Color and phenolic compounds reduction of Kraft Pulp Mill effluent by ozonation with some pretreatments

A study on the treatment of Kraft pulp mill effluent by ozonation alone, and by combined treatment of ozonation preceded by chemical coagulation, activated carbon adsorption or membrane filtration has been conducted. Initial effluent pH was a major factor deciding the treatment efficiency. When ozonation was conducted alone, more than 70% reduction of color and phenolic compounds could be achieved at pH 3. When ozonation was preceded by chemical coagulation or powdered activated carbon adsorption, more than 90% reduction of phenolic compounds could be achieved at similarly low pH. However powdered activated carbon followed by ozonation reduces phenolic compounds by 72% even without pH adjustment (pH 10).