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ABSTRACT: Enantiomeric compositions of three 2-arylpropionic acid (2-APA) drugs, ibuprofen, naproxen, and ketoprofen, were monitored in a membrane bioreactor (MBR) treating municipal effluent in a small rural town in Australia. Specific enantiomers were determined as amide diastereomers using the chiral derivatizing reagent, (R)-1-phenylethylamine (PEA), followed by gas chromatography-tandem mass spectrometry (GC-MS/MS). The six individual enantiomers were quantified by isotope dilution and the enantiomeric fractions (EFs) were determined. Over four separate sampling events, ibuprofen EF ranged from 0.88 to 0.94 (median 0.93) in the influent and 0.38 to 0.40 (median 0.39) in the effluent. However, no significant change in ketoprofen EF was observed, with influent EFs of 0.56-0.60 (median 0.58) and effluent EFs 0.54-0.68 (median 0.56). This is the first report of enantiospecific analysis of ketoprofen in municipal wastewater and it is not yet clear why such different behavior was observed compared to ibuprofen. Naproxen EF was consistently measured at 0.99 in the influent and ranged from 0.86 to 0.94 (median 0.91) in the effluent. This study demonstrates that EF is a relatively stable parameter and does not fluctuate according to concentration or other short-term variables introduced by sampling limitations. The enantiospecific analysis of chiral chemicals presents a promising approach to elucidate a more thorough understanding of biological treatment processes and a potential tool for monitoring the performance of key biological pathways. Chirality 25:301-307, 2013. © 2013 Wiley Periodicals, Inc.
Chirality 05/2013; 25(5):301-7. · 2.35 Impact Factor
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ABSTRACT: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous analysis of 6 ectoparasiticides - 2 synthetic pyrethroids (deltamethrin, cypermethrin) and 4 macrocyclic lactones (abamectin, doramectin, ivermectin and eprinomectin) in biosolids. The method was used to investigate the occurrence of these ectoparasiticides in beef cattle feedlot wastes in Australia from 5 commercial feedlot operations which employ varying waste management practices. Deltamethrin and cypermethrin were not detected in any of the samples while abamectin, ivermectin, doramectin and eprinomectin were detected in some of the samples with concentrations ranging from 1 to 36 μg/kg dry weight (d.w.) freeze dried feedlot waste. Levels of macrocyclic lactones detected in the feedlot wastes varied and were dependent on sample type. The effect of seasonal variations and waste management practices were also investigated in this study.
Environmental pollution (Barking, Essex: 1987) 01/2013; 174C:265-272. · 3.43 Impact Factor
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ABSTRACT: This study provides a comprehensive insight into the levels and fate of 14 endocrine disrupting chemicals (EDCs) through a package membrane bioreactor (MBR) plant treating municipal wastewater in New South Wales, Australia. Results showed that the MBR consistently achieved very high removal of the EDCs within the range of 94.6 to >99.9%. A mass-balance demonstrated that sorption to biomass was the main removal mechanism for 17β-estradiol, while biodegradation was responsible for the removal of the remaining 9 detected EDCs. This knowledge can be used to optimise the performance of MBRs in removing EDCs to achieve the best possible effluent quality for water reuse applications.
Ozwater conference, Sydney, Australia; 05/2012
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ABSTRACT: This study characterised the removal of five indigenous microbial indicators through a full-scale membrane bioreactor. Samples were taken from the raw sewage, mixed liquor and permeate and assayed for F-specific RNA bacteriophage, sulphite reducing clostridia, enterococci, E. coli and total coliforms. Log10 removal values for vegetative bacteria were in the range of 5.0 – 5.9 log10 units, and for clostridia, they were marginally lower at 4.9 log10 units. The removal of FRNA bacteriophage was in excess of 4.9 log10 units. This study also used probabilistic tools to characterise process variability. The data presented in this paper can be used to better inform the risk management of membrane bioreactors that are used in water recycling schemes.
