Abstract:
Sulphate (SO4) abundance in the earth’s crust contributes largely to industrial wastewater
contamination lowering the pH, which exuberates the dissolution of metals forming acidic
drainages. Biological sulphate reduction as a remediation process can be affected by factors
such as pH, temperature and high sulphide concentrations. In this study, sulphate-reducing
bacterial community enriched from mine wastewaters was applied in semi-automated bioreactors
to assess the effects of these factors on microbial sulphate reduction capacities. Low pH
(3.5) and temperature (10°C) were observed to promote the toxicity of sulphur-reduced species
on the consortium while mesophilic temperature (25°C) and near neutral pH (6.2) were
observed to induce optimum SO4 reduction attaining a maximum of 95% SO4 reduction.
Obtained SO4 reduction dynamics data was then applied in formulating a unique non-competitive
inhibition equation that models biogeochemical events during SO4 reduction under
varied pH and temperature conditions and predicts the efficacy of a bioremediation system.
