Waste water treatment
The chemical and physical conditions encountered in waste streams tend to besignificantly different from the conditions of drinking water treatment . For instance, the ranges of reactant concentrations, pH and temperature are greater in wastewater than they are in drinking water . Also, the scope of waste treatment includes the oxidation of airborne as well as waterborne pollutants .
Waste water application –
Chlorine dioxide is an extremely effective disinfectant and bactericide, equal or superior to chlorine on a mass dosage basis. Its efficacy has been well documented1 in the laboratory, in pilot studies and in full-scale studiesusing potable and wastewater. Unlike chlorine, chlorine dioxide does not hydrolyze in water. Therefore, its germicidal activity is relatively constant over a broad pH range.
Chlorine dioxide (ClO2) is effective as both a disinfectant and an oxidant in wastewater treatment. It has several distinct chemical advantages comparedto the traditional use of chlorine in wastewater treatment. Chlorine dioxide is a broad-spectrum microbiocide effective over a wide pH range. Chlorine dioxide is non-reactive with ammonia and most nitrogencontaining compounds, and thus is effective at lower dose levels than chlorine. It destroys phenolics, simple cyanides and sulfides by oxidation. For odor control, chlorine dioxide will oxidize sulfides without the formation of colloidal sulfur. It is also used to oxidize iron and manganese compounds.
ClO2 is widely used for wastewater deodorization. The formation of hydrogen sulfide often poses a problem for municipal wastewater treatment. Chlorine dioxide, a powerful oxidant, can be effectively used to control noxious, irritating, or pungent odors from many operations. Moreover, its unique selective properties permit more efficient application at a lower dosage and cost than chorine, hypochlorite, permanganate peroxide or ozone.
Chlorine dioxide safely oxidises phenols, cyanides, aldehydes, and mercaptans, reduced sulfur compounds and some pesticides. It is useful in both waste-water treatment and scrubber systems. Chlorine dioxide is an eco-friendly oxidant that is preferred by many regulating water utilities and supply authorities for final discharge disinfection.