed. Also the growth indices indicated that some plants can grow efficiently in the harsh environment created by green roofs in a dry climate. The root growth pattern showed that retained water in the drainage layer is an alternative source of water for plants. It was also shown that stormwater can be used as a source of irrigation water for green roofs during six months of the year at the study site. In summary, mild sloping intensive systems containing media type C and planted with either Chrysocephalum apiculatum or Disphyma crassifolium showed the best performance.
Publisher: BMJ
Date: 02-1995
DOI: 10.1136/BJO.79.2.153
Abstract: A retrospective review of all patients with a cytomegalovirus (CMV) related retinal detachment and HIV infection managed at the ocular immunology clinic at St Vincent's Hospital between January 1985 and June 1992 was performed. Over this period 142 patients with CMV retinopathy were managed and 17 eyes from 14 of these patients developed a retinal detachment related to CMV retinopathy. Fourteen eyes from 11 of these patients were treated surgically with combinations of laser photocoagulation, cryopexy, scleral buckling, vitrectomy, and silicone oil t onade. The use of laser photocoagulation alone in five patients resulted in an excellent visual outcome. The majority of patients (90.9%) benefited from surgery in that vision was either stabilised or improved.
Publisher: Springer Science and Business Media LLC
Date: 1993
DOI: 10.1038/EYE.1993.17
Publisher: Wiley
Date: 04-01-2012
DOI: 10.1002/JOC.3422
Publisher: Copernicus GmbH
Date: 23-12-2013
DOI: 10.5194/NHESS-13-3405-2013
Abstract: Abstract. In the lower River Murray in Australia, a combination of a reduction in the frequency, duration and magnitude of natural floods, rising saline water tables in floodplains, and excessive evapotranspiration have led to an irrigation-induced groundwater mound forcing the naturally saline groundwater onto the floodplain. It is during the attenuation phase of floods that these large salt accumulations are likely to be mobilised and discharged into the river. This has been highlighted as the most significant risk in the Murray–Darling Basin and the South Australian Government and catchment management authorities have subsequently developed salt interception schemes (SIS). The aim of these schemes is to reduce the hydraulic gradient that drives the regional saline groundwater towards the River Murray. This paper investigates the interactions between a river (River Murray in South Australia) and a saline semi-arid floodplain (Clark's floodplain) that is significantly influenced by groundwater lowering due to a particular SIS. The results confirm that groundwater extraction maintains a lower water table and a higher amount of fresh river water flux to the saline floodplain aquifer. In terms of salinity, this may lead to less solute stored in the floodplain aquifer. This occurs through three mechanisms, namely extraction of the solute mass from the system, reducing the saline groundwater flux from the highland to the floodplain and changing the floodplain groundwater regime from a losing to a gaining one. It is shown that groundwater extraction is able to remove some of the solute stored in the unsaturated zone and this can mitigate the floodplain salinity risk. A conceptual model of the impact of groundwater extraction on floodplain salinization has been developed.
Publisher: Elsevier BV
Date: 11-2011
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-2007
Publisher: MDPI AG
Date: 25-05-2020
DOI: 10.3390/SU12104313
Abstract: The mechanistic design of a concrete block pavement (CBP) can be very complicated and often requires the use of computer programs. This paper presents a new mechanistic-empirical method, which is implemented in a computer program (DesignPave) that calculates base course/sub-base thicknesses for a range of design inputs such as traffic load, interlocking properties, and material stiffness. A range of virgin and recycled unbound granular materials were also experimentally tested to characterize them for possible use as base course or sub-base materials. Combining the new mechanistic-empirical method and the range of base course/sub-base course materials (virgin and recycled aggregates), it was found that while a CBP containing recycled aggregates did not offer a significant direct financial benefit based on the characteristics or material costs, the associated environmental benefits were very high.
Publisher: Springer Science and Business Media LLC
Date: 19-06-2009
DOI: 10.1007/S10661-008-0318-2
Abstract: This study was carried out to evaluate the influence of porous check dam location on the retention of fine sediments in the Droodzan watershed in Southern Iran. Five long streams with several porous check dams that were more than 27 years old were studied. In each stream three check dams: at the very upstream section, at the middle section and at the far downstream section were selected for analysis. A number of s les from trapped sediments and from the undisturbed soils in the stream banks (adjacent to the check dams) were collected. Laboratory analysis showed that the soil s les taken from undisturbed banks have smaller particle sizes compared to the trapped sediments. The results indicated that the check dams located at the far downstream sections were more efficient at trapping fine sediment than those located at the middle sections. Also the check dams located at the middle sections were more effective than those located at the upstream sections. Comparison of sediment texture also showed that the portion of clay and silt trapped by the check dams decreased from the downstream sections toward the upstream sections. Hence, whenever, the retention of fine sediments is the primary function of the check dams, it appears that they should be located in the far downstream sections of a stream. The experimental analysis indicated that using broken and angular rocks instead of rounded rocks in porous check dam's construction improves the effectiveness of the check dams for the retention of fine sediments. The analysis of the failed check dams also showed that erosion of the bank sides underneath the check dams is the primary cause of dam collapse.
Publisher: Informa UK Limited
Date: 24-10-2013
Publisher: Desalination Publications
Date: 2017
Publisher: Springer Science and Business Media LLC
Date: 19-08-2016
DOI: 10.1007/S11356-016-7372-Z
Abstract: Understanding plant behaviour in polluted soils is critical for the sustainable remediation of metal-polluted sites including abandoned mines. Post-operational and abandoned metal mines particularly in semi-arid and arid zones are one of the major sources of pollution by soil erosion or plant hyperaccumulation bringing ecological impacts. We have selected from the literature 157 species belonging to 50 families to present a global overview of 'plants under action' against heavy metal pollution. Generally, all species of plants that are drought, salt and metal tolerant are candidates of interest to deal with harsh environmental conditions, particularly at semi-arid and arid mine sites. Pioneer metallophytes namely Atriplex nummularia, Atriplex semibaccata, Salsola kali, Phragmites australis and Medicago sativa, representing the taxonomic orders Caryophyllales, Poales and Fabales are evaluated in terms of phytoremediation in this review. Phytoremediation processes, microbial and algal bioremediation, the use and implication of tissue culture and biotechnology are critically examined. Overall, an integration of available remediation plant-based technologies, referred to here as 'integrated remediation technology,' is proposed to be one of the possible ways ahead to effectively address problems of toxic heavy metal pollution. Graphical abstract Integrated remediation technology (IRT) in metal-contaminated semi-arid and arid conditions. The hexagonal red line represents an IRT concept based on remediation decisions by combination of plants and microbial processes.
