| Chironomid larvae as a large zooplankton in the city water sources, especially the large population of lake and reservoir water with raw water into the water treatment process. Chironomid larvae in a strong antioxidant activity, the conventional water treatment disinfection process is difficult to effectively inactivated. Chironomid larvae breeding in the water treatment system, and Beauty Health Waterworks quartz sand filter layer, and can penetrate into the pipe network, and thus a serious impact on the water quality of the sensory indicators.Generated by the chlorination of drinking water disinfection by-products (DBPs) because of its "three Carcinogenic effect" by the wide public concern. Disinfection byproducts precursors in the natural organic matter, algae and bacteria, compared to algae and bacteria, chironomid larvae have greater individual, the higher the organic content of the body, but whether chironomid larvae can produce disinfection byproducts and related research. In this study, the dead body of chironomid larvae leachables and metabolites for the study, to investigate the formation law after chlorination and influencing factors.The results show that chironomid larvae die body dissolved substances and metabolites by chlorinated produced chloroform, dichloroacetonitrile, dichloroacetic acid and trichloroacetic acid.Chironomid larvae dead body dissolution by chlorination reaction after chloroform, dichloroacetic acid and trichloroacetic acid in the chlorination reaction process at each time point with the precursor concentration and chlorine dosage increases, with the prolongation of time chlorine dosage is2mg/L and10mg/L chlorination reaction in36h flat,20mg/L adding amount this time48h. Dichloroacetonitrile in the chlorination reaction process at each time point with the precursor concentration increases, the chlorine dosage is2mg/L with time continues to grow,10mg/L and20mg/L reaction time increased, reaching the maximum value at36h after dichloroacetonitrile concentration begins reduction.Chironomid larvae metabolites by chlorinated chloroform, dichloroacetic acid and trichloroacetic acid in the chlorination reaction process at each time point with the precursor concentration and chlorine dosage increases. Chloroform in chlorine dosage is2mg/L,10mg/L and20mg/L, the concentration of growth leveled off in the time of24h, and dichloroacetic acid and trichloroacetic acid in this time of48h. Dichloroacetonitrile in the chlorination reaction process at each time point with the precursor concentration and chlorine dosage increases, dichloro acetonitrile concentration in the chlorine dosage is2mg/L,10mg/L and20mg/L were increased gradually with the prolongation of time, and in36h reaches the maximum value, and then decreased gradually.Chironomid larvae dead body dissolved substances and metabolites of chlorination disinfection by-products by pH large. The chloroform in alkaline conditions by-products generated higher concentration. Dichloroacetic acid and trichloroacetic acid concentration in acidic to neutral by excessive time shows growth trend, and alkaline increase gradually, trichloroacetic acid concentration gradually began to decline. The dead body is dissolved substances chlorinated dichloroacetonitrile concentrations in pH7generation density is the biggest, from acidic to neutral when increase, significantly reduced by neutral to alkali. And metabolites after chlorination dichloroacetonitrile concentrations in pH6to produce a maximum, in acidic conditions increases, the nearly neutral under reducing conditions, under alkaline conditions, the concentration of0.The effect of reaction temperature dead body leachables of chlorination disinfection, the higher the temperature, the chloroform concentration is higher, while the dichloroacetonitrile, dichloroacetic acid and trichloroacetic acid concentration from10℃to25℃concentration gradually increased, and when the temperature from25℃to30℃by-products concentration decreased. Metabolites produced by-products dichloroacetonitrile in only the concentration was reduced with the increasing of temperature.Ammonia nitrogen increased to reduce the disinfection products increased, while the organic matter concentration increases the byproducts concentration increase. |
