OPTIMIZATION OF THE USE OF POLYELECTROLYTES FOR DEWATERING INDUSTRIALSLUDGES OF VARIOUS ORIGINS

Four different industrial slurries were flocculated with polymeric flo cculating agents (port sediment, sewage sludge, sugar beet washings an d an aluminum hydroxide suspension). The quantities of flocculating ag ent employed were optimized with the aid of a patented, portable flocc ulation and dewatering apparatus. Using sewage sludge as an example, i t was possible to arrive at predictions for particular doses of floccu lating by means of a combined method of dewatering experiments and ele ctrokinetical measurements. The results of monoflocculation and dual f locculation made it possible to deduce that there are similarities in the flocculation and dewatering behavior of slurries with comparable p arameters. Comparison of the sediment particles and the polymer coils revealed a size ratio of 60:1, with the former being the larger. This was then used to devise modifications to the patch charge model and th e bridging model as a function of the molar mass of the flocculating a gent. The modifications were found to agree well with the experimental findings and the structural conceptions of macromolecular substances.