ORCID Profile
0000-0002-7757-4163
Current Organisation
TU Wien
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Publisher: IWA Publishing
Date: 10-2019
DOI: 10.2166/WST.2019.378
Abstract: The emissions of climate-relevant nitrous oxides from wastewater treatment with aerobic granular sludge (AGS) are of special interest due to considerable structural as well as microbiological differences compared with flocculent sludge. Due to the compact and large structures, AGS is characterised by the formation of zones with different dissolved oxygen (DO) and substrate gradients, which allows simultaneous nitrification and denitrification (SND). N2O emissions from AGS were investigated using laboratory-scale SBR fed with municipal wastewater. Special attention was paid to the effects of different organic loading rates (OLR) and aeration strategies. Emission factors (EF) were in a range of 0.54% to 4.8% (gN2O/gNH4-Nox.) under constant aerobic conditions during the aerated phase and different OLR. Higher OLR and SND were found to increase the N2O emissions. A comparative measurement of two similarly operated SBR with AGS showed that the reactor operated under constant aerobic conditions (DO of 2 mg L−1) emitted more N2O than the SBR with an alternating aeration strategy. Total nitrogen (TN) removal was significantly higher with the alternating aeration since non-aerated periods lead to increased anoxic zones inside the granules. The constant aerobic operation was found to promote the accumulation of NO2-N, which could explain the differences in the N2O levels.
Publisher: IWA Publishing
Date: 06-2012
DOI: 10.2166/WPT.2012.030
Abstract: From an asset management perspective there is an ongoing challenge to make strategic investment decisions which are based on maintaining asset serviceability, effluent quality requirements and providing for growth. Additionally, in idual performance of treatment stages and changes in sewage flows and loads have to be considered to achieve an optimised outcome. Typically, large scale capital projects are required to address the many challenges that face a WWTP. However, significant cost savings can be made if smaller optimisation projects are pursued to maximise the capacity of existing infrastructure and therefore defer high cost capital upgrades. To achieve this end, SA Water started a formal process to review the capacity of each process element of the Bolivar WWTP and found several opportunities to optimise current process performance. Based on these outcomes a future strategy document was developed that enables the next major plant upgrade to be deferred by 8–10 years. This paper summarises SA Water's approach to develop such a documentation to allow a strategic asset management, optimise its capital expenditure and achieve significant cost savings. It also highlights some of the projects that were identified during this process to improve the current treatment plant performance.
Publisher: Desalination Publications
Date: 2019
Publisher: Elsevier BV
Date: 12-2022
DOI: 10.1016/J.SCITOTENV.2022.157593
Abstract: In this contribution, we analyse scenarios of advanced wastewater treatment for the removal of micropollutants. By this we refer to current mainstream, broad spectrum processes including ozonation and sorption onto activated carbon. We argue that advanced treatment requires properly implemented tertiary (nutrient removal) treatment in order to be effective. We review the critical aspects of the main advanced treatment options, their advantages and disadvantages. We propose a quantification of the costs of implementing advanced treatment, as well as upgrading plants from secondary to tertiary treatment when needed, and we illustrate what drives the costs of advanced treatment for a set of standard configurations. We propose a cost function to represent the total costs (investment, operation and maintenance) of advanced treatment. We quantify the implications of advanced treatment in terms of greenhouse gas emissions. Based on the indicators of total toxic discharge, toxicity at the discharge points and toxicity across the stream network discussed in Pistocchi et al. (2022), we compare costs and effectiveness of different scenarios of advanced treatment. In principle the total toxic load and toxicity at the points of discharge could be reduced by about 75 % if advanced treatment processes were implemented virtually at all wastewater treatment plants, but this would entail costs of about 4 billion euro/year for the European Union as a whole. We consider a "compromise" scenario where advanced treatment is required at plants of 100 thousand population equivalents (PE) or larger, or at plants between 10 and 100 thousand PE if the dilution ratio at the discharge point is 10 or less. Under this scenario, the length of the stream network exposed to high toxicity would not increase significantly compared to the previous scenario, and the other indicators would not deteriorate significantly, while the costs would remain at about 1.5 billion Euro/year. Arguably, costs could be further reduced, without a worsening of water quality, if we replace a local risk assessment to generic criteria of plant capacity and dilution in order to determine if a WWTP requires advanced treatment.
Publisher: IWA Publishing
Date: 11-2019
DOI: 10.2166/WST.2019.415
Abstract: In this research, sources of methane emissions of an anaerobic digester (AD) system at a municipal wastewater treatment plant (WWTP) with 260,000 population equivalent (PE) capacity were detected by a non-dispersive infrared (NDIR) camera. The located emissions were evaluated qualitatively and were documented with photographs and video films. Subsequently, the emission sources were quantified in idually using different methods like the Flux-Chamber method and s ling from the digester's circulation pipe. The dissolved methane in the sludge digester was measured via gas chromatography-mass spectrometry (GC-MS) and 6.8% oversaturation compared to the equilibrium after Henry's law was found. Additionally, the residual gas potential of the digestate was measured using batch tests with 10 days' additional stabilisation time. The PE-specific residual gas production of the full-scale AD was calculated to 12.4 g CH4/(PE · y). An extended chemical oxygen demand (COD) balance including methane emissions for the whole digester system was calculated. Also the measured methane loads were calculated and summed up. The total methane loss of the AD was calculated at 24.6 g CH4/(PE · y), which corresponds to 0.4% of the produced biogas (4,913 g CH4/(PE · y)). PE-specific methane emission factors are presented for each investigated (point) source like the sludge outlet at the digester's head, a leaking manhole sealing and cracks in the concrete structure.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 10-2022
Publisher: Elsevier BV
Date: 03-2018
Publisher: Springer Science and Business Media LLC
Date: 11-01-2023
DOI: 10.1007/S00506-022-00924-Y
Abstract: Abwasserkanäle und Abwasserreinigungsanlagen können relevante Quellen von Kohlendioxid, Lachgas und Methan sein. Direkte Kohlendioxidemissionen sind klimaneutral, da die organischen Bestandteile im Abwasser überwiegend aus biologischen Quellen stammen. Dagegen haben direkte Methan- und Lachgas-Emissionen einen signifikanten Einfluss auf das Klima. Der derzeit vorliegende Entwurf der EU-Richtlinie für kommunales Abwasser 91/271/EWG (Urban Wastewater Treatment Directive) greift erstmals Treibhausgasemissionen aus Abwasserkanälen und Kläranlagen auf und zielt auf deren Monitoring, Reporting und Reduktion ab. Die vorliegende Arbeit beschäftigt sich mit den direkten Gasemissionen von Methan und Lachgas aus Abwasserkanälen und Kläranlagen und deren Produktions- und Reduktionspfaden. Die Hauptemissionsquellen werden überblicksartig dargestellt und die Bedeutung dieser Emissionen wird auf nationaler Ebene eingeordnet. Potenziale und Maßnahmen zur Reduktion von Methan- und Lachgasemissionen aus dem Sektor Abwasser werden beleuchtet. Indirekte Treibhausgasemissionen aus dem Bezug von Strom sowie aus vorgelagerten Prozessen, wie z. B. aus der Herstellung und Transport von Fällmitteln, stellen auch wesentliche Emissionspfade dar. Die Relevanz der unterschiedlichen Treibhausgas-Emissionspfade der Abwasserentsorgung werden am Beispiel des CO 2 -Fußabdrucks von zwei Kläranlagen, einer mit simultaner aerober Schlammstabilisierung (SASS) und einer mit anaerober Stabilisierung (Schlammfaulung) diskutiert.
