The Mechanism of Cyanobacterium (M.aeruginosa) Microcystins Releasing by Chemical Oxidation in Drinking Water Treatment

TEM investigation was performed to analyze the characteristics of the cell breakage of cyanobacterium ( M.aeruginosa) after being oxidized by Cl₂, CIO₂ and O₃ respectively, and the mechanism of intracellular microcystins releasing and the removal effectiveness by different chemical oxidants was further discussed. The results show that all the three oxidants can cause decomposing of cyanobacterum cells and even cause intracellular microcystins releasing, while O₃ has the most serious effect. Under the low dosage (0.5 mg/L) of oxidants, the quantity of the release of intracellular microcystins caused by ClO₂ is most remarkable, and the intracellular microcystins removal by O₃ proves better than that by Cl₂ and ClO₂. Considering the safety factor of the intracellular microcystins removal, 03 should be given the priority when choosing chemical oxidant while Cl₂ is not recommended to remove cyanobacteriaum microcystins in the drinking water treatment.