Importance of suspended sediment (SPS) composition and grain size in the bioavailability of SPS-associated pyrene to Daphnia magna.
Hydrophobic organic compounds (HOCs) tend to associate with suspended sediment (SPS) in aquatic environments; the composition and grain size of SPS will affect the bioavailability of SPS-associated HOCs. However, the bioavailability of HOCs sorbed on SPS with different compositions and grain sizes is not well understood. In this work, passive dosing devices were made to control the freely dissolved concentration of pyrene, a typical HOC, in the exposure systems. The effect of pyrene associated with amorphous organic carbon (AOC), black carbon (BC), and minerals of SPS with grain sizes of 0-50 μm and 50-100 μm on the immobilization and enzymatic activities of Daphnia magna was investigated to quantify the bioavailability of pyrene sorbed on SPS with different grain sizes and compositions. The results showed that the contribution of AOC-, BC-, and mineral-associated pyrene to the total bioavailability of SPS-associated pyrene was approximately 50%-60%, 10%-29%, and 20%-30%, respectively. The bioavailable fraction of pyrene sorbed on the three components of SPS was ordered as AOC (22.4%-67.3%) > minerals (20.1%-46.0%) > BC (9.11%-16.8%), and the bioavailable fraction sorbed on SPS of 50-100 μm grain size was higher than those of 0-50 μm grain size. This is because the SPS grain size will affect the ingestion of SPS and the SPS composition will affect the desorption of SPS-associated pyrene in Daphnia magna. According to the results obtained in this study, a model has been developed to calculate the bioavailability of HOCs to aquatic organisms in natural waters considering both SPS grain size and composition.
School of Environment, Beijing Normal University, State Key Laboratory of Water Environment Simulation, Key Laboratory of Water and Sediment Sciences of Ministry of Education, Beijing 100875, China. Electronic address: xiaxh@bnu.edu.cn.
Xinghui
X
Xia
Hubei Provincial Center for Disease Control and Prevention, Wuhan 430079, China.
Xiaotian
X
Zhang
School of Environment, Beijing Normal University, State Key Laboratory of Water Environment Simulation, Key Laboratory of Water and Sediment Sciences of Ministry of Education, Beijing 100875, China.
Dong
D
Zhou
Department of Biotechnology, Delft University of Technology, Delft 2624BC, Netherlands.
Yimeng
Y
Bao
School of Environment, Beijing Normal University, State Key Laboratory of Water Environment Simulation, Key Laboratory of Water and Sediment Sciences of Ministry of Education, Beijing 100875, China.
Husheng
H
Li
School of Environment, Beijing Normal University, State Key Laboratory of Water Environment Simulation, Key Laboratory of Water and Sediment Sciences of Ministry of Education, Beijing 100875, China.
Yawei
Y
Zhai
D000818:Animals; D001682:Biological Availability; D002244:Carbon / Q000737:chemistry; D003621:Daphnia / Q000737:chemistry / Q000378:metabolism*; D019015:Geologic Sediments / Q000737:chemistry*; D010316:Particle Size; D011721:Pyrenes / Q000493:pharmacokinetics*; D014874:Water Pollutants, Chemical / Q000032:analysis
D011721:Pyrenes; D014874:Water Pollutants, Chemical; D002244:Carbon; C030984:pyrene
BC; Bioavailability; Freely dissolved concentration; Organic carbon; Passive dosing device; Suspended sediment