Comparative Studies on the Removal of ' Organic MicroPollutants from Drinking Water by Chlorine Dioxide, Ozone and Activated Carbon

Abstract

Survey for River Nile water indicated normal conditions for I physico-chemical parameters. Total dissolved solids and all cations and anions were within the acceptable limits. Oil and grease were detected in high concentration exceed the permissible limits in the Egyptian tandards I due to the transportation along the River Nile and the drainage of industrial

wastewater. Other organic pollutants identified in considerable concentrations and cause serious pollution of river were phenolic ddrivatives originated from wastewater and degradation products of some pbsticides used in agriculture. The derivatives identified were: phenol, o, m, p­ arninophenol; o, m, p- chlorophenol, catechol, hydroquinone and res rcinol. I 2- The use of ozone in water disinfection indicated its powerful oxidizng capacity when react with organic pollutants exist in water.\ Ozone removed 83.6 % of aminophenols and 79.5 % of chlorphenols \after 5 minutes at pH7 when applied in water contain such contaminants. The I

reaction alkaline products

of ozone with both aminophenols and chlorophenols was fast at I medium and then decreased as the pH decrease. Sevel-ai by-

were obtained m this reaction some of which are mu agenic

products. In case of aminophenols the primary by-products( were dihydroxyanilines and then ring cleavage leads to the formation of aliphatic acids by-products such as maleic acid, tartaric acid, formic acid, acetib acid, oxalic acid, glyoxalic acid and finally carbon dioxide.