Study On Synergistic Effect Of Hydrogen Peroxide Oxidation And Persulfate Oxidation For Treatment Of Chemical Wastewater

With the development of society and economy,chemical products more and more diverse,the amount of chemical waste water is increasing day by day.This has brought us huge economic benefits as well as causing serious environmental pollution.In recent years,the chemical industry's wastewater treatment and utilization has made great progress,but the wastewater discharge is not enough reaching the standard in our country.Currently under the policy of zero discharge of wastewater,zero-emission work is also gradually carried out.According to statistics,industrial wastewater treatment rate is 78.9%,but only 54.1%reach the standard.Therefore,it is of great practical significance to study and analyze the current situation of water treatment and to develop efficient and practical chemical wastewater treatment technologies and to recycle them.In this experiment,we take the wastewater from a second settling tank in Hangzhou,Zhejiang Province as our research target.Using advanced oxidation method for its depth treatment,to make the water reach the standards.The experiments using hydrogen peroxide oxidation and persulfate oxidation treated separatelyand then synergistic two oxidation methods,study on the effect of treatment for factors consisting of pH value,dosage of FeSO₄·7H₂O?H₂O₂ and Na₂S₂O₈,and reaction time,as well as the removal effect of COD under the best working conditions.The conclusions are as follows:?1?In the hydrogen peroxide oxidation of chemical wastewater experiments,the factors consisting of pH value,H₂O₂ dosage,mole ratio of H₂O₂ and FeSO₄·7H₂O and reaction time on the removal effect of COD were studied.In single factor experiment,under the conditions of pH value is 5.0,H₂O₂ dosage is 0.85g/L,mole ratio of H₂O₂ and FeSO₄·7H₂O is 3 and the reaction time is 60min,the treatment effect of chemical wastewater by hydrogen peroxide oxidation is the best.Response surface methodology uses pH value,H₂O₂ dosage,mole ratio of H₂O₂ and FeSO₄·7H₂O and reaction time as response factors,uses the removal effect of COD as the response to design the experiment.The interactions of pH value,H₂O₂ dosage,mole ratio of H₂O₂ and FeSO₄·7H₂O were obvious,while the reaction time had little interaction with other factors.The optimal conditions for response surface methodology optimization are as follows:pH value is 4.80,the dosage of H₂O₂ is 0.85g/L,mole ratio of H₂O₂ and FeSO₄·7H₂O is 2.40,and the reaction time is 60min,the removal effect of COD reached the maximum,at this time,it is 39.78%.?2?In the Persulfate oxidation of chemical wastewater experiments,the factors consisting of pH value,Na₂S₂O₈ dosage,mole ratio of Na₂S₂O₈ and FeSO₄·7H₂O and reaction time on the removal effect of COD were studied.In single factor experiment,under the conditions of pH value is 5.0,Na₂S₂O₈ dosage is 3g/L,mole ratio of Na₂S₂O₈and FeSO₄·7H₂O is 3 and the reaction time is 60min,the treatment effect of chemical wastewater by hydrogen Persulfate oxidation is the best.Response surface methodology uses pH value,Na₂S₂O₈ dosage,mole ratio of Na₂S₂O₈ and FeSO₄·7H₂O and reaction time as response factors,uses the removal effect of COD as the response to design the experiment.The interactions of pH value,Na₂S₂O₈ dosage,mole ratio of Na₂S₂O₈ and FeSO₄·7H₂O were obvious,while the reaction time had little interaction with other factors.The optimal conditions for response surface methodology optimization are as follows:pH value is 5.00,the dosage of Na₂S₂O₈ is 4.30g/L,mole ratio of Na₂S₂O₈ and FeSO₄·7H₂O is 3.00,and the reaction time is 60min,the removal effect of COD reached the maximum,at this time,it is 32.87%.?3?Study on synergistic effect of hydrogen peroxide oxidation and persulfate oxidation for treatment of chemical wastewater,examining the treatment effect on Fe²⁺/H₂O₂/Na₂S₂O₈ oxidation system for the actual chemical wastewater.Fix the pH value of 5.00 and the reaction time of 60min,to study the optimization of Fe²⁺/H₂O₂/Na₂S₂O₈ oxidation system of response surface methodology,through determining experiment factors,choosing the level,establishing experiment results and response equations,analyzing the response surface of the Fe²⁺/H₂O₂/Na₂S₂O₈ oxidation system,getting and verifing the best conditions.In the Fe²⁺/H₂O₂/Na₂S₂O₈ oxidation system,FeSO₄·7H₂O dosage,H₂O₂ dosage and Na₂S₂O₈ dosage have certain impacts on the treatment effect of chemical wastewate.The optimal conditions for response surface methodology optimization in the Fe²⁺/H₂O₂/Na₂S₂O₈ oxidation system are as follows:pH value is 5.00,the dosage of FeSO₄·7H₂O is 3.20g/L,the dosage of H₂O₂ is0.85g/L,the dosage of Na₂S₂O₈ is 4.00g/L,and the reaction time is 60min,the removal effect of COD reached the maximum,at this time,it is 45.27%,the experimental error was 0.83%,and the model predictions were good.