Study on Immobilization Activated Sludge by Polyvinyl Alcohol-sodium Alginate - Calcium Nitrate in Domestic Sewage Treatment

Preparation conditions of immobilization activated sludge were studied with polyvinyl alcohol-sodium alginate as carrier and calcium nitrate as cross linking agent. Physical properties and removal effect of immobilization activated sludge were also investigated, where cross linking agent was boric acid, calcium chloride, calcium nitrate, respectively. The effect of sewage treatment was compared with activated sludge cross optimum linker calcium nitrate and pure activated sludge. The results indicated that the optimum preparation conditions were as following: calcium nitrate concentration was 2%, cross link time was 12 h, cross link solution pH valve was 7.5. The properties of immobilization activated sludge was optimum, where cross linking agent was calcium nitrate; Immobilization activated sludge treat domestic sewage were better than dissociation sludge.