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A sensitive method based on ultrasound-assisted liquid extraction coupled with liquid chromatography was applied to screen 18 plastic-related contaminants in 168 food composites (namely fish fillets, chicken breast, canned tuna, leafy vegetables, bread and butter) collected in Montreal (Canada), Pretoria and Vhembe (South Africa). Bisphenol A (BPA), bisphenol S (BPS) and seven plasticizers (di-n-butyl phthalate (DBP), diethyl phthalate (DEP), (2-ethylhexyl) phthalate (DEHP), di-(2-ethylhexyl) adipate (DEHA), di-isononyl phthalate (DINP), di-(isononyl)-cyclohexane-1,2-dicarboxylate (DINCH)) were detected in different foods from both countries. DBP and DEP were the most frequently detected contaminants in food collected in Montreal (75% for both) and DINP was the most frequently detected contaminant in food from South Africa (67%). DEHA concentration in packaged fish were significantly higher than the values for non-packaged fish (p 0.01) suggesting that the packaging film can be one source of DEHA in fish.

Calcium-silicate mineral Polonite® and aluminum-based catalyst (AL-1010S), previously identified as promising materials for catalytic ozonation, were used as catalysts to investigate the impact of some operating conditions (ratio ozone feed concentration to catalyst load) and wastewater characteristics (chemical oxygen demand - COD and nitrite - NO2 concentration) on the disinfection and removal of contaminants of emerging concern (CECs) during catalytic ozonation of wastewater. Tests conducted in synthetic wastewater using two different ozone gas concentration (4 and 8 g (nm3)) and 6 different catalyst loads provided ratios of 0.08, 0.11, 0.16, and 0.32. Results from the experiments indicated that the ratio of 0.11 was optimal and reached residual disinfection below 2 MPN mL−1 from the initial concentration of 5 ± 2 × 105 MPN mL−1 and removal of atrazine (ATZ) above 80% from the initial concentration of 100 ± 10 μg L−1 for an ozone dose of 41–45 mg L−1. Catalytic ozonation with the selected materials enhanced disinfection and ATZ removal from synthetic wastewater (SWW) in comparison to non-catalytic ozonation by making the treatment performance less sensitive to increased chemical oxygen demand (COD) and nitrite (NO2) in the matrix. Validation of the results in real wastewater effluents confirmed that catalytic ozonation enhanced disinfection. Catalytic ozonation using Polonite® and AL-1010S provided residual bacteria level of 0.6 ± 0.42 MPN mL−1 and 0.29 ± 0.41 MPN mL−1, while non-catalytic ozonation lead to an average residual bacteria level of 1.26 ± 0.09 MPN mL−1 for the same range of transferred ozone dose. However, under the conditions tested, a limited number of CECs were extracted at levels above the limits of quantification and further validation work required to evaluate the performance of catalytic ozonation for the removal of CECs.

The purpose of this work was to identify novel materials that could be used for the catalytic ozonation of wastewater for improved removal of micropollutants and disinfection. The materials chosen for investigation were selected based on their commercial availability and composition characteristics that suggested that they could act as catalysts. Synthetic wastewater (SWW) was used to mimic municipal secondary effluent wastewater while obtaining constant and reproducible matrix characteristics. Polonite®, wollastonite, zeolite, TiO2-Al2O3 (8%/92%), and AL-1010S (AlO2-based) were tested for their potential impact on efficiency of disinfection, based on the removal of E. coli bacteria and removal of contaminants of emerging concern (CECs), relative to conventional ozonation. Atrazine (ATZ), ibuprofen (IBP), naproxen (NPX), and gemfibrozil (GBZ) were used as indicator compounds. Zeolite and wollastonite did not promote disinfection and CECs removal; TiO2-Al2O3 and AL-1010S provided improvement for both criteria, but to a lesser extent in SWW than in Milli-Q water; and Polonite® did not enhance the removal of CECs but led to the higher E. coli inactivation. These results suggest that Polonite®, AL-1010S, and TiO2-Al2O3 can act as catalysts and provide mechanisms to lower the ozone dose required to reach disinfection. The apparent kinetic constant of the reaction for the catalytic ozonation of ATZ, in the ultrapure water, was determined for Polonite®, TiO2-Al2O3 and AL-1010S. The reusability of the catalysts was demonstrated over four consecutive cycles of 6 h of treatment in a continuous flow ozonation system.

