Solidification of tannery wastes

The high chromium concentrations in tannery-wastewater treatment-plant slud ges, render them unsuitable for direct disposal. Therefore, one aims to fix the chromium of the tannery waste by adding different additive materials t o cause solidification. The properties of the raw sludge were determined an d subsequently, the sludge was mixed with cement and additives and left to solidify for 28 days. During the study, 28 different mixtures were prepared and their compressive strengths were determined. Standard elutriation test s were carried out with each solidified sample. Compressive strengths were obtained below the desired concrete strengths. Most of the pollutant parame ters in eluate were under the required values. (C) 2000 Elsevier Science B. V. All rights reserved.