半导体行业废水处理工程实例与效果分析

An engineering project for semiconductor industry wastewater treatment

半导体行业废水水质复杂,携带大量重金属、有毒氰化物、氟化物、氮、磷等污染物,同时具有可生化性差、C/N低的特点,难以直接采用生物方法处理。某高新技术产业园区污水处理厂采用“格栅+曝气沉砂池+高效沉淀池+改良型A^(2)/O+MBR+接触消毒池”的处理工艺,探究了该工艺实际运行5个月期间的进出水水质变化情况。运行结果表明,该处理工艺对进水中污染物均具有较好的去除效果,运行期间出水悬浮物、COD、NH_(4)^(+)-N、TN、TP和氟化物等污染物分别维持在4、26、1、8、0.1、1.5 mg/L以下,始终满足《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A类标准。此外,水处理电费约0.536元/m^(3),药剂费用约0.220元/m^(3),直接运行成本约0.756元/m^(3)。

The semiconductor industry wastewater is complex due to it contains large amount of pollutants such as heavy metals,toxic cyanide,fluoride,nitrogen,and phosphorus,etc.Meanwhile,the poor biodegradability and low C/N makes it difficult to directly use biological methods for treatment.The sewage treatment plant in a certain hightech industrial park adopts the treatment process of“grille+aeration sedimentation tank+high-efficiency sedimenta⁃tion tank+advanced A^(2)/O+MBR+disinfection tank”.The changes of influent and effluent water quality during the ac⁃tual operation for 5 months were explored.The results showed that the treatment process had a good removal effect on pollutants.During operation,pollutants such as suspended solids,COD,NH_(4)^(+)-N,TN,TP,and fluoride in effluent were maintained below 4,26,1,8,0.1,and 1.5 mg/L,respectively,which always met the first level class A stan⁃dards of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002).In addition,the electricity cost of water treatment was about 0.536 yuan/m^(3),the chemicals cost was about 0.220 yuan/m^(3),and the direct operating cost was about 0.756 yuan/m^(3).