Publisher: IWA Publishing
Date: 12-04-2018
DOI: 10.2166/WST.2018.170
Abstract: The study aims to simultaneously control micropollutants and bromate formations by using ozonation and peroxone process. The batch experiments were run with variations in specific ozone dose (SOD) and hydrogen peroxide-to-ozone (H2O2/O3) ratio. Based on the removal by ozonation and peroxone, micropollutants were categorized into three groups: non-reactive compounds (i.e. amidotrizoate), moderately reactive compounds (i.e. metoprolol, acesulfame potassium, bezafibrate, and benzotriazole), and highly reactive compounds (i.e. carbamazepine and diclofenac). For ozonation and peroxone process, the removals for highly reactive compounds and moderately reactive compounds were 82–99% and 29–99%, respectively. The removal of amidotrizoate was not observed in this study. The effect of ozonation on micropollutant removals was similar to the peroxone process. However, differences in bromate formation were observed. Bromate formation depended on the SOD, while addition of hydrogen peroxide suppressed the bromate formation. The peroxone process at the H2O2/O3 ratio of 0.3 was recommended to bromide-containing water below 100 µg·L−1 for simultaneous control of micropollutants and bromate. Enhancement in micropollutant removals, except for the non-reactive groups, was achieved with either higher SOD or the addition of hydrogen peroxide to ozonation. The micropollutant removal predicted from the second-order kinetic reaction with ozone and •OH exposures was higher than the observed data.
Publisher: Elsevier BV
Date: 02-2020
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.SCITOTENV.2019.01.143
Abstract: Understanding the fate of fecal pollution in the landscape is required for microbial risk analysis. The aim of this study was to assess the patterns and dynamics of beta-d-glucuronidase (GLUC), which has been suggested as a surrogate for fecal pollution monitoring, in a stream draining an agricultural headwater catchment. Automated enzymatic on-site measurements of stream water and sediments were made over two years (2014-2016) to quantify the sources and pathways of GLUC in a stream. The event water fraction of streamflow was estimated by stable isotopes. S les from field sediments on a hillslope, streambed sediment and stream water were analyzed for GLUC and with a standard E. coli assay. The results showed ten times higher GLUC and E. coli concentrations during the summer than during the winter for all compartments (field and streambed sediments and stream water). The E. coli concentrations in the streambed sediment were approximately 100 times those of the field sediments. Of the total GLUC load in the study period, 39% were transported during hydrological events (increased streamflow due to rainfall or snowmelt) of these, 44% were transported when the stream contained no recent rainwater. The results suggested that a large proportion of the GLUC and E. coli in the stream water stemmed from resuspended streambed sediments. Moreover, the results strongly indicated the existence of remnant populations of GLUC-active organisms in the catchment.
Publisher: MDPI AG
Date: 16-11-2021
DOI: 10.3390/W13223245
Abstract: A set of CALUX in vitro bioassays was applied for long-term toxicity monitoring at an advanced wastewater treatment plant comprising ozonation and granular activated carbon filtration for the abatement of contaminants of emerging concern (CEC). During the 13-month monitoring, eight reporter gene assays targeting different modes of action along the cellular toxicity pathway were accessed to evaluate the suitability and robustness of the technologies. Two approaches were followed: on the one hand, signal reduction during advanced treatment was monitored on the other hand, results were compared to currently available effect-based trigger values (EBTs). A decrease of the corresponding biological equivalent concentrations after the multibarrier system could be observed for all modes of action while the estrogenic activity decreased below the EBT already during ozonation, the potencies of oxidative stress-like and toxic PAH-like compounds still exceeded the discussed EBT after advanced treatment. Overall, the long-term monitoring confirmed the positive effect of the multibarrier system, commonly evaluated only by CEC abatement based on chemical analysis. It could be demonstrated that advanced WWTPs designed for CEC abatement are suitable to significantly decrease toxicity responses not only in the frame of pilot studies but under real-world conditions as well.
Publisher: MDPI AG
Date: 13-10-2021
DOI: 10.3390/EN14206618
Abstract: Biological methanation as a method of sector coupling between electric and gas grids is expected to be an integral part of the green energy change. Wastewater treatment plants (WWTPs) involving anaerobic digestion (AD) allow existing infrastructure to operate as energy conversion plants, to close carbon cycles and to generate long-term storable energy in the form of biomethane. Therefore, municipal raw sludge and additional organic residuals (co-substrates) are converted into biogas. Hydrogen is added to convert the carbon dioxide in the biogas into methane via biological methanation (BM). In this study, the energy amount that is convertible via BM in municipal digesters in Austria was calculated. The amount of energy, which can be transformed from electric surplus energy into biomethane, was assessed. Operational data from lab-scale digesters were combined with data from 28 Austrian full-scale wastewater treatment plants with AD. They represent 9.2 Mio population equivalents (PE), or 68% of Austria’s municipal AD capacity for WWTPs 50,000 PE (in sum, 13.6 Mio PE). Energy flows for BM including water electrolysis and anaerobic digestion were created on a countrywide basis. It was found that 2.9–4.4% (220–327 GWh·y−1) of Austria’s yearly renewable electricity production (7470 GWh·y−1) can be transformed into biomethane via BM in municipal digesters.
Publisher: Springer Science and Business Media LLC
Date: 09-05-2019
Publisher: Springer Science and Business Media LLC
Date: 24-09-2019
DOI: 10.1007/S00506-019-00623-1
Abstract: Im vorliegenden Artikel wird auf Basis unterschiedlicher Datenquellen in einem ersten Schritt die Belastung des Neusiedler Sees mit national oder gemeinschaftlich geregelten anthropogenen Spurenstoffen dargestellt. Darüber hinaus werden für ausgewählte Stoffe Eintragspfade in Wulka und Neusiedler See identifiziert und für weitere Stoffe wird ein mögliches Umweltverhalten im See dargestellt. Auch wenn derzeit ein umfassendes Monitoring von allen national oder gemeinschaftlich geregelten Spurenstoffen im Neusiedler See fehlt, kann für den überwiegenden Teil dieser Stoffe auf Basis von Untersuchungen in der Wulka bzw. Fischuntersuchungen im See eine Einhaltung der UQN angenommen werden. Für einzelne Stoffe ist eine Zielverfehlung geben oder anzunehmen. Für andere Stoffe ist zurzeit aufgrund analytischer Schwierigkeiten ein eindeutiger Befund nicht möglich. In Abhängigkeit vom Stoff und der Betrachtungsebene können sowohl Kläranlagenabläufe, landwirtschaftliche Erosion als auch die atmosphärische Deposition auf die Oberfläche des Sees die Einträge dominieren. Mit Bedachtnahme auf die große Zahl der in die aquatische Umwelt emittierten anthropogenen Spurenstoffe muss unabhängig von der Betrachtung von Einzelstoffen für den Neusiedler See eine ganz besondere Vulnerabilität für diese Form der Belastung diagnostiziert werden. Dies liegt vor allem an der Funktion des Sees als Stoffsenke. Persistente Spurenstoffe, die in den See gelangen, werden im Freiwasser aufkonzentriert oder in den Sedimentbereichen des Schilfs gespeichert, von wo sie allenfalls wieder mobilisiert werden können. Selbst wenn eine Vielzahl von schwer abbaubaren Spurenstoffen durch Ab- oder Umbau aus dem Freiwasser des Sees eliminiert wird, ist über die Endprodukte eines solchen Umbaus noch wenig bekannt bzw. sind diese aufgrund der Vielzahl möglicher Stoffe nicht gänzlich zu überwachen. Als Grundlage zur Entwicklung von Strategien für ein langfristiges und effizientes Management des Sees wäre ein regelmäßiges Monitoring von Spurenstoffen in See und Schilfgürtel deutlich zu verstärken, um Fehlentwicklungen im See frühzeitig erkennen zu können.
