Removal of chromium from tannery wastewater using waste-building material

Abstract

Waste-building materials, namely zeolite, tonsil and quarry stone, were chemically activated and used for chromium removal from tannery wastewater by a combined effect of filtration and adsorption. The parameters in the study were the support, the pH of the solution (8-11) and the particle size, described as mesh sieve (8-14). Maximum chromium recovery (93.7%) was obtained when using activated quarry stone with a particle size of 1410 μm (mesh sieve 14) and pH solution of 10.4. Fat and oil content from wastewater was decreased by 97.9%. Moreover, both the chromium recovered and the water treated were reused in the tanning process. Chromium sulfate solution was prepared with the chromium recovered and successfully tested for tanning purposes, and the water filtered was reused in the pickling stage as it contains the concentration of salt necessary for this process. Quality test for the tanned leather demonstrated the suitability of using the chromium recovered as tanning agent. This study presents, for the first time, the efficiency of quarry stone from waste building on chromium removal. © by PSP.