Zeta Potential, Dissolved Organic Carbon, and Removal of Cryptosporidium Oocysts by Coagulation and Sedimentation
نویسندگان
چکیده
This study evaluated the removal of viable Cryptosporidium parvum oocysts and changes in zeta potential during alum coagulation and sedimentation. Experiments were designed to evaluate oocyst removal and oocyst zeta potential at three initial dissolved organic carbon (DOC) concentrations and a wide range of alum doses and coagulation pH values. The study showed that changes in the initial DOC concentration affected the zeta potential of Cryptosporidium parvum oocysts and the removal of oocysts. Oocysts did not appear to be removed by a charge neutralization mechanism under the conditions used in this research. Sweep flocculation appeared to be the primary removal mechanism at the lowest DOC concentration tested in this study. For the highest DOC concentration tested, optimal coagulation conditions for oocyst removal coincided with optimal coagulation conditions for natural organic matter (NOM) removal, suggesting that NOM played a key role in the interaction between oocysts and the aluminum hydroxide precipitate. DOI: 10.1061/(ASCE)0733-9372(2004)130:12(1424) CE Database subject headings: Organic matter; Coagulation; Water treatment; Sedimentation; Abatement and removal.
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