Municipal wastewater treatment plants (WWTP) effluents are primary sources of pathogenic microorganisms and contaminants of emerging concern (CECs) released into the aquatic environment. Main concerns regarding these pollutants include transmission of waterborne diseases to humans and toxic and endocrine disrupting effects on aquatic organisms. In the coming years, WWTPs are expected to invest billions of dollars in upgrades to meet new regulatory requirements for wastewater from Environment Canada. For this reason, we investigated the performance of ozone when the technology is used for disinfection to overcome multiple risk factors such as disinfection, CEC removal, endocrine activity and toxicity for real effluents collected from three WWTPs. Two secondary effluents required mean specific ozone doses for disinfection of 0.25 and 1.04 gO3/gDOC whereas the advanced primary effluent required 1.52 gO3/gDOC to achieve a total coliform target disinfection criteria of 1000 MPN/100 ml (equivalent to 200 MPN/100 ml E. coli). At ozone doses for disinfection, CECs with high reactivity with ozone were removed at levels greater than the target CEC removal of 80% for all WWTP effluents. For the secondary effluents, ozone doses above 2.6 ± 0.6 gO3/gDOC were required to satisfy the target removal for the recalcitrant CECs. Within the disinfection ozone dose range, estrogenic activity was reduced by more than 98% and androgenic activity was removed by more than 68%, while the anti-estrogenic activity remained unchanged. Lastly, based on the luminescence inhibition of V. fischeri, ozone doses for disinfection produced secondary effluents exhibiting less than 20% inhibition, thus falling under the hazard classification “no acute/chronic toxicity”.

New treatment technologies and quality monitoring tools are needed for Contaminants of Emerging Concern (CECs) in wastewater. The purpose of this work was to assess the LuminoTox as a monitoring tool for CEC-associated toxicity in municipal wastewater during ozone treatment, and to evaluate the impact of different ozone feed concentrations at equivalent ozone doses for removing toxicity. The LuminoTox was sensitive at monitoring changes in toxicity of atrazine (ATZ) in synthetic wastewater (SWW) and in a 14 CECs mix in secondary effluent (SE) during ozone treatment. In both experiments, a decrease in toxicity was observed with increasing transferred ozone dose, which corresponded to a decrease in CEC concentration. For ATZ in SWW, a 5 ppm ozone feed showed better toxicity removal, up to 25% and 35% inhibition for LuminoTox algae biosensors SAPS I and SAPS II, respectively, for statistically equivalent ozone dose pairs of 43 mg (5 ppm ozone feed) and 36 mg (15 ppm ozone feed). The opposite was true for the 14 CECs in SE; the 15 ppm ozone feed showed better toxicity removal, up to a reduction of 37% and 40% for SAPS I and SAPS II inhibition, respectively, for statistically equivalent ozone dose pairs of 42 mg (5 ppm ozone feed) and 42 mg (15 ppm ozone feed). Different feed applications had an impact on the efficiency of toxicity removal for equivalent ozone doses; this efficiency appears to depend on the type of contaminants and/or wastewater matrix.

This study investigated the presence of a variety of pesticides (herbicides, fungicides, and insecticides) in effluent of three wastewater treatment plants as well as their endocrine activities using yeast-based in vitro assays. Although the presence of these contaminants of emerging concern is frequently reported to be present throughout the environment, their presence in wastewater treatment plants has been seldom studied. Of the 18 compounds investigated in this study, imidacloprid was the only compound not detected in all three WWTPs. Concentrations measured ranged from 3ng/L to 27μg/L for fluconazole. The yeast estrogenic and yeast androgenic screen assays were performed on target compounds in order to investigate their endocrine disruption and potential environmental risks to receiving waters. It was found that of the 14 compounds investigated 12 showed either antiestrogenic or antiandrogenic activity and seven compounds showed pleiotropic effects. In addition to confirming endocrine activities of pesticides using the yeast-based assays this study is one of the first to report activities for novel compounds including three neonicotinoids.

