Bio-extraction of precious metals from urban solid waste

Das, Sonali; Natarajan, Gayathri; Ting, Yen‐Peng

doi:10.1063/1.4974410

Cited by 16 publications

(8 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Au leached out using C. violaceum under two-step bioleaching are comparable to the studies of [ 12 , 24 , 29 ], with 68.50, 69.30, and 70.60% w/w of Au being bioleached, respectively. On the other hand, the bioleach obtained was higher than those reported by Kita et al [ 32 ]; Pham & Ting [ 33 ]; Tay et al [ 30 ], Dangton and Leepowpanth [ 34 ] and Das et al [ 35 ]; with a maximum of Au bioleachability, 60.00, 3.00, 30.00, 13.62, and 11.30% w/w, respectively. Instead of a batch reactor, shaking flasks were used in all prior research.…”

Section: Resultsmentioning

confidence: 58%

Optimization of Precious Metals Recovery from Electronic Waste by Chromobacterium violaceum Using Response Surface Methodology (RSM)

Jani

Sujá

Jamaludin

et al. 2023

Bioinorganic Chemistry and Applications

View full text Add to dashboard Cite

An effective recovery technology will be valuable in the future because the concentration of the precious metal contained in the source can be a key driver in recycling technology. This study aims to use response surface methodology (RSM) through Minitab software to discover the optimum oxygen level (mgL−1), e-waste pulp density (% w/v), and glycine concentration (mgL−1) for the maximum recovery of gold (Au) and silver (Ag). The method of precious metals recovery used for this study was taken from the bioleaching using 2 L of batch stirred tank reactor (BSTR). A Box-Behnken of RSM experimental statistical designs was used to optimize the experimental procedure. The result of the RSM optimization showed that the highest recovery was achieved at an oxygen concentration of 0.56 mgL−1, a pulp density of 1.95%, and a glycine concentration of 2.49 mgL−1, which resulted in the recovery of 62.40% of Au. The pulp density and glycine concentration greatly impact how much Au is bioleached by C. violaceum. As a result, not all of the variables analyzed seem crucial for getting the best precious metals recovery, and some adjustments may be useful in the future.

show abstract

Section: Resultsmentioning

confidence: 58%

Optimization of Precious Metals Recovery from Electronic Waste by Chromobacterium violaceum Using Response Surface Methodology (RSM)

Jani

Sujá

Jamaludin

et al. 2023

Bioinorganic Chemistry and Applications

View full text Add to dashboard Cite

show abstract

“…Metal dissolution is also influenced by its solubility. In the case of precious metals, acidophiles are widely used for gold mining operations, but normally copper is dissolved, and the precious metal reminds concentrated in the solid phase, being extracted by subsequent processes (Brandl et al, 2001; Das et al, 2017). In this study, we observed the leaching of small amounts of Au on day 7, in contrast with other acidophilic bacteria bioleaching studies (Marra et al, 2018).…”

Section: Resultsmentioning

confidence: 99%

Microbial biominers: Sequential bioleaching and biouptake of metals from electronic scraps

et al. 2022

View full text Add to dashboard Cite

Electronic scraps (e‐scraps) represent an attractive raw material to mine demanded metals, as well as rare earth elements (REEs). A sequential microbial‐mediated process developed in two steps was examined to recover multiple elements. First, we made use of an acidophilic bacteria consortium, mainly composed of Acidiphilium multivorum and Leptospidillum ferriphilum , isolated from acid mine drainages. The consortium was inoculated in a dissolution of e‐scraps powder and cultured for 15 days. Forty‐five elements were analyzed in the liquid phase over time, including silver, gold, and 15 REEs. The bioleaching efficiencies of the consortium were >99% for Cu, Co, Al, and Zn, 53% for Cd, and around 10% for Cr and Li on Day 7. The second step consisted of a microalgae‐mediated uptake from e‐scraps leachate. The strains used were two acidophilic extremotolerant microalgae, Euglena sp. (EugVP) and Chlamydomonas sp. (ChlSG) strains, isolated from the same extreme environment. Up to 7.3, 4.1, 1.3, and 0.7 µg by wet biomass (WB) of Zn, Al, Cu, and Mn, respectively, were uptaken by ChlSG biomass in 12 days, presenting higher efficiency than EugVP. Concerning REEs, ChlSG biouptake 14.9, 20.3, 13.7, 8.3 ng of Gd, Pr, Ce, La per WB. Meanwhile, EugVP captured 1.1, 1.5, 1.4, and 7.5, respectively. This paper shows the potential of a microbial sequential process to revalorize e‐scraps and recover metals and REEs, harnessing extremotolerant microorganisms.

show abstract

“…On the other hand, the growing demand for metals as solid urban wastes, such as fly ash, electronic scrap, and spent catalysts, may be considered as "secondary ores" for metal recovery, so most studies are focused on bioleaching of these kinds of wastes. Due to the increasing pressure for industries to adopt environmentally, friendly, and sustainable processes, bioleaching could be considered as a clean and green technology for metal extraction [17].…”

Section: Discussionmentioning

confidence: 99%

Acidithiobacillus thiooxidans DSM 26636: An Alternative for the Bioleaching of Metallic Burrs

2020

View full text Add to dashboard Cite

Metallic wastes from the metal-mechanic industry represent a serious environmental problem. The possible strategies to reduce the metal content of these industrial wastes is their biotreatment by means of sulfur-oxidizing bacteria, such as Acidithioobacillus thiooxidans DSM 26636, which has been reported as an excellent metal-leaching microorganism by its capability to oxide sublimed sulfur and produce sulfuric acid in the presence of metallic burrs, and leach metals. The metallic composition of burrs was determined by ICP-OES before and after its exposure to biological treatment. The bioleaching process was kept for 21 days at 30 °C at an orbital shaking of 150 rev/min by using Erlenmeyer flasks of 125 mL containing 30 mL of Starkey-modified media added with 0.33 g (1% w/v) of sublimed sulfur and 0.33 g (1% w/v) of metal burrs, and 3 mL of inoculum at logarithmic phase. Results showed that A. thiooxidans was able to grow at these conditions with a maximum sulfate production of 11,028 mg/L, sulfuric acid corresponded to 0.16 M, but no statistical difference was observed for days 14 and 21. A reduction in pH was observed from 2.5 to 1.3 units. Metal bioleaching in mg/kg corresponded Fe (4658.5 ± 291), Cr (237 ± 46), Al (185 ± 12), Si (71 ± 10.3), Mo (63 ± 3.6), Mn (46 ± 3.3), V (18 ± 0.94), Mg (22.2 ± 3.7), Ni (15.8 ± 1.5), and Cu (5.7 ± 1.9). Results showed that A. thiooxidans DSM 26636 was able to grow in the presence of metal-containing wastes, and although metal removal was feasible, more studies are needed to enhance metal removal.

show abstract

Bio-extraction of precious metals from urban solid waste

Cited by 16 publications

References 14 publications

Optimization of Precious Metals Recovery from Electronic Waste by Chromobacterium violaceum Using Response Surface Methodology (RSM)

Optimization of Precious Metals Recovery from Electronic Waste by Chromobacterium violaceum Using Response Surface Methodology (RSM)

Microbial biominers: Sequential bioleaching and biouptake of metals from electronic scraps

Acidithiobacillus thiooxidans DSM 26636: An Alternative for the Bioleaching of Metallic Burrs

Contact Info

Product

Resources

About