铁炭微电解与硫酸盐还原菌耦合修复铀尾矿库渗滤水的研究

Remediation of percolate water from uranium tailings reservoir by coupling iron-carbon micro-electrolysis and sulfate reducing bacteria

设计了铁炭微电解-硫酸盐还原菌(Fe/C-SRB)、铝炭微电解-硫酸盐还原菌(Al/C-SRB)、炭-硫酸盐还原菌(C-SRB)、铁炭微电解(Fe/C)、铝炭微电解(Al/C)和炭(C)6个反应器,并研究了它们修复铀尾矿库渗滤水中U、Mn、Zn、SO_(4)^(2-)以及NO_(3)^(+)的效果。结果显示:经过2.5 h,Fe/C-SRB系统出水U浓度降至0.05 mg/L以下;1 d后,Mn浓度降至10 mg/L以下;1 d后,Zn浓度降至0.05 mg/L以下;10 d后,SO_(4)^(2-)浓度降至50 mg/L以下;18 d后,NO_(3)^(+)浓度降至10 mg/L以下,均达到了相关国家排放标准,并运行稳定,处理效率显著高于其他反应器。60 d时,Fe/C-SRB系统填料中具有还原U(Ⅵ)功能的微生物Desulfotomaculum、Desulfovibrio和Desulfosporosinus群落丰度总和达到61.45%,与Al/C-SRB、C-SRB、Al/C、Fe/C和C系统相比,分别高了40.35%、60.06%、57.22%、59.73%和52.46%;渗滤水中33.20%的U(Ⅵ)被微生物和铁还原成U(Ⅳ)。本研究表明Fe/C-SRB是一种具有应用前景的修复铀尾矿库渗滤水的方法。

Six reactors,including iron-carbon micro-electrolysis coupling with sulfate reducing bacteria(Fe/C-SRB),aluminum-carbon micro-electrolysis coupling with sulfate reducing bacteria(Al/C-SRB),carbon coupling with sulfate reducing bacteria(C-SRB),iron-carbon micro-electrolysis(Fe/C),aluminum-carbon micro-electrolysis(Al/C)and carbon(C),were designed to investigate their effects on the remediation of U,Mn,Zn,SO_(4)^(2-)and NO_(3)^(+) in the percolate water from the uranium tailings reservoir.The results indicated that the concentration of U in the effluent of Fe/C-SRB reactor system decreased to 0.05 mg/L after 2.5 h.The concentration of Mn decreased to 10 mg/L and the concentration of Zn decreased to 0.05 mg/L after 1 d.The concentration of SO_(4)^(2-) decreased to 50 mg/L after 10 d,and the concentration of NO_(3)^(+) decreased to 10 mg/L after 18 d,all of which satisfied with the relevant national emission standards,and operated stably.The treatment efficiency of Fe/C-SRB reactor was significantly higher than that of other reactors.The total abundance of microbial communities including Desulfotomaculum,Desulfovibrio,and Desulfosporosinus with the function of reducing U(Ⅵ)in the filler of the Fe/C-SRB reactor system reached 61.45%,which was 40.35%,60.06%,57.22%,59.73%and 52.46%higher than that of Al/C-SRB,C-SRB,Al/C,Fe/C and C reactor systems at 60 d,respectively.The 33.20%of U(Ⅵ)in the leachate was reduced to U(Ⅳ)by microorganisms and iron.The study demonstrates that Fe/C-SRB is a promising method for remediating percolation water from uranium tailings reservoir.