A natural attenuation of arsenic in drainage from an abandoned arsenic mine dump

Fukushi, Keisuke; Sasaki, M; Satō, Tsutomu; Yanase, Nobuyuki; Amano, Hikaru; Ikeda, Hodaka

doi:10.1016/s0883-2927(03)00011-8

Cited by 239 publications

(154 citation statements)

References 20 publications

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“…These so-called "ochre precipitates" consist of Fe-phases precipitated from the AMD. In contrast with other well crystallized products of pyrite oxidation, such as hematite or goethite, these mine drainage minerals (MDM; Murad et al, 1994) consist of poorly crystallized oxyhydroxides and oxyhydroxysulphates of fibrous to spherical morphology such as ferrihydrite and schwertmannite, in addition to jarosite and goethite, showing extremely small particle size (b 1 nm spherical particle diameter) (Bigham et al, 1990(Bigham et al, , 1996Carlson and Schwertmann, 1981;Dold, 2003;Fukushi et al, 2003;Kawano and Tomita, 2001;Majzlan et al, 2004;Murad et al, 1994;Nordstrom and Alpers, 1999;Regenspurg et al, 2004;Williams et al, 2002;Yu et al, 1999), which greatly enhance the reactive surface area, allowing the metal adsorption to these mineral phases.…”

Section: Discussionmentioning

confidence: 99%

An integrative assessment of environmental degradation of Caveira abandoned mine area (Southern Portugal)

Silva

Durães

Reis

et al. 2015

Journal of Geochemical Exploration

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Since the end of the 1990s the Portuguese Iberian Pyrite Belt (IPB) is a typical European post-mining region with significant problems related to acid mine drainage (AMD), metal dispersion, mine waste management and unsafe mining infra-structures. The Portuguese government is providing particular attention on the sulphide abandoned mines and doing considerable investments on the mining recovery all over the country. The former Caveira mine was closed in the 1980s. It is considered an extremely impacted site due to the dimension of the areas affected by mining activities. Tailings, mine addicts and associated waste rock dumps, resulting from 129 years of pyrite and Cu exploitation, are spread along the Grândola stream. Despite the semi-arid climatic conditions of the area, the tailings are considerably eroded by the surficial waters, particularly during rainfall events. The past mining and smelting activities have resulted in severe contamination of the Grândola stream and its tributary by AMD (pH b 2) as well as degradation of surrounding stream sediments, soils and vegetation. In order to evaluate possible environmental risks, a sediment and surface water survey was carried out downstream the Caveira mine. The acidic effluent and mixed stream water show high Al, As, Ca, Cd, Cu, Fe, Hg, Mg, Mn, Ni, Pb and SO 4 concentrations, with several of these contaminants exceeding local and/or surface water quality standards. The data show a strong seasonal variation of surface water quality with poorer water quality during the dry and rainy seasons caused by evaporation and efflorescent salt dissolution, respectively. The variable flow regime at the local streams causes dilution of AMD rich in trace metals reaching background within 14 km downstream. The potential toxicity of stream metal concentrations was determined using cumulative criterion unit (CCU) scores and the modified AMD index (MAMDI), which highlighted As, Cd, Cu, Pb and Zn as the major sources of potential chronic stream toxicity, with emphasis on winter season. Although the threshold of the likely harm to aquatic life is exceeded at all sites, the two indexes highlight differences relating to the extension of contamination effects. The Average Index of Toxicity (AIT) showed that sediment contamination is very high even when the distance to mine promoted a decreasing in water metal concentrations, which are being precipitated in the sediments due to pH increase.

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Section: Discussionmentioning

confidence: 99%

An integrative assessment of environmental degradation of Caveira abandoned mine area (Southern Portugal)

Silva

Durães

Reis

et al. 2015

Journal of Geochemical Exploration

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“…3, it can be also found that XRD pattern of the sample is in conformity with those given in the literatures for the synthesized schwertmannite. 6,9) 3.2 Adsorption kinetics of phosphate Figure 4 shows the amount of P adsorption on the schwertmannite with coagulation time at different initial P concentrations. The amount of phosphate adsorption was increased by increasing of the initial P concentration varying from 10 to 40 mg/L.…”

Section: Characterization Of the Schwertmannite Samplementioning

confidence: 99%

Magnetic Removal of Phosphate from Wastewater Using Schwertmannite

et al. 2006

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A magnetic filtration has firstly been applied to the phosphate removal from wastewater by using schwertmannite, which is ferric oxyhydroxide sulfate with high capacity of phosphate adsorption. High efficiency of phosphate removal without using magnetic seeding was obtained at magnetic intensities of around 1 Tesla, which means no necessity to use a superconducting magnet. The kinetics data of phosphate adsorption have been found to be fitted well with a pseudo-second-order model and adsorption equilibrium data have been explained by the Langmuir isotherm. The effect of pH on the phosphate adsorption in this process was characterized by zeta potential measurement. It is proposed that ligand exchange is a dominant mechanism responsible for phosphate adsorption on schwertmannite.

