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Assessing the Bactericidal Efficiency of Polydex for the Disinfection of Drinking Water in Rural Areas of South Africa

Municipal Water Supply

  1. M. N. B. Momba,
  2. N. Makala,
  3. A. Okeyo

Published Online: 15 JUL 2005

DOI: 10.1002/047147844X.mw1841

Water Encyclopedia

Water Encyclopedia

How to Cite

Momba, M. N. B., Makala, N. and Okeyo, A. 2005. Assessing the Bactericidal Efficiency of Polydex for the Disinfection of Drinking Water in Rural Areas of South Africa. Water Encyclopedia. 1:382–387.

Author Information

  1. University of Fort Hare, Alice, South Africa

Publication History

  1. Published Online: 15 JUL 2005

Abstract

To evaluate the effectiveness of polydex for the removal of total coliforms (TC), fecal coliforms (FC), and presumptive Salmonella (PS), three types of water sources were considered, which included raw water from a river, filtered surface water, and groundwater. The water samples were treated with two different doses of polydex: 3.9 mg/l and 5.4 mg/l. The dose of 3.9 mg/l appeared to be suitable for the disinfection of filtered surface water and groundwater samples with turbidity values ranging between 0.59 and 8.18 NTU. In these water samples, no coliforms were detected 5 h after disinfection, and the copper residuals ranged between 1.01 and 2.96 mg/l 7 h after disinfection. The results revealed that the dose of 3.9 mg/l was not sufficient for the disinfection of highly turbid waters (>9 NTU). A dose of 5.4 mg/l used for the disinfection of these waters completely removed coliform bacteria 7 h after disinfection, and the copper residual in the finished water ranged between 2.52–3.06 mg/l. Although this study has revealed the effectiveness of polydex as a disinfectant, its efficiency may vary with the turbidity of water source. For turbid water, it is recommended that the dose of polydex be higher than the one recommended by the manufacturer.

Keywords:

  • disinfection;
  • polydex;
  • bactericidal;
  • drinking water;
  • rural community