Similar articles

Abstract: 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 (KMnO₄). 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.

[1] Cui, F.Y., Lin, T., Liu, D.M., Zhang, L.Q., 2005. Excess propagation and biological control of zooplanktonic cyclops in drinking water sources. Wat. Sci. Technol., 52(8):151-159.

[2] Driedger, A.M., Rennecker, J.L., Marinas, B.J., 2001. Inactivation of Cryptosporidium parvum oocysts with ozone and monochloramine at low temperature. Wat. Res., 35(1):41-48.

[3] Fiessinger, F., 1991. Advantages and disadvantages of chemical oxidation and disinfection of ozone and chlorine dioxide. Science of the Total Environment, 18:245-246.

[4] Gunter, U.V., Pinkernell, U., 2000. Ozonation of bromide-containing drinking waters: A delicate balance between disinfection and bromate formation. Wat. Sci. Technol., 41(7):53-59.

[5] Kanio, Y., Kimata, L., 2000. Inactivation of cryptosporidium spp. oocysts with ozone and ultraviolet irradiation evaluated by in vitro excystation and animal infectivity. Wat. Sci. Technol., 41(7):119-125.

[6] Lin, T., Cui, F.Y., Liu, D.M., Ma, F., Zhang, L.Q., 2006. Effect of food habits of some fishes on the biomanipulation in drinking water source management. Journal of Harbin Institute of Technology, 38(1):35-37.

[7] Liu, D.M., Cui, F.Y., Lin, T., Zhang, L.Q., 2004a. Preliminary study on biological control of cyclops of zooplankton in drinking water source. Journal of Harbin Institute of Technology (New Series), 11(2):184-190.

[8] Liu, D.M., Cui, F.Y., Lin, T., An, D., Zhao, Y.C., Zhang, F., Zheng, X.S., 2004b. Studies on the conditions of the removal method of zooplankton from water treatment process. Journal of Harbin Institute of Technology, 36(4):546-549.

[9] Liu, D.M., Cui, F.Y., He, W.J., Han, H.D., Zhang, M., Wu, Y.Q., Lin, T., 2005. Experimental studies of inactivation effect on cyclops of zooplankton in water with ozone. Journal of Harbin Institute of Technology, 37(sup.):269-272.

[10] Liu, D.M., Cui, F.Y., Lin, T., An, D., Zhang, M., 2006. Experimental studies on oxidizing removal of cyclops of zooplankton. High Technology Letters, 12(1):86-90.

[11] Reckhow, D.A., Singer, P.C., Malcolm, R.L., 1990. Chlorination of humic materials: byproduct formation and chemical interpretations. Environment Science and Technology, 24(11):1655-1664.

[12] Ruffell, K.M., Rennecker, J.L., Mariñas, B.J., 2000. Inactivation on of Cryptosporidium parvum oocysts with chlorine dioxide. Wat. Res., 34(3):868-876.