Publisher: Elsevier BV
Date: 04-2016
DOI: 10.1016/J.JENVMAN.2016.01.035
Abstract: The anaerobic ammonium oxidation (anammox) process is widely acknowledged to be susceptible to a wide range of environmental factors given the slow growth rate of the anammox bacteria. Surprisingly there is limited experimental data regarding the susceptibility of the anammox process to feed starvations which may be encountered in full-scale applications. Therefore, a study was established to investigate the impact of feed starvations on nitritation and anammox activity in a demonstration-scale sequencing batch reactor. Three starvation periods were trialled, lasting one fortnight (15 d), one month (33 d) and two months (62 d). Regardless of the duration of the starvation period, assessment of the ammonia removal performance demonstrated nitritation and anammox activity were reinstated within one day of recovery operation. Characterisation of the community structure using 16S rRNA and functional genes specific for nitrogen-related microbes showed there was no clear impact or shift in the microbial populations between starvation and recovery phases.
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.JENVMAN.2018.10.074
Abstract: Occurrence and concentration of a broad spectrum of micropollutants are investigated in Austrian river catchments, namely polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), organotin compounds, perfluoroalkyl acids (PFAAs) and metals. The parallel analysis across multiple environmental and engineered compartments sheds light on the ratio of dissolved and particulate transport and on differences in concentration levels between point and diffuse emission pathways. It is found that some PAHs and organotins are present in rivers, groundwater and bulk deposition at higher concentrations than in municipal wastewater effluents. Among PFAAs and metals, highest concentrations were recorded either in atmospheric deposition or in discharges from wastewater treatment plants. The relevance of the analysis across compartments is best shown by the case of perfluorooctanesulfonic acid (PFOS). Despite municipal wastewater effluents being the emission pathway with highest concentrations, this study reveals that not only rivers, but also atmospheric deposition and groundwater sometimes exceed the environmental quality standard for surface waters. Moreover, this work reveals partially counterintuitive patterns. In rivers with treated wastewater discharges, increasing levels of dissolved compounds were measured at rising flow conditions, whereas the opposite would be expected owing to the dilution effect. This might derive from the mobilisation from soil or suspended particulate matter or rather find its explanation in high concentrations in atmospheric deposition. These hypotheses require however being tested through targeted studies. Additional future research includes the analysis of how regional or catchment specific characteristics might alter the relative importance of different emission pathways, and the modelling of emission and river loads to assess their relative contribution to river pollution.
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.SCITOTENV.2021.152466
Abstract: The present work aimed to study the effect of ozonation on the organic sum parameters linked to enhanced biodegradability. Laboratory experiments were conducted with the effluent of four Austrian urban wastewater treatment plants with low food to microorganism ratios and different matrix characteristics. Biochemical oxygen demand over 5 days (BOD
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3EM00152K
Abstract: Evapotranspiration and indirect photodegradation, but also connectivity between open lake and reed belt play a major role in the fate of organic trace contaminants and in determining the water chemistry in the shallow Lake Neusiedl.
Publisher: MDPI AG
Date: 25-10-2021
DOI: 10.3390/W13212998
Abstract: Recent years came with a paradigm shift for wastewater treatment plants (WWTPs) to extend the sole purpose of contaminant removal to an additional function as resource recovery facilities. This shift is accompanied by the development of new European legislation towards better inclusion of resource recovery from wastewater. However, long operational lifespans and a multitude of treatment requirements demand thorough investigations into how resource recovery can be implemented sustainably. To aid the formulation of new legislation for phosphorus (P) recovery specifically, in 2017 we conducted a survey on Austrian WWTP-infrastructure, with a focus on P removal and sludge treatment, as well as disposal and sludge quality of all WWTPs above 2000 population equivalents (PE). Data were prepared for analysis, checked for completeness and cross-checked for plausibility. This study presents the major findings from this database and draws essential conclusions for the future recovery of P from wastewater. We see results from this study as useful to other countries, describing the current state of the art in Austria and potentially aiding in developing wastewater treatment and P recovery strategies.
Publisher: Elsevier BV
Date: 11-2008
DOI: 10.1016/J.WATRES.2008.08.016
Abstract: This study was designed to solve metal ion influence problem on phosphorus recovery from digested sewage sludge as MAP. The experimental steps were proceeded to maximize MAP production and its quality. Used experimental steps were: All digested sewage sludge s les were taken from Stuttgart University sewage treatment plant for research and education (LFKW). Four different forms of LFKW digested sewage sludge were used as feeding s le. These were: original digested sludge, diluted digested sludge, centrifuged digested sludge and incinerated digested sludge. A Donnan membrane unit having a Nafion 117 (DuPont) cation exchange membrane was used to remove metal ions from the s les used. Highest metal ion removal efficiencies, which were 98%, 97%, and 80% for Al, Ca and Fe ions, respectively, were obtained from incinerated digested sludge run. Incinerated digested sludge run was used as preliminary step for MAP production and high quality MAP was produced. Produced MAP fulfils all requirements related with Düngemittelverordnung 2003 and it could be used as a fertilizer in Germany.
Publisher: MDPI AG
Date: 08-10-2022
Abstract: The operational costs of wastewater treatment plants (WWTPs) are mainly driven by electric power consumption, making the energy-efficient operation an all-time present target for engineers and operators. A well known approach to reduce the demand for purchased electricity is the operation of an anaerobic sludge stabilisation process. Although anaerobic digesters make it possible to recover large quantities of energy-rich methane gas, additional strategies are required to handle the increased internal return flow of nitrogen, which arises with the sludge dewatering effluent (SDE). SDE treatment increases the oxygen demand and in turn the energy required for aeration. In this study, different SDE treatment processes were compared with regard to the treatment in mainstream, sidestream nitritation, as well as nitritation combined with anammox for two-stage and single-stage WWTPs. Although SDE treatment in sidestream nitritation was found to have no effect on the energy demand of single-stage WWTPs, this concept allows the treatment capacity in the activated sludge tank to be raised, while contributing to a high nitrogen removal under carbon limitation. In contrast, SDE sidestream treatment showed great potential for saving energy at two-stage WWTPs, whereby sidestream nitritation and the further treatment in the first stage was found to be the most efficient concept, with a savings of approx. 11% of the aeration energy.
