Study On Chlorination Disinfection Process Characteristics Based On UV/H₂O₂ Advanced Oxidation

With the improvement of living standards,people's requirements for drinking water are getting higher and higher.At the same time,organic pollution of water source water is aggravated,including synthetic organic matter and natural organic pollution.While the traditional water treatment technology has a poor effect on the removal of dissolved organic matter in water,it is an important issue to explore a new advanced treatment process for drinking water.Drinking water advanced oxidation technology?AOPs?has a very good removal effect on dissolved organic matter in water.Among them,UV/H₂O₂ advanced oxidation process is widely used in the industry due to its strong oxidation ability,high efficiency,no selectivity,no secondary pollution.attention.Disinfection is a vital part of drinking water treatment.Disinfection is essential to protect humans from pathogens such as bacteria,viruses and intestinal parasites.According to the data,the disinfection of drinking water in most parts of the world is still chlorinated.This is due to the low cost of chlorine disinfection,which can prevent the regrowth of microorganisms during the transportation of water and ensure the continuous disinfection effect.However,chlorination disinfection will produce disinfection by-products.Some disinfection by-products have strong teratogenic,carcinogenic and mutagenic effects,which pose a threat to human health.Therefore,it is very important to detect and control the amount of disinfection by-products.In this study,the effluent from the sand filter of Jinan Yuhua Pilot Base?the raw water is the water from the Yellow River Reservoir?was taken as the research object.Based on the original process,UV/H₂O₂ advanced oxidation and chlorination were coupled to form a UV/H₂O₂/Cl₂ combination process.Utilizing the oxidizing ability of UV/H₂O₂ advanced oxidation technology to remove organic pollutants in water,advanced oxidizing water is added to sodium hypochlorite?NaClO?and then enters the clear water tank.On the one hand,it neutralizes H₂O₂ remaining after advanced oxidation,and on the one hand,it chlorinates drinking water.For the purpose of disinfection,the relevant research results are as follows:?1?Oxidation of dimethyl isodecyl alcohol?2-MIB?in filtered water by UV/H₂O₂advanced oxidation process to determine the optimum process parameters of UV/H₂O₂ process when the concentration of 2-MIB in filtered water is 275 ng/L.The UV dose was 350 mJ/cm²and the H₂O₂ concentration was 6 mg/L.Under this parameter,the process was stable for 5days,and the consumption rate of H₂O₂ was stable at about 47%,and the removal rate of2-MIB was above 96%.?2?Water quality testing of advanced oxidation influent water,found that after treatment by UV/H₂O₂ process,four trihalomethanes?TCM?,dichloromonobromomethane?DCBM?,and chlorodibromomethane?DBCM?in water.And the formation potential of tribromomethane?TBM?increased,and the higher the concentration of H₂O₂,the greater the formation potential of trihalomethanes in the effluent;the formation potential of trihalomethanes in different molecular weight ranges was detected,and the potential was generated in each molecular weight range.The percentage of DOC in the large molecular weight range decreased,the proportion of DOC in the small molecular weight range increased,and the UV₂₅₄54 in the>3kDa interval was completely removed,all of which were converted to<3kDa,of which the ratio of<1kDa was 94.12%.The three-dimensional fluorescence spectrum analysis of advanced oxidation influent and water showed that the fluorescence intensity of tryptophan,tyrosine,soluble microbial metabolites?SMPs?,fulvic acid and humic acids decreased by 93.59%,81.9%and 77.36%,respectively.65.99%,53.70%,it can be seen that the UV/H₂O₂ process has a good removal effect on various dissolved organic substances.?3?The filtered water is treated by the UV/H₂O₂ advanced oxidation process to accelerate the decay of residual chlorine.It is found through experiments that with the increase of initial residual chlorine concentration,the residual chlorine attenuation coefficient decreases,but the total residual chlorine attenuation increases,and the residual chlorine attenuation coefficient is negatively correlated with the initial chlorine concentration;with the increase of H₂O₂concentration,The residual chlorine decays faster and the residual chlorine decay coefficient increases.By fitting the residual chlorine decay curve,it is found that the attenuation of residual chlorine conforms to the simple first-order reaction model,and the fitting correlation coefficient R² is above 0.95.The linear correlation between the residual chlorine attenuation coefficient and the H₂O₂ concentration is found.The chlorine attenuation coefficient is linearly related to the H₂O₂ concentration,and R² is above 0.95.?4?The filtered water is treated by the UV/H₂O₂ advanced oxidation process to increase the amount of chlorinated trihalomethane produced.It is found through experiments that with the increase of initial residual chlorine concentration,the amount of trihalomethanes increases.With the increase of H₂O₂ concentration,the amount of trihalomethanes increases,and the amount of trihalomethanes is The H₂O₂ concentration is positively correlated.Linearly fitting the amount of trihalomethanes with the concentration of H₂O₂,it was found that the two exhibited a good linear relationship,and the fitting correlation coefficient R² was above 0.92.?5?On the basis of the above experimental research,the UV/H₂O₂ advanced oxidation process is coupled with the chlorination treatment to form a UV/H₂O₂/Cl₂ combination process to simultaneously achieve the purpose of oxidative removal and chlorination of organic matter.Water quality,advanced oxidation water,and clear water from the clear water are used to test some water quality indicators,and the water quality safety of the combined process is judged.The results showed that the removal rate of 2-MIB was about 96.95%after UV/H₂O₂/Cl₂combination treatment;the removal rate of UV₂₅₄54 was 54.29%,the removal rate of TOC was15.59%;the three-dimensional fluorescence spectrum showed that the combination process,tryptophan,The fluorescence intensity of tyrosine,soluble microbial metabolites?SMPs?,fulvic acid and humic acids decreased by 94.29%,86.62%,90.83%,81.5%,and 84.28%,respectively,and the properties of organic matter changed.The COD_Mnn value was 1.42 mg/L,the removal rate was 21.55%,and the BDOC value was about 1.0 mg/L.?6?The production of four trihalomethanes in the UV/H₂O₂/Cl₂ combined process effluent is below the limit,and the total amount of trihalomethane is 0.076 mg/L,which meets the requirements in the Sanitary Standard for Drinking Water?GB5749-2006?;The SOS DNA damage test and the cell proliferation inhibition rate experiment on the process effluent showed that the combined process did not bring about the genotoxicity of drinking water.?7?The strong oxidizing property of the UV/H₂O₂/Cl₂ combination process can cope with most of the organic matter pollution in the water body,but due to the limitation of operating cost,the process can be used as an emergency treatment for sudden organic pollution.