Research on Coagulation/Sedimentation Process for Simulation of Fluorine-Containing Wastewater Treatment

Over discharge of fluoride will cause the environment pollution and human harm. Experiments were performed with the simulated fluoride wastewater to study the removal of fluoride. The effects on the residual fluoride concentration were investigated using lime-sedimentation and coagulation/sedimentation. The results showed that the fluoride contents were among 30mg/L-50mg/L, with lime alone. The fluoride concentration decresde to 30mg/L-40mg/L, using the combination of Ca(OH)2+PAM. The residual fluoride concentrations of 600mg/L, 900mg/L, 1200mg/L fluoride wastewater remained below 10mg/L by the combination of Ca(OH)2+PAM+PAC. It suggested PAM and PAC has an important increase effect on the fluoride removal. The suitable conditions for defluoridation with Ca(OH)2+PAM+PAC: PAC was 0.2mL, fluoride-calcium ratio was 2:1.1.