某铀尾矿库渗滤液综合处理工艺研究

Study on Comprehensive Treatment of Leachate From Uranium Tailings Pond

针对含铀、锰、氨氮等多种污染物的铀尾矿库渗滤液,采用离子交换法回收铀、电絮凝除重金属和气膜回收氨氮工艺进行综合回收处理。验证了离子交换法回收铀的效果;考察了电絮凝法在不同原水pH、曝气时间和电絮凝时间等条件下,对铀、锰等重金属离子的去除效果;研究了在不同氨氮浓度下,气膜对废水中氨氮的分离效果。结果表明,树脂对铀的一级去除率可达95.7%;在不调整原水pH(pH=7.5)和不曝气的条件下,电絮凝效果较好,电絮凝5 min出水中的铀和锰质量浓度分别降至99.79μg/L和0.06 mg/L;当原水中氨氮质量浓度低于297.00 mg/L时,经过气膜一次处理对氨氮的去除率大于99%,出水氨氮质量浓度降至1.91 mg/L。该渗滤液综合处理工艺可实现铀和氨氮的回收,以及多类污染物的达标。

In view of the leachate from uranium tailings pond containing uranium,manganese,ammonia nitrogen and other pollutants,the comprehensive recovery treatment was carried out by ion exchange to recovery uranium,electroflocculation to remove the heavy metal ions and gas membrane to recover ammonia nitrogen.The effect of ion exchange method on uranium recovery was verified.The removal effect of electroflocculation on uranium,manganese and other heavy metal ions was investigated under different pH of raw water,aeration time and electroflocculation time.And the separation effect of gas membrane on ammonia nitrogen in wastewater under different ammonia nitrogen concentration was studied.The results show that the first stage removal rate of uranium by resin can reach 95.7%.The electroflocculation effect is the best when the pH of raw water(pH=7.5)is not adjusted and no aeration is performed,the concentration of uranium and manganese in the effluent can be reduce to 99.79μg/L and 0.06 mg/L,respectively,after 5 min electroflocculation.When the ammonia nitrogen concentration in raw water is lower than 297.00 mg/L,the removal rate of ammonia nitrogen in effluent after one treatment is greater than 99%,and the ammonia nitrogen concentration is reduce to 1.91 mg/L.This process can realize the recovery of uranium and ammonia nitrogen,and the concentration of other kinds of pollutants is lower than the national standard.