Research And Engineering Application Of Pesticide Wastewater And Waste Gas Treatment Technology

Pesticide wastewater has the characteristics of high concentration of organic matter,toxicity,large fluctuations in water quality and quantity,and difficult treatment.Pesticide waste gas also has complex composition,large exhaust volume,irritation,and is also flammable,explosive,and corrosive.If the pesticide waste water and waste gas are not treated,it will cause serious harm to the water environment and air quality,and ultimately threaten human health.Although there are many kinds of processes for the treatment of pesticide waste water and waste gas,some treatment processes cannot be applied to engineering due to problems such as high cost and complicated operation.Therefore,this thesis mainly explores the treatment process of pesticide wastewater and waste gas.Taking the wastewater and waste gas station project of Jiangxi Hetian Technology Co.,Ltd.as a background,analyze the waste water and waste gas of the company’s original production process,explores the pesticide wastewater and waste gas treatment process applicable to the enterprise,and through field investigation,sampling analysis,and multi-party discussion,Experts reviewed and designed a complete treatment plan to ensure that the company’s pesticide wastewater and waste gas can be discharged stably up to the standard.The specific content is as follows:（1）Use coagulation sedimentation method to treat the wastewater of the integrated pond to initially remove the suspended solids and part of COD（chemical oxygen demand）in the wastewater.Commonly used coagulants and coagulants were screened,and the best process conditions for coagulation and sedimentation were determined through single factor analysis.The results show that PAC（Polyaluminium chloride）and PAM（Anionic Polyacrylamide）have the best coagulation and sedimentation effect on the wastewater.The best process conditions are when the initial p H of the wastewater is 8.0 and the dosage of PAC is 400 mg/L,The dosage of PAM is 5 mg/L,the stirring time is 30 min,and the settling time is 60 min.At this time,the COD removal rate of wastewater is 25.2%.（2）Fenton oxidation method is used to treat the coagulation sedimentation effluent to remove the difficult-to-degrade organic matter in the wastewater and increase the BOD/COD（BOD,Biochemical Oxygen Demand）.Single factor analysis and response surface analysis were used to explore the optimal process conditions for Fenton to oxidize the wastewater.The results show that when the amount of H₂O₂ is4.2 ml/L,the amount of Fe SO₄·7H₂O is 4.61 g/L,the initial p H is 4.3,and the reaction time is 75 min,the wastewater COD The removal rate is 45.1%,and the B/C is 0.36.（3）Regenerate the adsorption saturated activated carbon,explore the effects of regeneration temperature and regeneration time on the performance of the regenerated activated carbon,and explore whether the regenerated activated carbon can be reused.The four types of regenerated activated carbons,AC-1,AC-2,AC-3,and AC-4,were tested for adsorption of single simulated exhaust gas and adsorption of mixed simulated exhaust gas to explore their adsorption performance.The results show that when the regeneration temperature is 900℃and the regeneration time is 4 h,the adsorption performance of regenerated activated carbon is the best;by comparison,the adsorption performance of AC-2 regenerated activated carbon is the best,and the exhaust gas adsorption capacity is 364 mg/g.（4）Through the preliminary field investigation and experimental data analysis,the design standards and treatment processes of the wastewater and waste gas treatment project of Jiangxi Hetian Technology Co.,Ltd.were finally determined.The main process used in wastewater treatment is"coagulation sedimentation-iron carbon electrolytic and Fenton-hydrolysis-two-stage anaerobic and aerobic-coagulation and sedimentation-sand filtration-carbon filtration",and the main process used in waste gas treatment is"acid-base spraying-washing-dehumidification-Filtration-two-stage activated carbon adsorption".The process is safe,reliable,stable in operation and low in cost.