Study on treatment process of metallurgical fluorine-containing wastewater by coagulant sedimentation method
The excessive fluorine content in water will cause great damage to the environment.At present,coagulant sedi-mentation method is widely used to treat fluorine-containing wastewater in metallurgical industry.Therefore,in view of the many influencing factors and the lack of comprehensive evaluation of the defluorination effect in coagulant sedimentation process,the fluorine-containing wastewater produced in the production process of a steel company was studied.Orthogonal experiments were designed to investigate the effects of pH,polyaluminum chloride(PAC)dosage,polyacrylamide(PAM)dosage,PAC stirring time and PAM stirring time on the defluorination efficiency of fluorine-containing wastewater.The re-search results indicated that the primary and secondary factors affecting defluorination efficiency were as follows:pH＞PAC stirring time＞PAC dosage＞PAM stirring time＞PAM dosage.In addition,the influence of the above factors and single fac-tor changes such as temperature on the fluoride removal efficiency was studied.The results showed that defluorination effi-ciency under experimental conditions in this study was up to 99.3%when pH was 7,PAC dosage was 70 mL,PAM dosage was 2.5 mL,PAC stirring time was 15 min,PAM stirring time was 30 min,temperature was 30℃.In practical engineering applications,the total removal rate of fluoride ion by the coagulant sedimentation method was about 80%～90%,and the con-centration of fluoride ion was about 7 mg/L.The results illustrated that the coagulant sedimentation method could satisfy the fluoride discharge standard.
万方数据
维普