Publisher: Informa UK Limited
Date: 27-05-2015
DOI: 10.1080/15226514.2015.1131239
Abstract: Plants play a key role in the accumulation of metals in contaminated environment. Ephemeral plants, such as cyperus vaginatus, from the family Cyperaceae have been used in constructed wetlands to alter the biogeochemistry of waterlogged soils. High elemental content in wetlands often induces chemical changes in the root, stem and leaf of wetland plants. Elemental uptake and possible chemical changes in the roots of Cyperus vaginatus was investigated and compared with plants grown away from the wetland. Among the 9 heavy metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb) and metalloid (As) measured, with the exception of Mn, all metals had higher content in the plant roots grown within the wetland. This was followed by plants grown near to the wetland that receive stormwater occasionally and then plants grown far from the wetland. The 3-D fluorescence spectra record showed notable differences in the chemical composition of roots grown in the three locations. The spectra combined with parallel factor analysis showed three dominant fluorescence components. Comparison of the fluorescence signatures showed a continuum of spectral properties constrained by the degree of metal contamination.
Publisher: Informa UK Limited
Date: 22-09-2015
Publisher: DTU Library, Technical University of Denmark (DTU)
Date: 2005
DOI: 10.4122/1.1000001636
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.SCITOTENV.2018.12.052
Abstract: In a changing climate, while hydroclimatic variables such as precipitation may show non-stationary behaviour, a traditional Standardized Precipitation Index (SPI) is not capable of accurately predicting extreme meteorological droughts. In this study, we have developed a non-stationary Standardized Precipitation Index (NSPI) within the Generalized Additive Model in Location, Scale and Shape (GAMLSS) modelling framework. This incorporates various climate indices such as SOI, Niño3.4, PDO, SAM and DMI as external covariates to capture the non-stationary and nonlinear characteristics of precipitation and thereby droughts. This idea has been applied at 46 high quality rainfall stations in the state of South Australia. The results indicate that a non-stationary model that considers climate indices can reproduce the rainfall variability better than a stationary model thereby NSPI is better than a traditional stationary SPI (SSPI) at capturing drought characteristics. Bivariate frequency analysis shows that the recurrence interval of drought events exceeding any severity and duration of interest is significantly different for NSPI compared to SSPI. This study demonstrates the need to use a non-stationary drought index in a changing climate to accurately represent the drought characteristics.
Publisher: IOP Publishing
Date: 02-2017
Publisher: Springer Science and Business Media LLC
Date: 03-12-2017
Publisher: Springer Science and Business Media LLC
Date: 12-01-2016
Publisher: MDPI AG
Date: 18-11-2022
DOI: 10.3390/W14223759
Abstract: Living walls are becoming a widely used water-sensitive urban design technology that can deliver various economic, social and environmental benefits. One such benefit is to cool the surrounding environment through the process of evapotranspiration. This study measured the evapotranspiration from an instrumented prototype-scale living wall and calculated the resulting evaporative cooling effect. The range of the measured evapotranspiration rates from the living wall was from 41 to 90 mL/mm per plant pot. This equated to latent heat of vaporisation values from 171 to 383 MJ/month/m2. This was then compared with the performance of a non-vegetated water-sensitive urban design technology, namely, a porous concrete pavement. For a typical summer month in a warm temperate climate, it was found that a porous concrete pavement system only had between 4 and 15% of the cooling effect of an equivalent living wall.
Publisher: MDPI AG
Date: 06-11-2022
DOI: 10.3390/SU142114583
Abstract: The clogging of porous and permeable pavements is a problem that faces many municipalities and, because of the high associated costs, it has become a major impediment to the uptake of such water sensitive and sustainable technologies. This study has experimentally examined the performance of seven cleaning methods that were shown to be able to restore higher infiltration rates in partially clogged pavement systems. It was found that high-pressure water injection was the most effective cleaning method, particularly when combined with vacuuming. The highest restoration of infiltration rate was achieved using high-pressure water injection combined with the highest-pressure vacuum, which produced an average increase in infiltration rate of 20.9%. Cleaning a porous pavement involves removing the sediment that has caused clogging in the first place. In normal circumstances, this collected sediment would have to be dried before disposal to a landfill, which is another costly process. Through a sustainability analysis, the potential reuse of collected sediment was investigated and it was found that the resulting economic and environmental benefit-cost ratios were high.
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.SCITOTENV.2013.10.047
Abstract: Green roofs are an increasingly important component of water sensitive urban design systems and can potentially improve the quality of urban runoff. However, there is evidence that they can occasionally act as a source rather than a sink for pollutants. In this study, the water quality of the outflow from both intensive and extensive green roof systems were studied in the city of Adelaide, South Australia over a period of nine months. The aim was to examine the effects of different green roof configurations on stormwater quality and to compare this with runoff from aluminium and asphalt roofs as control surfaces. The contaminant concentrations in runoff from both intensive and extensive green roofs generally decreased during the study period. A comparison between the two types of green roof showed that except for some events for EC, TDS and chloride, the values of the parameters such as pH, turbidity, nitrate, phosphate and potassium in intensive green roof outflows were higher than in the outflows from the extensive green roofs. These concentrations were compared to local, state, national and international water quality guidelines in order to investigate the potential for outflow runoff from green roofs to be reused for potable and non-potable purposes. The study found that green roof outflow can provide an alternative water source for non-potable purposes such as urban landscape irrigation and toilet flushing.
Publisher: Unpublished
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 09-05-2015
Publisher: MDPI AG
Date: 21-04-2022
DOI: 10.3390/SU14094970
Abstract: Permeable pavements allow rainfall and surface runoff to infiltrate through their surface, and this reduces urban flooding by increasing water management efficiency. The design of permeable pavements depends heavily on rainfall and soil conditions for a particular area. This study investigates the required base course thickness in different areas across Australia that can effectively reduce flood intensities. A detailed hydraulic analysis was conducted, considering the pavement materials, soil characteristics and rainfall intensities across Australia. The research also developed a relationship between base course thickness, rainfall intensity and soil classification, which can facilitate reasonable predictions of required design thickness for any location. The results showed a strong relationship between soil characteristics and pavement thickness, with clay soils requiring increased pavement thickness correlated with rainfall intensity. A spatial analysis was conducted, producing a tool for initial screening on the design requirements, before proceeding with a detailed design.
Publisher: IWA Publishing
Date: 06-2013
DOI: 10.2166/WST.2013.172
Abstract: Twelve particle-bound polycyclic aromatic hydrocarbons (PAHs) were measured in the first flush regime of road runoff during nine events in Winterthur in Switzerland. The total PAH contents ranged from 17 to 62 μg/g. The PAH patterns measured at different time intervals during the first flush periods were very similar within each event irrespective of variation in suspended solids (SS) concentration within the first flush regime. However, the PAH patterns were different from event to event. This indicates that the environment plays an important role in PAH accumulation in SS. A toxicity identification evaluation approach using a toxicity equivalency factor (TEF) was applied to compare toxicities in the different events. The TEFs were found to be between 8 and 33 μg TEQ g−1 (TEQ: toxic equivalent concentration). In some cases, two events having similar total PAH contents showed two fold toxicity differences.
