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E-Waste Recycling Technologies
Published in Abhijit Das, Biswajit Debnath, Potluri Anil Chowdary, Siddhartha Bhattacharyya, Paradigm Shift in E-waste Management, 2022
Tanvir Alam, Rabeeh Golmohammadzadeh, Fariborz Faraji, M. Shahabuddin
One of the major drawbacks of bacterial bioleaching is the sensitivity of the microorganisms to the amount of heavy metals they are exposed to (Heydarian et al., 2018). This problem could be moderated through a process called adaptation at which the heavy metals are step-wise introduced to a series of bacteria subcultures in little amounts (Baniasadi et al., 2019). Therefore, the successful subculture of bacteria capable of tolerating higher amount of metallic contamination would be selected and employed for actual bioleaching step. It is also important to consider that the condition could be favourable for jarosite formation when sulphur-oxidizing and iron- oxidizing bacteria are employed for recycling of spent LIBs (Zeng et al., 2013). This can precipitate a proportion of the interesting metals; hence a good control over the process in necessary.
Bioleaching and engineering properties of ore materials (overview)
Published in Vladimir Litvinenko, EUROCK2018: Geomechanics and Geodynamics of Rock Masses, 2018
Anna V. Shidlovskaya, Anna A. Timchenko, Mark E. Smith
Bioleaching can be defined as liberation of metals through the direct or indirect action of microorganisms. Most of the microorganisms involved in bioleaching are characterized as being autotrophic, acidophilic, and aerobic. Microorganisms can tolerate a high concentration of metal ions. The main groups of microorganisms involved in bioleaching are shown in the Table 1. Most microorganisms grow as a biofilm attached to the surface of mineral particles. Microbial cells are embedded in a matrix of extracellular polymeric substance (EPS) where microorganisms are only 5–35% of biofilms mass [7]. Another part of biofilms consists of metabolism products of bacteria that cover the microbial cells. In an EPS, Fe2+ and thiosulfate are produced and then oxidized to sulfuric acid with elemental sulfur as a side product [3]. EPS plays an important role in cell attachment [4]. A study on the ability of microorganisms to adhere to mineral surface was carried out by Rodriguez et al. [8].
Bioleaching and engineering properties of ore materials (overview)
Published in Vladimir Litvinenko, EUROCK2018: Geomechanics and Geodynamics of Rock Masses, 2018
Anna V. Shidlovskaya, Anna A. Timchenko, Mark E. Smith
Bioleaching can be defined as liberation of metals through the direct or indirect action of microorganisms. Most of the microorganisms involved in bioleaching are characterized as being autotrophic, acidophilic, and aerobic. Microorganisms can tolerate a high concentration of metal ions. The main groups of microorganisms involved in bioleaching are shown in the Table 1. Most microorganisms grow as a biofilm attached to the surface of mineral particles. Microbial cells are embedded in a matrix of extracellular polymeric substance (EPS) where microorganisms are only 5–35% of biofilms mass [7]. Another part of biofilms consists of metabolism products of bacteria that cover the microbial cells. In an EPS, Fe2+ and thiosulfate are produced and then oxidized to sulfuric acid with elemental sulfur as a side product [3]. EPS plays an important role in cell attachment [4]. A study on the ability of microorganisms to adhere to mineral surface was carried out by Rodriguez et al. [8].
A Comprehensive Review on Cobalt Bioleaching from Primary and Tailings Sources
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Alex Kwasi Saim, Francis Kwaku Darteh
Biological methods can recover metals from primary and secondary sources more cheaply and sustainably than chemical approaches (Ilyas, Chi, and Lee 2013; Saim, Ofori-Sarpong, and Amankwah 2022). Bioleaching extracts insoluble metals from sulfide and laterite ores using microorganisms and their metabolic products. Bioleaching is becoming vital in hydrometallurgy for metal extraction and recovery since it is considered environmentally friendly and efficient. Bioleaching is presently the preferred method for processing low-grade ores with deleterious components that make pyrometallurgical extraction expensive (Brierley and Brierley 2013; Pathak, Morrison, and Healy 2017). Most metal bioleaching investigations have used sulfur- and iron-oxidizing bacteria and organic acid-producing fungi (Kumar and Yaashikaa 2020; Roberto and Schippers 2022). Biohydrometallurgy has been used commercially for the extraction of Cu and Au over the past 40 years (Darvanjooghi et al. 2022; Yin et al. 2018).
Hydrometallurgical processes for heavy metals recovery from industrial sludges
Published in Critical Reviews in Environmental Science and Technology, 2022
Viraj Gunarathne, Anushka Upamali Rajapaksha, Meththika Vithanage, Daniel S. Alessi, Rangabhashiyam Selvasembian, Mu. Naushad, Siming You, Patryk Oleszczuk, Yong Sik Ok
Bioleaching has several benefits over conventional chemical leaching approaches. Those are cost-effectiveness, facilitation of in-situ leaching, no energy consumption, no requirement for toxic chemical compounds, and less secondary waste generation (Johnson, 2013; Watling, 2006). Therefore, bioleaching is considered one of the most environmentally friendly and cost-effective approaches that can be applied for recovering metals from the industrial sludge. However, bioleaching is also associated with some drawbacks: specific microorganism strains are required for specific metals; conditions must be controlled for proper microbial activities; the recovery process can be time-consuming. Considering its applicability to a wide range of industrial wastes and associated heavy metals, and the process duration that is required to obtain an acceptable amount of metals, chemical leaching is often considered a better technique for recovering metals from the industrial sludge, as compared to bioleaching (Mikoda et al., 2019).
A review of chromite mining in Sukinda Valley of India: impact and potential remediation measures
Published in International Journal of Phytoremediation, 2020
Suman Nayak, Rangabhashiyam S, Balasubramanian P, Paresh Kale
Bioleaching is a biochemical process that uses both chemical substances and environmental microbes for the extraction of metal ions (Figure 4a). Conversely, with some modification, the process now involves the pretreatment of waste materials with acid and subsequently with iron- and sulfur-oxidizing microbes native to the sludge. Bioleaching can be achieved through direct leaching and indirect leaching. For direct leaching, non-soluble metal sulfides are oxidized to their water-soluble forms by chemolithotrophic bacteria while in the indirect route, elemental sulfur (S) is oxidized first to sulfuric acid by sulfur-oxidizing bacteria followed by the dissolution of metals by strong acid. The equations are as follows: