Bioavailability of Pyrene Associated with Suspended Sediment of Different Grain Sizes to Daphnia magna as Investigated by Passive Dosing Devices

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• 作者：Xiaotian Zhang ; Xinghui Xia ; Husheng Li ; Baotong Zhu ; Jianwei Dong
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：August 18, 2015
• 年：2015
• 卷：49
• 期：16
• 页码：10127-10135
• 全文大小：462K
• ISSN：1520-5851

文摘

Suspended sediment (SPS) is widely present in rivers around the world. However, the bioavailability of hydrophobic organic compounds (HOCs) associated with SPS is not well understood. In this work, the influence of SPS grain size on the bioavailability of SPS-associated pyrene to Daphnia magna was studied using a passive dosing device, which maintained a constant freely dissolved pyrene concentration (C_free) in the exposure systems. The immobilization and protein as well as enzymatic activities of Daphnia magna were investigated to study the bioavailability of SPS-associated pyrene. With C_free of pyrene ranging from 20.0 to 60.0 渭g L^鈥?, the immobilization of Daphnia magna in the presence of 1 g L^鈥? SPS was 1.11鈥?.89 times that in the absence of SPS. The immobilization caused by pyrene associated with different grain size SPS was on the order of 50鈥?00 渭m > 0鈥?0 渭m > 100鈥?50 渭m. When pyrene C_free was 20.0 渭g L^鈥?, the immobilization caused by pyrene associated with 50鈥?00 渭m SPS was 1.42 and 2.43 times that with 0鈥?0 and 100鈥?50 渭m SPS, respectively. The protein and enzymatic activities of Daphnia magna also varied with the SPS grain size. The effect of SPS grain size on the bioavailability of SPS-associated pyrene was mainly due to the difference in SPS ingestion by Daphnia magna and SPS composition, especially the organic carbon type, among the three size fractions. This study suggests that not only the concentration but also the size distribution of SPS should be considered for the development of a biological effect database and establishment of water quality criteria for HOCs in natural waters.