Ozwater conference, Sydney, Australia; 05/2012
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ABSTRACT: A highly sensitive method for the analysis of six sulfonamide antibiotics (sulfadiazine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethazine and sulfamethoxazole), two sulfonamide metabolites (N(4)-acetyl sulfamethazine and N(4)-acetyl sulfamethoxazole) and the commonly co-applied antibiotic trimethoprim was developed for the analysis of complex wastewater samples. The method involves solid phase extraction of filtered wastewater samples followed by liquid chromatography-tandem mass spectral detection. Method detection limits were shown to be matrix-dependent but ranged between 0.2 and 0.4 ng/mL for ultrapure water, 0.4 and 0.7 ng/mL for tap water, 1.4 and 5.9 ng/mL for a laboratory-scale membrane bioreactor (MBR) mixed liquor, 0.7 and 1.7 ng/mL for biologically treated effluent and 0.5 and 1.5 ng/g dry weight for MBR activated sludge. An investigation of analytical matrix effects was undertaken, demonstrating the significant and largely unpredictable nature of signal suppression observed for variably complex matrices compared to an ultrapure water matrix. The results demonstrate the importance of accounting for such matrix effects for accurate quantitation, as done in the presented method by isotope dilution. Comprehensive validation of calibration linearity, reproducibility, extraction recovery, limits of detection and quantification are also presented. Finally, wastewater samples from a variety of treatment stages in a full-scale wastewater treatment plant were analysed to illustrate the effectiveness of the method.
Talanta 01/2012; 89:407-16. · 3.79 Impact Factor
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ABSTRACT: Submerged membrane bioreactors (MBRs) have attracted a significant amount of interest for decentralised treatment systems due to their small footprint and ability to produce high quality effluent, which is favorable for water reuse applications. This study provides a comprehensive overview of the capacity of a full-scale decentralised MBR to eliminate 17 endocrine disrupting chemicals (EDCs) and five indigenous microbial indicators. The results show that the MBR consistently achieved high removal of EDCs (> 86.5%). Only two of the 17 EDCs were detected in the MBR permeate, namely 2-phenylphenol and 4-tert-octylphenol. Measured log10 reduction values of vegetative bacterial indicators were in the range of 5–5.3 log10 units, and for clostridia, they were marginally lower at 4.6 log10 units. Removal of bacteriophage was in excess of 4.9 log10 units. This research shows that MBRs are a promising technology for decentralised water reuse applications.
Journal of Water Reuse and Desalination. 01/2012; 2(2):67-73.
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ABSTRACT: Odour emissions from aluminium processing can cause an impact on local communities surrounding such facilities. Of particular concern is fugitive odours emitted from the handling and use of refinery condensate streams, particularly the digestion condensate. This study evaluated the application of using catalytic ozonation to treat alumina refinery condensate in order to remove the potential emission of odourous compounds from the industrial wastewater. The technical challenges in treating the alumina refinery condensate are the high pH and temperatures of the wastewater effluent (over 80 °C and pH above 10) due the industrial process. The odour removal efficiencies for different catalysts (FeCl(3), MnO, and MnSO(4)) under experimental conditions in terms of controlled pH, temperature and ozone dosage were determined before and after ozone treatment using dynamic olfactometry. The result demonstrated that the addition of both FeCl(3) and MnO catalysts improved odour removal efficiencies during the ozonation of alumina condensates at similar pH and temperature conditions. FeCl(3) and MnO had similar enhancement for odour removal, however MnO was determined to be more appropriate than MnSO(4) for odour removal due to the colouration of the treated condensate.
