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The solar UV/chlorine process has emerged as a novel advanced oxidation process for industrial and municipal wastewaters. Currently, its practical application to oil sands process-affected water (OSPW) remediation has been studied to treat fresh OSPW retained in large tailings ponds, which can cause significant adverse environmental impacts on ground and surface waters in Northern Alberta, Canada. Degradation of naphthenic acids (NAs) and fluorophore organic compounds in OSPW was investigated. In a laboratory-scale UV/chlorine treatment, the NAs degradation was clearly structure-dependent and hydroxyl radical-based. In terms of the NAs degradation rate, the raw OSPW (pH ∼ 8.3) rates were higher than those at an alkaline condition (pH = 10). Under actual sunlight, direct solar photolysis partially degraded fluorophore organic compounds, as indicated by the qualitative synchronous fluorescence spectra (SFS) of the OSPW, but did not impact NAs degradation. The solar/chlorine process effectively removed NAs (75-84% removal) and fluorophore organic compounds in OSPW in the presence of 200 or 300 mg L(-1) OCl(-). The acute toxicity of OSPW toward Vibrio fischeri was reduced after the solar/chlorine treatment. However, the OSPW toxicity toward goldfish primary kidney macrophages after solar/chlorine treatment showed no obvious toxicity reduction versus that of untreated OSPW, which warrants further study for process optimization.

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The occurrence of a variety of contaminants of emerging concerns (CECs) such as hormones and pharmaceuticals in municipal wastewater is an ongoing concern. In this study, UV/hydrogen peroxide (H 2 O 2 ) was applied to treat the secondary effluent from Gold Bar Wastewater Water Treatment Plant in Edmonton, Alberta, Canada. Bench-scale tests were conducted to investigate the direct UV photolysis and UV/H 2 O 2 oxidation of nine selected model micropollutants. The quantum yields at pH 7 were found to be between 0.0010 and 0.13. To investigate the effect of the water matrices, the degradation rate constants for 2,4-D and carbamazepine were determined in MilliQ water and wastewater. Overall, the estimated rates were higher in MilliQ water than those estimated in actual wastewater samples with differences of 34 and 37% for 2,4-D and carbamazepine, respectively. Differences in the pseudo first-order rate constants could be attributed to the matrix effects of the wastewater. The pilot-scale UV/H2O2 process did not appear to be able to remediate acute estrogenic activities in the reuse water to goldfish, whereas it had the potential to minimize the estrogenic effects of the reuse water in chronic exposures.