Bioleaching of spent hydro-processing catalyst using acidophilic bacteria and its kinetics aspect

ArticleinJournal of Hazardous Materials 152(3):1082-91 · May 2008with19 Reads
DOI: 10.1016/j.jhazmat.2007.07.083 · Source: PubMed
Abstract
Bioleaching of metals from hazardous spent hydro-processing catalysts was attempted in the second stage after growing the bacteria with sulfur in the first stage. The first stage involved transformation of elemental sulfur particles to sulfuric acid through an oxidation process by acidophilic bacteria. In the second stage, the acidic medium was utilized for the leaching process. Nickel, vanadium and molybdenum contained within spent catalyst were leached from the solid materials to liquid medium by the action of sulfuric acid that was produced by acidophilic leaching bacteria. Experiments were conducted varying the reaction time, amount of spent catalysts, amount of elemental sulfur and temperature. At 50 g/L spent catalyst concentration and 20 g/L elemental sulfur, 88.3% Ni, 46.3% Mo, and 94.8% V were recovered after 7 days. Chemical leaching with commercial sulfuric acid of the similar amount that produced by bacteria was compared. Thermodynamic parameters were calculated and the nature of reaction was found to be exothermic. Leaching kinetics of the metals was represented by different reaction kinetic equations, however, only diffusion controlled model showed the best correlation here. During the whole process Mo showed low dissolution because of substantiate precipitation with leach residues as MoO3. Bioleach residues were characterized by EDX and XRD.
    • Biohydrometallurgical processing of solid waste is similar to natural biogeochemical metal cycles and reduces the demand of resources, such as ores, energy and landfill space. This technology is environmentally friendly (in comparison to chemical method) and it is considered a green technology (generates less amount of waste) [3, 4]. The paper presents the experimental investigation recently carried out for the extraction of different metals from pcb with hydrometallurgical route.
    Full-text · Article · Jan 2017 · Chemosphere
    • SEM-EDX analysis of catalyst surface after bioleaching has shown the presence of sulphur besides Al, C, and O. However, contrary to previously reported product layer diffusion controlled bioleaching of Mo (Asghari et al., 2013; Mishra et al., 2008), extraction was found to be chemical reaction controlled which indicates slow reaction rate. This is in agreement with our previous discussion on the low solubility of Mo and formation of insoluble MoO 3 $H 2 O under acidic condition (Srichandan et al., 2014).
    [Show abstract] [Hide abstract] ABSTRACT: Spent catalyst bioleaching with Acidithiobacillus ferrooxidans has been widely studied and low Mo leaching has often been reported. This work describes an enhanced extraction of Mo via a two stage sequential process for the bioleaching of hydrodesulphurization spent catalyst containing Molybdenum, Nickel and, Aluminium. In the first stage, two-step bioleaching was performed using Acidithiobacillus ferrooxidans, and achieved 89.4% Ni, 20.9% Mo and 12.7% Al extraction in 15 days. To increase Mo extraction, the bioleached catalyst was subjected to a second stage bioleaching using Escherichia coli, during which 99% of the remaining Mo was extracted in 25 days. This sequential bioleaching strategy selectively extracted Ni in the first stage and Mo in the second stage, and is a more environmentally friendly alternative to sequential chemical leaching with alkaline reagents for improved Mo extraction. Kinetic modelling to establish the rate determining step in both stages of bioleaching showed that in the first stage, Mo extraction was chemical reaction controlled whereas in the subsequent stage, product layer diffusion model provided the best fit.
