Microcystis Aeruginosa And Chironomid Larvae Coexistence Study The Law Of Chloramine Disinfection By-Products

In recent years, water environmental pollution is serious. There are some species of algae, which is dominated by the microcystis aeruginosa in most eutrophic water body. Microcystis aeruginosa grows in water that contains rich organic matter, and camp floating life. Chironomid larvae feed on microcystis aeruginosa, and they are often existence in lakes or reservoirs, even go into city water supply system and bring adverse effects to the people’s health and life. In order to prevent the spread of disease in water,people usually adding chlorine, ozone or chloramine to water treatment process. However, ROOK had been confirmed to be disinfection by-products (DBPs), which would be produced during chlorine disinfection in 1974. Both microcystis aeruginosa and chironomid larvae are precursors of disinfection by-products, the effects of microcystis aeruginosa on chironomid larvae during chloramine disinfection, in terms of DBPs formation, is still unknown. In this study, the generating profiles of chloramination DPBs with the co-existence of microcystis aeruginosa and chironomid larvae will be studied, under different parameters of chloramine concentration, reaction time, pH and temperature.The formation of disinfection by-products were investigated during the chloramination of microcystis acruginosa and chironomid larvae solutions. These disinfection by-products included trichloromethane (TCM), dichloroacetonitrile (DCAN), chloral hydrate (CH), dichloropropanone (DCP), dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA). Trichloroacetonitrile (TCAN), trichloropropanone (TCP) and nitrotrichloromethane (TCNM) were not detected.With increasing chloramine dosage and reaction time, the concentration of TCM, DCAN, CH and TCAA increased. The formation trends of DCP of metabolites and dead body showed the opposite change. The metabolites of mixture made it decreased; the dead body of soluble made it increased.Effect of pH on formation trend of DBPs was distinct. Chloramine disinfection of microcystis aeruginosa and chironomid larvae metabolites, the concentration of TCM increased, the concentration of DCP firstly increased then decreased, the concentration of DCAN, CH, DCAA and TCAA decreased with increased pH. For dissolution of dead bodies, the concentration of TCM and TCAA increased, DCAN, CH and DCP decreased with increased pH, DCAA formation firstly increased then decreased the maximum level at pH 7.Under the different temperature, the ganeration trends of DBPs were different either. Chloramine disinfection of microcystis aeruginosa and chironomid larvae, the concentration. of TCM increased with increased temperature, DCP formation firstly increased then decreased. However, high temperature would inhibit the formation of DCAN.The presence of microcystis aeruginosa promotes the disinfection by-products formation of chironomid larvae during chloramination. The concentration of microcystis aeruginosa 108/L on chironomid larvae disinfection by-products have inhibitory effect. But the existence of microcystis aeruginosa and chironomid larvae in water, still impact the drinking water safety, therefore they should be removed before water treatment process.