The high concentration of trivalent chromium along with organic/inorganic compounds in tannery sludge causes severe ground-water contamination in the case of land disposal and chronic air pollution during incineration. In the present investigation the sludge was subjected to starved-air combustion at 800• C, which prevented the conversion of Cr 3+ to Cr 6+ . The efficiency of starved-air combustion was confirmed through differential thermo-gravimetric analysis (DTG), electron spin resonance (ESR) and Fourier transform infrared (FTIR) analysis. The calcined sludge was solidified/stabilized using fly ash, clay, lime and Portland cement as mixture constituents. The solidified specimens were tested for compressive strength and heavy metal fixation. The compressive strength and metal fixation of the calcined sludge (Cs)-fly ash (F)-cement (C) mortar at a ratio of 41.66% Cs, 41.66% F, 16.66% C were 185 kg cm −2 and 93.84%, respectively. The stabilization of chromium(III) in the cement gel matrix was confirmed with scanning electron microscopy. Leachability studies were carried out to determine the percentage of metal fixation and chemical oxygen demand in the leachate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.