Biological sulfate removal with low-cost carbon sources using cold-acclimated bacteria

Abstract

The main goal of this study was to develop a cost-efficient biological method for the removal of sulfate from mining effluents in cold conditions. A consortium of cold-tolerant sulfate-reducing bacteria (SRB) was tested at 6 °C regarding the utilization of economically viable, low-cost carbon sources, i.e., whey, conditioned sewage sludge, and peat, in the removal of sulfate from synthetic mining water. Succinate was used as a reference carbon source. Of all the studied low-cost carbon sources, conditioned sewage sludge proved to be the most efficient. Nuclear magnetic resonance (NMR) spectroscopy revealed that sewage sludge contained propionic acid, which proved to be utilizable by SRB under cold conditions. Peat both adsorbed the sulfate and acted as a nutrient source in the sulfate reduction process. When whey was used as a carbon source, only a slight decrease in sulfate concentration was detected. Succinate was found to work in a truly predictable and efficient way as a carbon source in biological sulfate reduction, even at the lowest concentration tested. The use of conditioned sewage sludge increased the bacterial diversity in liquid cultivations significantly. However, the number of SRB was highest in the succinate cultivations.

Review of Sulfate Removal in Low Concentration Brine Solutions

“…Research articles on sulfate removal are widely available in the scientific literature. [12][13][14][15][16] This survey covers a variety of approaches and techniques to treat streams with different levels of sulfate concentration, with a particular focus on streams that have low concentrations of this ion, i.e., lower than 2,000 mg L -1 . These studies not only address sulfate removal to comply with environmental regulations when disposing of effluents into water bodies, but also consider the importance of water reuse in industrial processes.…”

Use of propionic acid additions to enhance zinc removal from mine drainage in short residence time, flow-through sulfate-reducing bioreactors

“…The substrate comprised British Standards Institution (BSI) Publicly Available Specification (PAS) 100 compost (45% v/v), wood chips (45% v/v) and activated sludge from a municipal wastewater treatment plant (10%). Activated sludge, which contains high concentrations of organic matter (Peng et al, 2017), has previously been shown to be an effective carbon source for SRB (Virpiranta et al, 2021). A mm cover of water ensured that the substrate remained saturated (Fig.…”

“…methanol (Mayes et al, 2011), glycerol (Santos and Johnson, 2017), molasses (Nielsen et al, 2018), ethanol (Costa et al, 2009), acetate (Yildiz et al, 2019) and lactate (Zhang and Wang, 2014)). Propionic acid was chosen as a carbon additive in the research reported here as, together with propionate, it has been recognised as an effective carbon source for SRB (Qian et al, 2019;Virpiranta et al, 2021;Xu and Chen, 2020) and in preliminary trials using a range of carbon sources (unpublished results, Newcastle University) it proved the most effective at zinc removal.…”

Molecular regulation of conditioning film formation and quorum quenching in sulfate reducing bacteria

“…Sulfate reducing bacteria, e.g., Desulfobulus spp. Desulfobacterium autotrophicum, and Desulfotalea psychrophila are found in the water circulation system of the pulp and paper industry, where they cause biofilm formation and microbial corrosion aided by the presence of a high concentration of chlorine (Hussain et al, 2016;Virpiranta et al, 2019). The presence of organic macromolecules such as polysaccharides and polypeptides in drinking water has been proved to proliferate conditioning film formation on hydrophobic surfaces used as liners for drinking water systems (Francius et al, 2017).…”