Publisher: Springer Science and Business Media LLC
Date: 12-2011
Publisher: Copernicus GmbH
Date: 25-03-2013
DOI: 10.5194/HESSD-10-3897-2013
Abstract: Abstract. Evapotranspiration (ET) as the key component of hydrological balance is the most difficult factor to quantity. In the last decades, ET estimation has been benefitted from advances in remote sensing particularly in agricultural fields. However, quantifying evapotranspiration from mixed landscape vegetation environs is still complicated and challenging due to the heterogeneity of plant species, canopy covers, microclimate, and because of costly methodological requirements. Extensive numbers of studies have been conducted in agriculture and forestry that alternatively ought to be borrowed for mixed landscape vegetation studies with some modifications. This review describes general remote sensing-based approaches to estimate ET and their pros and cons. Considering the fact that most of them need extensive time investment, medium to high level of skills and are quite expensive, the simplest approach interface, is recommended to apply for mixed vegetation. Then, VI-based approach was discussed for two categories of agricultural and non-agricultural environs. Some promising studies were mentioned to support the suitability of the method for mixed landscape environs.
Publisher: Elsevier
Date: 2019
Publisher: IWA Publishing
Date: 20-08-2013
DOI: 10.2166/WCC.2013.059
Abstract: Harbour sediments include wash-off from different nearby catchments that have various landuse activities. In this study the spatial variation of polycyclic aromatic hydrocarbons (PAHs) in Sydney Harbour was studied by analysing the sediment. The sediment was collected from 12 locations and 16 PAHs that are prioritized by the United States Environmental Protection Authority were analysed. The concentrations in the sediment were in the range of 54–23,440 ng/g of total PAHs and this varied from location to location. The result suggests that the harbour is contaminated with PAHs from low concentration to very high concentration. Among the total PAHs, approximately 75% were medium to higher molecular weight 4- and 5-ring member PAHs. A toxicity identification evaluation (TEQ) approach using a toxicity equivalency factor (TEF) was applied to assess the sediment toxicity. The TEF was found to be between 22 and 8,277 ng TEQ/g. The TEQ value indicated potential adverse ecological and human health effects in many locations.
Publisher: International Society for Horticultural Science (ISHS)
Date: 06-2013
Publisher: Elsevier BV
Date: 2016
Publisher: Springer Science and Business Media LLC
Date: 24-07-2020
Publisher: Wiley
Date: 2010
DOI: 10.1002/HYP.7504
Publisher: Copernicus GmbH
Date: 21-06-2011
DOI: 10.5194/HESS-15-1879-2011
Abstract: Abstract. Water resources planning requires long-term projections of the impact of climate change on freshwater resources. In addition to intrinsic uncertainty associated with the natural climate, projections of climate change are subject to the combined uncertainties associated with selection of emissions scenarios, GCM ensembles and downscaling techniques. In particular, unknown future greenhouse gas emissions contribute substantially to the overall uncertainty. We contend that a reduction in uncertainty is possible by refining emissions scenarios. We present a comprehensive review of the growing body of literature that challenges the assumptions underlying the high-growth emissions scenarios (widely used in climate change impact studies), and instead points to a peak and decline in fossil fuel production occurring in the 21st century. We find that the IPCC's new RCP 4.5 scenario (low-medium emissions), as well as the B1 and A1T (low emissions) marker scenarios from the IPCC's Special Report on Emissions Scenarios are broadly consistent with the majority of recent fossil fuel production forecasts, whereas the medium to high emissions scenarios generally depend upon unrealistic assumptions of future fossil fuel production. We use a simple case study of projected climate change in 2070 for the Scott Creek catchment in South Australia to demonstrate that even with the current suite of climate models, by limiting projections to the B1 scenario, both the median change and the spread of model results are reduced relative to equivalent projections under an unrealistic high emissions scenario (A1FI).
Publisher: Springer Science and Business Media LLC
Date: 02-2015
Publisher: MDPI AG
Date: 22-02-2021
Abstract: Enzyme-induced carbonate precipitation (EICP) is a relatively new bio-cementation technique for ground improvement. In EICP, calcium carbonate (CaCO3) precipitation occurs via urea hydrolysis catalysed by the urease enzyme sourced from plants. EICP offers significant potential for innovative and sustainable engineering applications, including strengthening of soils, remediation of contaminants, enhancement of oil recovery through bio-plugging and other in situ field applications. Given the numerous potential applications of EICP, theoretical understanding of the rate and quantity of CaCO3 precipitation via the ureolytic chemical reaction is vital for optimising the process. For instance, in a typical EICP process, the rate and quantity of CaCO3 precipitation can depend significantly on the concentration, activity and kinetic properties of the enzyme used along with the reaction environment such as pH and temperature. This paper reviews the research and development of enzyme-catalysed reactions and its applications for enhancing CaCO3 precipitation in EICP. The paper also presents the assessment and estimation of kinetic parameters, such as the maximal reaction velocity (Vmax) and the Michaelis constant (Km), that are associated with applications in civil and geotechnical engineering. Various models for evaluating the kinetic reactions in EICP are presented and discussed, taking into account the influence of pH, temperature and inhibitors. It is shown that a good understanding of the kinetic properties of the urease enzyme can be useful in the development, optimisation and prediction of the rate of CaCO3 precipitation in EICP.
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.CHEMOSPHERE.2019.06.058
Abstract: In drinking water treatment, complete mineralization of organophosphorus pesticides (OPPs) by UV-based advanced oxidation processes (UV AOPs) is rarely achieved. The formation of intermediate oxidation byproducts would likely have some profound effects on toxicity of the reaction solutions. This study investigated the intermediate oxidation byproducts, transformation pathway and toxicity of malathion solutions during the treatment processes of UV alone, UV/H
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.JHAZMAT.2015.10.021
Abstract: This study explored the efficacy and efficiency of a simultaneous UV-catalyzed oxidation-coagulation process of titanium sulfate (UV/Ti(SO4)2) for efficient removal of As(III) from water. It revealed that, As(III) could be oxidized to As(V) during the UV catalyzed coagulation of Ti(SO4)2 with highly efficient As(III) removal in the pH range 4-6. The UV catalyzed oxidation-coagulation showed surprisingly effective oxidation of As(III) to As(V) within a short time. XPS indicated that 84.7% of arsenic on the coagulated precipitate was in the oxidized form of As(V) after the UV/Ti(SO4)2 treatment of As(III) aqueous solutions at pH 5. Arsenic remaining in solution at high pH was in the oxidized form As(V). Removal efficiencies of As(III) were investigated as a function of pH, Ti(SO4)2 dosage, initial As(III) concentration and irradiation energy. As(III) could almost completely be removed (>99%) by the photocatalytic oxidation-coagulation process with a moderate dose of Ti(SO4)2 in the pH range 4-6 at an initial arsenic concentration of 200 μg/L. The mechanisms of the photocatalytic coagulation oxidation of Ti(SO4)2 are similar to those of UV/crystalline TiO2 particles, involving the formation and reactions of the hydroxyl radical OH and superoxide HO2/O2(-).
