【摘要】：為研究硫酸鹽對重金屬形態(tài)分布的影響規(guī)律,評價不同條件下的重金屬生態(tài)風險,采集廣東清遠某電子垃圾拆解區(qū)附近河流底泥,通過投加不同濃度硫酸鹽,采用BCR四步提取法分析厭氧培養(yǎng)28 d期間銅、鉛、鋅、鎘的形態(tài)變化。結(jié)果表明:滅菌條件下,重金屬的形態(tài)基本保持不變;在空白條件下Cu、Pb、Zn和Cd 4種重金屬由不穩(wěn)定態(tài)向穩(wěn)定態(tài)轉(zhuǎn)化,其轉(zhuǎn)化率分別是7%、5%、11%和5%,鋅的變化最明顯;與空白相比,硫酸鹽的投加會加大這4種重金屬的轉(zhuǎn)化,其影響順序為:CuCdZnPb。硫酸鹽的投加可促進硫酸鹽還原菌的生長,當硫酸鹽濃度在286~655 mg·kg-1范圍時,硫酸鹽還原菌的數(shù)量隨著硫酸鹽濃度升高而增加。實驗運行到后期,高濃度的H2S會對硫酸鹽還原菌產(chǎn)生毒害作用,因此重金屬的形態(tài)并不會一直向穩(wěn)定態(tài)轉(zhuǎn)化,研究結(jié)果表明,高濃度硫酸鹽條件可降低重金屬的遷移能力,有利于重金屬污染場地的修復。
[Abstract]:In order to study the effect of sulfate on the distribution of heavy metal forms and evaluate the ecological risk of heavy metals under different conditions, the river sediment near an electronic waste dismantling area in Qingyuan, Guangdong Province was collected and the morphological changes of copper, lead, zinc and cadmium were analyzed by BCR four-step extraction with different concentrations of sulfate. The results showed that the morphology of heavy metals remained basically unchanged under sterilization conditions, and the conversion rates of Cu,Pb,Zn and Cd were 7%, 5%, 11% and 5%, respectively, and the change of zinc was the most obvious under the blank condition. Compared with the blank, the addition of sulfate would increase the transformation of these four heavy metals, and the influence order was as follows: CuCdZnPb. The addition of sulfate can promote the growth of sulfate-reducing bacteria. When the sulfate concentration is in the range of 286 鈮，

本文編號：2498398