部分亚硝化工艺处理稀土尾水应用研究

Application of partial nitrification process in treating rare earth wastewater

离子型稀土在开采过程及开采后的一定时段内会从矿床中渗滤出大量含氨尾水,对流域水环境造成严重污染。离子型稀土尾水具有高氨氮、低COD、低pH的特点,在部分亚硝化-厌氧氨氧化(partial nitritation-anammox,PN/A)工艺处理尾水的中试中,以机械搅拌澄清池作为部分亚硝化反应器,采用序批式运行确定工艺运行工况条件,通过连续进水模式进行参数验证。验证结果表明,在pH为8.1~8.8的条件下,DO为0.5~0.3mg/L时,氨氮转化率为50%~60%、亚硝酸盐积累率>85%,出水中亚硝酸盐与氮氨氮的比值为1~1.5,基本满足后续厌氧氨氧化单元的需求。

Ionic rare earth will leach a large amount of ammonia containing wastewater from the deposit during and after mining,causing serious pollution to the water environment of the basin.Ionic rare earth wastewater has the characteristics of high ammonia nitrogen,low COD and low pH.In the pilot test of wastewater treatment by partial nitrification anammox(PN/A)process,the mechanical stirring clarifier was used as a partial nitrification reactor,the process operation conditions were determined by sequential batch operation,and the parameters were verified by continuous influent mode.The verification results show that when pH is 8.1~8.8 and DO is 0.5~0.3 mg/L,the ammonia nitrogen removal rate is 50%~60%,the nitrite accumulation rate is more than(>)85%,and the ratio of nitrite nitrogen and ammonia nitrogen in effluent is 1~1.5,which basically meets the needs of subsequent anaerobic ammonia oxidation units.