Publisher: IWA Publishing
Date: 05-01-2021
DOI: 10.2166/WRD.2021.097
Abstract: Given the availability of technological solutions and guidelines for safe drinking water, direct potable reuse of reclaimed water has become a promising option to overcome severe lack of potable water in arid regions. However, the growing awareness of the presence of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARG) in corresponding raw wastes has led to new safety concerns. This study investigated the fate of ARB and intracellular and extracellular ARG after each treatment step of an advanced water treatment facility in Windhoek, Namibia. The New Goreangab Water Reclamation Plant (NGWRP) produces drinking water from domestic secondary wastewater treatment plant effluent and directly provides for roughly a quarter of Windhoek's potable water demand. Procedures to study resistance determinants were based on both molecular biology and culture-based microbiological methods. TaqMan real-time PCR was employed to detect and quantify intracellular resistance genes sul1, ermB, vanA, nptII and nptIII as well as extracellular resistance gene sul1. The NGWRP reduced the amount of both culturable bacterial indicators as well as the resistance genes to levels below the limit of detection in the final product. The main ozonation and the ultrafiltration had the highest removal efficiencies on both resistance determinants.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.JENVMAN.2015.04.027
Abstract: This study examined the impact of chemical oxygen demand (COD) loading and dissolved oxygen (DO) concentration on the stability and performance of granular sludge treating high saline municipal sewage. Under high DO concentrations of 4.0-7.0 mg/L, and COD loading rates of 0.98 and 1.55 kg/m(3)/d, rapid settling granules were established within four weeks of start-up. Under the highest COD load, a reduction in DO lead to the rapid deterioration of the sludge volume index (SVI) and washout of granules due to prolific growth of the filament Thiothrix Type 021N. Conversely, when operated under a lower COD load, a reduction in DO concentration had no adverse impact on the stability of SVI and granules. A decrease in DO also improved nitrogen removal performance, where simultaneous removal of ammonium (98%), total nitrogen (86%) and BOD5 (98%) were achieved when median DO concentrations were between 1.0 and 1.5 mg/L. Phosphate removal was lower than expected, however the level of biological phosphate removal activity observed appeared sufficient to maintain granule stability, even under low DO concentrations. Nitrous oxide emissions were also characterised, which ranged between 2.3 and 6.8% of the total nitrogen load. Our results confirmed that granular sludge is a viable option for the treatment of saline sewage.
Publisher: IWA Publishing
Date: 06-2011
DOI: 10.2166/WST.2011.634
Abstract: Aeration of activated sludge is a critical treatment step for the operation of activated sludge plants. To achieve a cost effective treatment process, assessing and benchmarking of aeration system performance are important measures. A simple means of gauging the relative condition of a fine bubble diffused aeration system is to evaluate the pressure loss of the diffusers as oxygen transfer tests are rarely applied during the lifetime of an aeration system. This paper shows an assessment of fine bubble diffuser systems in Baden-Württemberg, Germany, based on the results of a questionnaire sent to 941 WWTPs. Apart from the results with regards to the diffuser pressure loss, this paper also presents information on the current state of diffuser technology such as types and materials as well as the diffuser cleaning methods used in Baden-Württemberg. The majority of the WWTPs were equipped with tube diffusers (71%) with 50% of all plants having EPDM membranes installed. Regular mechanical cleaning is the most common cleaning method followed by regular pressure release/air-bumping programs during operations. With regard to the diffuser pressure loss it was found that 50% of the evaluated plants had a diffuser pressure loss that was twice as high as measured for new diffusers.
Publisher: MDPI AG
Date: 18-02-2022
DOI: 10.3390/MEMBRANES12020241
Abstract: Electrodialysis (ED) is a promising technology suitable for nutrient recovery from a wide variety of liquid waste streams. For optimal operating conditions, the limiting current density (LCD) has to be determined separately for each treated feed and ED equipment. LCD is most frequently assessed in the NaCl solutions. In this paper, five graphical methods available in literature were reviewed for LCD determination in a series of five feed solutions with different levels of complexity in ion and matrix composition. Wastewater from microbial fermentation was included among the feed solutions, containing charged and uncharged particles. The experiments, running in the batch ED with an online conductivity, temperature, and pH monitoring, were conducted to obtain data for the comparison of various LCD determination methods. The results revealed complements and ergences between the applied LCD methods with increasing feed concentrations and composition complexity. The Cowan and Brown method had the most consistent results for all of the feed solutions. Online conductivity monitoring was linearly correlated with the decreasing ion concentration in the feed solution and corresponding LCD. Therefore, the results obtained in this study can be applied as a base for the automatized dynamic control of the operating current density–voltage in the batch ED. Conductivity alone should not be used for the ED control since LCD depends on the ion exchange membranes, feed flow, temperature and concentration, ionic species, their concentration ratios, and uncharged particles of the feed solution.
Publisher: IWA Publishing
Date: 04-02-2021
DOI: 10.2166/WST.2021.045
Abstract: Operational data over 2 years from three large Austrian wastewater treatment plants (WWTPs) with design capacities of 4 million, 950,000 and 110,000 population equivalent (PE) were examined. Salt peaks, due to thawing road salt were detected and quantified by electrical conductivity, temperature and chloride measurement in the inflow of the WWTPs. Daily NaCl inflow loads up to 1,147 t/d and PE-specific loads of 0.26–0.5 kg NaCl/(PE · y) were found. To mimic the plants' behaviour in a controlled environment, NaCl was dosed into the inflow of a laboratory-scale activated sludge plant. The influence of salt peaks on important activated sludge parameters such as sludge volume index, settling velocity and floc size were investigated. Influent and effluent were s led extensively to calculate removal rates. Respiration measurements were performed to quantify activated sludge activity. Particle size distributions of the activated sludge floc sizes were measured using laser diffraction particle sizing and showed a decrease of the floc size by approximately two-thirds. The floc structure was examined and documented using light microscopy. At salt concentrations below 1 g/L, increased respiration was found for autotrophic biomass, and between 1 and 3 g NaCl/L respiration was inhibited by up to 30%.
Publisher: IWA Publishing
Date: 12-02-2015
Abstract: Continuous mass balancing defines a new standard in data quality validation. Likewise relying on the principles of mass conservation it outperforms long-term static mass balancing approaches because faults in data can be assigned to their time of occurrence. This research was carried out with practical application to routine operational data in mind and two major aspects are investigated to make this application feasible. Sludge concentrations of typically balanced components (chemical oxygen demand, total nitrogen, total phosphate) are not routinely measured in wastewater treatment plants. Therefore they need to be determined from alternative, more frequent measurements such as total suspended solids. To provide the necessary statistical basis for such determination, monthly sludge s ling was found sufficient. Further, contrary to long-term static mass balancing, the effects of delay between input and output loads must not be neglected in continuous mass balancing based on daily data. While a storage/release approach did not give the desired results, the consideration of hydraulic retention (first-order flow dynamics) fundamentally improved the performance of the proposed method.
Publisher: Wiley
Date: 26-06-2019
DOI: 10.1002/JCTB.6094
Publisher: Elsevier BV
Date: 08-2023
Publisher: IWA Publishing
Date: 30-10-2014
DOI: 10.2166/WST.2014.415
Abstract: Growing complexity of water monitoring instrumentation leads to specialized solutions in respect to sensor integration across several measurement device suppliers. Despite efforts of standardization for data interfaces and protocols, problems regarding the combination of several devices to gain the complete picture in terms of water quality remain. This assessment, especially accomplished from the perspective of a catchment area, requires a transition from sole use of data collectors toward an implementation of intelligent measurement networks. Several challenges and bottlenecks concerning distributed data collection are discussed starting with data acquisition up to the user-scope of utilizing data processing software. Finally, experiences using automated data inspection and export tools are discussed and a brief overview of expectable long-term data availability is given.
