酸法地浸采铀退役采区地下水二步修复法研究

酸法地浸采铀退役采区地下水具有酸性强、铀及SO42-浓度超标的特性，其修复是亟待研究解决的问题。本文以西北某地浸采铀退役采区地下水为研究对象，先采用CaO中和法去除其中的铀；再采用厌氧脱硫脱硫弧菌微生物膜反应器去除SO42-，并探究碳源与进水流速对去除中和处理后的地下水中的SO42-的影响。试验结果表明：每升地下水经0.167 g CaO中和处理后，pH值由3.0升至7.0左右，铀浓度从最初的0.4 mg/L降至0.04 mg/L，达到了排放标准，SO42-浓度从1349.2 mg/L降至840.3 mg/L；中和处理后的地下水经脱硫脱硫弧菌微生物膜反应器处理，当进水流速为1.0 mL/min、碳源为葡萄糖时，SO42-浓度从840.3 mg/L降至256 mg/L，也达到了排放标准。本项研究表明，先采用CaO中和法去除铀、再采用厌氧脱硫脱硫弧菌微生物膜反应器去除SO42-的二步修复法在酸法地浸采铀退役采区地下水处理中具有潜在应用前景。

A study on the two step remediation approach for groundwater in the decommissioned mining field of acid in situ leach uranium mining

Groundwater in the decommissioned mining field of acid-based in-situ leaching of uranium has such characteristics as strong acidity and excessive uranium and SO42- concentrations, and its remediation is an urgent problem to be studied and solved. In this paper, the groundwater in the decommissioned mining field of an acid in situ leach uranium mine in northwestern China was taken as the research object, and the CaO neutralization method was firstly applied for the removal of uranium. After that, an anaerobic Desulfovibrio desulfuricans microbial membrane reactor was constructed, and the effects of carbon source and influent flow rate on the removal of SO42- in the neutralized groundwater were explored. The results showed that after neutralization with 0.167 g CaO, the pH value of each liter of groundwater was raised from original 3.0 to 7.0, the uranium concentration was decreased from original 0.4 mg/L to 0.04 mg/L, which met the standard for discharge, and the SO42- concentration was decreased from original 1349.2 mg/L to 840.3 mg/L. The neutralized groundwater was then treated by the constructed Desulfovibrio desulfuricans microbial membrane reactor, and when the carbon source was glucose and the influent flow rate was 1.0 mL/min, the SO42- concentration was decreased from 840.3 mg/L to 256 mg/L, which also met the standard for discharge. This study shows that the two step remediation approach, in which uranium was firstly removed using CaO neutralization method and the SO42- was then removed by anaerobic Desulfovibrio desulfuricans microbial membrane reactor, has a potential application prospect in the treatment of groundwater in the decommissioning mining field of acid in situ leach uranium mining.