Pilot-scale UV/H2O2 advanced oxidation process for municipal reuse water: Assessing micropollutant degradation and estrogenic impacts on goldfish (Carassius auratus L.). (15th September 2016)

• Record Type: Journal Article
• Authors: Shu, Zengquan; Singh, Arvinder; Klamerth, Nikolaus; McPhedran, Kerry; Bolton, James R.; Belosevic, Miodrag; Gamal El-Din, Mohamed
• Is Part Of: Water research. Volume 101(2016)
• Page Start: 157
• Page End: 166
• Publication Date: 2016-09-15
• Subjects: Micropollutants -- Endocrine disruption -- Estrogen receptors -- Aromatase -- Pilot-scale UV/H2O2 process -- Fluence-based degradation rate constant; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2016.05.079
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Low concentrations (ng/L- μ g/L) of emerging micropollutant contaminants in municipal wastewater treatment plant effluents affect the possibility to reuse these waters. Many of those micropollutants elicit endocrine disrupting effects in aquatic organisms resulting in an alteration of the endocrine system. A potential candidate for tertiary municipal wastewater treatment of these micropollutants is ultraviolet (UV)/hydrogen peroxide (H2 O2 ) as an advanced oxidation process (AOP) which was currently applied to treat the secondary effluent of the Gold Bar Wastewater Treatment Plant (GBWWTP) in Edmonton, AB, Canada. A new approach is presented to predict the fluence-based degradation rate constants ( k f ′) of environmentally occurring micropollutants including carbamazepine [(0.87–1.39) × 10 −3 cm 2 /mJ] and 2, 4-Dichlorophenoxyacetic acid (2, 4-D) [(0.60–0.91) × 10 −3 cm 2 /mJ for 2, 4-D] in a medium pressure (MP) UV/H2 O2 system based on a previous bench-scale investigation. Rather than using removal rates, this approach can be used to estimate the performance of the MP UV/H2 O2 process for degrading trace contaminants of concern found in municipal wastewater. In addition to the ability to track contaminant removal/degradation, evaluation of the MP UV/H2 O2 process was also accomplished by identifying critical ecotoxicological endpoints (i.e., estrogenicity) of the treated wastewater. Using quantitative PCR, mRNA levels of estrogen-responsive (ER) genes ERα1, ERα2, ERβ1, ERβ2 and NPR as well as two aromatase encoding genes (CYP19a and CYP19b) in goldfish ( Carassius auratus L.) were measured during exposure to the GBWWTP effluent before and after MP UV/H2 O2 treatment (a fluence of 1000 mJ/cm 2 and 20 mg/L of H2 O2 ) in spring, summer and fall. Elevated expression of estrogen-responsive genes in goldfish exposed to UV/H2 O2 treated effluent (a 7-day exposure) suggested that the UV/H2 O2 process may induce acute estrogenic disruption to goldfish principally because of the possible formation of various oxidation by-products. However, prolonged exposure of goldfish (60 days) in UV/H2 O2 treated effluent showed a restoration trend of ER gene expressions, especially in the summer. Collectively, our findings provide valuable indications regarding the long-term in vivo assessment of the MP UV/H2 O2 process for removing/degrading endocrine disrupting compounds detected in the municipal wastewater effluents. Graphical abstract: Highlights: UV/H2 O2 treatment of 2, 4-Dichlorophenoxyacetic acid and carbamazepine assessed for reuse water. Bench-scale fluence-based degradation rate constants determined. Fluence-based approach allows for comparisons between treatment processes. Pilot-scale investigation of estrogenic responses of goldfish after treatment. Prolonged exposure to UV/H2 O2 treated water led to restored estrogen gene response.