Publisher: Elsevier BV
Date: 12-2022
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.SCITOTENV.2022.157401
Abstract: Within the new policy framework shaped by the EU Green Deal and the Circular Economy Action Plans, the field of wastewater and sludge treatment in Europe is subject to high expectations and new challenges related to mitigation of greenhouse gas emissions, micropollutant removal and resource recovery. With respect to phosphorus recovery, several technologies and processes have been thoroughly investigated. Nevertheless, a systemic and detailed understanding of the existing infrastructure and of the related environmental and economic implications is missing. Such basis is essential to avoid unwanted consequences in designing new strategies, given the long lifespan of any infrastructural change. This study couples a newly collected and highly detailed database for all wastewater treatment plants in Austria bigger than 2000 population equivalent with a combination of analyses, namely Substance Flow Analysis with focus on nutrient and metal distribution in different environmental and anthropogenic compartments, Energy Flow Analysis, Life Cycle Assessment and cost estimation. The case study of Austria is of special interest, given its highly autonomous administration in federal states and its contrasting traits, ranging from flat metropolitan areas like Vienna to low-populated alpine areas. The significant impact of electricity demand of wastewater treatment on the overall Cumulative Energy Demand (CED) shows the importance of optimization measures. Further, the current system of wastewater and sludge disposal have a low efficiency in recovering nutrients and in directing pollutants as heavy metals into final sinks. Sludge composting with subsequent use in landscaping does not only show an unfavorable environmental balance, but it is the only relevant route leading to additional CED and Global Warming Potential emissions and to the highest transport volume. Altogether, the outcomes of this study provide a sound basis to further develop national strategies for resource recovery aimed to optimize trade-offs between different economic and environmental objectives.
Publisher: Elsevier BV
Date: 12-2022
DOI: 10.1016/J.SCITOTENV.2022.158016
Abstract: Fluorescence spectroscopy has become a widely used technique to characterize dissolved organic matter (DOM) and organic hazardous micro-pollutants in natural and human-influenced water bodies. Especially in rivers highly impacted by municipal and industrial wastewater treatment plants' effluents, the fluorescence signal at low-flow is mainly dominated by these discharges. At river high-flow, their influence decreases due to dilution effects, and at the same time, other compounds of DOM, stemming from diffuse inputs, can increase or even dominate. Therefore, whereas the analysis of DOM is little informative on the changing sources and pathways of emissions, fluorescence spectroscopy can enhance our understanding and our possibilities of monitoring such dynamics in river catchments. This paper analyzed s les from seven high-flow events in an Austrian river. Firstly, independent DOM components were discriminated using a parallel factor analysis (PARAFAC) to show the varying composition of DOM during different phases of high-flow events. Furthermore, partial least squares (PLS) and sparse PLS (sPLS) regression were applied to identify excitation and emission wavelengths, serving as proxy parameters for quantifying dissolved organic carbon (DOC) and chloride. The PLS models show the best prediction accuracy but use the entire excitation-emission matrix in exchange. In selecting predictors, the use of excitation and emission wavelengths adjusted via sPLS is superior to the extracted PARAFAC components. The sPLS model yields 16 wavelength combinations for DOC (RMSE
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.SCITOTENV.2022.157764
Abstract: Surface water pollution with poly- and perfluorinated compounds (PFAS) is a well-recognized problem, but knowledge about contribution of different emission pathways, especially diffuse ones, is very limited. This study investigates the potential of the pathway oriented MoRE model in shedding light on the relevance of different emission pathways on regional scale and in predicting concentrations and loads in unmonitored rivers. Modelling was supported with a tailor-made monitoring programme aimed to fill gaps on PFAS concentration in different environmental compartments. The study area covers the whole Austrian territory including some additional transboundary catchments and it focuses on perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). These two PFAS are regulated and therefore their production and use in Europe are currently decreasing. Nevertheless, these compounds are still emitted into the environment via legacy pollution and as transformation products from other PFAS. These two compounds were selected for this study in view of the larger information availability compared to other PFAS. Despite considerable uncertainties in the input data, model validations show that this approach performs significantly better than previous modelling frameworks based on population-specific emission factors, population density and wastewater treatment plant information. The study reveals the predominance of emissions via municipal wastewater treatment plants for PFOS and a relevant role of diffuse emission pathways for PFOA. Results suggest that unpaved areas contribute the biggest share to total diffuse emissions, but the estimation of these pathways is affected by the highest uncertainty in the input data and requires better input data from monitoring. Once the currently growing substance-specific data sets on the concentration of PFAS, others than PFOS and PFOA, in different environmental compartments, will reach an adequate quality, the model presented here will be easily applicable to them.
Publisher: Elsevier BV
Date: 11-2016
Publisher: MDPI AG
Date: 10-01-2022
DOI: 10.3390/SU14020734
Abstract: Sustainability and circularity are currently two relevant drivers in the development and optimisation of industrial processes. This study assessed the use of electrodialysis (ED) to purify synthetic erythritol culture broth and for the recovery of the salts in solution, for minimising the generation of waste by representing an efficient alternative to remove ions, ensuring their recovery process contributing to reaching cleaner standards in erythritol production. Removal and recovery of ions was evaluated for synthetic erythritol culture broth at three different levels of complexity using a stepwise voltage in the experimental settings. ED was demonstrated to be a potential technology removing between 91.7–99.0% of ions from the synthetic culture broth, with 49–54% current efficiency. Besides this, further recovery of ions into the concentrated fraction was accomplished. The anions and cations were recovered in a second fraction reaching concentration factors between 1.5 to 2.5 times while observing low level of erythritol losses ( %), with an energy consumption of 4.10 kWh/m3.
Publisher: Elsevier BV
Date: 08-2011
Publisher: Wiley
Date: 25-11-2019
DOI: 10.1002/JCTB.6252
Publisher: Springer Science and Business Media LLC
Date: 23-05-2020
Publisher: IWA Publishing
Date: 04-06-2016
DOI: 10.2166/WST.2016.264
Abstract: The influence of temperature and solids retention time (SRT) on high-solid digestion of municipal sewage sludge was investigated in laboratory-scale reactors. Digestion with high-solid concentration reduces the required digestion volume and is advantageous for urban areas. The experimental conditions comprised total suspended solids (TSS) in digested sludge between 4.0 and 4.6%, temperatures in a range of 33 to 41 °C and the SRT between 10 and 25 d. High-solid digestion operates with increased NH4-N concentrations released from organic compounds. The anaerobic process can be limited by high NH4-N concentration and toxic NH3. In this study a stable digestion was observed up to 2,000 mg L−1 NH4-N and 75 mg L−1 NH3. Volatile suspended solids (VSS) and chemical oxygen demand removal was 53% and 57% respectively. However, digestion with 10 d SRT led to a declined VSS removal of 49%. The removal at 41 and 37 °C showed minor differences, while reduced NH4-N release and reduced methane production were observed at 33 °C. For economic reasons, high-solid digestion at 41 °C is not recommended, but will not impair VSS removal. The outcomes of this study confirm that digestion with up to 7.8% TSS in the feed is feasible for the tested temperatures and SRT down to 15 d.
