Pig slurry treatment processes studied in France: main techniques adapted to the management of slurry in areas of structural surplus

Abstract

Because of their large size, many above-ground animal breeding units (especially pig units) producing manure are confronted with environmental problems. Apart from the difficulty of rationally managing the effluent by spreading the manure on farming land, the problems are aggravated in sensitive areas by the smells and in certain areas where there is a high concentration of breeding units, by the excess fertiliser produced. Farms have to change quickly to meet environmental protection regulations. Treatment techniques may have to be used in an attempt to resolve these problems. These techniques incur additional costs which have to be estimated depending on the various processes that can be envisaged and the financial arrangements that may have to be made. This paper deals with pig manure and is divided into three sections: the first part summarises the main characteristics of pig manure and the various forms of fertilising elements it contains; the second part defines the treatments and their aims and the third part describes the characteristics and results of the main processes studied in France.