title: Removal of parabens and their chlorinated by-products by periphyton: influence of light and temperature.
abstract: The extensive use of parabens as preservatives in food and pharmaceuticals and personal care products results in frequent detection of their residuals in aquatic environment. In this work, the adsorption and removal of four parabens (methyl-, ethyl-, propyl-, and butyl-paraben) and two chlorinated methyl-parabens (CMPs) by periphyton were studied. Characteristics of the periphyton were identified to explore the possible relationship between paraben removal and periphyton properties. Results showed that linear adsorption coefficients (Kd) vary from 554.4 to 808.6 L kg-1for the adsorption parabens and CMPs to autoclaved periphyton. The adsorption strength is positively related to the hydrophobicity of these compounds. Removal of parabens from water by periphyton was efficient with half-life (t1/2) values estimated using first-order kinetic model ranging from 0.49 to 3.29 days, but CMPs were more persistent with t1/2ranging from 1.15 to 25.57 days, and t1/2increased with the chlorination degree. Higher incubation temperature accelerated the removal of all tested compounds, while a better removal of CMPs was observed in dark condition. Analysis of periphyton properties suggests that bacteria played a more important role in the removal of CMPs, but no specific relationship between periphyton properties and paraben removal ability can be established.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road No. 7, Wuhan, 430072, People's Republic of China.|Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, 430223, China.
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Song
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road No. 7, Wuhan, 430072, People's Republic of China.
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road No. 7, Wuhan, 430072, People's Republic of China.
authors.forename: Hongyi
authors.initials: H
authors.lastname: Ao
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, Nanjing, 210008, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road No. 7, Wuhan, 430072, People's Republic of China. chenxi.wu@ihb.ac.cn.
authors.forename: Chenxi
authors.identifier: http://orcid.org/0000-0002-2908-9841
authors.initials: C
authors.lastname: Wu
mesh_terms: D000327:Adsorption; D006207:Half-Life; D054879:Halogenation; D008027:Light; D010226:Parabens; D013696:Temperature; D014873:Water Pollutants; D018508:Water Purification / Q000379:methods*
chemical_list: D010226:Parabens; D014873:Water Pollutants; C015358:methylparaben
keywords: Aquatic ecosystem; Carbon source utilization; Dissipation; Metabolites; Microbial community; Preservatives