This study investigated the significant influence of HCO3 – on the degradation of contaminants of emerging concern (CECs) during nitrate photolysis at 254 nm for water reuse applications. The second-order rate constants for the reactions between selected contaminants with carbonate radical (CO3 •–) were determined at pH 8.8 and T = 20 °C: estrone ((5.3 ± 1.1) × 108 M–1 s–1), bisphenol A ((2.8 ± 0.2) × 108 M–1 s–1), 17α-ethynylestradiol ((1.6 ± 0.3) × 108 M–1 s–1), triclosan ((4.2 ± 1.4) × 107 M–1 s–1), diclofenac ((2.7 ± 0.7) × 107 M–1 s–1), atrazine ((5.7 ± 0.1) × 106 M–1 s–1), carbamazepine ((4.2 ± 0.01) × 106 M–1 s–1), and ibuprofen ((1.2 ± 1.1) × 106 M–1 s–1). Contributions from UV, reactive nitrogen species (RNS), hydroxyl radical (•OH), and CO3 •– to the CEC decomposition in UV/NO3 – in the presence and absence of HCO3 – were investigated. In addition, possible transformation products and degradation pathways of triclosan, diclofenac, bisphenol A, and estrone in UV/NO3 –/HCO3 – were proposed based on the mass (MS) and MS2 spectra. Significant reduction in the cytotoxicity of bisphenol A was observed after the treatment with UV/NO3 –/HCO3 –.

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Advanced oxidation using UV and hydrogen peroxide (UV/H 2 O 2) has been widely applied to degrade contaminants of emerging concern (CECs) in wastewater for water reuse. This study investigated the degradation kinetics of mixed CECs by UV/H 2 O 2 under variable H 2 O 2 doses, including bisphenol A, estrone, diclofenac, ibuprofen, and triclosan. Reverse osmosis (RO) treated water samples from Orange County Water District's Groundwater Replenishment System (GWRS) potable reuse project were collected on different dates and utilized as reaction matrices with spiked additions of chemicals (CECs and H 2 O 2) to assess the application of UV/H 2 O 2. Possible degradation pathways of selected CECs were proposed based on high resolution mass spectrometry identification of transformation products (TPs). Toxicity assessments included cytotoxicity, aryl hydrocarbon receptor-binding activity, and estrogen receptor-binding activity, in order to evaluate potential environmental impacts resulting from CEC degradation by UV/H 2 O 2. Cytotoxicity and estrogenic activity were significantly reduced during the degradation of mixed CECs in Milli-Q water by UV/H 2 O 2 with high UV fluence (3200 mJ cm À2). However, in GWRS RO-treated water samples collected in April 2017, the cytotoxicity and estrogen activity of spiked CEC-mixture after UV/H 2 O 2 treatment were not significantly eliminated; this might be due to the high concentration of target CEC and their TPs, which was possibly affected by the varied quality of the secondary treatment influent at this facility such as sewer-shed and wastewater discharges. This study aimed to provide insight on the impacts of post-UV/H 2 O 2 CECs and TPs on human and ecological health at cellular level.

AimsTo perform a wastewater‐based analysis to explore the impact of newly legalized retail cannabis sales on its use and to determine if this approach could estimate the size of the legal market place, which began 1 August 2014 in the study area.DesignLaboratory study of raw wastewater samples collected and analyzed over the 3‐year period from 2014 to 2016.Setting and ParticipantsSamples obtained from the two wastewater treatment plants that serviced a municipality of 200 000 people in the state of Washington, USA.MeasurementsQuantitative analysis of 24‐hour composite influent samples for the metabolite of the active ingredient in cannabis, 11‐nor‐9‐Carboxy‐Δ9‐tetrahydrocannabinol (THC‐COOH) were performed by liquid chromatography coupled to mass spectrometry.FindingsWastewater estimates for THC‐COOH increased by 9% per quarter, suggesting a doubling in cannabis consumption from 1 December 2013 to 31 December 2016. State‐sold THC increased at nearly 70% per quarter, while stores operated from 1 August 2014 to 31 December 2016. Estimating the proportion of the total cannabis market supplied by state‐regulated cannabis from these data is not currently achievable.ConclusionA wastewater‐based measure of cannabis consumption suggests a significant increase in consumption in Washington, USA following legalization, and that legal sales appear to have displaced a large portion of the illicit market.

Introduction of oil and gas extraction wastewaters (OGWs) to surface water leads to elevated halide levels from geogenic bromide and iodide, as well as enhanced formation of brominated and iodinated disinfection byproducts (DBPs) when treated. OGWs contain high levels of chemical additives used to optimize extraction activities, such as surfactants, which have the potential to serve as organic DBP precursors in OGW-impacted water sources. We report the first identification of olefin sulfonate surfactant-derived DBPs from laboratory-disinfected gas extraction wastewater. Over 300 sulfur-containing DBPs, with 43 unique molecular formulas, were found by high-resolution mass spectrometry, following bench-scale chlor­(am)­ination. DBPs consisted of mostly brominated species, including bromohydrin sulfonates, dihalo-bromosulfonates, and bromosultone sulfonates, with chlorinated/iodinated analogues formed to a lesser extent. Disinfection of a commercial C12-olefin sulfonate surfactant mixture revealed dodecene sulfonate as a likely precursor for most detected DBPs; disulfur-containing DBPs, like bromosultone sulfonate and bromohydrin disulfonate, originated from olefin disulfonate species, present as side-products of olefin sulfonate production. Disinfection of wastewaters increased mammalian cytotoxicity several orders of magnitude, with chloraminated water being more toxic. This finding is important to OGW-impacted source waters because drinking water plants with high-bromide source waters may switch to chloramination to meet DBP regulations.