反硝化细菌生物反应器去除地浸采铀矿山退役采区地下水中NO3--N的试验研究

摘要

地浸采铀矿山退役采区地下水的NO3--N污染是一备受关注的问题。本文通过对取自某地浸采铀矿山退役采区的污泥进行驯化，得到了能去除地浸采铀矿山退役采区污染地下水中NO3--N的反硝化细菌，自行设计了上流式固定床反硝化细菌生物反应器，研究了 pH 值、C/N 比和水力停留时间（HRT ）对反硝化细菌生物反应器去除地浸采铀矿山退役采区污染地下水中NO3--N的影响。研究结果表明：当进液pH值为6.50、NO3--N浓度为1000 mg/L、HRT 为2.3 h时，NO3--N的去除率和去除速率分别达97％和388 mg/（h · L ），生物反应器处理废水的能力达0.35 m3/（h · m3）；当进液NO3--N浓度为550 mg/L、HRT为1.4 h时，NO3--N的去除率和去除速率分别达96％和368 mg/（h · L ），生物反应器处理废水的能力达0.62 m3/（h · m3）；反硝化细菌生物反应器适宜的运行条件是p H值为5.00～8.00，C/N比为0.6～0.8。%The pollution of groundwater by NO3- in the decommissioned mining area in an in-situ leach uranium mine is being paid more and more attention .The denitrifying bacteria by domesticating the sludge taken from the decommissioned mining area in an in-situ leach uranium mine in North West of China were obtained .An up-flow fixed-bed denitrifying bacteria bioreactor was designed .The effects of pH ,the ratio of carbon to nitrogen and HRT on the removal of NO3--N from the polluted groundwater in the decommissioned mining area in the in-situ leach uranium mine by the denitrifying bacteria bioreactor were investigated .The results show that when pH ,the concentration of NO3--N and HRT are set to 6.50 ,1 000 mg/L and 2.3 h ,respectively ,the removal of the NO3--N amounts to 97% ,the NO3--N degradation rate is 388 mg/(h · L) and the capacity of the bioreactor is 0.35 m3/(h · m3 ) .When pH ,the concentration of NO3--N and HRT are set to 6.50 ,550 mg/L and 1.4 h ,respectively ,the removal of the NO3--N amounts to 96% and the capacity of the bioreactor is 0.62 m3/(h · m3 ) .T he bioreactor should work on the operation conditions that pH is 5.00-8.00 and the ratio of carbon to nitrogen is 0.6-0.8 .