QUALITY IMPROVEMENT OF CERAMIC BRICKS BY INCORPORATION OF SLUDGE FROM WATER TREATMENT UNITS

Abstract

Sludge from water treatment units was incorporated into clay in order to produce bricks with enhanced performance on mechanical properties. The residue can be potentially reused due to mineral similarity with clay. Powder X-ray diffraction and FT-IR spectroscopy revealed that the main constituents of sludge and clay are mainly related to quartz, kaolinite, gibbsite and muscovite. Thermogravimetry assays showed good similarity on decomposition profiles, although the ash content after calcination at 1000ºC was for the sludge samples. Uppon addition of 10 to 15 % of sludge, values of compressive strength and water absorption index values reached acceptable limits, whilst the performance of pure-clay bricks performance was off-graded. These results demonstrate a potential recyclability of sludge in structural ceramic bricks, not only to comply with minimization of environmental impact but also to increase quality and market price of these products.

Keywords

• Sludge from water treatment units
• Ceramic
• Recycling
• Physical-mechanical properties