Publisher: Thomas Telford Ltd.
Date: 04-2008
DOI: 10.1680/WAMA.2008.161.2.55
Abstract: This paper investigates the suitability of sand filters for harvesting and treating stormwater for non-potable reuse purposes. A stormwater sand filtration device was constructed in a small urban catchment in Sydney, Australia. A sand filter is typically used in water-sensitive urban design (WSUD) as a component of a treatment train to remove pollution from stormwater before discharge to receiving waters, to groundwater or for collection and reuse. This paper describes an 18 month field study undertaken to determine the effectiveness and pollutant removal efficiency of a sand filter, and the differences in the pollutant removal efficiency of two grades of sand. A comparison of pollutant removal with previous literature on sand filters showed similar efficiencies but nutrient removal was higher than expected. A further unexpected result was that the coarse filter media performed as well as the fine media for most pollutant types and was superior in suspended solids removal. Improved modelling equations for predicting suspended solids and total phosphorus removal in sand filters are also presented in this paper.
Publisher: Thomas Telford Ltd.
Date: 03-2012
DOI: 10.1680/WAMA.2012.165.3.161
Abstract: Permeable pavements are generally used in water-sensitive urban design as a component of a treatment train and as a source control measure for reducing stormwater flows and pollutant loads. In Australia, permeable pavement systems are an emerging technology and consequently there are few installations more than 10 years old. The performance of permeable pavements in terms of treatment of urban stormwater runoff from a number of typical, but different urban catchments is discussed. Water quality monitoring was carried out in the field to quantify the improvement that permeable pavement systems can make to runoff quality at a car park located at North Haven in Adelaide, South Australia, that utilise both conventional and permeable pavement systems. Extensive laboratory analysis using stormwater collected from four sites was carried out to assess the effectiveness of permeable pavement systems for reducing pollutant discharges. In general, the permeable pavement systems were found to improve stormwater quality when tested at a 5% significance level. The results show that, on average, permeable pavements were able to reduce nutrient concentrations (total nitrogen and total phosphorus), heavy metals (zinc, lead, copper, cadmium and nickel) and total suspended solids. The reductions in pollutant concentrations can be mainly attributed to mechanical filtration by various components of the permeable pavement system.
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier BV
Date: 04-2017
Publisher: International Society for Horticultural Science (ISHS)
Date: 06-2013
Publisher: Informa UK Limited
Date: 12-2011
Publisher: Informa UK Limited
Date: 06-07-2012
Publisher: MDPI AG
Date: 09-03-2020
DOI: 10.3390/W12030747
Abstract: This study investigated the distribution of heavy metals in vegetative biofiltration columns irrigated by synthetic greywater. Twelve species of ornamental plants (three plants from each species) were planted in the same designed 36 biofiltration columns. S les of effluent water, soils, roots, shoots and leaves were collected and analyzed. It was observed that before irrigation, the distribution of copper was in soils (0%), roots (42%), leaves (37%) and shoots (21%). After irrigation, this distribution changed to soils (29%), roots (39%), leaves (17%) and shoots (15%). It was found that lead concentrations decreased in soils from (84% to 7%), but increased in plants (from 16% to 93%) following irrigation with greywater. In contrast, the distribution of zinc changed from leaves (46%), roots (22%) and soils (16%) before irrigation to 89% in leaves and soils and 11% in shoots following irrigation. The chromium distribution before and after irrigation was found to be almost unchanged in soils, shoots and effluent water, but it increased in roots (19.4% to 26.9%) and decreased in leaves (11.4% to 5.8%). The outcomes of this study demonstrated that heavy metals mostly accumulate in soils and roots, and it is necessary to investigate their potential detrimental effects on the receiving environment.
Publisher: SAGE Publications
Date: 12-12-2012
Abstract: This paper describes a full-scale experimental investigation into the effects of box gutter geometry on the open channel flow conditions above siphonic roofwater outlets. In particular, the effects of channel width (300, 400, 480 and 600 mm) and length (14.86 and 32.00 m) were investigated through measurements of flow rate, water depth and longitudinal velocity in the box gutter. The experimental results showed that for the same outlet flow rate, the depth of water in the gutter varied by up to 211% for the two different gutter lengths tested. Generally, the greatest water depths for the different flow rates were recorded in the 400-mm wide gutter and the lowest water depths were recorded in the 300-mm wide gutter. It was also found that the maximum flow rate through the single 110-mm diameter outlet varied depending on the width of the gutter. Practical application: The depth of water in the open channel box gutters above the outlets of siphonic drainage systems is an important design variable and it is imperative to be able to accurately estimate these water depths during all phases of operation to reduce flood damage risk. This research study has found that for the same flow rate, varying the length of gutter on either side of a siphonic outlet strongly influences the depth of water along the gutter and above the outlet. The results suggest that there may be an optimum gutter width and length for which different siphonic outlets may perform more efficiently.
Publisher: MDPI AG
Date: 06-12-2022
DOI: 10.3390/SU142316282
Abstract: An increase in impermeable surface areas with urban development contributes to the rapid and large amount of surface runoff during rainfall. This often requires higher capacity stormwater collection systems, which can cause stress on the existing drainage system and this subsequently contributes to urban flooding. However, urban runoff can be reduced and managed for flood control and converted into a useful resource by harvesting and reusing the water. This can be achieved by switching from impermeable to permeable pavements. However, the amount of stormwater that can be harvested in a permeable pavement system depends on many factors, including rainfall, the water reuse demand and the materials used. This research aims to assess the requirements for permeable pavement design across Australia to balance demand, runoff reduction and construction requirements. A design approach employing the hydrological effects of the infiltration system was adopted for the analysis, along with a spatial analysis for a probabilistic prediction. A relationship was also established to predict a probable design thickness of pavement for various parameters. The research showed that in most Australian cities, for a 120 mm permeable pavement thickness, 40–80% of rainfall-runoff could be harvested, meeting about 10–15% of domestic water demand. The approach developed in this study can be useful for screening the potential of permeable pavements for water harvesting and for predicting spatially where a circular economic approach can be more efficient.
