Agronomic Characterisation of Sewage Sludge: Residual Effects

The progressive implementation of the EU Urban Waste Water Treatment Directive 91/271/EEC is increasing the quantities of sewage sludge requiring disposal. Agronomic use of sewage sludge should be based on crop fertiliser requirements and heavy metals content. Sewage sludge fertiliser potential depends on the stabilisation treatments of sewage sludge: composting, anaerobic digestion, aerobic digestion or pelleting (EPA, 1994). The objective of this experiment was to evaluate the fertiliser effectiveness and residual effects of three types of sewage sludge treated in three different ways