Generation of Alkalinity by Stimulation of Microbial Iron Reduction in Acid Rock Drainage Systems: Impact of Natural Organic Matter Types

Abstract

To determine the role of organic matter in the attenuation of acid rock drainage (ARD), microcosm-based experiments were performed using ARD stimulated with plants and manures. Initial mineralogical, organic geochemical and microbial analyses indicated a predominance of goethite, a substantial amount of organic carbon originating from local sources, and a bacterial community comparable with those detected in a range of ARD sites worldwide. After 100 days of incubation, changes in the mineralogical, organic and microbiological composition of the ARD demonstrated that the plant additions stimulate microbes with the potential to degrade this organic matter but do not necessarily cause substantial Fe(III) reduction. Conversely, the greatest observed stimulation of Fe(III) reduction, associated with an increase in pH to near-neutral values, was observed using manure additions. These results demonstrate that the use of the optimal natural carbon source is important and can promote the metabolism of microorganisms potentially fuelling a range of geomicrobial processes, including iron and sulfate reduction.

Effects of Hanwoo (Korean cattle) manure as organic fertilizer on plant growth, feed quality, and soil bacterial community

“…Acidibacter was increased by organic manure application and correlated with SOC content ( Guo et al., 2017 ; Jimenez-Castaneda et al., 2020 ; Zhang et al., 2021 ). Additionally, Acidibacter plays a role in the microbial reduction of Fe (III), and Fe (III) reduction by manure addition leads to an increase in pH ( Falagán and Johnson, 2014 ; Jimenez-Castaneda et al., 2020 ). Thus, the enhanced microbial formation of Acidibacter by CM, HM, and HM+CF affected the pH of the soil.…”

Addition of organic acids to acid mine drainage polluted wetland sediment leads to microbial community structure and functional changes and improved water quality

“…Previous studies have demonstrated that specific organic compounds enhance certain microbial organisms in AMD treatment systems, with different carbon substrates, acting as electron donors, selecting for different bacterial taxa (Salomo et al, 2009). For example, Jimenez-Castaneda et al (2020) demonstrated that the addition of different complex (e.g. plant biomass) or simple (e.g.…”

“…Pelobacter carbinolicus) can perform Fe(III) reduction like Geobacter and may also be capable of reducing elemental S (Lovley et al, 1995). It has been shown that Fe(III) reduction can also lead to an increase in pH (Adams et al, 2007;Jimenez-Castaneda et al, 2020), and so is beneficial to AMD remediation.…”

“…It has previously been proposed that the efficiency of passive mine drainage remediation using constructed wetlands and bioreactors can be enhanced by simple interventions (giving a 'semi-passive' approach) including addition of organic carbon substrates, to sustain heterotrophic sulfate-reducing bacteria (SRB) (Gibert et al, 2004;Costa and Duarte, 2005;Jimenez-Castaneda et al, 2020), or manipulation of oxygen levels, such as by aeration to enhance Fe oxidation (Kirby et al, 2009;Chen and Jiang, 2012;Fernandez-Rojo et al, 2017). For example, altering the type and amount of organic carbon substrates will select for, and enhance the growth of microorganisms carrying out these remediation processes (Hiibel et al, 2011;Zhang and Wang, 2014), especially since the availability of dissolved organic carbon sources is often a major limiting factor (Neculita et al, 2007).…”

Phylogenetic diversity contributes more to sediment magnetism than abundance during incubation of iron‐reducing sediment from a non‐active volcanic lake in Northeast China

“…2019; Jimenez‐Castaneda et al . 2020). FeRB can transform Fe(III) to Fe(II) under the anaerobic subsurface conditions and obtain energy for growth from the oxidized fermentable organic compounds.…”