改良电絮凝法处理综合电镀废水重金属

Treatment of Heavy Metals in Comprehensive Electroplating Wastewater by Modified Electroflocculation

电镀废水是重金属污染物污染环境的主要来源之一,某电镀园区污水处理厂采用传统的以Fenton为主体的组合工艺对电镀废水进行处理,在运行过程中出水水质偶有超标现象,且运行过程中产泥量较高,处理成本也随之提高。文章采用改良电絮凝法对某电镀园区污水处理厂综合电镀废水进行处理,经小试试验确定最优电絮凝工艺运行参数后进行中试研究。结果表明,初始反应pH值为3、电流密度为75A/m^(2)、反应停留时间为2h、倒极时间为10min、30%H_(2)O_(2)投加量为0.3g/L条件下,中试试验出水能稳定达到后期生化进水的要求。进水总镍质量浓度为12.200~18.100mg/L,出水总镍质量浓度为0.043~0.096mg/L,进水总铜质量浓度为4.100~6.800mg/L,出水总铜质量浓度为0.059~0.120mg/L,进水总铬质量浓度为5.200~7.500mg/L,出水总铬质量浓度为0.022~0.081mg/L。同时,与原有工艺对比,该工艺运行成本大大降低,并具有良好的应用前景。研究所得到的相关中试研究成果为后续改良电絮凝法工程化提供了技术支持,也为电镀废水处理提供其他经济有效的处理方法。

Electroplating wastewater is one of the main sources of heavy metal pollution to the environment.A wastewater treatment plant(WWTP)in an electroplating park uses the traditional Fenton composite process to treat electroplating wastewater,which occasionally exceeds the standard in the operation process,and the amount of sludge produced in the operation process is high,and the treatment cost also increases.The modified electrocoagulation method was used to study the comprehensive electroplating wastewater from a WWTP in an electroplating park.The pilot test was conducted after the optimal operation parameters of the electrocoagulation process in lab test.Results showed that the initial reaction pH value was 3,the current density was 75 A/m^(2),the reaction retention time was 2 h,the reversal time was 10 min,and the dosage of 30%hydrogen peroxide was 0.3 g/L.Under this condition,the pilot test showed that the water could stably meet the requirements of biochemical water inflow in the later stage.Total nickel in influent and effluent were 12.200~18.100 mg/L and 0.043~-0.096 mg/L,total copper in influent and effluent were 4.100~6.800 mg/L and 0.059~0.120 mg/L,total chromium in influent and effluent were 5.200~7.500 mg/L and 0.022~0.081 mg/L.At the same time,compared with the original process,the operation cost was reduced and had a good application prospect.The pilot study results obtained in this study provides technical support for the subsequent engineering of improved electrocoagulation,as well as other cost-effective treatment methods for electroplating wastewater treatment.