The presence of micropollutants in the environment and their toxic impacts on the aquatic environment have raised concern about their inefficient removal in wastewater treatment plants. In this study, the fate of micropollutants of four different classes was simulated in a conventional activated sludge plant using a bioreactor micropollutant fate model coupled to a settler model. The latter was based on the Bürger-Diehl model extended for the first time to include micropollutant fate processes. Calibration of model parameters was completed by matching modelling results with full-scale measurements (i.e. including aqueous and particulate phase concentrations of micropollutants) obtained from a 4-day sampling campaign. Modelling results showed that further biodegradation takes place in the sludge blanket of the settler for the highly biodegradable caffeine, underlining the need for a reactive settler model. The adopted Monte Carlo based calibration approach also provided an overview of the model's global sensitivity to the parameters. This analysis showed that for each micropollutant and according to the dominant fate process, a different set of one or more parameters had a significant impact on the model fit, justifying the selection of parameter subsets for model calibration. A dynamic local sensitivity analysis was also performed with the calibrated parameters. This analysis supported the conclusions from the global sensitivity and provided guidance for future sampling campaigns. This study expands the understanding of micropollutant fate models when applied to different micropollutants, in terms of global and local sensitivity to model parameters, as well as the identifiability of the parameters.

The continuous release of pharmaceutical compounds in the environment is of concern due to their potential toxicological effects on living organisms, even at low concentrations. The insufficient removal of bioactive contaminants such as pharmaceuticals by conventional wastewater treatment processes has led scientists to investigate and develop efficient technologies such as advanced oxidation processes (AOPs) to address the issue. The objective of the present work was to study the applicability of thermally-prepared Sb-doped Sn 80% -W 20% -oxide thin film coated electrodes for the photoelectrocatalytic degradation of a recalcitrant pharmaceutical compound, carbamazepine (CBZ). The efficiency of photolytic and photocatalytic processes for removal of CBZ were also evaluated for comparison. The formation of transformation products was investigated and the results showed lower levels of transformation products in the water treated by the photoelectrocatalytic method compared to the photolytic and photocatalytic methods, by the end of 60-min treatment. This suggests a potentially lower overall toxicity of the final solution treated by the photoelectrocatalytic method. An estimation of the energy consumption to reach an order of magnitude reduction in the concentration of CBZ for each type of process indicated a lower energy requirement for the photoelectrocatalytic method, with the highest energy efficiency observed at the applied current density of 6 mA/cm 2 .

The widespread deterioration of our water systems requires new wastewater treatment technologies to ensure environmental protection. Conventional wastewater treatments were not designed for, and are therefore ineffective, at removing contaminants of emerging concern (CECs) such as pharmaceuticals, personal care products, pesticides, and industrial chemicals. Furthermore, treatment processes capable of breaking down CECs may produce toxic transformation products more harmful than the parent chemicals. Heterogeneous photocatalytic ozonation provides a promising option with high degradation and mineralization of organic compounds. The aim of the present paper is to review ecotoxicity reduction in water treated by heterogeneous photocatalytic ozonation as a measure of process viability. The discussion investigates changes in toxicity based on a variety of toxicity tests performed to evaluate potential effects on ecosystems, the types of catalysts and radiation sources used, the nature of the target contaminants, and the type of water matrix treated. Acute toxicity testing, TiO2 catalysts, and mercury-vapour lamps including blacklights were dominant in the reviewed studies, investigated in 86%, 84% and 79% of the papers, respectively. Pharmaceuticals were the main group of chemicals treated and the water matrices used were predominantly pure water and secondary effluent. Overall, the findings of these studies provide evidence that photocatalytic ozonation is an efficient process to remove persistent organic compounds while, most of the time, not increasing the toxicity of the effluent (as reported by 86% of the studies). Due to the wide variation in experimental set-ups, no clear correlation between reaction conditions and toxicity was determined, however, V. fischeri acute toxicity assays and chronic/sublethal tests appeared most sensitive to transformation products. Future studies need to a) incorporate multiple toxicity tests to produce a more reliable and inclusive ecotoxicity assessment of treated effluent and b) investigate immobilized catalysts and energy efficient radiation sources (i.e. solar and LEDs) for industrial applications.

