K_(2)FeO_(4)-PAC联用混凝处理低浓度含氟有机废水的研究

Research on treatment of low concentration fluoride-containing organic wastewater by potassium ferrate-PAC coagulation

以太阳能光伏企业生产废水一级钙盐沉淀后出水为研究对象,配制模拟水样,F-质量浓度为30 mg/L,异丙醇质量浓度为94.36 mg/L(TOC值56.56 mg/L),采用高铁酸钾(K_(2)FeO_(4))-聚合氯化铝(PAC)联用混凝沉淀法对水样进行处理.分别考察了单独使用K_(2)FeO_(4)及与PAC联合使用时药剂投加量等因素对F-和有机物去除效果的影响.结果 表明,K_(2)FeO_(4)和PAC具有协同絮凝作用,且K_(2)FeO_(4)能改善絮体结构,二者联用时可有效提高污染物去除率,其中pH是较为关键的影响因素.最优实验条件下,F-和TOC去除率分别为71.13%和5.25%.同时发现,K_(2)FeO_(4)对异丙醇的矿化程度不高,使得TOC下降幅度不大.

To study the primary effluent after calcium salts precipitation during treating wastewater generated in solar photovoltaic companies,a simulated water sample is prepared with a fluoride concentration of 30 mg·L^(-1) and an isopropyl alcohol concentration of 94. 36 mg·L^(-1)(corresponding TOC value is 56. 56 mg·L^(-1)).The sample is treated by coagulating sedimentation with combination of potassium ferrate(K_(2)FeO_(4)) and poly aluminum chloride( PAC). The impact of potassium ferrate dosage and other factors on the removal of fluoride and organic matters is investigated when using potassium ferrate alone. Then the effect of PAC dosage and other factors on the results when using potassium ferrate together with PAC is investigated.Results show that there exists synergistic flocculation effect between K_(2)FeO_(4) and PAC,potassium ferrate can improve the floc structure.The combination of K_(2)FeO_(4) and PAC can improve effectively the removal rate to pollutants.Under the optimal experimental conditions,the removal rates of fluoride and TOC can reach 71.13% and 5.25% respectively,and pH is the key factor comparatively. It is also found that the mineralization degree of potassium ferrate to isopropyl alcohol is not high,which makes TOC concentration decrease little.