ESTIMATION OF BREAKUP AND AGGREGATION COEFFICIENTS IN FLOCCULATION BY A NEW ADJUSTMENT ALGORITHM

This paper presents a new adjustment algortihm for parameter estimation based on a modified least-squares method. This algorithm has been developed to estimate the floc aggregation rate coefficient (KA) and the floc breakup coefficient (KB) of a batch flocculation process according to the model proposed by Bratby. Numerical simulations show the good performance characteristics of the new algorithm. When applied to experimental data, the algorithm allows one to see the poor definition of the flocculation model, which presents a dependence of the term KB/KA on the mean velocity gradient. By considering this dependence, also observed by other authors, this paper suggests some modifications in the original flocculation model that improve greatly the adjustment of the model to the experimental results. The new adjustment algorithm permits one to study further modifications in the flocculation model in a simple manner and could be a useful tool to improve the conceptual model of this type of processes. © 1990.