Cocaine and amphetamines were detected in untreated and treated sewage in the wastewater treatment plants of three Canadian cities, and community consumption patterns estimated from the concentrations of the drugs in untreated wastewater were consistent with estimates of the use of illicit drugs in Canada.

Several drugs of abuse, including amphetamines, cocaine and its metabolite, benzoylecgonine and several opioid prescription drugs were detected in wastewater from two Canadian cities, a small community (75,000 population) and a large urban center (1.6 million population). The objective of this study was to evaluate community use of these drugs in two cities with large differences in population size and demographics. In addition, we evaluated the use of the Polar Organic Chemical Integrative Sampler (POCIS) as a monitoring tool for drugs of abuse

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11The concentrations of 17 drugs of abuse (DOAs), including cocaine, several amphetamine, 12 opioid drugs and two metabolites, benzoylecgonine (BE) a metabolite of cocaine and 2-13 Ethylidene-1,5-Dimethyl-3,3-Diphenylpyrolidine (EDDP) a metabolite of methadone, were 14 investigated in an urban watershed that is heavily impacted by discharges of municipal 15 acetylcodeine (a-codeine) and oxycodone. Heroin and methadone were not detected at any 25 sample locations. Amphetamine (AMP), methamphetamine (METH), 3,4-methylenedioxy-26 methamphetamine (MDMA), and EDDP were not detected in the samples collected at the 27 drinking water intake. Many of the DOAs were not removed effectively in the DWTP, including 28 cocaine, BE, methylenedioxyamphetamine (MDA), ephedrine, and several prescription opioids, 29 most probably because the DWTP was operating at or above its rated treatment capacity. These 30 data indicate that there can be transport of DOAs from wastewater sources into drinking water in 31 urban watersheds. 32 33

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• The ozonation of six drugs of abuse and one human drug metabolite was carried out.• Drug removals vary between 3 and 50% for the ozone doses tested.• The main transformation products of the drugs of abuse were identified.• The most plausible structure of a transformation product of MDMA was elucidated. a b s t r a c t a r t i c l e i n f o In this study amphetamine, methamphetamine, methylenedioxymethamphetamine (MDMA), cocaine (COC), benzoylecgonine (BE), ketamine (KET) and oxycodone (OXY) in wastewater at concentrations of 100 μgL −1 were subjected to ozone to determine their removals as a function of ozone dose and to identify significant oxidation transformation products (OTPs) produced as a result of ozonation. A method based on high resolution mass spectrometry and differential analysis was used to facilitate and accelerate the identification and structural elucidation of the transformation products. The drug removal ranged from 3 to 50% depending on the complexity of the matrix and whether a mixture or individual drugs were ozonated. Both transient and persistent oxidation transformation products were identified for MDMA, COC and OXY and their chemical formulae were determined. Three possible structures of the persistent transformation product of MDMA (OTP-213) with chemical formula C 10 H 16 O 4 N, were determined based on MS n mass spectra and the most plausible structure (OTP-213a) was determined based on the chemistry of ozone. These results indicate that ozone is capable of removing drugs of abuse from wastewater to varying extents and that persistent transformation products are produced as a result of treatment.

• 19 drugs of abuse were studied throughout a wastewater treatment plant.• Drug levels were generally comparable between composite, POCIS and grab samples.• Overall drug removals during wastewater treatment varied between −84 and 90%.• Time-shifted mass balancing eliminated negative removals obtained with other approaches. 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. a b s t r a c t a r t i c l e i n f o

Sulfamethoxazole (SMX) is a widely used antibiotic which has been detected in surface water samples in the ng/L range and also detected in drinking water samples. To limit the environmental impact, ozonation treatment of waste streams has been proposed. However, the degradation products created by ozonation as well as their toxicity have not been reported. In this study, we investigated the degradation products of SMX formed during ozonation and the effects of these products on mammalian cultured cells. In addition to alcohols and nitrates, sulfanilamide was identified as the larger molecular weight compound of the degradation products detected. Cells exposed to the degradation products of SMX maintained their polyhedral geometry longer than the control cells. Proliferation of the cells exposed to the degradation products was not negatively affected when compared with the control cells. The results of this study show that bioactive degradation products can be formed by ozonation of SMX.