曝气生物滤池用于电镀废水深度处理的研究

Advanced Treatment of Electroplating Wastewater by Biological Aerated Filter

广东省清远市某电镀工业园排放的废水水质复杂,且水量不断增加,较原设计值超出很多,导致处理后的出水水质达不到相关标准的要求。为此,采用曝气生物滤池(BAF)工艺对现有设施出水进行深度处理。试验结果表明,当气水比为5:1、BAF的有效容积为3 L时,最佳的进水流量为2 L/h,即水力停留时间为1.5 h。在此条件下,对CN-的去除率达到80%左右,对COD的去除率稳定在60%左右,当进水CN-浓度≤1.5 mg/L、COD≤200 mg/L时,均可保证出水水质达到《电镀污染物排放标准》(GB 21900—2008)。在小试的基础上于现有工艺后增加了2组BAF,工程正常运行2个月以来处理效果稳定,对COD和CN-的平均去除率分别达到50%和75%,废水处理成本仅约为0.3元/m3。可见,该工艺在电镀废水处理中具有非常广阔的应用前景。

Quality of electroplating wastewater from industrial park in Qingyuan City, Guangdong Province is complex, and wastewater quantity increases continuously, which is more than the original design value, resulting in the effluent quality can not meet the discharge standards. The biological aerated filter （BAF） process was applied in advanced treatment of electroplating wastewater. The results show that when the ratio of air to water is 5 ： 1 and the working volume of the reactor is 3 L, the optimum in- fluent flow rate is 2 L/h namely the hydraulic retention time （HRT） of BAF is 1.5 h. Under the condi- tions of that HRT, the removal rates of CN- and COD are more than 80% and about 60% respectively. When the influent concentrations of CN- and COD are equal to or less than 1.5 mg/L and 200 mg/L re- spectively, the effluent quality can reach the Emission Standard of Pollutants for Electroplating （GB 21900- 2008）. Based on the small-scale test, two sets of BAF are added after the existing process. Since the BAF system is put into ogeration for 2 months, it has stable treatment effect of the electroplating wastewater. The average removal ：：ates of COD and CN- are 50% and 75% respectively. The cost of wastewater treatment is about 0.3 yuan/m3. The BAF system has very wide application prospect in the treatment of the electroplating wastewater.