Diatrizoate, a recalcitrant iodinated contrast medium, has been detected in wastewaters and water bodies worldwide, with concentrations in hospital wastewaters in the μg/L range. Considering that conventional wastewater treatment technologies and ozonation fail to adequately remove diatrizoate, there is a need for researching alternative treatment technologies. In the present work, aqueous solutions of diatrizoate were treated in a compact (7.5 mL liquid volume) non-thermal plasma–liquid reactor. Oxygen and air plasmas were used for diatrizoate removal, with oxygen plasma performing better. After 20 min of treatment of 200 μg/L diatrizoate in pure water, oxygen led to 90% degradation whereas air achieved only 20% degradation. Two diatrizoate concentrations were studied: 10 mg/L to facilitate the identification of transformation products when using an oxygen plasma and 200 μg/L, a concentration in the range expected in hospital wastewater. For the oxygen plasma treatment, the energy efficiency for removing diatrizoate was 0.140 g/kWh for C0 = 10 mg/L and 0.006 g/kWh for C0 = 200 μg/L. The following transformation products of diatrizoate were identified: m/z 486A, 504A, 504B, 628, 630A, 630B (previously described in literature) and m/z 486B, 550, 555, 565, 578 (novel). Acute toxicity tests on Aliivibrio fischeri revealed no residual toxicity associated to transformation products. Since diatrizoate is a particularly recalcitrant aqueous organic pollutant, its successful removal and the lack of formation of toxic transformation products indicates that the developed plasma-based technology is promising for treating challenging wastewaters, such as hospital wastewaters.

Bench-scale reverse osmosis results were compared to pilot-scale results to evaluate the usefulness of bench-scale studies in assessing full-scale membrane performances in the context of reusing wastewater from a novel saline soil remediation technology. Salt rejection and water recovery capacity were accurately estimated by bench-scale tests, with an average water recovery capacity of 56% with an applied pressure of 3100 kPa and a salt rejection of 92% at 2760 kPa. However, fouling, and concentration polarization were found to differ between scales. Concentration polarisation was 41% higher for the pilot-scale tests, which might be explained by differences in membrane configuration; coupon versus spiral-wound.

Salt-contaminated soil generated by industrial activities has become a problem of concern over the last decades. While existing treatment technologies for these soils are efficient, the wastewater produced remains the major drawback. In this study, a novel application of forward osmosis (FO) was tested. The FO process operated in osmotic dilution mode was investigated in order to concentrate saline soil treatment wastewater and produce valuable process water. FO was chosen for this application since it is a low-energy technology and process adapted for complex liquid streams. Results from this study indicate that FO operated in osmotic dilution mode with a 1 M CaCl 2 draw solution is able to recover 50% of the initial wastewater volume with an initial total dissolved solids concentration of 16.3 g/L. Following treatment, the draw solution can be reused as a cationic exchange solution with CaCl 2 concentrations between 0.41 M and 0.44 M. No important solute transport from the feed to the draw solution was observed, except for some potassium drawn by the draw solution. This study demonstrated the potential of integrating the FO technology in the soil treatment industry in order to enhance water reuse in water-intensive processes.

