Environmental characterisation of sewage sludge/paper ash-based composites in relation to their possible use in civil engineering.

The environmental acceptability of geotechnical composites made of treated municipal sewage sludge (SwS) and paper ash (PA) after two different curing periods has been investigated. The mineral composition of such composites, including their content of major oxides, is mainly influenced by the PA. The content of potentially toxic elements (PTEs) in the initial materials and in the composites varies considerably.