Removal of sulphate and phosphate from aqueous solutions using a food grade polysaccharide as flocculant

Abstract

The mucilage extracted from the seeds of Tamarindus indica pods, a food grade natural polysaccharide, is used as a flocculant for removal of sulphate and phosphate ions in aqueous medium. The maximum removal obtained was 73.71% for sulphate ions and 75.71% for phosphate ions after 30 min. The optimum mucilage dose was 50 mg/L for both sulphate and phosphate ions. The maximum removal was obtained at acidic pH for both the ions. A series of contact time experiments were conducted to assess the system variables such as concentrations of mucilage and ions and pH. The conductivity measurements were also done and correlated with the percent removal. This eco-friendly food grade polysaccharide was proved to be a very good flocculant for the removal of sulphate and phosphate ions.