电脱盐污水的预处理方法

以聚合氯化铝(PAC)为混凝剂,当电脱盐污水pH值为7.8~8.4,固体悬浮物、石油类物质和化学需氧量(CODCr)质量浓度依次为150~2400,90~1000,800~4300 mg/L时,分别采用混凝沉淀工艺和混凝沉淀-催化氧化组合工艺对其进行预处理。结果表明:采用前者,在PAC体积浓度为5 mL/L,反应温度为50℃,沉淀时间为60 min的最佳条件下,处理后污水CODCr和石油类物质质量浓度分别为441,51.1 mg/L,满足HJ 2045-2014要求;采用组合工艺,在上述条件下,对混凝后电脱盐污水进行催化氧化处理,当双氧水体积浓度为3 mL/L,硫酸亚铁质量浓度为0.9 g/L时,处理后的电脱盐污水上述各值分别降至122,14.1 mg/L。

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The electric desalting sewage with pH value of 7.8-8.4 and mass concentrations of suspended solids,petroleum substances and chemi-cal oxygen demand(CODCr)of 150-2400,90-1000,800-4300 mg/L respectively,was pretrea-ted by the coagulating sedimentation process and co-agulating sedimentation-catalytic oxidization com-bined process with polyaluminumchloride(PAC)as coagulant.The results showed that after treating by the former process,the mass concentration of CODCr and petroleum substances in the treated sewage was 441,51.1 mg/L respectively under the optimum conditions of PAC volume concentration of 5 mL/L,reaction temperature of 50℃and precipitation time of 60 min,which could meet the requirements of HJ 2045—2014.Using the combined process,the electric desalting sewage after coagulation was trea-ted by the catalytic oxidization method when the vol-ume concentration of hydrogen peroxide was 3 mL/L and the mass concentration of ferrous sulfate was 0.9 g/L,the above values of the treated electric desalting sewage reduced to 122,14.1 mg/L respec-tively.