Study On Treatment Of High Concentration Wastewater In Fluorine Chemical Industry

A large amount of high concentration fluorinated wastewater is produced in the process of producing fluorinated materials.In order to solve the problem of standard discharge of fluorine-containing wastewater in Changshu 3F Fluorochemical Industry Co.,Ltd.,this paper adopted chemical-coagulation precipitation method to carry out the fluorine removal test,and determined the best combination of agents and process conditions through single factor investigation experiment.The use of chemical coagulation and sedimentation method to treat industrial wastewater containing fluorine and the combination of precipitant,coagulant and coagulant AIDS can overcome the difficulties of slow sedimentation of sludge.The method has the advantages of simple equipment,simple operation and low cost.In this paper,CaC12 and CaO were used as precipitating agents to remove fluorine by chemical coagulation precipitation.The experimental results show that when CaCl2 is used as a precipitator,when the pH value of chemical precipitation process is 8,coagulation precipitation process pH value is 6.5,Ca/F is 2.4,PAC and PAM dosage are 40mL/L and 33.3ml/L respectively,the effluent fluoride ion concentration can be reduced to less than 10mg/L,reaching the first level standard of Comprehensive Sewage Discharge Standard.When CaO is used as the precipitator,when the pH value of chemical precipitation process is 6,Ca/F is 1.5,coagulation precipitation process pH value is 6,PAC and PAM dosage are respectively 33.3ml/L and 33.3ml/L,the effluent fluoride ion concentration can be reduced to less than 10mg/L,meeting the national emission standard.