ORCID Profile
0000-0002-0634-0546
Current Organisations
IT University of Copenhagen
,
Charles Darwin University
,
International Scientific Journals
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Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.SCITOTENV.2018.08.100
Abstract: Achromobacter denitrificans strain PR1, previously found to harbour specific degradation pathways with high sulfamethoxazole (SMX) degradation rates, was bioaugmented into laboratory-scale membrane bioreactors (MBRs) operated under aerobic conditions to treat SMX-containing real domestic wastewater. Different hydraulic retention times (HRTs), which is related to reaction time and loading rates, were considered and found to affect the SMX removal efficiency. The availability of primary substrates was important in both bioaugmented and non-bioaugmented activated sludge (AS) for cometabolism of SMX. High HRT (24 h) resulted in low food to microorganism ratio (F/M) and low SMX removal, due to substrate limitation. Decrease in HRT from 24 h to 12 h, 6 h and finally 4 h led to gradual increases in primary substrates availability, e.g. organic compounds and ammonia, resulted in increased SMX removal efficiency and degradation rate, and is more favorable for high-rate wastewater treatment processes. After inoculation into the MBRs, the bioaugmentation strain was sustained in the reactor for a maximum of 31 days even though a significant decrease in abundance was observed. The bioaugmented MBRs showed enhanced SMX removal, especially under SMX shock loads compared to the control MBRs. The results of this study indicate that re-inoculation is required regularly after a period of time to maintain the removal efficiency of the target compound.
Publisher: John Benjamins Publishing Company
Date: 31-12-2016
Abstract: This paper employs the analytical tools of Cultural Linguistics to investigate the Vietnamese cultural conceptualizations of bụng (belly) and lòng (abdomen), both of which are considered to be the location of thoughts and feelings. Based on our corpus of Vietnamese idioms and proverbs, The Tale of Kieu , and several selected modern poems, we found that, while they share many cultural conceptualizations in common, lòng is used more in figurative contexts than bụng . bụng and lòng are the seat and container of thoughts and emotions. lòng is viewed as a vast sea, vast cloth, piece of land/soil, stone, and a changeable living entity. lòng, besides having size and quality, is believed to metaphorically have weight and color. An ethnographic survey reveals the Vietnamese sociocultural historical context, ethnomedicine, and philosophical beliefs that motivate the centralization on the abdominal area to metaphorically host people’s thoughts and emotions. Our investigation again reveals that language is a “memory bank” (Sharifian 2011, p. 5), this time for cultural conceptualizations that have prevailed at different stages in Vietnamese history.
Publisher: Springer Science and Business Media LLC
Date: 09-08-2011
DOI: 10.1007/S00253-011-3499-5
Abstract: Membrane bioreactors (MBR) are an important and increasingly implemented wastewater treatment technology, which are operated at low food to microorganism ratios (F/M) and retain slow-growing organisms. Enhanced biological phosphorus removal (EBPR)-related organisms grow slower than ordinary heterotrophs, but have never been studied in detail in MBRs. This study presents a comprehensive analysis of the microorganisms involved in EBPR in pilot- and full-scale MBRs, using fluorescence in situ hybridization (FISH), as well as an overall assessment of other relevant microbial groups. The results showed that polyphosphate accumulating organisms (PAOs) were present at similar levels in all studied MBRs (10% ± 6%), even those without a defined anaerobic zone. Glycogen accumulating organisms were also detected, although rarely. The FISH results correlated well with the observed P removal performance of each plant. The results from this study suggest that a defined anaerobic zone is not necessarily required for putative PAO growth in MBRs, since polyphosphate storage may provide a selective advantage in fulfilling cell maintenance requirements in substrate-limited conditions (low F/M).
