Study On The Generation Characteristics Of Disinfectant By-products In Surface Water Treatment

Rational utilization of surface water resources can alleviate the demand for water resources.Water treatment process can optimize the water quality to meet the corresponding water quality standards.Disinfection is an indispensable link in the process of water treatment,which can ensure the safety of water quality.After disinfection,a certain concentration of disinfection by-products（DBPs）will be produced,which will threaten human health in drinking water and affect the ecological environment in other water bodies.In this thesis,the source water of South-to-North Water Diversion Project（Handan section）and Fuyang River were used as experimental water to study the influence of different parameters on the concentration of DBPs,the removal rule of pre oxidation coagulation sedimentation process on the formation potential of DBPs,and the removal rule of DBPs after each unit of water purification process.The main conclusions are as follows:（1）Through chlorine disinfection test,the influence of pH value,contact time,chlorine dosage and Br^-concentrations on DBPs concentration were analyzed.The results showed that the key influencing factors of DBPs were different in different source Water.Therefore,controlling a single influencing factor may not effectively control the concentration of DBPs.（2）Three chemical pre-oxidants,KMn O₄,H₂O₂and Na Cl O,were used to treat the two kinds of source water combined with coagulation sedimentation process.The removal rules of Trihalomethanes formation potential（THMFP）and Haloacetic acids formation potential（HAAFP）were observed.The results showed that when the dosage of H₂O₂was 1.5 mg/L,the concentrations of THMFP and HAAFP were the lowest.The removal rates of THMFP and HAAFP in source water of South-to-North Water Diversion Project（Handan section）were 27.6%and 63.7%,respectively.The removal rates of THMFP and HAAFP in source water of Fuyang River were 37.2%and 42.1%,respectively.（3）The source water of South-to-North Water Transfer Project（Handan Section）was selected as the test water.The removal rates of UV₂₅₄,turbidity,algae and COD_Mn,DBPs concentration and DBPFP removal characteristics were studied by changing the pre oxidant and disinfection dosing point.The results show that the process of chemical preoxidation coagulation sedimentation sand filtration can remove various substances to a certain extent.（4）The distribution of the disinfection by-products formation potential（DBPs FP）of two kinds of source water and the control of chemical preoxidation/coagulation sedimentation process on DBPs FP were comprehensively considered.As a source of drinking water,the composition of organic matter in the south to North Water Diversion Project（Handan section）is relatively simple and easy to remove under the protection of water source and along the way.While Fuyang River is affected by human activities along the coast,the organic matter in the water is more complex,and there are many kinds of DBPs.