Design and Operation of Empirical Manganese-Removing Bioreactors and Integration into a Composite Modular System for Remediating and Recovering Metals from Acidic Mine Waters (original) (raw)
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Science of The Total Environment, 2005
Mine drainage waters vary considerably in the range and concentration of heavy metals they contain. Besides iron, manganese is frequently present at elevated concentrations in waters draining both coal and metal mines. Passive treatment systems (aerobic wetlands and compost bioreactors) are designed to remove iron by biologically induced oxidation/ precipitation. Manganese, however, is problematic as it does not readily form sulfidic minerals and requires elevated pH (N8) for abiotic oxidation of Mn (II) to insoluble Mn (IV). As a result, manganese removal in passive remediation systems is often less effective than removal of iron. This was found to be the case at the pilot passive treatment plant (PPTP) constructed to treat water draining the former Wheal Jane tin mine in Cornwall, UK, where effective removal of manganese occurred only in one of the three rock filter components of the composite systems over a 1-year period of monitoring. Water in the two rock filter systems where manganese removal was relatively poor was generally bpH 5, whereas it was significantly higher (~pH 7) in the third (effective) system. These differences in water chemistry and manganese removal were due to variable performances in the compost bioreactors that feed the rock filter units in the composite passive systems at Wheal Jane. An alternative approach for removing soluble manganese from mine waters, using fixed bed bioreactors, was developed. Ferromanganese nodules (about 2 cm diameter), collected from an abandoned mine adit in north Wales, were used to inoculate the bioreactors (working volume ca. 700 ml). Following colonization by manganese-oxidizing microbes, the aerated bioreactor catalysed the removal of soluble manganese, via oxidation of Mn (II) and precipitation of the resultant Mn (IV) in the bioreactor, in synthetic media and mine water from the Wheal Jane PPTP. Such an approach has potential application for removing soluble Mn from mine streams and other Mn-contaminated water courses.
Water
Many global mining activities release large amounts of acidic mine drainage with high levels of manganese (Mn) having potentially detrimental effects on the environment. This review provides a comprehensive assessment of the main implications and challenges of Mn(II) removal from mine drainage. We first present the sources of contamination from mineral processing, as well as the adverse effects of Mn on mining ecosystems. Then the comparison of several techniques to remove Mn(II) from wastewater, as well as an assessment of the challenges associated with precipitation, adsorption, and oxidation/filtration are provided. We also critically analyze remediation options with special emphasis on Mn-oxidizing bacteria (MnOB) and microalgae. Recent literature demonstrates that MnOB can efficiently oxidize dissolved Mn(II) to Mn(III, IV) through enzymatic catalysis. Microalgae can also accelerate Mn(II) oxidation through indirect oxidation by increasing solution pH and dissolved oxygen produ...
Water Research, 2014
Manganese-oxidizing bacteria a b s t r a c t Soluble manganese (Mn) presents a significant treatment challenge to many water utilities, causing aesthetic and operational concerns. While application of free chlorine to oxidize Mn prior to filtration can be effective, this is not feasible for surface water treatment plants using ozonation followed by biofiltration because it inhibits biological removal of organics.
BioMed Research International, 2015
Manganese is a contaminant in the wastewaters produced by Brazilian mining operations, and the removal of the metal is notoriously difficult because of the high stability of the Mn(II) ion in aqueous solutions. To explore a biological approach for removing excessive amounts of aqueous Mn(II), we investigated the potential of Mn(II) oxidation by both consortium and bacterial isolates from a Brazilian manganese mine. A bacterial consortium was able to remove 99.7% of the Mn(II). A phylogenetic analysis of isolates demonstrated that the predominant microorganisms were members ofStenotrophomonas,Bacillus, andLysinibacillusgenera. Mn(II) removal rates between 58.5% and 70.9% were observed forBacillussp. andStenotrophomonassp. while theLysinibacillusisolate 13P removes 82.7%. The catalytic oxidation of Mn(II) mediated by multicopper oxidase was not properly detected; however, in all of the experiments, a significant increase in the pH of the culture medium was detected. No aggregates insi...
Biosorption of manganese in drinking water by isolated bacteria
Journal of Applied …, 2010
Water is an important nutrition for living thing, such as humans, animals and plants. Nowdays, it has been polluted with inorganic contaminants which are discharged from industries. Manganese is one of the inorganics contaminant that causes low hemoglobin level, nuerotoxicity, pipes clogging and bad taste if the concentrations in water exceed the regulated limit. A biological treatment process was investigated to treat the manganese through the biosorption mechanisme by using biological aerated filter (BAF) system. The microbes were taken from sewage activated sludge and isolated in agar media and identified by using Biolog Microstation System. These microbes included both Gram positive and Gram negative groups and the morphology were rod shape (Bacillus). The screening test has been done to select the highest manganese uptake by these strains and further studies under laboratory condition as a function of pH, biosorbent dosages, and manganese toxicities were investigated comparison with biosorbent of sewage activated sludge. The biosorption isotherms were fitted with Langmuir to represent the equilibrium of the maximum manganese uptake by bacteria. The screening resulted that HAH1 has a higher manganese uptake capacity than others strain with 13.31 mg Mn2+/g biomass at pH 6 and biomass dosage of 0.1 g. The further studies resulted, manganese biosorption increased with rise in pH 3-8, biosorbent dosages, and manganese toxicities. The Langmuir isotherm model revealed HAH1 was a better biosorbent of manganese than sewage activated sludge with the maximum biosorption capacity (qmax) of 55.56 mg Mn2+/g biomass and Kd value of 133.44.
