铜矿区含低浓度NH_(4)^(+)-N、Cu^(2+)污水的处理

Treatment of wastewater containing NH_(4)^(+)-N and Cu^(2+)in copper mining area

针对铜矿区含低浓度NH_(4)^(+)-N、Cu^(2+)污水的特征,采用吸附法+曝气生物滤池(BAF)联合工艺处理此类污水。研究了改性铜渣基陶粒对模拟污水中Cu^(2+)的去除规律,考查了铜渣基陶粒填料的BAF对模拟污水吸附脱铜后液中NH_(4)^(+)-N的去除效果。结果表明:在Cu^(2+)初始浓度为50 mg/L、溶液初始pH值约为5.00,陶粒添加量20 g/L,温度35℃,时间120 min的条件下,改性陶粒对模拟污水中Cu^(2+)的吸附效果较佳,其平衡吸附量可达0.936 mg/g;在陶粒添加量为40 g/L,温度35℃条件下,对含Cu^(2+),NH_(4)^(+)-N初始浓度分别为20、100 mg/L的模拟污水进行同步吸附处理时,改性陶粒对Cu^(2+)的去除率达80%,污水中剩余Cu^(2+)的浓度仅为4.0 mg/L,但对NH_(4)^(+)-N的去除效果不明显;在水力停留时间HRT=6 h、碳氮比m(C/N)=4/1、pH=8.00左右、曝气量为1.2 L/min的较优工艺下,BAF对模拟污水脱铜后液中NH_(4)^(+)-N的去除率达96%;吸附法与BAF联合工艺可有效处理铜矿区含低浓度NH_(4)^(+)-N,Cu^(2+)污水,处理后Cu^(2+),NH_(4)^(+)-N浓度达国家排放标准要求。

In view of the characteristics of wastewater sewage containing low-concentration NH_(4)^(+)-N and Cu^(2+)in copper mining areas,amethod combined adsorption with biological aerated filter(BAF)processes was applied to for this kind of sewage treatment.The adsorption and removal of Cu^(2+)in simulated sewage by modified copper slag-based ceramsite were explored.And the removal efficiency of BAF filled with the ceramsites on NH_(4)^(+)-N in simulated wastewater after copper removed by adsorption process was investigated under different operating conditions.The results showed that under the optimum conditions of the initial concentration of Cu^(2+)in sewage being 50 mg/L,the initial pH value about 5.00,the ceramsite addition of 20 g/L,the temperature of 35℃,and the adsorption time 120 min,the modified ceramsite had a good adsorption effect on Cu^(2+)with the equilibrium adsorption capacity reaching about 0.936 mg/g.Under the conditions of the initial concentrations of Cu^(2+)and NH_(4)^(+)-N in simulated wastewater 20 and 100 mg/L,respectively,adding content of ceramsite 40 g/L,temperature 35℃,the removal rate of Cu^(2+)adsorbed by the modified ceramsite reached 80%with the rest Cu^(2+)concentration being only 4.0 mg/L,while the removal effect of the ceramsite on NH_(4)^(+)-N was not obvious.When the simulated wastewater was treated by BAF after Cu^(2+)in it was removed by the modified ceramsite,under the optimum conditions of hydraulic residence time HRT=6 h,carbon-nitrogen ratio m(C/N)=4/1,pH=8.00 and aeration rate of 1.2 L/min,the removal rate of NH_(4)^(+)-N reached 96%.The combined process of adsorption and biological aerated filter(BAF)technique could effectively treat the wastewater containing low concentration of NH_(4)^(+)-N and Cu^(2+)in copper mine area,and the rest concentrations of Cu^(2+)and NH_(4)^(+)-N in the wastewater both met the requirements of national emission standards.