In this study the levels of 19 drugs of abuse were estimated throughout a wastewater treatment plant using polar organic chemical integrative samplers (POCIS), 24 h composite samples and grab samples. Overall removal efficiencies and removals in between each treatment unit were calculated using load data for each sampling technique as well as removals that take into account the hydraulic residence time distribution of the treatment plant (time-shifted mass balancing approach). Amphetamine-type stimulants, cocaine and its major metabolite, benzoylecgonine and opioid levels determined with 24 h composite samples were generally comparable to those obtained with POCIS and grab samples. Negative mass balances resulting from the estimation of overall removal efficiencies by POCIS, day-to-day mass balancing of 24 h composite and grab sample data did not occur when the hydraulic retention time (HRT) distributions of the plant were taken into account for calculation. Among the compounds investigated, cocaine exhibited the highest overall removal (90%) while codeine had the lowest with 13%, respectively. Sampling between the treatment units revealed that highest removal occurs during biological treatment as compared to primary or secondary clarification. Methylenedioxyamphetamine (MDA), fentanyl, dihydrocodeine and heroin were not detected in wastewater at any of the sampling locations at the treatment plant regardless of the sampling technique. The study demonstrates the benefits of applying the time-shifted mass balancing approach to the calculation of removals of drugs of abuse during wastewater treatment.

The presence of the synthetic estrogen 17α-ethinylestradiol (EE2) in the environment is of increasing concern due to the endocrine disruption of aquatic organisms. Incomplete removal from wastewater (WW) is one of the main sources of EE2 in aquatic ecosystems, thus improving processes like biological WW treatment/activated sludge (AS) is becoming significantly important. There are opposing results regarding EE2 biodegradability by AS; one discrepancy is the efficacy of heterotrophic bacteria. This research demonstrated the ability of heterotrophs commonly present in AS (B. subtilis, P. aeruginosa, P. putida, R. equi, R. erythropolis, R. rhodochrous, R. zopfii) to remove EE2. R. rhodochrous was the most successful with no detectable EE2 after 48 h; the other bacteria achieved 21%-61% EE2 removal. No additive or synergistic effects were observed due to the combination of the bacterial cultures with maximum EE2 removals of 43% after 300 h.

Enterobacter aerogenes have a known ability to convert glycerol (GL) in a fermentative process to yield hydrogen and ethanol as the main by-products. The concentration of some media constituents was optimized to maximize biohydrogen yield and rate of production. E. aerogenes were cultured in aerobic conditions, and then transferred into anaerobic conditions before being cultured in a minimum mineral synthetic media (MMSM) containing 15 g/L GL. The concentration of selected salts were optimized in the following ranges: 0–300 mg/L MgSO 4 , 0–14 g/L Na 2 EDTA, 0–10 mg/L CaCL 2 , 0–10 g/L Na 2 HPO 4 , and 0–9.7 g/L KH 2 PO 4 . The results of the full factorial design indicated that the production of biohydrogen required a minimal concentration of 3.5 mg/L EDTA, 200 mg/L MgSO 4 .7H 2 O and no CaCl 2 .2H 2 O. A significant interaction between EDTA and MgSO 4 was also observed. Results from the phosphate salts optimization showed that Na 2 HPO 4 gave better results than KH 2 PO 4 . The optimal conditions determined using pure glycerol (commercial grade glycerol), were successfully applied to the fermentation of crude glycerol from biodiesel production. The results indicated promising yields of 0.79 and 0.84 mol/mol of glycerol for bioethanol and biohydrogen, respectively, and this at a faster rate than reported previously for E. aerogenes .

A method was developed to assess leaching of several poly(vinyl chloride) (PVC) plasticizers in aqueous media using gas chromatography (GC), and compared to a gravimetric standard test method (ASTM Method D1239). The GC method was a more direct measurement of plasticizer concentration in the aqueous phase. The leaching of commercial plasticizers, as well as several series of "green" candidate plasticizers, were assessed as a function of their molecular characteristics and compared to the industry standard PVC plasticizer, di-2-ethylhexyl phthalate (DEHP). It was found that plasticizers containing longer alkyl chains or non-polar branching emanating from polar structural units, increased the hydrophobicity of the molecule and reduced its aqueous leaching rate. Several "green" plasticizer candidates were found to minimize aqueous leaching to rates ten times below that of DEHP; notably dioctyl succinate (DOS), dihexyl maleate (DHM), methyl cyclohexyl diester (MCDE), diethylhexyl succinate (DEHS), hexanediol dibenzoate (C6), and the commercially available Hexamoll® DINCH.