Publisher: Elsevier BV
Date: 11-2014
DOI: 10.1016/J.SCITOTENV.2014.08.046
Abstract: This paper presents the results of a hydrological investigation of four medium scale green roofs that were set up at the University of South Australia. In this study, the potential of green roofs as a source control device was investigated over a 2 year period using four medium size green roof beds comprised of two growth media types and two media depths. During the term of this study, 226 rainfall events were recorded and these were representative of the Adelaide climate. In general, there were no statistically significant differences between the rainfall and runoff parameters for the intensive and extensive beds except for peak attenuation and peak runoff delay, for which higher values were recorded in the intensive beds. Longer dry periods generally resulted in higher retention coefficients and higher retention was also recorded in warmer seasons. The average retention coefficient for intensive systems (89%) was higher than for extensive systems (74%). It was shown that rainfall depth, intensity, duration and also average dry weather period between events can change the retention performance and runoff volume of the green roofs. Comparison of green and simulated conventional roofs indicated that the former were able to mitigate the peak of runoff and could delay the start of runoff. These characteristics are important for most source control measures. The recorded rainfall and runoff data displayed a non-linear relationship. Also, the results indicated that continuous time series modelling would be a more appropriate technique than using peak rainfall intensity methods for green roof design and simulation.
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 11-2011
Publisher: Thomas Telford Ltd.
Date: 05-2012
Abstract: Bioretention basins and permeable pavements are two widely implemented water sensitive urban design (WSUD) technologies. While their applications are extensive, their effectiveness as a result of changes in rainfall patterns is an emerging and important research question. This paper describes how these systems behave under varying rainfall conditions in Australian cities. To illustrate this, two design parameters, namely emptying times for permeable pavements and scour velocities for bioretention systems, were investigated. The study revealed that there are two groups of cities displaying almost similar peak flow characteristics – high (Darwin, Cairns, Brisbane, Townsville and Sydney) and low (Alice Springs, Hobart, Melbourne, Perth and Adelaide). It was shown that selection of an optimal storage size to ensure appropriate emptying times for permeable pavements requires a balance between managing dry periods, reuse demand and economic considerations. Increase of high flows increases the risk of scouring in bioretention basins, which is particularly significant for the first group of cities. Finally, the paper describes the importance of peak flow estimation method and appropriate selection of modelling time step for sustainable implementation of WSUD in Australia.
Publisher: Informa UK Limited
Date: 19-07-2019
Publisher: American Society of Civil Engineers
Date: 05-09-2002
Publisher: Informa UK Limited
Date: 08-2013
Publisher: Informa UK Limited
Date: 12-2010
Publisher: Routledge
Date: 03-07-2013
Publisher: International Society for Horticultural Science (ISHS)
Date: 06-2013
Publisher: Elsevier BV
Date: 07-2020
Publisher: Wiley
Date: 14-03-2015
DOI: 10.1002/JOC.3982
Publisher: MDPI AG
Date: 17-03-2018
DOI: 10.3390/W10030337
Publisher: MDPI AG
Date: 15-07-2019
Abstract: Living walls (LW) have been widely proposed as a form of green infrastructure to improve aesthetics, energy consumption, and microclimate in urban environments by adding densely-planted vegetation to the outside walls of buildings. Scientific studies using multiple treatments in a single LW face challenges due to the close physical proximity of different treatments, particularly the potential for plants above to influence those below. A study on a west-facing LW was undertaken to investigate 36 unique treatments in Adelaide, South Australia, for nine months. The LW comprised combinations of six native plant species, three soil substrates and two irrigation volumes. The LW consisted of 144 modular trays mounted on a wall in a 12 × 12 grid with four replicates of each treatment. The location of each treatment was designed to account for a cascading carry-over effect that may be present when one plant is placed above another. Carry-over effect of the model designed showed mixed results among the plant groups identified. It was also found that long-form plants can significantly shade smaller plants below them. Experimental research into the performance of plants in mixed species LW should consider the carry-over effect to account for this.
Publisher: Pleiades Publishing Ltd
Date: 05-2013
Publisher: American Society of Civil Engineers
Date: 17-03-2022
Publisher: Elsevier BV
Date: 09-2019
DOI: 10.1016/J.JENVMAN.2019.05.151
Abstract: The trapping of sediments within permeable pavements during infiltration is an important process that contributes to their water quality treatment performance. However, this process also leads to clogging, which decreases the infiltration capacity of the pavement. With different rainfall intensities and durations, this study investigates the amount and size of sediment passing through a porous paver, as well as through the gravel-filled gaps that separate adjacent pavers. One of the major challenges in this study was to design an experiment where the characteristics of the sediment particles that are trapped while passing through these two different infiltration pathways are assessed. This was overcome by developing a new type of rainfall application device in combination with a two-tiered sediment capturing system. A better understanding of the infiltration pathways of sediment and the associated clogging processes should help designers improve the effective life of permeable pavements. Overall, it was found that while the porosity of porous pavers serves a useful function in terms of removing excess surface water during and after a rainfall event, it serves little purpose in removing sediment from stormwater.
Publisher: WIT Press
Date: 12-07-2011
DOI: 10.2495/SDP110211
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.SCITOTENV.2019.03.357
Abstract: Planting of street trees in cities and other high-density urban environments can provide significant social, economic and environmental benefits. However, street trees in pavements can often lead to shallow root growth resulting in damage to pavements, kerbs, roads and buried services. This study investigated whether pavement damage by tree roots could be reduced by planting trees in a permeable pavement system with an underlying layer of 20 mm diameter gravel to direct tree roots deeper into the pavement structure. A six-year duration field experiment was conducted to compare the growth of trees and their root systems in a conventional impermeable pavement with growth in a series of permeable pavements with different depths of underlying gravel basecourse. The results demonstrated that permeable pavements with underlying gravel layers encouraged tree roots to travel deeper into the underlying subgrade soil, thereby reducing costly pavement damage. This effect was more pronounced with deeper rather than shallower basecourse layers. While permeable pavements affected tree root growth, they had no significant influence on tree height after six years' growth.
