Research On The Removal Characteristics Of Natural Organic Matter In Source Water By UV/persulfate Advanced Oxidation Technology

Studies have shown that natural organic matter（NOM）in source water reacts with chlorine during the chlorination of water plants to form halogenated disinfection by-products with carcinogenic,teratogenic and mutagenic effects,which poses a potential threat to human health.The removal of NOM has attracted the attention of the industry.The conventional water treatment technology has limited removal efficiency of NOM.In recent years,the UV-based advanced oxidation technology has received extensive attention because of its good decontamination performance.This subject investigated the research progress of the UV-based advanced oxidation technology to remove natural organic matter,combined with the research situation of advanced oxidation technology at home and abroad,carried out the comparison experiment of UV/H₂O₂,UV/TiO₂ and UV/persulfate technology.The advanced oxidation technology of sulfate radicals has a good effect on the removal of organic matter,and has the advantages of simple equipment,high processing efficiency,low secondary pollution,and a wide range of pH applications.Therefore,for the advanced oxidation technology to remove natural organic matter,we selected UV/persulfate system.Humic acid（HA）is the main component of natural organic matter（NOM）and contributes a lot to the generation of disinfection by-products.Therefore,this topic first selected humic acid as the research object.The experiment mainly discussed the concentration of persulfate,the light time,pH value and inorganic anions in water on the removal effect.The experimental measurement indexes are DOC,UV₂₅₄,three-dimensional fluorescence（3D-EEM）and the generation potential of disinfection by-products.The above indexes are used to characterize the removal effect of natural organic matter.Characterize the content of organic matter in water by UV₂₅₄54 and DOC;qualitatively and semi-quantitatively analyze the changes of water-like fluorescent substances during UV/PS treatment by three-dimensional fluorescence-parallel factor method（EEM-PARAFAC）;the kinetics and degradation mechanism of UV/PS treatment of humic acid were explored.The study found that UV/PS advanced oxidation technology（laboratory scale experiment）can successfully degrade humic acid.Under neutral conditions,when the dose of PS is 0.4mM,after UV irradiation for 160min,HA is significantly degraded by UV/PS treatment(UV₂₅₄54 removal rate is⁸9%)and partially mineralized（⁶2.5%）.The THMFP generation potential（THMFP）also decreases significantly（THMFP removal rate is about 85.4%）.With the increase of light time,a strong linear relationship was observed between UV₂₅₄and DOC.The removal rate of HA at low pH is significantly better than that at high pH.In addition,Cl^-and HCO₃^-have an inhibitory effect on the removal of humic acid.Cl^-inhibition has a tendency to slow down after increasing,and the inhibitory effect is weaker than HCO₃^-.Through qualitative and semi-quantitative analysis of the fluorescence spectrum of humic acid,it was found that the fluorescent compounds（C1 and C2）in HA were significantly degraded,and the changes of C1 and C2 had a certain correlation with the change trend of THMFP.Secondly,a study was conducted on the removal characteristics of natural organic matter in the source water.The experimental research object is the actual source water,and the UV/PS technology is used to remove the natural organic matter in the source water.To further study the removal characteristics of the natural organic matter in the actual water body,the experiment uses the resin enrichment and separation technology to classify the natural water organic matter and explore the effect of UV/PS technology on the removal of different components of natural organic matter in the actual water body,using various technical means to explore the degradation mechanism and the impact of the degradation process on disinfection by-products.Analyze the removal effect of UV/PS technology on different components of natural organic matter in actual water,and study the generation of disinfection by-products of different components.The research results show that UV/PS technology has significant potential to reduce natural organic matter in water,and UV/PS advanced oxidation technology has a good effect on the removal of hydrophilic components of natural organic matter in actual water.In the experiment,the raw water,different components and the generation potential of disinfection by-products in the treatment process were measured.By analyzing the generation of disinfection by-products of different components and the influence of the degradation process on the generation potential of disinfection by-products,the hydrophobic components of natural organic matter were found contributes greatly to the generation of disinfection by-products.In summary,through carrying out the above experiments,we have in-depth understanding of the removal characteristics of natural organic matter in the source water by ultraviolet/persulfate advanced oxidation technology.