Journal of Resources and Ecology >
Microbiological Approach for Leaching Out Metallic Elements from Electric and Electronic Waste
John ANGEL SNEHA, E-mail: angel.jaivam@gmail.com |
Received date: 2021-07-20
Accepted date: 2022-06-29
Online published: 2023-04-21
After the computer and mobile revolution, electric and electronic waste had become a serious threat to urban and rural communities equally. Prevention of the hazardous exposure and proper management are challenging in developing nations. One way to turn the crisis to opportunity is to extract metals from this Waste Electronic and Electric Equipment (WEEE) is making waste into a source of metal ores. The involvement of microbes in this technology could increase the boons by being an eco-friendly technique for reducing the hazardous nature. This article reviews the mechanisms involved in the process of bioleaching, the microorganisms employed, methods used and various developments as well as limitations along with recent advances and future prospects of the process of bioleaching of metals from WEEE.
Key words: bioleaching; WEEEs; MPPCBs
John ANGEL SNEHA , Gurumurthy KALAICHELVAN . Microbiological Approach for Leaching Out Metallic Elements from Electric and Electronic Waste[J]. Journal of Resources and Ecology, 2023 , 14(3) : 667 -674 . DOI: 10.5814/j.issn.1674-764x.2023.03.020
Fig. 1 Direct and Indirect mechanisms of Bioleaching (Mishra and Rhee, 2014) |
Fig. 2 Intermediates of thiosulfate pathway on pyrite (Huang and Li, 2014) |
Fig. 3 Illustrative representation of (a) thiosulfate pathway (b) polysulfide pathway (Vera et al., 2013) |
Table 1 Types of microbes involved in bioleaching from Industrial waste (Mishra and Rhee, 2010) |
Types | Acidophilic bioleachers | Cyanogenic bioleachers | Fungal bioleachers | ||||
---|---|---|---|---|---|---|---|
Micro-organism involved | Acidithiobacillus sp | At. thiooxidans | Sulfobacillus | Chromobacterium violaceum | Pseudomonas fluorescens | Bacillus megaterium | Aspergillus niger |
Types of wastes treated | Flue ash, Electronic scraps, Exhausted battery, Exhausted refinery catalyst, Exhausted petroleum catalyst | Sewage sludge, Sediment, Tannery sludge | Electronic scrap | Waste electric device, Jewelry waste/ Automobile catalyst | Jewelry waste/ Automobile catalyst | Jewelry waste/ Automobile catalyst | Fly ash, Spent fluid cracking catalyst |
Metals leached out | Al, Zn, Cu, Cd, Co, Li, Ni, V, Mo | Cu, Mn, Zn, Ni, Cr | Cu, Ni, Sn, Al, Zn | Au, Ag, Pt | Ag, Pt, Au | Ag, Pt, Au | Al, Zn, Cu, Cd, Mo, V |
Table 2 Chemical composition of different culture media for bioleaching studies (Deveci et al., 2003) (Unit: g L-1) |
Culture media | MgSO47H2O | (NH4)2SO4 | KH2PO4 | KCl | Ca(NO3)2 H2O |
---|---|---|---|---|---|
T&K media | 0.4 | 0.4 | 0.4 | ‒ | ‒ |
9K media | 0.5 | 3 | 0.5 | 0.1 | 0.01 |
ES media | 0.4 | 0.2 | 0.1 | 0.1 | ‒ |
Leathen media | 0.5 | 0.15 | 0.01 | 0.05 | 0.05 |
Norris media | 0.2 | 0.2 | 0.2 | ‒ | ‒ |
Table 3 Pros and cons of different metal leaching techniques (Habibi et al., 2020) |
Pros and cons | Pyro-hydrometallurgy | Hydrometallurgy | Biohydrometallurgy |
---|---|---|---|
Pros | The energy obtained is also utilised separately | Shortest process time The recovered metals are used in the manufacturing of other products | Environmentally friendly Simpler and cheaper operation and maintenance Lower energy requirement. Operation at surrounding pressure and temperature that is not excess |
Cons | Requires high energy input to sustain the temperature at which the process takes place Emission of harmful gases, such as polychlorinated dioxins and furans (PCDD/PCDF) Emission of metals, including Pb, As, and Cd. Strong gas emissions, including CO2 and CO used as reducer Requires high concentration of metals in ores | Requires complicated process plants as well as maintenance Requires large amounts of leaching agents Cost of operation is high Liability due to using of dangerous chemical during the treatment Can’t be applied for materials with high contamination The dangerous acid waste may find its ways in to the local water sources | Longer period of operation compared with hydrometallurgy |
Table 4 Metallic composition of Lithium-ion mobile battery (Naseri et al., 2019) |
Metal (%(ww-1)) | Manganese | Cobalt | Aluminium | Copper | Nickel | Lithium | Iron | Sulfur | Silicon | Magnesium | Sodium | Titanium | Niobium |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
X-ray fluorescence | 22.0 | 17.11 | 9.45 | 6.60 | 2.82 | - | 0.19 | 0.17 | 0.11 | 0.06 | 0.06 | - | 0.01 |
Chemical digestion | 21.31 | 16.54 | 9.12 | 5.93 | 2.56 | 2.22 | 0.04 | - | - | 0.04 | Not tested | 0.02 | - |
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[9] |
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[11] |
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[12] |
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