Use of Sewage Sludge in the Production of Light-Weight Ceramic Bricks
Sewage sludge consists of a solid mixture of biological and mineral origin. It is the main byproduct of Effluent Treatment Stations. Its final draining has been a relevant environmental problem in several countries. In Brazil, due to the growth of the urban population and the requirements of environmental agencies, efficient ways for sludge disposal or effluent treatment have been investigated. Possible discarding solutions include incineration, pelletization, energy production and addition to fertilizers. This work focuses on the use of sludge in the ceramic industry for the production of light ceramic blocks, since this residue is basically composed of organic substances which volatilize during high temperature sintering. Mixtures containing different contents residue and clayed materials were prepared. For each mixture, after processing, the physical and mechanical properties of the burned pieces were measured, with emphasis on water absorption and linear shrinkage tests carried out as a function of the sintering temperature. Gresification diagrams were plotted for the temperature range of 850 °C to 1150 °C. The addition of the residue provided an increase in the porosity of the material. Light blocks were sintered and presented adequate mechanical resistance for application as building material.
Paula Maria Vilarinho
R. P. S. Dutra, U. U. Gomes, R. M. Nascimento, A. E. Martinelli, C. A. Paskocimas, "Use of Sewage Sludge in the Production of Light-Weight Ceramic Bricks", Materials Science Forum, Vols. 514-516, pp. 1706-1710, 2006