Publisher: Wiley
Date: 30-12-2010
DOI: 10.1002/HYP.7928
Publisher: Canadian Center of Science and Education
Date: 13-08-2013
DOI: 10.5539/EP.V2N4P10
Publisher: Elsevier BV
Date: 08-2013
Publisher: Springer Science and Business Media LLC
Date: 18-04-2013
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.JENVMAN.2019.06.021
Abstract: Kerb side inlets with adjacent leaky wells are an emerging tool to harvest stormwater and to reduce runoff volumes and peak flow rates. This is achieved by collecting the first flush runoff into kerb side storages and infiltrating this water into the surrounding soil, thereby also reducing stormwater pollutant loadings. The hydraulic performance of the kerb side inlet, filter media and surrounding soil are key factors in the performance of these systems. However, no field or laboratory data are currently available for the hydraulic performance of a kerb side tree inlet pit. In this study, 12 tree inlet pits were constructed and filled with various media types including gravel, water treatment solids (a recycled waste product), sandy loam and clay to examine (1) leaky well infiltration rates (2) emptying times of the wells and (3) the well capacity (runoff storage volume) before and after runoff filtering through the wells. Using a laboratory model, the water harvesting performance of the kerb side inlet plate was also examined for various road longitudinal slopes. Using the field and laboratory data, simulation of the well performance was undertaken using the Model for Urban Stormwater Improvement Conceptualisation (MUSIC) to assess the capacity of these systems to reduce runoff volumes at the residential street scale. It was hypothesised that the type of filter media used in leaky well systems has a significant impact on the infiltration rate, regardless of the native soil type through which the stormwater eventually infiltrates. The results showed that the infiltration rates of systems filled with gravel were significantly higher than for the other media types, and this was followed by water treatment solids, sandy loam and clay. The results of the MUSIC modelling indicated that 2.8% of the mean annual runoff volume in the catchment could be harvested by the systems at the case study site. It was found that selection of high infiltration rate media and regular maintenance are the key factors for maintaining long-term performance of these systems.
Publisher: MDPI AG
Date: 29-03-2018
DOI: 10.3390/W10040403
Publisher: Springer Science and Business Media LLC
Date: 07-11-2015
Publisher: Elsevier BV
Date: 06-2013
Publisher: Springer Science and Business Media LLC
Date: 11-11-2015
Publisher: Elsevier BV
Date: 05-2011
Publisher: Elsevier BV
Date: 09-2016
Publisher: Springer Science and Business Media LLC
Date: 02-02-2016
DOI: 10.1007/S10661-016-5116-7
Abstract: Dissolved organic matter is an important component of biogeochemical processes in aquatic environments. Dissolved organic matter may consist of a myriad of different fractions and resultant processing pathways. In early January 2011, heavy rainfall occurred across South East Queensland, Australia causing significant catchment inflow into Lake Wivenhoe, which is the largest water supply reservoir for the city of Brisbane, Australia. The horizontal and vertical distributions of dissolved organic matter fractions in the lake during the flood period were investigated and then compared with stratified conditions with no catchment inflows. The results clearly demonstrate a large variation in dissolved organic matter fractions associated with inflow conditions compared with stratified conditions. During inflows, dissolved organic matter concentrations in the reservoir were fivefold lower than during stratified conditions. Within the dissolved organic matter fractions during inflow, the hydrophobic and humic acid fractions were almost half those recorded during the stratified period whilst low molecular weight neutrals were higher during the flood period compared to during the stratified period. Information on dissolved organic matter and the spatial and vertical variations in its constituents' concentrations across the lake can be very useful for catchment and lake management and for selecting appropriate water treatment processes.
Publisher: Informa UK Limited
Date: 03-2005
Publisher: Trans Tech Publications, Ltd.
Date: 07-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.295-297.873
Abstract: One of the most important characteristics of porous concrete is the ability to capture and transport water. The permeability of porous concrete is therefore needs to be evaluated. This paper will investigate various methods for testing the permeability of porous concrete and compares the different results from falling head and constant head tests. The hydraulic theories were then applied into the analysis to determine the permeability of the porous concrete s les.
Publisher: Trans Tech Publications, Ltd.
Date: 12-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.168-170.1590
Abstract: With the increasing popularity of pervious concrete as a pavement material, researchers and concrete manufacturers have paid more attention to research needs. Pervious concrete is currently used in low traffic volume areas such as parking lots, footpaths and driveways. This is because it generally has lower strength than conventional concrete. This paper aims at developing a computational model to simulate the behaviour of pervious concrete under compression. Since compressive strength is one of the most important properties for concrete, a virtual model will provide a better understanding of its mechanical performance, which in turn will improve both the mix design and the material strength in the future. The discrete element method was applied and the results of calculations based on particle flow analysis are compared to the experimental data.
Publisher: MDPI AG
Date: 02-2023
DOI: 10.3390/ENVIRONMENTS10020026
Abstract: Living walls are fast becoming a ubiquitous feature of modern living and are widely implemented in commercial buildings in both internal and external environments. However, there are several challenges associated with maintaining healthy plant growth on these water sensitive urban design systems. This experimental study of an instrumented prototype-scale living wall has found that there is a close relationship between the plants, substrates and adopted irrigation regimes. In this study, plant selection was found to be more critical than either substrate or irrigation regime selection. This research also found that both the location of the plants on the wall and irrigation volume significantly affected the plants’ ultimate total dry weight. In particular, plants were found to grow taller on the upper section of the living wall compared to the middle and lower sections. It is recommended that particular attention should be given to plant location and the amount of irrigation water supplied at different positions on the living wall.
Publisher: CRC Press
Date: 28-04-2023
Publisher: Elsevier BV
Date: 2009
Publisher: Elsevier BV
Date: 10-2014
Publisher: Thomas Telford Ltd.
Date: 08-2016
Abstract: Greywater reuse is becoming popular in water scarce regions, but the key challenges are collection, appropriate treatment and storage. Conceptually, an aggregate base course in permeable pavements can provide both treatment and storage facilities for greywater, particularly in arid regions where urban runoff is not an abundant water resource. A prototype permeable pavement unit was constructed to evaluate this concept. The unit was filled with supply water, ablution greywater and laundry greywater, and various water quality parameters were monitored daily. While most parameters showed an improvement in quality after 1 d of storage, pH and sodium ions were found in excessive amounts in the laundry greywater. In addition, the unit was found to be inefficient in reducing total aerobic and total coliform bacteria. The study revealed that permeable pavements can serve as a treatment and storage unit in greywater reuse schemes subject to the inclusion of appropriate disinfection and sodium ion reduction measures.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7EW00530J
Abstract: The effects of recycling spent filter backwash water (SFBW) on the removal of 14 organic pesticides were examined in a simulated conventional drinking water treatment process.
