Effects of Carbon Nanotubes, Chars, and Ash on Bioaccumulation of Perfluorochemicals by Chironomus plumosus Larvae in Sediment
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- 作者：Xinghui Xia ; Xi Chen ; Xiuli Zhao ; Huiting Chen ; Mohai Shen
- 刊名：Environmental Science & Technology (ES&T)
- 出版年：2012
- 出版时间：November 20, 2012
- 年：2012
- 卷：46
- 期：22
- 页码：12467-12475
- 全文大小：328K
- 年卷期：v.46,no.22(November 20, 2012)
- ISSN：1520-5851
文摘
This study examined the effect of five types of carbonaceous materials (CMs) in sediment on bioaccumulation of perfluorochemicals (PFCs) by Chironomus plumosus larvae. The CMs included two multiwalled carbon nanotubes (MWCNT10 and MWCNT50), maize straw- and willow-derived chars, and maize straw-origin ash. The PFCs included perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA). The CMs with different concentrations (0鈥?.5% dry weight) were amended into sediments spiked with PFCs and aged for 60 d. The uptake rate constants (ks) for each PFC to larvae differed with different CM amendments (p < 0.05), while elimination rate did not change significantly (p > 0.05). Decreasing PFC concentration in larvae (CB) was found with increasing CM concentration (fCM) in the sediments, and a linear positive correlation existed between 1/CB and fCM (p < 0.05). The effect of CMs on PFC bioaccumulation agreed well with the CM properties; MWCNT10 with the highest specific surface area resulted in the lowest ks values and biota鈥搒ediment accumulation factors (BSAF), with a BSAF reduction of 66%鈥?7% by a 1.5% amendment. The mechanism was explored by analyzing the aqueous phase concentrations of PFCs and the sorption of PFCs on sediments amended with CMs. The results suggested that the decreasing trend of PFCs in larvae was caused by the decreasing aqueous phase concentration with increasing CM concentration. In the studied conditions with low PFC concentrations, the bioaccumulation of PFCs was a linear partitioning between pore water and biota, and the sorption of PFCs to the sediment/CM mixtures was a two domain linear distribution. This study suggests that both the type and concentration of carbonaceous materials in sediment can affect the bioaccumulation of PFCs to benthic organisms through changing their aqueous phase concentrations.