    Full-text · Article · Jun 2016
    • Some researchers, argues that the bacterial action is an outcome of a physicochemical modification of the mineral surface due to the physical contact of bacteria, and called direct attack. In this process, bacterial membrane components interact directly with the metal moieties of the ore by using an enzymatic type of mechanism (Mishra et al., 2008). Brouwers et al., 2000 Waasbergen et al., 1996 Waasbergen et al., 1996
    Article · Jun 2016
    • Some researchers, argues that the bacterial action is an outcome of a physicochemical modification of the mineral surface due to the physical contact of bacteria, and called direct attack. In this process, bacterial membrane components interact directly with the metal moieties of the ore by using an enzymatic type of mechanism (Mishra et al., 2008). Brouwers et al., 2000 Waasbergen et al., 1996 Waasbergen et al., 1996
    [Show abstract] [Hide abstract] ABSTRACT: Biomining is defined as the technologies that utilize microbial community for the extraction of metals from its ore or wastes and facilitate a greener recovery. Extraction of manganese by biomining is now a thing of the present and not just a hypothesis, as it was few decades back. The severe industrial importance of manganese has led to augmented global production of manganese in the last few years which has led to a decrease in the amount of high grade ores. It has also resulted in pollution of both terrestrial and aquatic ecosystems due to the generation of massive amounts of manganese containing wastes. Therefore, biomining is now being employed to recover manganese low grade ores and solid mining wastes which serve a dual purpose of both resource recycling and bioremediation. Manganese bio recovery can be accomplished by a wide range of bacterial and fungal strains capable of growing under diverse environmental conditions. They solubilise manganese by direct and indirect mechanisms thereby aiding its recovery. Bacterial solubilisation is mainly carried out by direct mechanism which involves the direct contact of the cell with the metal. However fungal solubilisation is mostly correlated with indirect mechanism which does not require direct contact of the cells with metal particles and involves solubilisation by the help of bio generated metabolites that mainly includes organic acids. Many enzymes like Muilticopper oxidase, Manganese reductase and Peptidyl-prolyl-cis-trans isomerise have been linked to manganese solubilisation. The present scenario of commercial manganese recovery through booming is very encouraging and this technology holds immense potential for future metal recovery and bioremediation endeavours. KEYWORDS: Biomining, Manganese, Bioremediation, Waste, Bacteria, Fungus
    Full-text · Chapter · Mar 2016 · Chemosphere
    • For small particle, this can be explained by a Stokes regime (Eq. (7)) (Mishra et al., 2008). The applicability of each kinetic model was derived using the metal leaching data from Fig. 2. Results for each model are plotted in Fig. 5(a, c and e).
    [Show abstract] [Hide abstract] ABSTRACT: Application of bioleaching process for metal recovery from electronic waste has received an increasing attention in recent years. In this work, a column bioleaching of copper from waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans has been investigated. After column bioleaching for 28d, the copper recovery reached at 94.8% from the starting materials contained 24.8% copper. Additionally, the concentration of Fe(3+) concentration varied significantly during bioleaching, which inevitably will influence the Cu oxidation, thus bioleaching process. Thus the variation in Fe(3+) concentration should be taken into consideration in the conventional kinetic models of bioleaching process. Experimental results show that the rate of copper dissolution is controlled by external diffusion rather than internal one because of the iron hydrolysis and formation of jarosite precipitates at the surface of the material. The kinetics of column bioleaching WPCBs remains unchanged because the size and morphology of precipitates are unaffected by maintaining the pH of solution at 2.25 level. In bioleaching process, the formation of jarosite precipitate can be prevented by adding dilute sulfuric acid and maintaining an acidic condition of the leaching medium. In such way, the Fe(2)(+)-Fe(3+) cycle process can kept going and create a favorable condition for Cu bioleaching. Our experimental results show that column Cu bioleaching from WPCBs by A. ferrooxidans is promising. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Jul 2015
    • (F4), weak organic (F5), strong organic (F6), and residual and oxides during the bioleaching process (Mishra et al., 2008). However, the biogenically produced organic acids play a major and direct role in the bioleaching process.
    [Show abstract] [Hide abstract] ABSTRACT: The objective of this study was to optimize the experimental conditions for bioleaching of arsenic (As) using Herbaspirillum sp. GW103 and to understand the interaction between bacteria and As during bioleaching. Five variables, temperature, time, CaCO 3 , coconut oil cake, and shaking rate, were optimized using response surface methodology (RSM) based Box-Behnken design (BBD). Maximum (73.2%) bioleaching of As was observed at 30ºC, 60 h incubation, 1.75% CaCO 3 , 3% coconut oil cake, and 140 rpm. Sequential extraction of bioleached soil revealed that the isolate Herbaspirillum sp. GW103 significantly reduced 28.6% of water soluble fraction and increased 38.8% of the carbonate fraction. The results of the study indicate that the diazotrophic bacteria Herbaspirillum sp. could be used for bioleaching As from mine soil.
    Full-text · Article · Jun 2015
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