Water Science & Technology 01/2012; 66(8):1781-6. · 1.12 Impact Factor
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ABSTRACT: Odourous emissions from sewer networks and wastewater treatment plants (WWTPs) can significantly impact a local population. Sampling techniques such as wind tunnels and flux hood chambers are traditionally used to collect area source samples for subsequent quantification of odour emission rates using dilution olfactometry, however these methods are unsuitable for assessing liquid samples from point sources due to the large liquid volumes required. To overcome this limitation, a gas phase sample preparation method was developed for assessing the total Odour Emission Ability (OEA) from a liquid sample. The method was validated using two volatile organic sulphur compounds (VOSCs), dimethyl-trisulphide (DMTS) and bismethylthiomethane (BMTM) that are frequently detected from sewers and WWTPs and are relatively stable compared with common VOSCs like mercaptan or methyl mercaptan. The recovery rates of DMTS and BMTM were quantified by injecting a known volume of a standard liquid sample into Tedlar bags using a static injection and a dynamic injection methodology. It was confirmed that both dynamic and static injection methods at ambient condition achieved high recovery rates with no need to consider increasing evaporation by elevating the temperature. This method can also be used to assess odour removal effectiveness of liquids by comparing the OEA before and after the treatment tests. Two application examples were presented.
Water Science & Technology 01/2012; 66(9):1828-33. · 1.12 Impact Factor
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Chemometrics and Intelligent Laboratory Systems 01/2012; 118:41 - 50. · 1.92 Impact Factor
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ABSTRACT: Accurate and conservative information about pathogen inactivation rates is needed as the basis for safe manure management on beef cattle feedlots. The survival of indicators and pathogens in faecal pen manure, stockpiled manure and manure compost was measured with autochthonous indicator bacteria (Escherichia coli, Clostridium perfringens, enterococci, total coliforms) and pathogens (Listeria monocytogenes, Campylobacter jejuni) using culture and/or real-time quantitative PCR (qPCR) methods. Additionally, the manures were incubated at 20, 37, 50 and 60 °C in microcosms to quantify the persistence of autochthonous microorganisms and selected process performance surrogates (Clostridium sporogenes, green fluorescent protein-labelled E. coli and L. monocytogenes). Estimated qPCR cell counts indicated that up to four orders of magnitude more target cells were present compared with the culturable counts. Corresponding T(90) estimates were up to sixfold higher. This study demonstrates the benefits of nucleic acid-based quantification of pathogen inactivation in cattle manures and concludes that the concurrent analysis of microorganisms by molecular and culture methods provides complementary value.
FEMS Microbiology Ecology 03/2011; 77(1):200-10. · 3.41 Impact Factor
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ABSTRACT: This study provides a comprehensive insight into the levels and fate of nine commonly used pharmaceuticals (amitriptyline, atenolol, gemfibrozil, ibuprofen, ketoprofen, metformin, naproxen, paracetamol and simvastatin) through a full-scale membrane bioreactor (MBR) in New South Wales, Australia. Seven out of the nine studied pharmaceuticals were detected in the raw sewage with average concentrations in the range of 1.29 – 33.3 µg.L-1, while gemfibrozil and simvastatin were below the analytical detection limit (1 ng.L-1). The MBR consistently achieved high removal efficiencies of the detected pharmaceuticals, in the range of 77.2 – 99.9%. A mass-balance showed that sorption to biomass was the dominant removal mechanism for amitriptyline while biodegradation/transformation was responsible for removing all other pharmaceuticals. This study revealed that log D (Log Kow corrected for ionisation at the ambient pH) provides an effective estimation of the sorption capacity of these pharmaceuticals to biomass.
gwf-Wasser/Abwasser. 01/2011; 152(S1/2011):98-102.
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ABSTRACT: There is widespread speculation that sewage treatment plants (STPs) and aquatic environments in general may be breeding grounds for antibiotic resistant bacteria. We examine the question of whether low concentrations of antibiotics in STPs can provide or contribute to a selective pressure facilitating the acquisition or proliferation of antibiotic resistance among bacteria in the receiving environment. Examination of available literature suggests that relative levels of antibiotic resistance may be increased during sewage treatment processes. However, it is unclear whether this may be partially the result of horizontal gene transfer or entirely due to clonal propagation. While there is circumstantial evidence that the presence of antibiotics or other related genetic promoters in STP wastewaters may contribute to selective pressures for these processes, a definite role is yet to be demonstrated. Future researchers would benefit from the application of non-culture-based techniques because culture limits the possible observations to a small subset of STP microbial diversity.
