BIOSOLIDS LAND APPLICATION IN FRANCE: A COMPARATIVE STUDY WITHFERTILISERS FOR THE EFFECT ON PLANTS AND SOILS

摘要

This study looks at the behaviour of metal trace elements contained in sludges and fertilizers,rnwhen they are mixed with a clay soil. It has been made using plant containers, with threernurban residual sludges and one industrial sludge, plus a fertilizer, placed in a plant house withrncontrolled temperature and humidity. Some of the pots have been seeded with ryegrass andrncompared to controls.rnThe addition of biosolids has increased the production of ryegrass plant matter and reduced itsrnwater consumption. The roots, have absorbed greater quantities of metal trace elements thanrnthe above ground parts, and blocked their transfer. No significant differences have beenrnobserved between the mixtures with or without biosolids, except for the industrial one whichrnhas induced higher levels. The flux of trace metal elements brought in by the biosolids has notrnproduced a significant rise in the initial stock of soil metals.