研究Fe0-奥奈达希瓦氏菌(Shewanella oneidensis,S.oneidensis)(MR-1)协同还原去除水相中的U(Ⅵ)时,共存金属离子Cu^(2+)、Ca2+、Mn2+和Zn2+存在时分别对U(Ⅵ)还原效果的影响。结果表明:在10.0~50.0 mg·L-1范围内,共存Ca2+和Zn2+对U(Ⅵ)的还原有一定的抑制,且影响大小与其浓度呈正相关,共存Cu^(2+)几乎完全抑制了U(VI)的还原;在Cu^(2+)浓度低于5.0 mg·L-1时,其对U(VI)的还原存在一定程度的抑制。在Fe0-S.oneidensis还原U(Ⅵ)的初期,10.0~50.0 mg·L-1的Mn2+对U(Ⅵ)的还原有抑制作用,18 h后,Mn2+对U(Ⅵ)的还原基本没有影响,且高浓度的Mn2+对U(Ⅵ)的还原有微弱的促进作用。共存金属离子对六价铀还原酶还原U(Ⅵ)的影响研究表明,Cu^(2+)、Ca2+和Zn2+对U(Ⅵ)还原酶的活性有一定的抑制作用,其中Cu^(2+)的最明显,而Mn2+对还原酶的活性有微弱的催化作用。
Microbial reduction technology using Shewanella oneidensis with Fe0 was employed to treat U (VI) in wastewater. Anaerobic experiments were conducted to evaluate the influence of the coexistent metal ions, such as Cu2+, Ca/+ , Mn2+, and Zn2+ , on the reductive removal rate of U( VI ). The results demonstrated that the reduction of U(VI) was significantly inhibited when the concentration of Cu2+ was 10.0 to 50.0 mg · L- 1. When the concentration of Cu2 + ions was less than 5.0 mg · L-1 , the reduction of U ( VI ) was only slightly inhibited. The coexistence of Ca2 + and Zn2 + showed a remarkable negative effect on U(VI) reduction, and the effect of these ions on the reduction of U ( VI ) was positively correlated with their concentration. The coexistence of Mn2 + can caused the inhibition of the U(VI) reduction in the early reaction phase at a Mn2 + concentration of 10.0 to 50.0 mg · L-1. However, little influence was found on the reduction of U(VI) when the process lasted more than 18 hours. A higher concentration of Mn2+ could promote U(VI) reduction slightly. The results of the reduction of U( VI ) with different metal ions indicate that, as a catalyst, Mn2 + has little influence on the activity of the U ( VI ) reductase, but Cu2 + , Ca2 + , and Zn2 +could inhibit the enzyme activity, with Cu2+being the most prominent in this regard.