Publisher: IWA Publishing
Date: 09-03-2018
DOI: 10.2166/WST.2018.111
Abstract: High total suspended solids (TSS) digestion of municipal sewage sludge reduces the required space and volume for digestion plants. However, an important consequence of high TSS is the major influence on sludge rheology. The present case study investigates the rheology of sludge from a 130 m3 high solids digestion pilot plant at Vienna's main wastewater treatment plant (4 M PE120). Raw sludge ranged from 6 to 8% TSS and digested sludge from 3.2 to 4.6%. TSS show an exponential impact on rheological parameters. Increasing raw sludge TSS from 6 to 8% at least doubles the shear stress and increases friction loss by a factor of three. However, under real operating conditions simulated at the pilot plant, there are additional impact factors. The mixing ratio between waste activated and primary sludge influences raw sludge rheology, while solids retention time and loss on ignition affects digested sludge rheology. Nevertheless, friction loss calculations based on a simple power law relationship between shear rate and shear stress proved to be applicable and sufficiently accurate for both raw and digested sludge with high TSS. Altogether, this case study underlines the relevance of comprehensive rheological considerations, measurements and calculations when designing high TSS sludge digestion.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 03-2017
Publisher: Informa UK Limited
Date: 02-2012
Publisher: Elsevier BV
Date: 12-2023
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.TALANTA.2018.11.056
Abstract: A water quality analyzer based on the working principle of capillary electrophoresis (CE) was developed to determine ionic inorganic nitrogen compounds contained in wastewater s les. The instrument provides simultaneous quantification of anions and cations by superimposing hydrodynamic pumping with electrokinetic motion. It features a single separation capillary with contactless conductivity detection and a sequential injection manifold for fluid handling. Dynamic adaption of the system calibration was enabled by the use of a high precision pressure regulator to cover a wide measurement range showing low relative standard deviations (< 2 %) and high measurement accuracy comparable to conventional wastewater analyzers. The prototype is transportable, integrated in a 19 in. rack and connected to a membrane filter system developed for direct s le aspiration in the wastewater process. For operation on site, only a power supply and a network connection for remote control is necessary. Continuous operation was demonstrated over 24 h at the aeration tank of a pilot scale wastewater treatment plant at TU Wien and a good correlation with laboratory results was achieved. At this time, there is no device available, on the market, to analyze all nitrogen species in one assembly with limited hardware complexity and chemical demand. This entails a significant step forward towards automated water quality monitoring with respect to the implementation of new advanced wastewater treatment technologies.
Publisher: Springer Science and Business Media LLC
Date: 30-03-2022
Publisher: MDPI AG
Date: 27-03-2023
DOI: 10.3390/PR11041013
Abstract: Biological methanation of carbon dioxide using hydrogen makes it possible to improve the methane and energy content of biogas produced from sewage sludge and organic residuals and to reach the requirements for injection into the natural gas network. Biofilm reactors, so-called trickling bed reactors, offer a relatively simple, energy-efficient, and reliable technique for upgrading biogas via ex-situ methanation. A mesophilic lab-scale biofilm reactor was operated continuously for nine months to upgrade biogas from anaerobic sewage sludge digestion to a methane content %. To supply essential trace elements to the biomass, a stock solution was fed to the trickling liquid. Besides standard parameters and gas quality, concentrations of Na, K, Ca, Mg, Ni, and Fe were measured in the liquid and the biofilm using ICP-OES (inductively coupled plasma optical emission spectrometry) to examine the biofilms load-dependent uptake rate and to calculate quantities required for a stable operation. Additionally, microbial community dynamics were monitored by licon sequencing (16S rRNA gene). It was found that all investigated (trace) elements are taken up by the biomass. Some are absorbed depending on the load, others independently of it. For ex le, a biomass-specific uptake of 0.13 mg·g−1·d−1 for Ni and up to 50 mg·g−1·d−1 for Mg were measured.
Publisher: IOP Publishing
Date: 12-04-2019
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 09-2022
Publisher: IWA Publishing
Date: 23-11-2017
DOI: 10.2166/WST.2017.596
Abstract: Depending on design capacity, agitators consume about 5 to 20% of the total energy consumption of a wastewater treatment plant. Based on inhabitant-specific energy consumption (kWh PE120−1 a−1 PE120 is population equivalent, assuming 120 g chemical oxygen demand per PE per day), power density (W m−3) and volume-specific energy consumption (Wh m−3 d−1) as evaluation indicators, this paper provides a sound contribution to understanding energy consumption and energy optimization potentials of agitators. Basically, there are two ways to optimize agitator operation: the reduction of the power density and the reduction of the daily operating time. Energy saving options range from continuous mixing with low power densities of 1 W m−3 to mixing by means of short, intense energy pulses (impulse aeration, impulse stirring). However, the following correlation applies: the shorter the duration of energy input, the higher the power density on the respective volume-specific energy consumption isoline. Under favourable conditions with respect to tank volume, tank geometry, aeration and agitator position, mixing energy can be reduced to 24 Wh m−3 d−1 and below. Additionally, it could be verified that power density of agitators stands in inverse relation to tank volume.
Publisher: IWA Publishing
Date: 05-2013
DOI: 10.2166/WST.2013.096
Abstract: In this paper a method to determine the cycle time for sequencing batch membrane bioreactors (SBMBRs) is introduced. One of the advantages of SBMBRs is the simplicity of adapting them to varying wastewater composition. The benefit of this flexibility can only be fully utilised if the cycle times are optimised for the specific inlet load conditions. This requires either proactive and ongoing operator adjustment or active predictive instrument-based control. Determination of the cycle times for conventional sequencing batch reactor (SBR) plants is usually based on experience. Due to the higher mixed liquor suspended solids concentrations in SBMBRs and the limited experience with their application, a new approach to calculate the cycle time had to be developed. Based on results from a semi-technical pilot plant, the paper presents an approach for calculating the cycle time in relation to the influent concentration according to the Activated Sludge Model No. 1 and the German HSG (Hochschulgruppe) Approach. The approach presented in this paper considers the increased solid contents in the reactor and the resultant shortened reaction times. This allows for an exact calculation of the nitrification and denitrification cycles with a tolerance of only a few minutes. Ultimately the same approach can be used for a predictive control strategy and for conventional SBR plants.
Publisher: IWA Publishing
Date: 05-2013
DOI: 10.2166/WST.2013.090
Abstract: Optimising the energy consumption and energy generation of wastewater treatment plants (WWTPs) is a topic with increasing importance for water utilities in times of rising energy costs and pressures to reduce greenhouse gas (GHG) emissions. Assessing the energy efficiency and energy optimisation of a WWTP are difficult tasks as most plants vary greatly in size, process layout and other influencing factors. To overcome these limits it is necessary to compare energy efficiency with a statistically relevant base to identify shortfalls and optimisation potential. Such energy benchmarks have been successfully developed and used in central Europe over the last two decades. This paper demonstrates how the latest available energy benchmarks from Germany have been applied to 24 WWTPs in South Australia. It shows how energy benchmarking can be used to identify shortfalls in current performance, prioritise detailed energy assessments and help inform decisions on capital investment.
