Study On Generation,Migration,Transformation And Degradation Technology Of Halogenated Methylsulfonic Acid

The main research object of this paper is halogen methyl sulfonic acid(HMSAs),which includes chloromethylsulfonic acid(Cl-MSA),dichloromethyl sulfonic acid(Cl₂-MSA),trichloromethyl sulfonic acid(Cl₃-MSA),monobromomethyl sulfonic acid(Br-MSA)and trifluoromethane sulfonic acid(F₃-MSA).HMSAs is a new disinfection by-product(DBPs)in recent years.Considering the harmful of DBPs to human body,the pollution status of HMSAs in China was studied.This paper investigates the pollution of waterworks in most parts of the country,the waterworks in Beijing especially,typical sewage works in Beijing,and rivers in Beijing,and obtains the rules of the generation,migration and transformation of HMSAs.At last,the degradation of HMSAs was discussed,which has positive significance for controlling the pollution of HMSAs.Because of HMSAs is a new type of DBPs,the literature of HMSAs was reported less.In the first chapter of this article,through reading the related literatureis of DBPs which similar structures and properties with HMSAs relatively,such as halogen acid(TAAs)and trihalomethanes(THMs).This method can understand the generation,detection,migration,transformation and degradation of HMSAs indirectly.Through the relevant methods reported in the literature,HMSAs research program was developed indirectly.The second chapter introduces the detection method of HMSAs in water sample and sludge mainly.In this chapter,through the optimization of various conditions,HMSAs in water samples and sludge could be concentrated and enriched,combined with the LC-MS/MS under the optimal detection conditions,the detection method of HMSAs was successfully established,which made the basic preparation for the research of HMSAs.The chapter 3 introduces the current situation of HMSAs pollution.The concentrations of five kinds of HMSAs were measured in the inlet and outlet water of waterworks in typical cities of China,the concentration of Cl₂-MSA was the highest,with the average concentration at the inlet and outlet levels around 50.88 ng·L^-1 and336.02 ng·L^-1,indicating that chlorination was the main cause of HMSAs.It is found that the pollution of HMSAs is more serious in the economically developed and densely populated areas.The conclusion of correlation analysis is that MSA is uncertain of the precursor of HMSAs.Because of the concentration of F₃-MSA has little changed between the inlet and outlet water and the chlorination experiment is impossible to produce fluorinated organic matter,F₃-MSA is not a disinfection by-product,but F₃-MSA as a kind of HMSAs,the migration and transformation of F₃-MSA in this paper is still have a simple study.The cause of HMSAs is also the focus of research.Macroscopically,natural organic matter such as humic acid and fulvic acid can form HMSAs after chlorination;microcosmically,the organic matter containing sulfur element is the main reason for the formation of HMSAs.Therefore,it is concluded that organic compounds containing sulfur are likely to form HMSAs.At the end of this chapter,a nonlinear mathematical model is found to predict the formation of HMSAs by studying various factors affecting the formation of HMSAs.Therefore,this chapter has a comprehensive understanding of HMSAs from its pollution status,causes and mathematical prediction model.The fourth chapter introduces the migration and transformation of HMSAs in sewage plant mainly.HMSAs are produced in drinking water plants and transferred to sewage plants through sewage pipe network after the daily use of people.Due to the low concentration of HMSAs,the concentration in sewage is relatively stable,about 50ng·L^-1,but in sludge,due to the adsorption of activated sludge mainly,the concentration of HMSAs is higher,about 2000 ng·L^-1.HMSAs is a kind of organic pollutant that is difficult to be degraded.The degradation of HMSAs by microorganisms through aerobic,facultative and anaerobic processes is little relatively,through the adsorption of inorganic particles and activated sludge to achieve the removal of HMSAs mainly.This chapter introduces the adsorption of inorganic particles and activated sludge on HMSAs,the influence of temperature and p H on the adsorption especially,which provides theoretical support for the migration and transformation of HMSAs in sewage plant.The fifth chapter introduces the migration and transformation of HMSAs in Beijing rivers.HMSAs are discharged from sewage plants,and urban rivers are the main recipients.The study found that the concentration of HMSAs in the river water was about half the concentration in the water from the sewage plant.It also found that the river water was seriously polluted due to the high population density and irregular sewage discharge.Adsorption of sediment is the main method to remove HMSAs from river water.The degradation pathways of organic pollutants in rivers mainly include microbial degradation,natural light degradation and sediment adsorption process,etc.,but for the refractory HMSAs,sediment adsorption is the main way.For this reason,this chapter introduces the adsorption kinetics and thermodynamics of sediment adsorption of HMSAs mainly.Through the influence of p H value,temperature,ion strength and organic matter on the sediment surface,the migration and transformation of HMSAs in the river were understood comprehensively.The chapter 6 introduces the terminal degradation method of HMSAs.Through the investigation of the literature,various degradation methods were compared,and the method of micro-electrolysis of composite carbon-based nano zero-valent iron material was selected to degrade HMSAs by oxidation finally,Because of this kind of material has the advantages of little pollution to the environment,high economic benefit and strong maneuverability.This chapter introduces the preparation process of this material,compares the advantages and disadvantages of several materials,and discusses the main factors affecting the degradation of HMSAs,finally,the mechanism of degradation of HMSAs by micro electrolysis was studied.It was found that within the range of p H=3?9,the removal efficiency of HMSAs was maintained at 95.5?99.7%after 30 min of contact reaction.Through continuous dynamic simulation experiments,it was verified that this material had a stable removal effect on target pollutants.In this paper,the detection,generation,migration,transformation and degradation rules of HMSAs are introduced systematically.The change rules of HMSAs from water works to sewage works and then from sewage works to rivers are introduced in detail,and the migration and transformation process of HMSAs in the whole water body is introduced systematically.This paper is the first time to study HMSAs,and has made a positive contribution to control of DBPs pollution in water.