Optimum conditions of the treatment of organic matters in gray water by Ozone

Abstract

Wastewater treatment processes are critical and economical to improve the quality, remove the more significant part of the contaminants from wastewater and solve the water crisis, which may provide new water sources. To conserve water, the gray water (GW) must be recycled. The use of Ozone in water treatment is a chemical treatment based on the infusion of Ozone into water or wastewater. In this study, the best conditions for treating gray water with Ozone were investigated to achieve the best removal of organic matters represented by chemical oxygen demand (COD), Biochemical oxygen demand (BOD₅), Total organic carbon (TOC), Oils and Greases. It was experimentally concluded that the ozone treatment is positively affected by the increase in pH, the ozone concentration and the time of exposure to Ozone. The ideal conditions for ozone treatment were determined according to the quality of the resulting water and not according to the removal values of organic materials. These conditions are pH 8, ozone concentration of 40mg/l and ozone exposure time of 30 min. Keywords: Gray water; Ozonation; Water Treatment; COD.