Publisher: Informa UK Limited
Date: 05-02-2017
Publisher: Springer Science and Business Media LLC
Date: 19-07-2012
Publisher: Springer Science and Business Media LLC
Date: 06-06-2016
DOI: 10.1007/S00253-016-7617-2
Abstract: Membrane bioreactors (MBRs) are an advanced technology for wastewater treatment whose wide application has been hindered by rapid fouling of the membranes. MBRs can be operated with long sludge retention time (SRT), a crucial parameter impacting microbial selection in the reactor. This also affects filtration performance, since a major fouling agent are the extracellular polymeric substances (EPS). In this study, the impact of the SRT on the ecophysiology of the MBRs and, consequently, on membrane fouling was evaluated. A MBR was operated under a SRT of 60 days followed by a SRT of 20 days. A comprehensive analysis of the microbial community structure and EPS proteins and polysaccharide profiles of the mixed liquor and cake layer was carried out throughout both operation periods. The results of this study showed that the imposition of a shorter SRT led to a shift in the dominant bacterial populations. The mixed liquor and cake layer communities were very different, with Actinomycetales order standing out in the cake layer at SRT of 20 days. Overall, higher EPS concentrations (particularly proteins) were found at this SRT. Furthermore, EPS profiles were clearly affected by the SRT: it was possible to correlate a group of soluble EPS proteins with the SRT of 60 days, and a lower sludge age led to a lower ersity of polysaccharide sugar monomers, with an increase of glucose and galactose in the cake layer. This study improves our knowledge regarding the molecular reasons for fouling, which may contribute to improve MBR design and operation.
Publisher: John Benjamins Publishing Company
Date: 14-12-2017
Abstract: The fact that English has been used as a means of global communication appears to bring about the association of English with multiple cultural conceptualisations regardless of its roles in different contexts. The purpose of the present paper is to explore and argue for the existence of ‘Vietnamese English’, a variety developed by Vietnamese users of English with its own lexical specifics and underlying cultural conceptualisations. The most important areas of the study will include: (1) lexical innovations in Vietnamese English found in the data of the Vietnam Heritage Magazine and locally developed English textbooks in Vietnam (2) the cultural schemas, categories and metaphors that are entrenched in instances of lexical innovation and (3) a s le of documenting entries for a yet-to-be-compiled Vietnamese English Dictionary based on the findings.
Publisher: Informa UK Limited
Date: 04-07-2017
DOI: 10.1080/08927014.2017.1333112
Abstract: The impact of sludge retention time (SRT) on the biofouling of a membrane bioreactor (MBR) by extracellular polymeric substances (EPS) was investigated. The MBR was operated at 60 and 20 d SRT. The gel layer (recovered through optimized membrane autopsy methods) and the cake layer were analyzed for their content and profile of EPS proteins and polysaccharides. The change to a shorter SRT led to decreased membrane filterability, concomitant with a higher expression of EPS proteins in the cake layer, which were identified as being mainly related with biosynthesis and stress functions. The gel layer was more substantial in internal fibers, with polysaccharides being the major component in this layer. With the decrease in SRT (and filterability decrease), the overall polysaccharide content and sugar variety increased. In conclusion, SRT impacted not only on the quantity but also the composition of EPS molecules, and both were shown to be important in biofouling.
Publisher: Springer Science and Business Media LLC
Date: 24-05-2012
DOI: 10.1007/S00253-012-4157-2
Abstract: Extracellular polymeric substances (EPS) are keys in biomass aggregation and settleability in wastewater treatment systems. In membrane bioreactors (MBR), EPS are an important factor as they are considered to be largely responsible for membrane fouling. Proteins were shown to be the major component of EPS produced by activated sludge and to be correlated with the properties of the sludge, like settling, hydrophobicity and cell aggregation. Previous EPS proteomic studies of activated sludge revealed several problems, like the interference of other EPS molecules in protein analysis. In this study, a successful strategy was outlined to identify the proteins from soluble and bound EPS extracted from activated sludge of a lab-scale MBR. EPS s les were first subjected to pre-concentration through lyophilisation, centrifugal ultrafiltration or concentration with a dialysis membrane coated by a highly absorbent powder of polyacrylate-polyalcohol, preceded or not by a dialysis step. The highest protein concentration factors were achieved with the highly absorbent powder method without previous dialysis step. Four protein precipitation methods were then tested: acetone, trichloroacetic acid (TCA), perchloric acid and a commercial kit. Protein profiles were compared in 4-12 % sodium dodecyl sulphate polyacrylamide gel electrophoresis gels. Both acetone and TCA should be applied for the highest coverage for soluble EPS proteins, whereas TCA was the best method for bound EPS proteins. All visible bands of selected profiles were subjected to mass spectrometry analysis. A high number of proteins (25-32 for soluble EPS and 17 for bound EPS) were identified. As a conclusion of this study, a workflow is proposed for the successful proteome characterisation of soluble and bound EPS from activated sludge s les.
Location: Portugal
Location: Portugal
Location: Portugal
Location: Portugal
Location: Portugal
No related grants have been discovered for Ana Filipa Silva.