Removal of the fluoroquinolone antibiotic levofloxacin (LEVO) was studied in two oxidation processes: photocatalysis (UVC lamp (254 nm), TiO 2 ) and ozonation. LEVO ( C o = 20 mg/L) was no longer detected after an ozone dose of 20.5 mg/L and after 180 min of photocatalytic oxidation. COD removals of 59% and 70% were measured for 270 mg/L of transferred ozone dose and 300 min of photocatalytic oxidation, respectively. Extensive treatment with ozone did not result in further reduction in COD levels reaching a plateau at the above mentioned value, however increased irradiation time led to increased COD removal during photocatalytic treatment. Both treatment methods proved to be effective ways of removing antibacterial activity. From agar diffusion test with Escherichia coli , it was observed that a transferred ozone dose of at least 20.5 mg/L and 180 min of irradiation were enough to completely remove antibacterial activity. Both treatments methods were shown to efficiently remove LEVO and its antibacterial activity and show promising results as possible applications for removal of antibiotics in wastewater.

Photolytic and photocatalytic removals of 17α-ethinylestradiol (EE2) and levonorgestrel (LNG) in pharmaceutical wastewater were investigated under UVC radiation. Wastewater collected from WYETH, St-Laurent, Canada contained high concentrations of EE2 and LNG in suspension and coloring agent tartrazine in solution. Aqueous phase removals of EE2 and LNG were studied as individual contaminants in water and in complex matrices including: co-contaminants in water, in simulated synthetic wastewater and in the wastewater. After 30 min of UVC photocatalysis of the individual contaminants, removal efficiencies of EE2 and LNG were 92% and 97%, respectively, while higher photolytic removal was observed for LNG (94%) compared to EE2 (60%). Hydroxyl radicals were shown to contribute significantly to the removal of both compounds in water. In contrast to EE2, photolytic removal of LNG was higher than its photocatalytic removal efficiencies in all complex matrices. Higher photolytic removal of LNG was attributed to the fact that it absorbs UVC radiation considerably more than EE2. Lower photocatalytic removals of LNG in complex matrices compared to its photocatalytic removal as an individual contaminant was due to the presence of EE2 at concentrations up to five times larger than LNG in water, thus leading to increased competition for hydroxyl radicals and retarding LNG removal. In the wastewater matrix photocatalytic removals for EE2 and LNG were similar at 48%, whereas the photolytic removal of LNG (76%) was higher than EE2 (29%). The applicability of UVC processes for reduction of hormone content in similar wastewaters was demonstrated.

Enterobacter aerogenes has a known ability to convert glycerol during a fermentative process to yield hydrogen and ethanol as the main products. A Box-Behnken design and response surface methodology were used to determine the optimal concentration of some media constituents and oxygen to maximize the yield of biohydrogen. Results indicated that the concentration of the salts studied: NH 4 NO 3 , FeSO 4 , and Na 2 HPO 4 and; the presence of oxygen in the pre-culture significantly influence the production of biohydrogen. Optimal conditions were determined to be 7.5% O 2 in the inoculum transfer step, ratio of inocula 18%, 8 g/L of Na 2 HPO 4 , 0.00625 g/L of FeSO 4 and 1.5 g/L of NH 4 NO 3 . These optimal conditions resulted in a measured yield of 0.85 mol H 2 /mol glycerol at a substrate concentration of 15 g/L and a maximum predicted yield of 0.95 mol H 2 /mol glycerol at a substrate concentration of 21 g/L. These results were obtained using lower concentrations of salts than in previous studies, corresponding to a 76% cost savings. These experimental results also demonstrated the importance of optimizing the amount of oxygen present in the biological system rather than maintaining complete anaerobic conditions.

