Sustainable Use of Sludges from Sewage Plants as Fertilizer

摘要

Sludge from municipal sewage plants contains nutrients for cropproduction and contaminants, predomi- nantly heavy metals. Metals arestored in the root zone, will be taken up by plants and also removedfrom the fields with crops. A goal of a sustainable agricultureshould be in spite of the Application of sludge as a fertilizer, tokeep the metal con- Tent in soils below levels, which excludenegative effects On human health. The present medium contents ofcopper, zinc and lead in Sludge of Lower Saxony do not allow asustainable appli- Cation on farm land.