Cationic Starch and Polyaluminum Chloride as Coagulants for River Nile Water Treatment

Traditional water coagulants cause many problems in drinking water treatment processes and the quality of the produced water. In this current research, cationic starches (CSTs) were prepared with different degree of substitutions; DS (0.34, 0.85 and 0.97). The efficiency of the as prepared CST and the commercial polyaluminum chlorides (PAC) were evaluated in Nile water turbidity reduction. The application of coagulants in the treatment of Nile River water showed that the turbidity caused by algal biomass were decreased to 61.5% by using 0.5 ppm of CST; DS 0.85. For effective algal cells removal, pre-chlorination process is required. The maximum treatment was obtained through pre-chlorination/coagulation process using CST (DS = 0.97) with turbidity removal percentage; 73.1% and total algal removal reached 94.8%. All tested coagulants have a great effect on total bacteria counts in the presence of chlorine as a disinfectant without any significant changes in drinking water quality criteria.