Critical Reviews in Environmental Science and Technology 01/2011; 41(3):243-270. · 4.84 Impact Factor
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ABSTRACT: Odorous emissions from sewers and wastewater treatment plants are a complex mixture of volatile chemicals that can cause annoyance to local populations, resulting in complaints to wastewater operators. Due to the variability in hedonic tone and chemical character of odorous emissions, no analytical technique can be applied universally for the assessment of odour abatement performance. Recent developments in analytical methodologies, specifically gas chromatography, odour assessment approaches (odour wheels, the odour profile method and dynamic olfactometry), and more recently combined gas chromatography-sensory analysis, have contributed to improvements in our ability to assesses odorous emissions in terms of odorant concentration and composition. This review collates existing knowledge with the aim of providing new insight into the effectiveness of sensorial and characterisation approaches to improve our understanding of the fate of odorous emissions during odour abatement. While research in non-specific sensor array (e-nose) technology has resulted in progress in the field of continuous odour monitoring, more successful long term case-studies are still needed to overcome the early overoptimistic performance expectations. Knowledge gaps still remain with regards to the decomposition of thermally unstable volatile compounds (especially sulfur compounds), the inability to predict synergistic, antagonistic, or additive interactions among odorants in combined chemical/sensorial analysis techniques, and the long term stability of chemical sensors due to sensor drift, aging, temperature/relative humidity effects, and temporal variations. Future odour abatement monitoring will require the identification of key odorants to facilitate improved process selection, design and management.
Water Research 10/2010; 44(18):5129-49. · 4.86 Impact Factor
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ABSTRACT: The occurrence of 10 pathogens and three fecal indicators was assessed by quantitative PCR in manures of Australian feedlot cattle. Most samples tested positive for one or more pathogens. For the dominant pathogens Campylobacter jejuni, Listeria monocytogenes, Giardia spp., Cryptosporidium spp., and eaeA-positive Escherichia coli, 10² to 10⁷ genome copies g⁻¹ (dry weight) manure were recovered.
Applied and environmental microbiology 10/2010; 76(20):6947-50. · 3.69 Impact Factor
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ABSTRACT: A membrane bioreactor (MBR) was assessed for the removal of estrogens, androgens, and a selection of pharmaceuticals and personal care products. The biomass and aqueous components of the MBR were investigated to determine whether removal was by biodegradation or by adsorption to the biomass. Removal was monitored using chemical analysis by gas chromatography/mass spectrometry (GC-MS) as well as biological analysis using estrogenic and androgenic yeast assays. Results showed that the MBR was effective in removing the compounds of concern from raw influent with removal rates between 78 and 99%. Removal efficiencies were comparable or better than those reported for conventional activated sludge systems, which was attributed to the relatively high sludge retention time of the MBR. The biomass component showed significant concentrations of salicylic acid, triclosan, and 4-tert-octylphenol. Estrogenic and androgenic activity was also measured in the biomass. Estrone was identified as the main compound responsible for the estrogenic activity. It was concluded that the main removal pathway was biodegradation, but sorption to biomass may also be important, particularly for triclosan and 4-tert-octylphenol.
Environmental Toxicology and Chemistry 09/2009; 28(12):2537-45. · 2.81 Impact Factor
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05/2009: pages 305 - 328; , ISBN: 9783527622726
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ABSTRACT: A novel filtration mode is presented to reduce fouling propensity in membrane bioreactors (MBR). During this mode, an elevated high instantaneous flux (60Lm(-2)h(-1)) is initially applied for a short time (120s), followed by a longer filtration (290s) at lower flux (10.3Lm(-2)h(-1)) and a backwash in each filtration cycle. The mixed mode is expected to limit irreversible fouling as the reversible fouling created during the initial stage appears to protect the membrane. Hydraulic performance and the components of foulants were analyzed and compared with conventional continuous and backwash modes. It was found that the mixed mode featured lower trans-membrane pressure (TMP) after 24h of filtration when compared to other modes. The mixed mode was effective in preventing soluble microbial products (SMP) attaching directly onto the membrane surface, keeping the cake layer weakly compressed, and reducing the mixed liquor suspended solids (MLSS) accumulation on the membrane. This strategy reduced the resistances of both the cake layer and the gel layer. A factorial experimental design was carried out for eight runs with different conditions to identify the major operational parameters affecting the hydraulic performances. The results showed that the value of the flux in the initial high-flux period had the most effect on the performance of the mixed mode: high initial flux (60Lm(-2)h(-1)) led to improved performance.
