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Marine pollution, ecotoxicology and sustainability
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Accumulation of quaternary ammonium compounds as emerging contaminants in sediments collected from the Pearl River Estuary, China and Tokyo Bay, Japan
Monday 7th @ 1130-1150, Conference Room 7
Xi Dai* , State Key Laboratory of Marine Environmental Science, College of Oceanography & Earth Science, Xiamen University, Xiamen, China
Xiaolin Li, State Key Laboratory of Marine Environmental Science, College of Oceanography & Earth Science, Xiamen University, Xiamen, China
Cuicui Wang, State Key Laboratory of Marine Environmental Science, College of Oceanography & Earth Science, Xiamen University, Xiamen, China
James C.W. Lam, Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong SAR, China.
Nobuyoshi Yamashita, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
Eriko Yamazaki, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
Yuichi Horii, Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
Weifang Chen, State Key Laboratory of Marine Environmental Science, College of Oceanography & Earth Science, Xiamen University, Xiamen, China
Presenter Email: daixi@xmu.edu.cn |
| Relatively high concentrations of BACs and DADMACs were detected on the surface of two sedimentary cores from China and Japan, suggesting a highly quaternary ammonium compounds (QACs)-polluted status of the two countries. A sediment core was collected from the Pearl River Estuary (PRE) using a standard box corer in November 2013, while a gravity corer equipped with an inner polycarbonate tube was used to sample a sediment core from Tokyo Bay (TB) in 2012. Quantification of QACs was performed by UPLC-MS-MS using an Agilent 1290 UPLC coupled with 6490 triple quadrupole mass spectrometer. Quantification of QACs was based on the response of pure standards of nine target compounds: DADMAC10:10, DADMAC12:12, DADMAC14:14, DADMAC16:16 and DADMAC18:18, and BAC12, BAC14, BAC16 and BAC18. The vertical distribution of in two sediment cores collected from the PRE and TB were investigated to understand the historical input of QACs and their diagenetic behavior in the urban estuarine environments. The vertical distribution of BACs was found to be similar to that of DADMACs in PRE, China. Their levels increased gradually from the 1950s, with two peaks appearing in the early 1960s and 1980s. The down-core variations of BAC and DADMAC concentrations in TB initially increased and then decreased achieving the maximum concentrations in the 1970s. The declining environmental concentrations of QACs suggest a compositional change of commodities and the effectiveness of emission controls. For the individual QAC homologues, BAC homologues dropped significantly over time, while DADMAC compositions were relatively stable. DADMAC18:18 represented an average level of 61% and 87% in PRE and TB, respectively. The high levels of BACs in sediments indicate extensive commercial usage during that period, and that of DADMACs mainly suggest their excellent adsorption efficiency and poor biodegradation. Therefore, the differences of concentration and composition profiles of BACs and DADMACs in sediment cores from the PRE and TB are due to the usage patterns of QACs. These findings are useful to identify sources, transport and differential fate on current and historical contamination in the PRE and TB and to reconstruct the pollution history of QACs in Asia. |
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