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“…The changes in ion concentrations were listed in Table 1 (4)(5)(6). The B value for the initial pH 5 was higher than the B values for both the acidic and basic solutions.…”

Section: Effect Of Ph On Ion Exchange Reactionmentioning

confidence: 97%

“…6) Figure 1 exhibits a schematic representation of schwertmannite based on the akaganeite structure simulated by Fukushi et al,4) in which SO 4 ions share two O atoms with the surrounding octahedrally coordinated Fe atoms through bidentate bridging coordination (-Fe-O-SO 2 -O-Fe-).…”

Section: Ion Exchange Mechanism On Schwertmannitementioning

confidence: 99%

Evaluation of Selective Separation of Phosphorous Components from Plating Baths Using Schwertmannite

et al. 2008

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Selective separation of phosphorous ion compounds in plating baths is of great interest. Schwertmannite, found as a strong P-sorbent in our pervious works, was used for this purpose as an inorganic chemical adsorbent. The effect of pH as a significant operating parameter on P-adsorption on schwertmannite in this process as well as on the stability of schwertmannite was thoroughly investigated. The experimental results showed that the hypophosphite H 2 PO 2 Ϫ was relatively difficult to exchange with sulfate units in schwertmannite in comparison with monoorthophpsphite H 2 PO 3 Ϫ and monoorthophosphate H 2 PO 4 Ϫ . Moreover, batch kinetic trials revealed that the obtained data was fairly fitted to pseudo-second-order models.KEY WORDS: phosphorous; plating baths; schwertmannite; selective separation.schwertmannite was also examined in the solution of various pH by measuring the change in Fe 3ϩ ion concentration of dissolved schwertmannite into the solution. ExperimentalSchwertmannite was prepared from commercial powders (Sophia Co. Ltd.) in an average particle size of 6.3 mm. The schwertmannite sample was already purified from calcium sulfate. The stock solutions of H 3 PO 2 , H 3 PO 3 , and H 3 PO 4 of 30 mM (10 Ϫ3 mol · dm Ϫ3) in concentration and 250 cm 3 in volume were used as standard solutions in the experiments. Diluted NaOH solution was used to adjust the pH of the base solutions used for electroless plating. In the batch experimental works, 3 g of schwertmannite sample was added to a solution containing the three phosphorous-base acids and then the solution was agitated for 90 min in room temperature. Schwertmannite particles were separated from the solution by paper filter of 1 mm in pores. The quantitative changes in the concentrations of the three kinds of phosphorous ions, SO 4 2Ϫ ion and Fe 3ϩ ion were measured by using a capillary electrophoresis analyzer (Otuka electric Co. Ltd., CAPI-3200). Schwertmannite, as prepared, was suspended in the hydrochloric acid solution of pH 5 and then the changes in pH, SO 4 2Ϫ and Fe 3ϩ dissolved into the solution were measured to evaluate the chemical stability of the schwertmannite sample. Loaded schwertmannite containing saturated amount of H 3 PO 3 was suspended into a 1 M solution of Na 2 SO 4 , or to 1 M H 2 SO 4 of pH 0.1 to characterize the inverse exchange reactions between H 3 PO 3 and SO 4 2Ϫ ions. Results and Discussion Ion Exchange Mechanism on SchwertmanniteSchwertmannite is a poorly crystalline material in which the essential structural sulfate can be contained within tunnels of an ordered akaganeite-like structure or into the positions on the surface of schwertmannite crystallites. 6) Figure 1 exhibits a schematic representation of schwertmannite based on the akaganeite structure simulated by Fukushi et al.,4) in which SO 4 ions share two O atoms with the surrounding octahedrally coordinated Fe atoms through bidentate bridging coordination (-Fe-O-SO 2 -O-Fe-).2) The results of our pervious work, 9) indicated that surface-coordinated SO 4 groups ar...

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A natural attenuation of arsenic in drainage from an abandoned arsenic mine dump

Cited by 239 publications

References 20 publications

An integrative assessment of environmental degradation of Caveira abandoned mine area (Southern Portugal)

An integrative assessment of environmental degradation of Caveira abandoned mine area (Southern Portugal)

Magnetic Removal of Phosphate from Wastewater Using Schwertmannite

Evaluation of Selective Separation of Phosphorous Components from Plating Baths Using Schwertmannite

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