Pig manure conversion into fodder - by purifying with waste waters in biological purification plant, dewatering and drying

In a process for eliminating pig excrement and converting into a fodder prod. the raw excrement is purified together with waste waters in a biological purification plant, the impurities contd. in the waste waters and in the liq. part of the excrement being converted into proteins by the action of microorganisms; the solid part of the excrement is purified mechanically and biochemically; the biomass and the solid part of the excrement are sepd. off together and the substrate obtd. is dewatered and dried to give a prod. which can be used as fodder or stored; and the purified liq. part of the swine excrement and the purified waste-waters are released into rivers. The process avoids pollution arising from large-scale pen-rearing of pigs and at the same time enables the undigested fodder contd. in the excrement (30-50% of the excrement consists of undig ested fodder) to be recovered and again used as fodder. The fodder obtd. is pleasant-smelling, hygienic, and acceptable to pigs.