This study investigated the chlorination of Microcystis aeruginosa extracellular organic matter（EOM） solutions under different conditions, to determine how the metabolites produced by these organisms affect water safety and the formation of assimilable organic carbon（AOC）. The effects of chlorine dosages, coagulant dosage, reaction time and temperature on the formation of AOC were investigated during the disinfection of M.aeruginosa metabolite solutions. The concentration of AOC followed a decreasing and then increasing pattern with increasing temperature and reaction time. The concentration of AOC decreased and then increased with increasing chlorination dosage, followed by a slight decrease at the highest level of chlorination. However, the concentration of AOC decreased continuously with increasing coagulant dosage. The formation of AOC can be suppressed under appropriate conditions. In this study, chlorination at 4 mg/L, combined with a coagulant dose of 40 mg/L at 20°C over a reaction time of 12 hr, produced the minimum AOC.
Effects of reaction time, chlorine dosage, pH and temperature on the formation of disinfection byproducts （DBPs）, were investigated during the chloramination of Cyclops metabolite solutions. The results showed that some species of DBPs like trichloromethane （TCM）, dichloroacetic acid （DCAA） and trichloroacetic acid （TCAA） could accumulate to their respective stable values with a progressive elevation in reaction time and monochloramine concentration. And 1,1,1-2-trichloropropanone （1,1,1- TCP） content decreased correspondingly with a continuous increase of reaction time. The amounts of chloral hydrate （CH）, chloropicrin （TCNM）, 1,1,1-TCP and DCAA firstly increased and then decreased with increasing monochloramine doses. Higher temperature resulted in a decrease of CH, dichloroacetonitrile （DCAN）, 1,1-dichloropropanone （1,1-DCP）, 1,1,1-TCP, DCAA and TCAA concentration, pH affected the formation of the different DBPs distinctly. TCM accumulateded with the increase of pH under 9, and DCAA, TCAA, CH and 1,1-DCP decreased continuously with increasing pH from 5 to 10, and other DBPs had the maximum concentrations at pH 6-7.
