Applicability of Tannery Sludge in Cement Industry

India is one of the top five producing countries of leather in the world. However, leather industries produce several tons of partially dried tannery sludge (TS) while various tanning processes caused a significant contribution to serious environmental issues. Thus, it will be very much important to use the TS effectively in waste-based industries. In the present study, the applicability of TS in cement industry was investigated. For this purpose, chemical composition of the dried tannery sludge powder was explored. The pH level and moisture content of the sludge were 7.8 and 35.6%, respectively. It was observed that a variety of oxides and trace metals are present as the chemical composition in TS. In addition to that, Portland Cement (PC) was partially replaced by tannery sludge at amounts 0%, 5%, 15%, and 25%. Using the replacement, mortar was prepared, and their compressive strength was determined. Results demonstrate that 15% replacement of TS yields highest compressive strength. It was resolved that the amount of chromium in tannery sludge accelerates the cement hydration process. Thus, the pozzolanic characteristics of the TS had an impact on the rise in the compressive strength. Therefore, while employing PC as a binder, tannery waste may be considered a sustainable raw material for construction industry.