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Treatment of zinc-rich acid mine water in low residence time bioreactors incorporating waste shells and methanol dosing
- Source :
- Journal of Hazardous Materials. 193:279-287
- Publication Year :
- 2011
- Publisher :
- Elsevier BV, 2011.
-
Abstract
- Bioreactors utilising bacterially mediated sulphate reduction (BSR) have been widely tested for treating metal-rich waters, but sustained treatment of mobile metals (e.g. Zn) can be difficult to achieve in short residence time systems. Data are presented providing an assessment of alkalinity generating media (shells or limestone) and modes of metal removal in bioreactors receiving a synthetic acidic metal mine discharge (pH 2.7, Zn 15 mg/L, SO(4)(2-) 200mg/L, net acidity 103 mg/L as CaCO(3)) subject to methanol dosing. In addition to alkalinity generating media (50%, v.v.), the columns comprised an organic matrix of softwood chippings (30%), manure (10%) and anaerobic digested sludge (10%). The column tests showed sustained alkalinity generation, which was significantly better in shell treatments. The first column in each treatment was effective throughout the 422 days in removing >99% of the dissolved Pb and Cu, and effective for four months in removing 99% of the dissolved Zn (residence time: 12-14 h). Methanol was added to the feedstock after Zn breakthrough and prompted almost complete removal of dissolved Zn alongside improved alkalinity generation and sulphate attenuation. While there was geochemical evidence for BSR, sequential extraction of substrates suggests that the bulk (67-80%) of removed Zn was associated with Fe-Mn oxide fractions.
- Subjects :
- Geologic Sediments
Environmental Engineering
Health, Toxicology and Mutagenesis
Alkalinity
chemistry.chemical_element
Zinc
Mining
chemistry.chemical_compound
Bioreactors
Limit of Detection
Bioreactor
Environmental Chemistry
Sulfate-reducing bacteria
Waste Management and Disposal
Sewage
Chemistry
Methanol
Extraction (chemistry)
Environmental engineering
Hydrogen-Ion Concentration
Acid mine drainage
Pollution
Manure
Lead
Environmental chemistry
Acids
Copper
Water Pollutants, Chemical
Subjects
Details
- ISSN :
- 03043894
- Volume :
- 193
- Database :
- OpenAIRE
- Journal :
- Journal of Hazardous Materials
- Accession number :
- edsair.doi.dedup.....04ad8a78ceab180005a3e076e3c54e08