Efficiency Study on VAE Emulsion Wastewater Treatment with Ferric Chloride by Coagulation-Flotation Process

To obtain an effective treatment process for VAE emulsion wastewater,coagulation-flotation is used.Influences of hydraulic condition,pH value,coagulant dosage and raw water quality on treatment efficiencies are investigated.Resultsindicate that coagulation-flotation with ferric chloride is an effective treatment process for VAE emulsion wastewater.The treatment efficiency is influenced by hydraulic condition,pH value,coagulant dosage,raw water quality and other factors.The optimum conditions are 350 r/min of mixing intensity,8 min of mixing time,50% of reflux ratio,and 7-9 of pH value.Under the best experimental condition,turbidity and COD of raw water decreases to 26.89 NTU from 2 653 NTU,and 64.71 mg/L from 3 085 mg/L.The removal rate of which can reach 99% and 97.5% respectively,when ferric chloride dosage is 175 mg/L.The effluent quality can satisfy the second level discharge standard specified in the Integrated Wastewater Discharge Standard(GB 8978-96).The experiment results can provide a technology reference for the engineering application.