Determination of optimal coagulant dosing rate using empirical models

摘要

Determining coagulant dosing rate currently depends on the Jar-teal and the experience of the operators in many cases. The nature of this practice makes it difficult to cope quickly with the rapid fluctuation of raw water quality, mainly because, it lakes a relatively long time to obtain Jar-test results. For promptly predicting required coagulant doses in response to water quality changes, a concept for optimum coagulant dosage control based on empirical models is proposed For the purpose of this study, synthetic raw water made of kaolin in suspension was used to simulate natural raw water. The mathematical model proposed here offers the possibility for the "wastewater treatment plants operators to choose the optimal coagulant dosing (in this case aluminum sulfate) without other preliminary tests, only by knowing some parameters like influent turbidity, pH, temperature. The relationship between raw water quality and coagulant dosage is established by using Design Of Experiment (DOE), Response Surface Models (RSM) and optimization for the accumulated operating data determined by Jar-test.