Comparing Alum and Ferric Chloride in Removal of Pollutants from Sulfite Pulping Plant Effluent

In this research the effect of usual coagulants, alum and ferric chloride has been investigated on treatment of activated sludge effluent in Mazandaran wood and paper plant which uses neutral sulfite semi chemical (NSSC) pulping process. Performance of two coagulants in removal of pollutants from sulfite mill plant effluents were studied. The effect of different coagulants dosage on pH was investigated. The economical considerations and the operating parameters for two coagulants were compared.This study shows that ferric chloride caused the better results. This feature of ferric chloride supports the idea that the Fe is more amenable to hydrolysis than Al. Economic consideration show revealed by using ferric chloride instead of Alum in wood and paper industry, the chemical costs reduced significantly.