Preparation and characterization of a new coagulant based on the sago starch biopolymer and its application in water turbidity removal by Qudsieh, I. Y. M., Fakhru'l, Razi A., Kabbashi, N. A., Mirghani, M. E. S., Fandi, K. G., Alam, M. Z, Muyibi, Suleyman Aremu, Nasef, Mohamed Mahmoud