Occurrence and removal of benzotriazoles and ultraviolet filters in a municipal wastewater treatment plant

We investigated the occurrence and removal of four benzotriazoles (BTs) (benzotriazole: BT: 5-methylbenzotriazole: 5-TTri; 5-chloro-benzotriazole: CBT; 5,6-dimethyl-benzotriazole: XTri) and six UV filters (benzophenone-3: BP-3; 3-(4-methylbenzylidene)camphor: 4-MBC; octyl 4-methoxycinnamate: OMC; 2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5-chloro benzotriazole: UV-326; 2-(2'-Hydroxy-5'-octylphenyl)-benzotriazole: UV-329; octocrylene: OC) in a full scale municipal wastewater treatment in South Australia. BT, 5-TTri and BP-3 were found as the dominant compounds detected in the wastewater samples with average concentrations up to 5706 +/- 928 ng/L, 6758 +/- 1438 ng/L and 2086 +/- 1027 ng/L in influent, and up to 2439 +/- 233 ng/L, 610 +/- 237 ng/L and 153 +/- 121 ng/L in effluent, respectively. In the biosolid, 4-MBC and OC were found with the highest concentrations of 962 +/- 135 ng/g and 465 +/- 65 ng/g, respectively. Sorption onto sludge played a dominant role in the removal for UV filters, especially for 4-MBC, UV-326 and OC, which accounted for 54%-92% of influent loads, while biological degradation played a significant role for the other compounds. (C) 2011 Elsevier Ltd. All rights reserved.