Disinfection Study with ClO2 for Recycling Demijohns in Drinking Water Industry

Abstract

The disinfection of recycling polymer based demijohns using in drinking water industry was targeted by using chlorine dioxide containing solutions. 1.5 L volume polyethylene terephthalate bottle was chosen as container to characterize the polymeric demijohn. Disinfection of the intentionally contaminated containers was performed with the 0.3–2 ppm range ClO₂ containing washing solutions which were prepared from the stock solution. Active matter concentration, washing time and the washing number were studied in gradient. Disinfection efficacy of ClO₂ on Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was investigated. The bacteria were chosen according to “Implementing Regulation on Water Intended for Human Consumption”. Viable bacterial cell was enumerated by membrane filtration method. The results were established as colony forming unit. The increasing of the concentration decreased the washing time is another determined result.