Acid mine drainage secondary resource
Acidic, metal- and sulfate-bearing drainage generated when mining exposes sulfide-bearing materials to oxidation. This record denotes the heterogeneous liquid mine-derived feed, distinct from natural ore, individual dissolved elements, coal-mine-drainage treatment solids, and isolated precipitate phases. The characterized Brazilian copper-mine and South African mining-facility waters below are separate source-specific samples, not a universal composition or interchangeable reactor feed. No constituent criticality designation or industrial recovery performance is transferred to this resource.
Microbial & Biochemical Mechanisms (2)
Off-line precipitation using gas from a sulfidogenic consortium
separation
Microbial
Gas generated in a separate inoculated sulfate-reducing reactor was sparged into real copper-mine drainage, producing a filterable solid assigned to the covellite crystalline phase. The microorganisms supplied the upstream sulfidogenic system; direct cell contact with the product and a benefit over matched chemical sulfide were not established. The same Silva2019 experiment is represented from its mineral-product perspective in cmmmech:covellite; these records are not independent replication. Collected solid is not a quantified copper recovery yield or a verified high-purity commercial product.
Experimental Context & Analytical Limits:
Laboratory study. One-litre drainage samples from an unnamed copper mine in Para State, Brazil had initial pH 5.1 and source-reported soluble Cu 325 mg/L, Mn 10.50 mg/L and Zn 0.12 mg/L. Separate exposures lasted 48 or 96 h; solids were vacuum-filtered and dried at 60 degrees C overnight. Upstream, a mixed acidophilic sulfate-reducing consortium from anaerobic northern-Chile river sediment occupied a 2.3 L reactor, with 1-2 mm porous glass beads occupying 40% of its volume. Reactor conditions were pH 4.5, 30 degrees C, 40 rpm and 150 mL/min N2/CO2 (70/30). Its Cu-free synthetic drainage feed was pH 2.5, with 13.86 mM sulfate, 5 mM glycerol and 0.01% w/v yeast extract. These reactor settings and synthetic feed are not downstream bottle conditions or real-water composition. Quantitative H2S delivery, downstream temperature/mixing, independent replication and matched uninoculated or reagent-H2S comparators are not supplied.
Laboratory study. One-litre drainage samples from an unnamed copper mine in Para State, Brazil had initial pH 5.1 and source-reported soluble Cu 325 mg/L, Mn 10.50 mg/L and Zn 0.12 mg/L. Separate exposures lasted 48 or 96 h; solids were vacuum-filtered and dried at 60 degrees C overnight. Upstream, a mixed acidophilic sulfate-reducing consortium from anaerobic northern-Chile river sediment occupied a 2.3 L reactor, with 1-2 mm porous glass beads occupying 40% of its volume. Reactor conditions were pH 4.5, 30 degrees C, 40 rpm and 150 mL/min N2/CO2 (70/30). Its Cu-free synthetic drainage feed was pH 2.5, with 13.86 mM sulfate, 5 mM glycerol and 0.01% w/v yeast extract. These reactor settings and synthetic feed are not downstream bottle conditions or real-water composition. Quantitative H2S delivery, downstream temperature/mixing, independent replication and matched uninoculated or reagent-H2S comparators are not supplied.
Curated Evidence Points:
Support
Source:
silva2019
Sections 2.1-2.3 and Figure 1 separate the inoculated gas generator from real-water precipitation. Figures 2-3 and 5 and Table 2 support solid collection and the authors' covellite phase assignment. This supports a laboratory separation route using biogenic gas, not a universal biological requirement, direct mineral biosynthesis by a named strain, or industrial deployment.
Partial
Source:
silva2019
No final aqueous copper concentration, isolated solid mass or closed copper balance is supplied. Table 3 reports Cu/S wt% pairs 87.67/73.99 and 70.97/106.08, whose sums exceed 100%; its mass-entry ratios are described elsewhere as molar ratios. These unresolved entries do not establish bulk purity or stoichiometric yield. Final pH 2.1, settling and color changes cannot quantify recovery or identify the proposed intermediate species. The isolated CuS98 label in Section 3.1 conflicts with consistent 96 h arm labels.
Context_only
Source:
silva_versions
The retained original and prior full-text v2 reconciliation are distinguished in the source dossier; the updated-version metadata is not treated as a correction of the composition or mass-balance gaps.
Concentration changes during treatment with an enriched community
other
Microbial
A living mixed community enriched from real drainage was present during laboratory treatment associated with decreasing sulfate and metal concentrations. Sulfate reduction and metal-sulfide precipitation are proposed by the authors, but the reported concentration comparisons, community profiles and biochemical tests do not independently establish a specific precipitate, enzyme, causal species, microbial enhancement over controls, or isolated metal recovery.
Experimental Context & Analytical Limits:
Akinpelu2021 used screened drainage from an unnamed mining facility in Mpumalanga, South Africa, stored at 4 degrees C; Table 1 gives raw pH 2.9 +/- 0.2 and sulfate 8080 +/- 10 mg/L. Anaerobic Postgate-medium enrichment preceded reactor adaptation for 21 d at 35 degrees C and 250 rpm, with source-described pH 7-7.5, 10% inoculum and 0.8 L medium in a 1 L working volume; the exact volume accounting is incomplete. Seventy percent of broth was replaced weekly during adaptation. The source describes daily 100 mL raw-water additions for seven days as continuous operation, followed by 14 d static batch operation. Effluent withdrawal, hydraulic residence time and cumulative sampling/feed mass accounting are not specified sufficiently to reconstruct a balance. A consortium-free control is mentioned, but numerical control outcomes are absent from the inspected main figures/tables and Table S1. Measurements are called triplicate; independent biological reactor replication and the meaning of every reported +/- value remain unclear.