Publisher: IWA Publishing
Date: 06-2008
DOI: 10.2166/WST.2008.334
Abstract: A medium-scale membrane bioreactor was tested in a large tourist resort on the south-western coast of Turkey with the treated wastewater subsequently being used for irrigational purposes. The wastewater treatment system was designed to eliminate carbonaceous and nitrogenous substances. Treatment efficiency was monitored by means of regular chemical and microbiological analyses. Information was collected on water use at different locations of the hotel. Specific values based on the number of guests were determined. Wastewater streams from kitchen, laundry and rooms were analysed to investigate the various contribution from these points. The social acceptance of the guests concerning the on-site wastewater treatment and reuse in the hotel was analysed using a questionnaire. The investigations indicated that the treated wastewater provides the required chemical and hygienic conditions to satisfy requirement for its reuse in irrigation. The acceptance by guests was encouraging for such applications.
Publisher: IWA Publishing
Date: 19-09-2016
DOI: 10.2166/WST.2016.390
Abstract: This work presents operating costs and energy consumption of Austrian municipal wastewater treatment plants (WWTPs) (≥10,000 PE-design capacity) that have been classified into different size groups. Different processes as well as cost elements are investigated and processes with high relevance regarding operating costs and energy consumption are identified. Furthermore, the work shows the cost-relevance of six investigated cost elements. The analysis demonstrates the size-dependency of operating costs and energy consumption. For the examination of the energy consumption the investigated WWTPs were further classified into WWTPs with aerobic sludge stabilisation and WWTPs with mesophilic sludge digestion. The work proves that energy consumption depends mainly on the type of sludge stabilisation. The results of the investigation can help to determine reduction potential in operating costs and energy consumption of WWTPs and form a basis for more detailed analysis which helps to identify cost and energy saving potential.
Publisher: IWA Publishing
Date: 2012
DOI: 10.2166/WST.2012.777
Abstract: A series of batch experiments investigating two different pH control strategies, initial pH adjustment and continuous pH control, have been carried out in large laboratory-scale reactors with working volumes of 30 L. In both cases, pH was varied between 5 and 7.5. Sucrose concentrations were also varied starting from 0 up to 30 g/L. Higher hydrogen production yields can be achieved by batch experiments through continuous pH control than by simple initial pH adjustment. In the case of continuous pH control, maximization of hydrogen yield was acquired for slightly acidic pH of 6.5. Continuous pH control in the neutral pH range of 7.0 and in pH lower than 6.5, induced a reduction in the hydrogen production yield. Sucrose can be completely degraded only for a pH higher than 6. Lower pH values seem to inhibit the hydrogen-producing bacteria. Under the conditions of continuous pH adjustment at pH 6.5 and a sucrose concentration of 25 g/L the maximum hydrogen yield of 1.79 mol H2/mol hexose was obtained. These conditions could be applied for the batch start-up of large fermentors.
Publisher: Springer Science and Business Media LLC
Date: 13-01-2023
DOI: 10.1007/S00506-022-00920-2
Abstract: In der vorliegenden Studie wurde die Wirksamkeit einer Adsorptions‑/Fällmittel-Prototypsuspension der Firma Donau Chemie AG zur simultanen Entfernung von Spurenstoffen und Phosphor aus kommunalem Abwasser untersucht. Die Suspension enthält Polyaluminiumchlorid zur Fällung von gelöstem Orthophosphat, Pulveraktivkohle (PAK) zur Adsorption von organischen Spurenstoffen sowie anorganische Stabilisatoren, die die Suspension der PAK unterstützen. Vergleichende Laborversuche mit herkömmlicher PAK und der Prototypsuspension mit einem PAK-Gehalt von 16,5 % wurden mittels zweier unabhängiger Methoden (Spurenstoffanalytik und In-vitro-Bioassays) bewertet. Die Ergebnisse zeigten, dass die Suspension zu einer Verbesserung der Oberflächeneigenschaften der Aktivkohle führt und somit eine höhere Anzahl von bekannten und unbekannten Substanzen adsorbiert werden kann. Die Anwendbarkeit der Suspension wurde in drei verschiedenen Abwässern untersucht und ist vor allem vom Verhältnis zwischen gelöstem organischem Kohlenstoff (dissolved organic carbon – DOC) und Gesamtphosphor im Zulauf abhängig. Bei höheren DOC-Konzentrationen ist ein höherer Anteil an PAK in der Suspension notwendig, um eine massive Überdosierung des Fällmittels zu verhindern. Während des großtechnischen Versuchs, der auf einer kommunalen Kläranlage durchgeführt wurde, kam es zu einem Anstieg der prozentuellen Entfernung um mehr als 90 % für Carbamazepin, mehr als 50 % für Diclofenac und Metoprolol und um etwa 30 % für Benzotriazol. Bei einer konstanten Dosiermenge von 90 L d −1 wurde die auf Basis der Labortests erwartete Spurenstoffentfernung von mehr als 75 % für alle Stoffe erreicht. Der Prototyp zeigte sich als einfacher zu lagern und zu dosieren als herkömmliche PAK. Weiters kann die vorhandene Infrastruktur für die chemische Phosphorfällung für die organische Spurenstoffentfernung mitgenutzt werden.
Publisher: Springer Science and Business Media LLC
Date: 26-01-2023
DOI: 10.1007/S00506-022-00922-0
Abstract: In den letzten Jahren kam es zu einem Paradigmenwechsel bei Kläranlagen, der den alleinigen Zweck der Abwasserreinigung um eine zusätzliche Funktion der Ressourcenrückgewinnung erweiterte. Dieser Wandel geht mit der Entwicklung neuer Rechtsvorschriften einher, die eine bessere Ressourcenrückgewinnung aus dem Abwasser ermöglichen wollen. Lange Betriebszeiten und eine Vielzahl von Behandlungsanforderungen verlangen jedoch gründliche Untersuchungen, wie eine Ressourcenrückgewinnung nachhaltig umgesetzt werden kann. Um Grundlagen für die Ausarbeitung einer neuen Gesetzgebung speziell für die Rückgewinnung von Phosphor (P) zu erarbeiten, wurde 2017 eine Umfrage zur österreichischen Kläranlageninfrastruktur durchgeführt. Der Fokus dabei lag auf Informationen zu Phosphor-Entfernung, Schlammbehandlung und -entsorgung sowie der Schlammqualität aller Kläranlagen über 2000 Einwohnerwerte (EW). Die erhobenen Daten wurden zuerst auf Vollständigkeit und Plausibilität geprüft und dann einer umfassenden Analyse unterzogen. Die vorliegende Studie stellt die wichtigsten Erkenntnisse der Datenanalyse vor und leitet daraus Überlegungen ab, die für eine zukünftige Rückgewinnung von P aus Abwasser zu berücksichtigen sind.
