Photochemical Degradation Of Organochlorine Pesticides In Water

At present,the organochlorine compounds in water environment pollution has become a serious social problem,the organochlorine compounds tend to have the characteristics of refractory and toxicity,endangering the public safety and health.Organochlorine pesticide is one of organochlorine compounds in water,every year China use a lot of organochlorine pesticide,these compounds through farmland pesticide spraying,surface runoff,and factory waste water discharged into water.pesticide compounds in the environment can occur photochemical degradation directly and indirectly photochemical degradation,namely direct absorb light energy to chemical bonds break,or through a catalyst or a material suction light degradation occurred after passing light,led to pesticide generated process of small molecule compounds,carbon dioxide and water,study the photochemical degradation behavior of organochlorine pesticide in water will help further understanding the migration and transformation laws of organochlorine pesticide in water,help human to solve the problem of serious water pollution in human.In this paper,we based on the existing research,study the humic acid concentration,Fe(?)concentration,pH change and other environmental factors on the influence of organochlorine pesticide photodegradation.In this experiment,we set up six different concentration of humic acid solution,the research in the BHC,heptachlor,aldrin,polychlorinated biphenyls(PCBs)in one of the degradation reaction.We found that the concentration of humic acid in 30 mg/L,BHC,heptachlor,aldrin,high chlorinated biphenyls degradation rate increased with the concentration of humic acid and speed up,while low chlorinated biphenyls(PCBs)in humic acid concentration of 10 mg/L,the degradation rate increases with the increase of concentration of humic acid and,in the humic acid concentration between 10 to 30 mg/L,the degradation rate decreases with the increase of concentration of humic acid.In this experiment,we use silica gel column method for grouping humic acid and scored four different molecular weight of the size of the level,the research on the BHC,heptachlor,aldrin,polychlorinated biphenyls(PCBs)the influence of photodegradation.The study found that the small molecular weight of humic acid components,the photodegradation of organochlorine compounds have promoting effect,and large molecular weight of humic acid composition has inhibitory effect on photodegradation of organochlorine compounds.In the experimental,we set up four different concentrations of Fe(?)solution,the BHC study,heptachlor,aldrin,polychlorinated biphenyls(PCBs)in the degradation reaction.The study found that Fe(?)concentration change on the BHC,heptachlor,aldrin,polychlorinated biphenyls(PCBs)photodegradation effect is not significant.In the experimental,we set up five different pH of reaction solution,the BHC study,heptachlor,aldrin,polychlorinated biphenyls(PCBs)in the degradation reaction.Research found that the reaction solution pH is a little low or high,organochlorine compounds degradation rate is low,but when the reaction solution pH is too low or too high,the reaction solution of acidic or alkaline pH value,the degradation of organochlorine compounds rate is higher.