TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: A dewetting agent (5) is added to the sludge or the fibrous additive. The dewetting agent is cationic and/or amphoteric. The cationic dewetting agent is quaternary ammonium or phosphonium compound in which the nitrogen or phosphorus atom is bonded to 1-22C alkyl and the hydrophobic portion of the molecule carries a positive charge; or a pyridine derivative in which the nitrogen atom assumes a quaternary form, e.g. alkyl (6-22C) pyridinium halide structure, alkyl (6-22C) imidazolinium compound in which the nitrogen atom assumes a quaternary form. The amphoteric dewetting agent is alkyl (3-10C) polyamine carboxylate, 2-alkyl (6-18C) (dimethyl) ammonioacetate, 2-dimethyl(3-alkyl (6-18C) carboxamidopropyl) ammonioacetate, 3-dimethyl(3-alkyl(6-18C) carboxamidopropyl) ammonio-2-hydroxy-1-propane sulfonate, 3-alkyl (6-18C)-(dimethyl) ammonio-1-propane sulfonate, 3-dimethyl(3-alkyl(6-18C) carboxamidopropyl) ammonio-2-hydroxy-1-propane phosphate, sodium 2-(2-hydroxyethyl (2-alkyl(6-18C) carboxamidoethyl)amino) acetate, disodium 2-carboxylatomethyl(2-(2-hydroxyethyl alkyl(6-18C) carboxamido)ethyl)amino acetate, or 3-alkyl (6-18C) aminopropanoic acid.    TECHNOLOGY FOCUS - POLYMERS - Preferred Materials: The fibrous additive may comprise natural and/or synthetic fiber. The natural fiber is a cellulosic fiber derived from by- products from the harvesting of grain, grain processing, sugar processing, fruit and edible vegetable processing, oilseed plants, timber processing, pulp, paper processing, community lignocellulose waste, and textile processing. The synthetic fiber is derived from textile processing, preferably polyamide, polypropylene, or polyester. The polymeric flocculant is polyacrylamide, poly N,N'-dialkylaminoalkylmethacrylate (e.g. poly (dimethylaminoethyl acrylate/acrylamide) copolymer, poly (dimethylaminoethyl methacrylate/acrylamide) copolymer), acrylamide, acrylamide copolymer, polyvinyl alcohol, polychitosan, polyethyleneimine, polyvinylimidazoline, or polydiallyl amine.