Publisher: Informa UK Limited
Date: 13-05-2015
Publisher: SAGE Publications
Date: 23-04-2009
Abstract: The main purpose of this study was to examine negative pressures in siphonic downpipes and to see whether these can be controlled through breaking the siphonic action by injecting air at certain points in a vertical downpipe. The study also investigated cavitation and its propagation through a prototype scale siphonic system. The paper presents methods for limiting the minimum pressure in siphonic downpipes in tall buildings. A distinctive drop in pressure between approximately —70 kN/m 2 and —96 kN/m 2 occurred in a 80 mm diameter downpipe and it was not possible to sustain pressures between these limits. The pressure drop to -96 kN/m 2 caused the formation of a distinctive cavitation zone. Any increase in downpipe length, beyond the cavitation zone, produced a proportional increase in the cavitation zone length. Practical application: Cavitation is perceived to be a serious problem for designers of siphonic drainage systems to be installed in tall buildings. Using full-scale testing this paper provides evidence that in practice cavitation in plastic downpipes is unlikely to cause damage. The paper also provides guidelines for maximum spacing of air inlets to limit the minimum pressure to ∼70 kN/m 2 below atmospheric pressure without significantly decreasing the system capacity.
Publisher: Springer International Publishing
Date: 2023
Publisher: MDPI AG
Date: 10-06-2016
DOI: 10.3390/RS8060492
Publisher: Springer Science and Business Media LLC
Date: 18-03-2015
Publisher: International Society for Horticultural Science (ISHS)
Date: 11-2010
Publisher: American Society of Civil Engineers (ASCE)
Date: 08-2005
Publisher: Elsevier BV
Date: 05-2023
Publisher: Elsevier BV
Date: 04-2011
Publisher: Wiley
Date: 12-02-2014
DOI: 10.1002/JOC.3933
Publisher: IWA Publishing
Date: 07-2013
DOI: 10.2166/WST.2013.251
Abstract: A review is made of current methods for assessing future changes in urban rainfall extremes and their effects on urban drainage systems, due to anthropogenic-induced climate change. The review concludes that in spite of significant advances there are still many limitations in our understanding of how to describe precipitation patterns in a changing climate in order to design and operate urban drainage infrastructure. Climate change may well be the driver that ensures that changes in urban drainage paradigms are identified and suitable solutions implemented. Design and optimization of urban drainage infrastructure considering climate change impacts and co-optimizing these with other objectives will become ever more important to keep our cities habitable into the future.
Publisher: Springer Science and Business Media LLC
Date: 20-08-2017
Publisher: Springer Science and Business Media LLC
Date: 08-09-2019
DOI: 10.1007/S11356-018-3083-Y
Abstract: The TREENET inlet is an emerging water-sensitive urban design technology that consists of a novel kerb side inlet coupled with a leaky well infiltration system. The inlets have been retrofitted to existing roads since 2006 however, there is currently little information available on the effectiveness of these inlet and leaky well systems. This study investigated the performance of the kerb side inlets and leaky well system for water quality improvement prior to infiltration to native soil. The leaky wells included four filter media types, namely gravel, water treatment solids, sandy loam and clay. To compare the performance of the four filter media types, batch and column studies were performed in the laboratory. The best performance was observed using the sandy loam as a filter media, followed by clay, water treatment solids and then gravel. The selection of effective media for removal of heavy metals is important as each media type has different pollutant removal capacity, infiltration and clogging performance.
Publisher: Elsevier BV
Date: 02-2016
Publisher: Thomas Telford Ltd.
Date: 12-2064
DOI: 10.1680/WAMA.900053
Abstract: The management of three connected reservoirs for the capture, storage and supply of urban stormwater is modelled using a pump-to-fill policy that minimises the volume of water lost to overflow. A discrete state Markov model is used with constant daily demand from the supply reservoir and stochastic inflow to the capture reservoir. The pump-to-fill policy is completely deterministic and depends only on the current volume in the supply, storage and capture reservoirs. By judicious ordering of the states the very large transition matrix is shown to possess a nested block upper Hessenberg structure. Standard censoring methods reduce the analysis of the system to a characteristic sequence of full-to-full transitions for the supply reservoir. The nested block structure of the original transition matrix is captured using special recursive algebraic procedures that enable a further reduction to a sequence of simultaneous full-to-full transitions for the supply and storage reservoirs. Capabilities of the model are demonstrated through application to a hypothetical three-reservoir network for the capture and supply of water. The methods proposed in this paper could be used to calculate the steady-state probabilities for three-reservoir storage systems and could assist projections for future water supply capabilities. This paper also provides insight into how the analysis could be extended to systems of more than three reservoirs.
Publisher: Springer Science and Business Media LLC
Date: 20-08-2016
Publisher: Wiley
Date: 17-05-2013
DOI: 10.1002/JOC.3482
Publisher: American Society of Civil Engineers (ASCE)
Date: 09-2005
Publisher: Thomas Telford Ltd.
Date: 09-2021
Abstract: Enzyme-induced carbonate precipitation (EICP) is a bio-cementation technique and a sustainable method of ground improvement. This study examines the influence of the concentrations of substrates [S 0 ] and enzymes [E 0 ] as well as enzyme activity (A E ) on the calcium carbonate (CaCO 3 ) precipitation ratio (PR) using 130 test-tube experiments. It was found that the effect of enzyme concentration and activity on PR can be explained using a normalisation of [E s ] = [E 0 ] × A E , where [E s ] is the adjusted enzyme concentration. PR increased non-linearly with increasing [E s ]/[S 0 ] and reached 100% at a threshold [E s ]/[S 0 ] value of approximately 20 kU/mol. An exponential function was developed that could capture the relationship between PR and [E s ]/[S 0 ] with reasonable accuracy. This observation was further evaluated with data from the literature consisting of a further 100 test-tube experiments. EICP solutions consisting of [E s ]/[S 0 ] = 20 kU/mol were found to be optimum for soil treatment. The established function was later extended to predict strength gain as measured by the unconfined compressive strength (UCS) and the splitting tensile strength (STS) for EICP-treated soils and could predict the strength gain (UCS/STS) with reasonable accuracy. Results from scanning electron microscopy images, energy-dispersive X-ray spectroscopy and X-ray powder diffraction showed that the precipitated calcium carbonate in test tubes and treated soil was mostly calcite crystals with different morphologies, possibly due to the level of purity of the urease enzyme used.