Water Research 09/2008; 42(14):3677-84. · 4.86 Impact Factor
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ABSTRACT: An activated sludge aeration control concept was developed utilizing off-gas nitrous oxide concentrations as a surrogate for autotrophic nitrifying bacterial inhibition and aeration air as a master control variable. The control concept was evaluated using a simulated pilot scale bioreactor (mathematically calibrated liquid phase process model and a model to link off-gas nitrous oxide generation to liquid phase conditions) as a data generator. When applied to the simulated system, the process controller was successful at maintaining the process at the desired operating setpoint and promoting stable operation by minimizing periods of significant inhibition. Furthermore, it provided a more efficient use of the air supplied to the bioreactor during periods of varying feed loading by matching the air supply to the metabolic demands, substantially reducing periods of over and under-aeration. The findings of this research demonstrate the potential for off-gas nitrous oxide monitoring as a completely non-invasive alternative to liquid phase monitoring used in conventional dissolved oxygen control. Investigations are currently underway at the laboratory scale to evaluate the benefits and limitations associated with this control concept, with particular emphasis on implementation issues and the quantification of potential aeration and cost savings.
Biotechnology and Bioengineering 04/2008; 101(1):109-18. · 3.95 Impact Factor
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ABSTRACT: Continuous, in situ monitoring of air, water and land quality is fundamental to most environmental applications. Low cost and non-invasive chemical sensor arrays provide a suitable technique for in situ monitoring. Their ability and performance under realistic conditions is discussed in this paper. Published studies report promising results despite a number of limitations that are associated with both the technology itself and its application in ever changing ambient conditions. Early investigations include the analysis of single substances as well as odour and wastewater organic load monitoring. Reported applications typically highlight the sensitivity of the currently available sensors to changes in temperature, humidity and flow rate. Two types of approaches are recommended to deal with these effects: either working under fixed experimental conditions or measuring the external parameters to numerically compensate for their change. The main challenge associated with the use of non-specific sensor arrays lies in establishing a relationship between the measured multivariate signals and the standards metrics that are traditionally used for quality assessment of gas mixtures. For instance, odour monitoring requires calibration against olfactometric measurements while investigations of wastewater samples still need to be correlated with organic pollution parameters such as BOD, COD or TOC. On the other hand, results obtained in the field have demonstrated how sensor arrays can be readily used as simple alarm devices or as early warning systems based on a general air/water quality index.
Journal of Environmental Monitoring 01/2004; 5(6):852-60. · 1.99 Impact Factor
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ABSTRACT: Real-time monitoring of wastewater quality remains an unresolved problem to the wastewater treatment industry. In order to comply with increasingly stringent environmental regulations, plant operators as well as instrument manufacturers have expressed the need for new standards and improved comparability and reliability of existing techniques. A review of currently available methods for monitoring global organic parameters (BOD, COD, TOC) is given. The study reviews both existing standard techniques and new innovative technologies with the focus on the sensors' potential for on-line and real-time monitoring and control. Current developments of biosensors, optical sensors and sensor arrays as well as virtual sensors for the monitoring of wastewater organic load are presented and the interests and limitations of these techniques with respect to their application to the wastewater monitoring are discussed.© 2001 Society of Chemical Industry
Journal of Chemical Technology & Biotechnology 03/2001; 76(4):337 - 348. · 2.17 Impact Factor