Akinpelu2021 used screened drainage from an unnamed mining facility in Mpumalanga, South Africa, stored at 4 degrees C; Table 1 gives raw pH 2.9 +/- 0.2 and sulfate 8080 +/- 10 mg/L. Anaerobic Postgate-medium enrichment preceded reactor adaptation for 21 d at 35 degrees C and 250 rpm, with source-described pH 7-7.5, 10% inoculum and 0.8 L medium in a 1 L working volume; the exact volume accounting is incomplete. Seventy percent of broth was replaced weekly during adaptation. The source describes daily 100 mL raw-water additions for seven days as continuous operation, followed by 14 d static batch operation. Effluent withdrawal, hydraulic residence time and cumulative sampling/feed mass accounting are not specified sufficiently to reconstruct a balance. A consortium-free control is mentioned, but numerical control outcomes are absent from the inspected main figures/tables and Table S1. Measurements are called triplicate; independent biological reactor replication and the meaning of every reported +/- value remain unclear.
Curated Evidence Points:
Partial
Source:
akinpelu2021
Sections 2.1-2.3 and 3.2, Figures 2-3 and Table 5 support the reported culture-associated concentration comparison. Table 5 reports raw versus post-treatment Cu 0.46 +/- 0.05 versus 0.04 +/- 0.001 mg/L and Fe 2308 +/- 5.51 versus 260.3 +/- 2.78 mg/L. These are source-reported concentrations, not mass yields; the exact Table 5 treatment day and sampled phase are unresolved. ICP-OES after 1% HNO3 treatment does not itself establish the table's ionic oxidation-state labels. Medium-derived ions, dilution, precipitation and sampling losses are not reconciled. Figures 1-3 provide no mineral-phase characterization, and no collected product mass or purity is reported.
Partial
Source:
akinpelu_supplement
Table S1 supplies pooled biochemical responses, including hydrogen sulfide production, without member-resolved causality or a matched sulfate-reduction enzyme assay. Community abundance and culturable biochemical identifications do not show that a particular Bacillus species or metallo-aminopeptidase caused the observed metal changes.
Context_only
Source:
cited_sequence_study
The current public inventory returns one wastewater-metagenome run for the cited study. It supports accession provenance only; the mapping to both raw and treated sample labels and organism-specific causal assignments remains unresolved. No species/strain CURIE is assigned to this mixed community.
Sources & References
-
silva2019: Silva et al. (2019). Covellite (CuS) Production from a Real Acid Mine Drainage Treated with Biogenic H2S. Metals 9(2), 206. Complete retained publisher PDF/XML; Sections 2.1-2.3, Figures 1-5 and Tables 1-4. Publisher version notes identify the 22 February 2019 updated version; the composition and yield limitations are preserved.
https://doi.org/10.3390/met9020206 (accessed 2026-10-15) -
silva_versions: Publisher article version notes for Silva et al. (2019): original 9 February and updated version of record 22 February 2019, with later HTML updates. Version metadata does not establish a separate experiment.
https://www.mdpi.com/2075-4701/9/2/206/notes (accessed 2026-10-15) -
akinpelu2021: Akinpelu et al. (2021). Performance of microbial community dominated by Bacillus spp. in acid mine drainage remediation systems: A focus on the high removal efficiency of SO4(2-), Al(3+), Cd(2+), Cu(2+), Mn(2+), Pb(2+), and Sr(2+). Heliyon 7(6), e07241. Complete six-page published original, Sections 2.1-2.5 and 3.1-3.2, Figures 1-3 and Tables 1-5.
https://doi.org/10.1016/j.heliyon.2021.e07241 (accessed 2026-10-15) -
akinpelu_supplement: Official EuropePMC supplementary archive for PMC8215182, including mmc1.docx Table S1 biochemical test results and original main figures. Test responses are distinct from direct sulfate-reduction enzyme assays.
https://www.ebi.ac.uk/europepmc/webservices/rest/PMC8215182/supplementaryFiles (accessed 2026-10-15) -
cited_sequence_study: ENA public read-run inventory for cited SRA study SRP149893, resolving PRJNA474088, SRR7269217, SRX4172875 and SAMN09291489 as wastewater-metagenome material. This returned inventory alone does not map both paper labels Sa and Sb to separate runs or authenticate a causal consortium member.
https://www.ebi.ac.uk/ena/portal/api/filereport?accession=SRP149893&result=read_run&fields=study_accession,study_title,experiment_accession,run_accession,scientific_name,sample_accession&format=tsv (accessed 2026-10-15)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-15T19:32:44Z |
codex (GPT-6; codex) | CREATE | Curated the mine-derived liquid resource and two qualified laboratory microbial treatment studies from full primary evidence and supplements. Preserved control, composition, mass-balance and sequence-mapping gaps; linked the prior covellite representation of the same 2019 experiment. |
Record source: data/records/acid-mine-drainage.yaml