稀有稀土钨冶炼氨氮废水MBR处理过程的影响因素

Study on influence factors of MBR treatment process of rare earth tungsten smelting ammonia nitrogen wastewater

以稀有稀土钨冶炼氨氮废水为研究对象,考察不同HRT、碳氮比和DO对MBR过程处理效能的影响,并通过响应曲面法对MBR系统去除NH4^+-N的运行条件进行优化。试验结果表明:COD和NH4^+-N的去除率总体上表现随HRT、DO值增加而提高,DO为2.0 mg/L时,系统表现出较好的同步硝化反硝化性能。系统对COD和NH4^+-N的去除不受碳氮比变化影响,但提高碳氮比有利于系统反硝化的进行。响应曲面分析结果表明在水力停留时间为20.51 h、碳氮比为6.88∶1和溶解氧浓度为3.25 mg/L的条件下,NH4^+-N去除率可达90.4%。

Taking rare earth tungsten smelting ammonia nitrogen wastewater as the research object,this paper studies the effects of different HRT,C/N and DO on the treatment efficiency in the MBR process,and optimizes the operating conditions of MBR system to remove NH4^+-N by response surface methodology.The test results show that the removal rate of COD and NH4^+-N generally increases with the increase of HRT and DO values.When the DO is 2.0 mg/L,the system shows good simultaneous nitrification and denitrification performance.The removal of COD and NH4^+-N by the system is not affected by the change of C/N,but increase of C/N is beneficial to the denitrification of the system.The results of response surface analysis show that the removal rate of NH4^+-N can reach 90.4%under the conditions of hydraulic retention time of 20.51 h,carbon-to-nitrogen ratio of 6.88 and dissolved oxygen concentration of 3.25 mg/L.