In this study, photolytic and photocatalytic removal of the antibiotic sulfamethoxazole (SMX) under UVC radiation ( λ = 254 nm) was investigated. The light intensity distribution inside the batch photoreactor was characterized by azoxybenzene actinometry. The intensity of incident radiation was found to be a strong function of position inside the reactor. 12 mg L −1 of SMX was completely removed within 10 min of irradiation under UVC photolysis, compared to 30 min under TiO 2 photocatalysis. COD measurement was used as an indication of the mineralization efficiency of both processes and higher COD removal with photocatalysis was shown. After 6 h of reaction with photolysis and photocatalysis, 24% and 87% removal of COD was observed, respectively. Two of the intermediate photo-products were identified as sulfanilic acid and 3-amino-5-methylisoxazole by direct comparison of the HPLC chromatograms of standards to those of treated solutions. Ecotoxicity of treated and untreated solutions of SMX towards Daphnia magna was also investigated. It was found that a 3:1 ratio of sample to standard freshwater and a high initial concentration of 60 mg L −1 of SMX were used to obtain reliable and reproducible results. The photo-products formed during photocatalytic and photolytic processes were shown to be generally more toxic than the parent compound.

In this study of wastewater treatment plants in three Canadian cities, selected illicit drugs, including cocaine and its major metabolite, benzoylecgonine (BE), amphetamine, methamphetamine and ecstasy (i.e. MDMA) were detected in untreated wastewater. Cocaine was the most widely used illicit drug at a median level for the 3 cities of 15.7 doses per day per 1000 people. For the other drugs, the median doses per day per 1000 people were 1.8 for amphetamine, 4.5 for methamphetamine and 0.4 for ecstasy. Methamphetamine use was highest in the largest city and cocaine use was lowest in the smallest city. Removal of the illicit drugs by wastewater treatment was generally >50%, except in a WWTP that uses primary treatment. The community consumption estimate for ecstasy in the present study is far below published estimates of the prevalence of ecstasy use among the Canadian population, which may be due to only occasional use of ecstasy.

In this study the antibiotic sulfamethoxazole (SMX) was subjected to ozone treatment. Solutions of 60 mg/L and 100 microg/L SMX in pure water and secondary municipal effluent were treated. The removal profile of SMX and its oxidation products was monitored as a function of transferred ozone dose in both matrices. No difference was observed in the ozone dose required for the concentration of SMX to fall below the limit of detection in pure water and wastewater. New peaks with the same retention times were obtained on the HPLC chromatograms for all conditions studied. Solutions with an initial concentration of 60 mg/L required 83 mg/L of ozone to fall below the limit of detection and eight oxidation products were detected. Solutions with an initial concentration of 100 microg/L required 14 mg/L of ozone and only four oxidation products were detected. The four peaks obtained during experiments at low concentration were observed at the same retention times as four of the peaks obtained in higher concentration samples. In ozonated wastewater these products were identified as: 4-aminobenzene sulfonamide, N-(3-phenylpropyl)-acetamide, 2-methyl-benzoxazole and phenol. In addition, methanol, ethanol, acetic acid, methyl acetate and ethyl acetate were identified in the higher concentration samples.

An investigation of biological hydrogen production from glucose by Clostridium beijerinckii was conducted in a synthetic wastewater solution. A study examining the effect of initial pH (range 5.7–6.5) and substrate loading (range 1–3 g COD/L) on the specific conversion and hydrogen production rate has shown interaction behaviour between the two independent variables. Highest conversion of 10.3 mL H 2 /(g COD/L) was achieved at pH of 6.1 and glucose concentration of 3 g COD/L, whereas the highest production rate of 71 mL H 2 /(h L) was measured at pH 6.3 and substrate loading of 2.5 g COD/L. In general, there appears to be a strong trend of increasing hydrogen production rate with an increase in both substrate concentration and pH. Butyrate (14–63%), formate (10–45%) and ethanol (16–40%) were the main soluble products with other volatile fatty acids and alcohols present in smaller quantities.