Tannery wastewater sludge ash for the production of waterproofing membrane: A technical and environmental feasibility study

Sludge from tannery effluent treatment processes is a by-product of leather-ma king industry, in which chrome compounds are the most common used materials. The objective of this work was to investigate the effects and feasibility in the use of tannery sludge ash as a partial or total replacement of usual mineral filler such as in manufacture of waterproofing membranes. The effects of sludge ash on the morphology and mechanical properties of membranes were investigated. Leaching tests were carried out in order to guarantee that the fulfilment of "filler function" was done in respect with environmental criteria. Besides, a Life Cycle Assessment (LCA ) analysis was performed in order to assess the environmental performances of the waterproofing membrane filled by tannery sludge ash in comparison with the conventionally filled membrane. The performances of the membranes and the results of environmental assessment indicate that tannery sludge ash may be used as total replacement of CaCO3 for waterproofing membranes.