Biosolubilization of Cr (VI) from Tannery Sludge: Process Modeling, Optimization, Rate Kinetics and Thermodynamics Aspects

Abstract

Leather is one among the significant commodities carry extensive fare profit to the Federal Democratic Republic of Ethiopia. In leather industries, chrome tanning is one of the main process for producing less susceptible to decomposition and more durable leather. Chrome tanning results in a huge amount of Cr content toxic sludge waste which poses a risk to the earth. In the present work, the optimization process parameters, initial pH, temperature, and elemental sulfur (S0 ) concentration were examined by Response Surface Methodology (RSM) for the bacterial evacuation (bioleaching) of Cr from the tannery sludge. From the RSM analysis, an equation of polynomial model was produced for the Cr removal effectiveness. Further, the optimized parameters have been recognized by solving the polynomial model through RSM. So as to get the worldwide optimized conditions, the model was settled using a technique dependent on a MATLAB tool, Genetic Algorithm (GA). Moreover, an investigation was led at various temperatures with fixed optimized initial pH and S0 concentration to assess the impact of temperature on the Cr removal by bioleaching. Using these exploratory outcomes, the kinetics for the activation energy, reaction rate-constant, rate-controlling step, and thermodynamic parameters were resolved. Such a study will be useful for designing and building up the ideal bioleaching system for sludge detoxification in leather processing industries.