Bioleaching Process for Copper Extraction from Waste in Alkaline and Acid Medium

Flotation wastes are becoming a valuable secondary raw material and source of many metals and semimetals worldwide with the possibilities of industrial recycling. The flotation tailings contain oxide and sulfide minerals that have not been sufficiently stabilized and form acidic mine waters, which in turn contaminate groundwater, rivers, and reservoi6sediments. An effective way to recycle these mine wastes is to recover the metals through leaching. While the focus is on acid bioleaching by iron- and sulfur-oxidizing bacteria, alkaline leaching, and the removal of iron-containing surface coatings on sulfide minerals contribute significantly to the overall environmental efficiency of leaching. For this study, static and percolate bioleaching of copper from flotation waste at the Bor copper mine in Serbia was investigated in alkaline and then acidic environments. The aim of the study was to verify the effect of alkaline pH and nutrient stimulation on the bioleaching process and element extraction. A sample was taken from a mine waste site, which was characterized by XRF analyses. The concentration of leached copper was increased when copper oxide minerals dissolved during alkaline bioleaching. The highest copper yield during alkaline bioleaching was achieved after 9 days and reached 67%. The addition of nutrients in acidic medium enhanced the degradation of sulfide minerals and increased Cu recovery to 74%, while Fe and Ag recoveries were not significantly affected. Combined bioleaching with alkaline media and iron- and sulfur-oxidizing bacteria in acidic media should be a good reference for ecological Cu recovery from copper oxide and sulfide wastes.

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Effects of activated carbon on treatment of photo-processing waste by sulfur-oxidizing bacteria

Water Science & Technology ◽

10.2166/wst.1997.0276 ◽

1997 ◽

Vol 35 (7) ◽

pp. 187-195 ◽

Cited By ~ 2

Author(s):

Binle Lin ◽

K. Futono ◽

A. Yokoi ◽

M. Hosomi ◽

A. Murakami

Keyword(s):

Activated Carbon ◽

Treatment Effectiveness ◽

Environmental Concern ◽

Type Systems ◽

Continuous Treatment ◽

Processing Waste ◽

Treatment Technology ◽

Adsorption Effect ◽

Sulfur Oxidizing ◽

Sulfur Oxidizing Bacteria

Establishing economic treatment technology for safe disposal of photo-processing waste (PW) has most recently become an urgent environmental concern. This paper describes a new biological treatment process for PW using sulfur-oxidizing bacteria (SOB) in conjunction with activated carbon (AC). Batch-type acclimation and adsorption experiments using SOB/PAC, SOB/PNAC, and SOB reactor type systems demonstrated that AC effectively adsorbs the toxic/refractory compounds which inhibit thiosulfate oxidization of SOB in PW. Thus, to further clarify the effect of AC, we performed a long-term (≈ 160 d) continuous-treatment experiment on 4- to 8-times dilution of PW using a SOB/GAC system which simulated a typical wastewater treatment system based on an aerobic activated sludge process that primarily uses acclimated SOB. The thiosulfate load and hydraulic retention time (HRT) were fixed during treatment such that they ranged from 0.8-3.7 kg S2O32-/l/d and 7.7-1.9 d, respectively. As expected, continuous treatment led to breakthrough of the adsorption effect of GAC. Renewing the GAC and continuing treatment for about 10 d demonstrated good treatment effectiveness.

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Acidophilic Iron- and Sulfur-Oxidizing Bacteria, Acidithiobacillus ferrooxidans, Drives Alkaline pH Neutralization and Mineral Weathering in Fe Ore Tailings

Environmental Science & Technology ◽

10.1021/acs.est.1c00848 ◽

2021 ◽

Author(s):

Qing Yi ◽

Songlin Wu ◽

Gordon Southam ◽

Lachlan Robertson ◽

Fang You ◽

...

Keyword(s):

Acidithiobacillus Ferrooxidans ◽

Mineral Weathering ◽

Alkaline Ph ◽

Sulfur Oxidizing ◽

Ph Neutralization ◽

Sulfur Oxidizing Bacteria

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Sulfur bacteria promote dissolution of authigenic carbonates at marine methane seeps

The ISME Journal ◽

10.1038/s41396-021-00903-3 ◽

2021 ◽

Author(s):

Dalton J. Leprich ◽

Beverly E. Flood ◽

Peter R. Schroedl ◽

Elizabeth Ricci ◽

Jeffery J. Marlow ◽

...

Keyword(s):

Carbonate Rocks ◽

Sulfur Oxidation ◽

Methane Seeps ◽

Etch Pits ◽

Active Dissolution ◽

Authigenic Carbonates ◽

Sulfur Bacteria ◽

Sulfur Oxidizing ◽

Sulfur Oxidizing Bacteria

AbstractCarbonate rocks at marine methane seeps are commonly colonized by sulfur-oxidizing bacteria that co-occur with etch pits that suggest active dissolution. We show that sulfur-oxidizing bacteria are abundant on the surface of an exemplar seep carbonate collected from Del Mar East Methane Seep Field, USA. We then used bioreactors containing aragonite mineral coupons that simulate certain seep conditions to investigate plausible in situ rates of carbonate dissolution associated with sulfur-oxidizing bacteria. Bioreactors inoculated with a sulfur-oxidizing bacterial strain, Celeribacter baekdonensis LH4, growing on aragonite coupons induced dissolution rates in sulfidic, heterotrophic, and abiotic conditions of 1773.97 (±324.35), 152.81 (±123.27), and 272.99 (±249.96) μmol CaCO3 • cm−2 • yr−1, respectively. Steep gradients in pH were also measured within carbonate-attached biofilms using pH-sensitive fluorophores. Together, these results show that the production of acidic microenvironments in biofilms of sulfur-oxidizing bacteria are capable of dissolving carbonate rocks, even under well-buffered marine conditions. Our results support the hypothesis that authigenic carbonate rock dissolution driven by lithotrophic sulfur-oxidation constitutes a previously unknown carbon flux from the rock reservoir to the ocean and atmosphere.

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