Publisher: Springer Science and Business Media LLC
Date: 26-07-2023
DOI: 10.1007/S00506-023-00984-8
Abstract: Der Kommissionsvorschlag für die kommunale Abwasserrichtlinie schreibt die Implementierung einer 4. Reinigungsstufe vor, wenn bestimmte Kriterien erfüllt sind. Dementsprechend müssen große Kläranlagen (≥ 100.000 EW) sowie Anlagen ≥ 10.000 EW, die in spurenstoffempfindliche Gebiete einleiten, ausgebaut werden, um eine 80 %ige Entfernung, gemittelt über mindestens sechs Indikatorsubstanzen zu erreichen. Schätzungen für Österreich reichen von 93 bis 278 auszurüstende Kläranlagen. 278 ist eine Maximalbetrachtung ohne vorherige Risikobewertung und unter Annahme der neu vorgeschlagenen Umweltqualitätsnormen. Sowohl die Ozonung als auch die Aktivkohlebehandlung sind geeignet, um die Mindestanforderungen zu erreichen. Die spezifischen jährlichen Kosten können anhand einer einfachen Funktion grob abgeschätzt werden und liegen bei 16, 8 und 4 €/EW/a für Anlagen mit 10.000, 50.000 oder 200.000 EW Ausbau . Die Wechselwirkung mit anderen EU-Rechtsvorschriften und aktuellen Themen der Abwasserreinigung birgt sowohl Synergien, wie z. B. eine solide Grundlage für die weitere Aufbereitung zur Wasserwiederverwendung für die landwirtschaftliche Bewässerung, als auch Herausforderungen, z. B. für die neu vorgeschlagenen strengeren Umweltqualitätsnormen für per- und polyfluorierte Alkylsubstanzen.
Publisher: Elsevier BV
Date: 05-2022
Publisher: IWA Publishing
Date: 08-2011
DOI: 10.2166/WST.2011.694
Abstract: Aeration is a crucial part of the biological wastewater treatment in activated sludge systems and the main energy user of WWTPs. Approximately 50 to 60% of the total energy consumption of a WWTP can be attributed to the aeration system. The performance of the aeration system, and in the case of fine bubble diffused aeration the diffuser performance, has a significant impact on the overall plant efficiency. This paper seeks to isolate the changes of the diffuser performance over time by eliminating all other influencing parameters like sludge retention time, surfactants and reactor layout. To achieve this, different diffusers have been installed and tested in parallel treatment trains in two WWTPs. The diffusers have been performance tested in clean water tests under new conditions and after one year of operation. A set of material property tests describing the diffuser membrane quality was also performed. The results showed a significant drop in the performance of the EPDM diffuser in the first year which resulted in similar oxygen transfer efficiency around 16 g/m3/m for all tested systems. Even though the tested silicone diffusers did not show a drop in performance they had a low efficiency in the initial tests. The material properties indicate that the EPDM performance loss is partly due to the washout of additives.
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.SCITOTENV.2016.07.019
Abstract: Phosphorus (P) is an essential and limited resource. Municipal wastewater is a promising source of P via reuse and could be used to replace P derived from phosphate rocks. The agricultural use of sewage sludge is restricted by legislation or is not practiced in several European countries due to environmental risks posed by organic micropollutants and pathogens. Several technologies have been developed in recent years to recover wastewater P. However, these technologies target different P-containing flows in wastewater treatment plants (effluent, digester supernatant, sewage sludge, and sewage sludge ash), use erse engineering approaches and differ greatly with respect to P recycling rate, potential of removing or destroying pollutants, product quality, environmental impact and cost. This work compares 19 relevant P recovery technologies by considering their relationships with existing wastewater and sludge treatment systems. A combination of different methods, such as material flow analysis, damage units, reference soil method, annuity method, integrated cost calculation and a literature study on solubility, fertilizing effects and handling of recovered materials, is used to evaluate the different technologies with respect to technical, ecological and economic aspects. With regard to the manifold origins of data an uncertainty concept considering validity of data sources is applied. This analysis revealed that recovery from flows with dissolved P produces clean and plant-available materials. These techniques may even be beneficial from economic and technical perspectives under specific circumstances. However, the recovery rates (a maximum of 25%) relative to the wastewater treatment plant influent are relatively low. The approaches that recover P from sewage sludge apply complex technologies and generally achieve effective removal of heavy metals at moderate recovery rates (~40-50% relative to the WWTP input) and comparatively high costs. Sewage sludge ash is the most promising P source, with recovery rates of 60-90% relative to the wastewater P. The costs highly depend on the purity requirements of the recycled products but can be kept comparatively low, especially if synergies with existing industrial processes are exploited.
Publisher: Springer International Publishing
Date: 2015
Publisher: Elsevier BV
Date: 06-2023
Publisher: Elsevier BV
Date: 10-2022
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.JENVMAN.2018.10.101
Abstract: Up to now, aerobic granulation of activated sludge is only realised in SBRs, where the discontinuous feed and sedimentation allow the formation of dense granules with excellent settling properties. However, aerobic granulation in continuous-flow plants (CFP) is gaining more and more interest in order to exploit the advantages of these excellent sludge properties to construct compact and efficient WWTP. Within the scope of this project, a SBR and CFP were operated in parallel to investigate the aerobic granulation of activated sludge and to compare the biomass in terms of their structure and settling behavior. CFP operation included two experimental phases with different reactor designs. The use of synthetic wastewater during phase I led to a biomass with a SVI of 42 ml g
Publisher: Springer Science and Business Media LLC
Date: 12-2009
Publisher: IWA Publishing
Date: 16-06-2021
DOI: 10.2166/WST.2021.228
Abstract: Large wastewater treatment plants (& ,000 population equivalents) treat more than 80% of the wastewater treated on a global scale, today it might be even & %. They therefore provide the most relevant contribution to water protection from urban and industrial wastewater. This was already the case in 1971 when academics realised that progress in the scientific community alone will not succeed in a rapid transfer of research results to practitioners in design and operation of these plants. At the same time, it was recognised that urgent problems in practice are not recognised early enough by the globally networking scientific community. The most effective means of solving these problems was the creation of a new forum where experts from both sides meet. Scientists normally create their special conferences and workshops to enhance global co-operation in their specific field of research and development. This is reflected in the existence of many IWA Specialist Groups (SG) with global representation. The IWA Large Wastewater Treatment Plants (LWWTP) events and the formation of the LWWTP Specialist Group have been the first to take care of a complex technology for water protection, where specialists from most other SGs can meet and discuss together with the practitioners designing and operating treatment plants. In fact, many new Specialist Groups had their origin in the workshop series starting in 1971 in Vienna, taking care of many specific problems reported from practice. The managers and chief operators of large plants, usually only served by meetings of national professional associations, got a new opportunity for global exchange of knowledge and experience together with the global network of scientists and researchers.
Start Date: 2015
End Date: 2018
Funder: European Commission
View Funded ActivityStart Date: 2023
End Date: 2025
Funder: Österreichische Forschungsförderungsgesellschaft
View Funded ActivityStart Date: 2000
End Date: 2001
Funder: Deutsche Forschungsgemeinschaft
View Funded ActivityStart Date: 2000
End Date: 2002
Funder: Deutsche Bundesstiftung Umwelt
View Funded ActivityStart Date: 2003
End Date: 2007
Funder: Bundesministerium für Bildung und Forschung
View Funded ActivityStart Date: 2016
End Date: 2018
Funder: Österreichische Forschungsförderungsgesellschaft
View Funded ActivityStart Date: 2019
End Date: 2021
Funder: Österreichische Forschungsförderungsgesellschaft
View Funded ActivityStart Date: 2018
End Date: 2020
Funder: Oesterreichische Nationalbank
View Funded ActivityStart Date: 2005
End Date: 2007
Funder: Bundesministerium für Bildung und Forschung
View Funded Activity