Water Research, 2010
The interaction of chemical, physical and biological factors that affect the fate, transport and redox cycling of manganese in engineered drinking water systems is not clearly understood. This research investigated the presence of Mn-oxidizing and-reducing bacteria in conventional water treatment plants exposed to different levels of chlorine. Mn (II)-oxidizing and Mn(IV)-reducing bacteria, principally Bacillus spp., were isolated from biofilm samples recovered from four separate drinking water systems. Rates of Mnoxidation and-reduction for selected individual isolates were represented by pseudo-firstorder kinetics. Pseudo-first-order rate constants were obtained for Mn-oxidation (range: 0.106e0.659 days À1), aerobic Mn-reduction (range: 0.036e0.152 days À1), and anaerobic Mnreduction (range: 0.024e0.052 days À1). The results indicate that microbial-catalyzed Mnoxidation and-reduction (aerobic and anaerobic) can take place simultaneously in aqueous environments exposed to considerable oxygen and chlorine levels and thus affect Mnrelease and-deposition in drinking water systems. This has important implications for Mnmanagement strategies, which typically assume Mn-reduction is not possible in the presence of chlorine and oxidizing conditions.
Fundamental Study on the Removal of Mn2+ in Acid Mine Drainage using Sulfate Reducing Bacteria
Materials transactions, 2004
The optimum conditions for Mn 2þ removal from acid mine drainage was studied by a SRB (sulfate reducing bacteria) bioreactor. Chemical experiments with Na 2 S as a S 2À source were conducted to investigate the effects of pH, coexisting metal ions, and the components in a growth medium for SRB on MnS formation from Mn 2þ solutions. The amount of Mn removed from the Mn 2þ solutions decreased with decreasing pH. The Zn 2þ or Fe 2þ coexisting in the solutions consumed S 2À by forming ZnS or FeS, and this inhibited Mn removal. Sodium citrate, a component of the growth medium for SRB, formed a complex with Mn 2þ and suppressed MnS formation. Biological experiments using the SRB reactor were carried out at 37 C and it was confirmed that the Mn 2þ concentration decreased to less than 10 gÁm À3 from 100 gÁm À3 at neutral pHs (pH 5-7) after 100 hours when other metal ions and sodium citrate were absent. The formed precipitate was identified to be metastable-MnS with a band gap of about 3.8 eV by XRD, XRF, and UV-VIS.
Simultaneous removal of iron and manganese from acid mine drainage by acclimated bacteria
Journal of Hazardous Materials, 2020
A bacterial consortium for efficient decontamination of high-concentration Fe-Mn acid mine drainage (AMD) was successfully isolated. The removal efficiencies of Fe and Mn were effective, reaching 99.8 % and 98.6 %, respectively. High-throughput sequencing of the 16S rRNA genes demonstrated that the microbial community had changed substantially during the treatment. The Fe-Mn oxidizing bacteria Flavobacterium, Brevundimonas, Stenotrophomonas and Thermomonas became dominant genera, suggesting that they might play vital roles in Fe and Mn removal. Moreover, the pH of culture increased obviously after incubation, which was benefit for depositing Fe and Mn from AMD. The specific surface area of the biogenic Fe-Mn oxides was 108-121 m 2 /g, and the surface contained reactive oxygen functional groups (-OH and −COOH), which also improved Fe and Mn removal efficiency. Thus, this study provides an alternative method to treat AMD containing high concentrations of Fe and Mn. 1. Introduction Acid mine drainage (AMD) is severely threatening the safety of aquatic and terrestrial ecosystems (Aguinaga et al., 2018; Auld et al., 2017). Available methods for AMD treatment include traditional neutralization techniques, magnetic nanoparticles, lignite and zeolite, and membrane methods, among others (Rand and Ranville, 2019). Traditional neutralization techniques require additions of commercially produced alkali, which is expensive and generate a large volume of sludge, especially in AMD that contains high levels of iron/ferrous ions
International Journal of Mineral Processing, 1997
In the present paper a study on bioleaching of manganiferous ores by heterotrophic mixed cultures is reported. The main goal of this work has been to study the bioreduction process of MnO2 in lab-scale reactor and pilot plant tests, in order to investigate the process' pergormances in a scale larger than in shaken flasks. Lab-scale reactor tests were carried out in a batch and in a semi-continuous regime, monitoring manganese extraction yields and microbial growth. In the bioleaching tests 95–100% of manganese extraction (in 36–48 h of treatment using a content of pulp equal to 20% (w/v) of ore having a Mn grade of 17–20%) was obtained. Final tests in a pilot plant (V = 70L) were performed under non-sterilised conditions. From the experimental results a flowsheet of the process has been proposed. An approximate economical analysis of the bioleaching process has also been reported. The experimental results showed the technical feasibility of the process although several problems have to be resolved to allow for a full-scale application, such as the biomass disposal, the purification of the leach liquor before the final manganese recovery and the too high cost of the process.