Cationic polymers for sludge dewatering

摘要

A method and a composition for dewatering sludges are described. The method for dewatering sludges includes treating the sludge with a flocculant aid and with a flocculant, whereafter the sludge is dewatered. The method is characterised in that the flocculant aid is an inorganic compound; the flocculant aid and the flocculant are provided as a solid composition comprising 0.1-10 parts by weight of flocculant aid per part by weight of flocculant; water is added to the composition to provide an aqueous solution or dispersion of the composition; said aqueous composition is added to the sludge; and that the sludge is dewatered. The composition for dewatering sludges is characterised in that it comprises a mixture of a solid inorganic flocculant aid with a solid flocculant at a ratio of 0.1-10 parts by weight of flocculant aid per part by weight of flocculant.