Abstract
A coagulation treatment is one of countermeasures for long-term turbid water in a reservoir that occurs after a large inflow discharge or in a large-scale water circulation. The conventional coagulant has a problem of treating withdrawn sludge and the development of natural coagulant which can be deposited in a reservoir is demanded. We have taken allophane for this study and have conducted some investigations for practical use. We used turbid water collected from a reservoir. The investigations have been conducted by means of experiments in settling cylinders. We found that both distribution of coagulant and agitation of turbid water were indispensable for coagulation treatment. Moreover, we found that sufficient duration of distribution brought effective coagulation. Finally, we found that the allophane has limited coagulation performance, which can be estimated by measuring zeta potential.
