Effects Of Microcystis Aeruginosa Generation Of Disinfection Byproducts Chironomid Larvae

Drinking water disinfection process for disinfection has nearly hundred years of history,but the chlorination by-products can cause severe mutagenic,teratogenic and carcinogenic effects. These DBPs mainly include trihalomethanes(THMs) and haloacetic acids(HAAs). Natural organic matter(NOM), such as humic acid and fulvic acid, is the well-known precursor of DBPs. Algal cells also affect DBPs generation during chlorination. Algal cells contain large amounts of organic nitrogen, such as polysaccharoses, proteides, aminophenol and other organic acids, and these substances can thereby transform into nitrogenous DBPs after their dissolution and following chlorination. In some real cases, water eutrophication is often accompanied by a large number of growth of chironomid larvae, and which is widely distributed in the reservoir, lake and other surface. Due to its stronger resistance to oxidation. Chironomid larva can’t be effectively inactivated by the conventional disinfection methods and inactivated biomass or the debris will have a negative impact on the user sensory indicators and even panic. Microcystis aeruginosa and chironomid larvae after chlorine disinfection DBPs can be generated.But The effects of alga on chironomid larvae metabolites, in terms of DPBs formation, is still unknown. In this study, the generating profiles of chlorination DPBs with the co-existence of alga (microcystis aeruginosa) and chironomid larvae metabolite dissolution will be studied, under different parameters of reaction time, pH, temperature, Cl:N.Research on microcystis aeruginosa to chironomid larvae metabolites and carcass dissolution generated in the process of chlorination DBPs.The results show that:in the chlorination process, will produce Trihalomethanes, Haloacetic acids, Haloacetonitriles, Haloketones, including chloroform (TCM), dichloroacetic acid(DCAA), trichloroacetic acid (TCAA),chloral hydrate (CH), trichloropicrin(TCAN),1,1,1-threechloroacetone(1,1,1-TCP),1,1-two chloride acetone(1,1-DCP).Patina of microcystis aeruginosa exist not only affects the generation of DBPs, but will also change some of the change trend of DBPs. Microcystis aeruginosa will promote TCM, CH, 1,1-DCP,1,1,1-TCP, TCAN, TCNM formation, can inhibit the accumulation of HAAs instead. Microcystis aeruginosa will change TCAN and the change trend of TCNM.Prolonging the reaction time,the concentration of TCM,DCAA,TCAA increased,TCAN and 1,1,1-TCP increased to a certain extent and then reduce.TCNM and 1,1-DCP that produce from metabolites prolonged reaction time the concentrations will increases first and then decreases,the concentration of CH from dead soluble substance solution will increases first and then decreases.pH affected BDPs formation differently.To metabolites of Microcystis aeruginosa and chironomid larvae,TCM and DCAA increased gradually,CH,TCAA,TCAN,TCNM with the variation of pH first increased and then decreased.1,1-DCP and 1,1,1-TCP gradually decreases.For the dissolution of dead bodies of Microcystis aeruginosa and chironomid larvae,the concentration of TCM increased gradually,CH,1,1-DCP,DCAA,TCAA show a different change from TCM.1,1,-TCP,TCAN,TCNM with the variation of pH increased first and then decreased.Under the different temperature,generation of DBPs are not the same.Elevated temperature will make the metabolites of Microcystis aeruginosa and chironomid larvae and dead concentrations of DBPs in TCM,DCAA,TCAA,TCNM increased.Rise temperature in the metabolites of 1,1-DCP and 1,1,1-TCP will inhibit their formation.Produced in the metabolites of TCAN decreased with increasing temperature. the dead soluble substance solution of CH and TCAN is highest amount at 20℃.For the most DBPs, they are decreased as Cl/N ratio declined.