The Study On The Resourceful Treatment Technology Of Sorbic Acid Wastewater

The sorbic acid wastewater were formed in the process of condensation, hydrolysis, refining. The main pollutions were acetic acid, crotonaldehyde, polyvinyl and sorbic acid etc.The wastewater had high content of oganic and chlorine ions,low biologic ability. There were many studies on the treatment of sorbic acid wastewater.However,there was still some difficulty industrialization because of cost and low efficiency.Considering the present treatment and special situation of wastewater, the coagulation - evaporation - stripper - ultrasound combined with Fenton reagent oxidation process were used to treat sorbic acid wastewater.The factors in each stage were discussed in detail, involving slection and dosage of coagulating agent,stiring time in process of coagulation, solid solubility and boiling points in process of evaporation, effect of steam consumption and recovery rate on CODcr of the bottom of column in process of stripping.Effect of ultrasonic power,ferrous sulfate and hydrogen peroxide concentration on CODcr removal rate were discussed in ultrasound combined with Fenton reagent advanced oxidation processing unit.At the same time,the oxidation kinetics were studied.The Aspen simulation software were used to industrial simulation and conducted economic analysis.The main conclusion can be got as follows:1,The obtained optimum conditions of coagulation process were:taking Ca(OH)2 compounding with PAM as coagulating reagent,dosage of Ca(OH)2 and PAM:16 g/L and 5mg/L,flocculation temperature 50℃,stirring time 3min,stirring speed 200r/min, CODcr removal rate could up to 43.1%,floc settling velocity is 0.9m/h.2,Salt and organic compounds with high boiling point were removed in process of evaporation, CODcr was reduced to 16640mg/L.3,In the process of stripping ,keeping feed rate at 20L/h,when the recovery rate was 1.1% of the feed,steam amount was 2.3kg/h, CODcr could be reduce to 1887mg/L.4,When ultrasonic power was 400w,reaction temperature was 60℃,dosage of H2O2 and Fe2+ were 6.020mL/L and 0.04mol/L respectively, reaction time 40mins,under these conditions, CODcr could be reduced to less than 100mg/L.5,Associated with the reaction temperature, concentration of H2O2 and Fe2+ , the linear regression were used for quantitative analysing CODcr removal at different degradation time, the ultimate get-type kinetic equation as follows: -dc/dt=20.807exp(-14907/RT)[FeSO4]0.7443[H2O2]0.57966,The technical parameters of evaporation and stripping unit were defined by Aspen simulation software and verified its feasibility for industrial applications.This treatment of wasterwater were entirelly feasible and realized the environmental benefits and economic benefits totally.