Removal of cyclops in pre-oxidizing cooperation water treatment process

• Published in: Journal of Zhejiang University. A. Science Vol. 8; no. 11; pp. 1826 - 1830
• Main Authors: Liu, Dong-mei, Cui, Fu-yi, Wu, Ya-qin, Lin, Tao, Zhang, Min, Yu, Ming-xue
• Format: Journal Article
• Language: English
• Published: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China 01.10.2007; State Key Laboratory of Urban Water Resource and Environment, Harbin 150090, China%School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China%College of Environmental Science and Engineering, Hohai University, Nanjing 210098,China
• Subjects: Cyclops; 水处理; 浮游动物; 钝化作用; Water treatment; O3; Inactivation; Cyclops of zooplankton; O3/H2O2 pre-oxidation
• ISSN: 1673-565X; 1862-1775
• DOI: 10.1631/jzus.2007.A1826

Zooplankton cyclops propagates profusely in waterbody, cannot be effectively inactivated by conventional disinfection process, and becomes a troublesome drinking water treatment problem. In this work, the qualitative and quantitative experimental studies were carried out on inactivation of zooplankton cyclops using oxidants, such as chlorine （Cl2）, chlorine dioxide （ClO2）, ozone （O3）, hydrogen peroxide （H2O2）, ozone/hydrogen peroxide （O3/H2O2）, chloramines （Cl2-NH3） and potassium permanganate （KM4nO4）. The influences of various factors include different oxidant dosages, organic substance contents and pH values. The results showed that currently available oxidants used all might inactivate cyclops in some extent. According to the experimental results, chlorine dioxide, ozone, ozone/hydrogen peroxide and chloramines can be selected as effective oxidants for inactivating cyclops because of their strong inactivation abilities. Then the synergic removal effects on cyclops with ozone, ozone/hydrogen peroxide pre-oxidation followed by conventional water treatment processes were investigated, The results showed that ozone and ozone/hydrogen peroxide pre-oxidation can inactivate cyclops effectively, which then can be removed thoroughly by conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.65 mg/L of ozone and 6 mg/L of hydrogen peroxide, with the inactivation rate being 62% before conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.8 mg/L of ozone, with the inactivation rate being 50% before conventional water treatment processes. For different oxidants, when removal rate was the best, the inactivation rate was not the same. These results may provide reference and model for actual waterworks.