The fractionation of natural coagulant extracted from common bean by use of ultrafiltration membranes

Abstract

In the age of rapid degradation of environment, the use of natural coagulants for water and wastewater treatment represents a promising idea which is in line with the global sustainable initiatives. Since these coagulants are of organic nature and have complex composition, it is important to separate components which show coagulation activity from those which do not show. In this work, ultrafiltration membranes with MW cut off of 10,000 Da and 30,000 Da were used for fractionation of natural coagulant extract obtained from common bean seed. Coagulation efficiency of these fractions was assessed by jar tests in model water. Coagulation conditions (pH and applied dose of coagulant) were optimized for each fraction. The fraction of extract with molecular weight lower than 10,000 Da was showed as the best coagulant with coagulation efficiency more than 40% at pH 10 and applied dose 2.5 ml/l.