Rad]OH pre-treatment of algae blooms and degradation of microcystin-LR in a drinking water system of 480 m3/day: Comparison with ClO2

Abstract

The widespread occurrence of harmful algae blooms in drinking water sources has resulted in significant challenges for safeguarding water bodies globally. During algae bloom outbreaks, an OH drinking water treatment system with a capacity of 480 m3/day, was built in the Xinglin water plant in Xiamen, China. The OH, which was produced using the strong ionization discharge combined with hydrodynamic cavitation effect, was applied in the pre-treatment of algae blooms and degradation of microcystin-LR (MC-LR). Results indicated that OH pre-treatment of 0.88 mg/L inactivated five species of algae from 35,180 to 220 cells/mL during conveying of algae bloom water within 9.8 s, subsequently all remaining living and dead algae were removed by the sand filtration. However, ClO2 pre-treatment existed alive and dead algae of 7830 cells/mL, which could pass through the sand filtration tank into pipe networks. Meanwhile, OH degraded the MC-LR from 14.4 μg/L to ND. Analysis of OH-degraded mechanism indicated that OH could mineralize MC-LR by key opening the benzene ring. With OH pre-treatment and ClO2 disinfection of 0.31 mg/L, no BrO3−, trihalomethanes and haloacetic acids were detected in this system, and all indexes of water quality and DBPs satisfied the Chinese Standards for Drinking Water. Therefore, this OH drinking water treatment system shows great promise for practical applications in the removal of algae blooms and degradation of MC-LR.