Reduction of Cr(VI) utilizing biogenic sulfide: an experimental and mathematical modeling approach

摘要

The aim of this work was to analyze the performance of a wastewater system for Cr(VI) and sulfate compounds reduction via mathematical modeling. The considered process is coupled to chemical reactors to achieve its tasks. The first stage of the considered process is a biological sulfate-reducing reactor, by which sulfate compounds can be reduced to biogenic sulfide; then, in the second stage, the above-mentioned biogenic sulfide is fed to a second reactor in which the Cr(VI) is reduced, allowing high Cr(VI) concentration removal. The kinetic model of the biological sulfate-reducing process and the Cr(VI) reduction via biogenic sulfide reactions were experimentally corroborated and employed as a benchmarck for the wastewater process analysis via numerical simulations to achieve several feasible operation conditions, under the system's constraints. The mathematical model was extended to a continuous operation, where numerical experiments were carried out predicting an excellent removal of 99% of Cr(VI) and 75% of sulfate compounds.