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.WATRES.2014.12.015
Abstract: Low-energy pollutant removal strategies are now being sought for water sensitive urban design. This paper describes investigations into the water quality and quantity of sixteen, low-maintenance and unfertilized intensive and extensive green roof beds. The factors of Slope (1° and 25°), Depth (100 mm and 300 mm), Growing media (type A, type B and type C) and Species (P1, P2 and P3) were randomized according to a split-split plot design. This consisted of twelve vegetated green roof beds and four non-vegetated beds as controls. Stormwater runoff was collected from drainage points that were installed in each area. S les of run-off were collected for five rainfall events and analysed for water retention capacity and the water quality parameters of NO₂, NO₃, NH₄, PO₄, pH, EC, TDS, Turbidity, Na, Ca, Mg and K. The results indicated significant differences in terms of stormwater water quality and quantity between the outflows of vegetated and non-vegetated systems. The water retention was between 51% and 96% and this range was attributed to the green roof configurations in the experiment. Comparing the quality of rainfall as inflow, and the quality of runoff from the systems showed that green roofs generally acted as a source of pollutants in this study. In the vegetated beds, the intensive green roofs performed better than the extensive beds with regard to outflow quality while in the non-vegetated beds, the extensive beds performed better than intensive systems. This highlights the importance of vegetation in improving water retention capacity as well as the role of vegetation in enhancing pollutant removal in green roof systems. In addition growing media with less organic matter had better water quality performance. Comparison of these results with national and international standards for water reuse confirmed that the green roof outflow was suitable for non-potable uses such as landscape irrigation and toilet flushing.
Publisher: Mary Ann Liebert Inc
Date: 07-2016
Publisher: IWA Publishing
Date: 12-2009
DOI: 10.2166/WST.2009.753
Abstract: Permeable pavement reservoirs provide an important opportunity for the harvesting and storage of stormwater for reuse. This research aims to determine whether storage in dolomite, calcite and quartzite mineral aggregates in the base course of a permeable pavement impacts on the survival of the pathogen indicator organism Escherichia coli (E. coli) in storage. The reasons for depletion were also investigated. Twelve model permeable pavement storage reservoirs were filled, in triplicate, with dolomite, calcite and quartzite. Three reservoirs contained no aggregate. After filling with pathogen spiked rainwater, the concentration of E. coli was examined for 22 days in the reservoirs. The reservoirs were then agitated to determine if there was E. coli present which was not in aqueous suspension. The results of the experiments show that there is no significant difference in the depletion of E. coli found in reservoirs without aggregate, and those filled with dolomite or calcite. The rate of depletion was found to be significantly lower in the quartzite filled reservoirs. Agitation of the reservoirs yielded increases in the aqueous concentration of E. coli in all reservoir types, suggesting that the bacteria are adhering to the surface of the mineral aggregate and to the reservoir walls.
Publisher: Springer International Publishing
Date: 2015
Publisher: American Society of Civil Engineers
Date: 23-03-2023
Publisher: Elsevier BV
Date: 06-2015
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.SCITOTENV.2019.01.018
Abstract: A Constructed Floating Wetland (CFW) is a relatively recent innovation in stormwater treatment and is a hydroponic device that is designed to move up and down with changing water levels as urban runoff enters a stormwater retention pond. This floating capability is designed to improve the pollutant removal efficiency of the CFW. The CFW studies undertaken so far have produced encouraging results under a range of conditions such as system size, inflow pollutant concentrations, climatic conditions, and coverage ratio. However, these results have not yet been drawn together to better understand how the various design features of a CFW influence its performance. This paper reviews the available field investigations with the aim of helping guide and improve the experimental designs and installations of future CFW installations. This in turn will improve the knowledge and acceptance of these recently developed stormwater treatment systems. One of the findings of this review was that using a percentage coverage design approach may not be as effective as improving the design efficiency. Understanding the hydraulics of the entire pond and CFW system is also critical to effective design. The review also found that the performance evaluation of future CFW installations would be improved if consideration is given to including both baseline monitoring and experimental controls.
Publisher: MDPI AG
Date: 04-08-2020
DOI: 10.3390/SU12156281
Abstract: Microbial-induced calcite precipitation (MICP) is a promising new technology in the area of Civil Engineering with potential to become a cost-effective, environmentally friendly and sustainable solution to many problems such as ground improvement, liquefaction remediation, enhancing properties of concrete and so forth. This paper reviews the research and developments over the past 25 years since the first reported application of MICP in 1995. Historical developments in the area, the biological processes involved, the behaviour of improved soils, developments in modelling the behaviour of treated soil and the challenges associated are discussed with a focus on the geotechnical aspects of the problem. The paper also presents an assessment of cost and environmental benefits tied with three application scenarios in pavement construction. It is understood for some applications that at this stage, MICP may not be a cost-effective or even environmentally friendly solution however, following the latest developments, MICP has the potential to become one.
Publisher: Thomas Telford Ltd.
Date: 21-09-2023
Abstract: Microbial or enzyme-induced calcium carbonate precipitation (MICP/EICP) are relatively new ground improvement technique. In this study, the mechanical behaviour of biotreated (MICP/ EICP) and untreated sands were investigated in light of the critical state soil mechanics framework using a series of direct simple shear (DSS) tests. A wide range of CaCO 3 content (C C ), initial void ratio after consolidation (e 0 ) and effective initial normal stress (σ′ N 0 ) was considered. The biotreated specimens showed improved shear strength and dilative tendency compared to untreated specimens with similar initial states. The ultimate state for the biotreated sand shifted towards a smaller void ratio (e) than e at the critical state of untreated sand at the same σ′ N in e–log σ′ N space. Compared to untreated sand, a significantly larger ultimate state stress ratio was achieved for the biotreated sand, particularly at high C C and low σ′ N 0 . The characteristic features of undrained behaviour, such as instability stress ratio, stress ratio at phase transformation and flow potential showed good relationships with modified initial state parameter, void ratio after biotreatment and C C . Bonding ratio, (τ/σ′ N ) bond was used to quantify the interparticle bonding. The peak value of (τ/σ′ N ) bond for the biotreated sand was significantly larger than zero, particularly at high C C and low σ′ N 0 , while the peak (τ/σ′ N ) bond for the untreated sand was negligible. It is also observed that the mobilisation and degradation of CaCO 3 bonds in biotreated sand during DSS shearing are influenced by both C C and σ′ N 0 .
Publisher: Wiley
Date: 2010
DOI: 10.1002/JOC.1901
Publisher: MDPI AG
Date: 19-11-2014
DOI: 10.3390/W6113528
Publisher: American Society of Civil Engineers
Date: 05-2008
Publisher: American Society of Civil Engineers
Date: 28-05-2013
Publisher: Unpublished
Date: 2014
Publisher: IWA Publishing
Date: 08-2012
Publisher: Springer Science and Business Media LLC
Date: 30-09-2014
Publisher: Taiwan Association for Aerosol Research
Date: 2018
Start Date: 2005
End Date: 2005
Funder: Australian Research Council
View Funded ActivityStart Date: 2008
End Date: 2010
Funder: Australian Research Council
View Funded ActivityStart Date: 2004
End Date: 2006
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 2013
Funder: Australian Research Council
View Funded ActivityStart Date: 2009
End Date: 2012
Funder: Australian Research Council
View Funded ActivityStart Date: 2012
End Date: 2015
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 2003
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 2014
Funder: Australian Research Council
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