Advances in Development of Bioreactors Applicable to the Treatment of Ard

Nordwick, Suzzann; Zaluski, Marek; Park, Brian; Bless, Diana

doi:10.21000/jasmr06021410

Cited by 4 publications

(3 citation statements)

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“…The process is influenced by seasonal rate variations (i.e. reduced alkalinity generation rates in cold temperatures; Kuyucak et al 2006), but these reduced rates can be lessened by selecting cold-hardy varieties of sulfate-reducing bacteria (Janin and Harrington 2015;Nordwick et al 2006). Sorption, coprecipitation, and exchange to precipitated Fe and Mn, organic materials, and soil-like materials are additional mechanisms for metal removal.…”

Section: Acidity and Alkalinitymentioning

confidence: 99%

Review of Passive Systems for Acid Mine Drainage Treatment

et al. 2016

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acid neutralization and oxidation and precipitation of the resulting metal flocs. Before selecting an appropriate treatment technology, the AMD conditions and chemistry must be characterized. Flow, acidity and alkalinity, metal, and dissolved oxygen concentrations are critical parameters. This paper reviews the current state of passive system technology development, provides results for various system types, and provides guidance for sizing and effective operation.Keywords Anoxic limestone drains · Bioreactors · Limestone leach beds · Low-pH Fe oxidation channels · Open limestone channels · Wetlands Acid Mine DrainageOxidation of pyritic materials during and after mining produces sulfuric acid and metal ions. These products react with host rock and surface and groundwater to create a range of water chemistries from pH 2 to 8 and elevated ion concentrations. Such waters have traditionally been called acid mine drainage (AMD) and alkaline mine drainage. I n this paper, we use AMD when the water is acidic and state clearly in the text when the water being referred to is not acidic. When AMD enters surface water bodies, biotic impairment often occurs through direct toxicity, habitat alteration by metal precipitates, nutrient cycle alterations, or other mechanisms, and the water often becomes unsuitable for domestic, agricultural, and industrial uses. The process of pyrite oxidation and its effects on water resources have been known for centuries (Nordstrom 2011;Seal and Shanks 2008) and AMD is a worldwide concern (Younger and Wolkersdorfer 2004). Damaging effects of AMD have been described by researchers in Asia (David 2003; Wei Abstract When appropriately designed and maintained, passive systems can provide long-term, efficient, and effective treatment for many acid mine drainage (AMD) sources. Passive AMD treatment relies on natural processes to neutralize acidity and to oxidize or reduce and precipitate metal contaminants. Passive treatment is most suitable for small to moderate AMD discharges of appropriate chemistry, but periodic inspection and maintenance plus eventual renovation are generally required. Passive treatment technologies can be separated into biological and geochemical types. Biological passive treatment technologies generally rely on bacterial activity, and may use organic matter to stimulate microbial sulfate reduction and to adsorb contaminants; constructed wetlands, vertical flow wetlands, and bioreactors are all examples. Geochemical systems place alkalinity-generating materials such as limestone in contact with AMD (direct treatment) or with fresh water upgradient of the AMD. Most passive treatment systems employ multiple methods, often in series, to promote 1 3Mine Water Environ (2017) 36:133-153

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Section: Acidity and Alkalinitymentioning

confidence: 99%

Review of Passive Systems for Acid Mine Drainage Treatment

et al. 2016

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“…The autopsy on the bioreactors revealed a convoluted biochemical environment that was probably caused by the dramatic change in the ARD chemistry after the first 10 months of operation. The material examined during the autopsy showed the mixed results of processes that were occurring at low pH and a reasonably high load of metals with the subsequent reactions that were characteristic for water of neutral pH laden with much less of the dissolved metals (Zaluski et al, 2003). The abundance of TOC present (20% by weight) in the organic matter chamber at the end of the project demonstrated that the bioreactors would have worked equally efficiently with a much smaller supply of organic carbon, provided the same residence time of ARD was maintained.…”

Section: On-site Srb Bioreactormentioning

confidence: 99%

Advances in Development of Bioreactors Applications for the Treatment of Acid Mine Waters

Bless¹,

Zaluski²,

Nordwick³

et al. 2006

JASMR

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Demonstrations and technology development conducted under the Mine Waste Technology Program (MWTP) have lead to significant improvements of sulfate-reducing bacteria (SRB) bioreactors used to treat acid rock drainage (ARD). Benefits of this technology include the reduction of dissolved metal ions to insoluble metal sulfides and the neutralization of the acid rock drainage resulting from the production of bicarbonate from the oxidation of organic nutrients by the sulfate-reducing bacteria. Over the past 15 years, MSE has conducted many bench-scale and design tests along with several pilot-scale field demonstrations. This paper addresses engineering design criteria including the selection of organic media, maintenance of system permeability, and strategies for mitigation of ARD at remote sites with relatively small discharge. Specific applications and results from field SRB bioreactors and associated research are presented. They include: (1) An in situ bioreactor in flooded subsurface mine workings where the bioreactor was operated from 1993 to 2005. (2) A set of field bioreactors that allowed various operational attributes to be evaluated including pretreatment and operational temperature. This demonstration was conducted over a three-year period. (3) A set of both anaerobic and aerobic field bioreactors that operated in staged fashion to show the comprehensiveness of bioreactor applications for acid rock drainage treatment. (4) A bench-test study that focused on the effectiveness of SRB to reduce dissolved sulfate and heavy metals. (5) A bench test and field verification of the advantages of horizontal flow configuration in SRB bioreactors. (6) A reactive cartridge, a component of a modular SRB bioreactor that can be easily transported to remote sites.

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“…Bioreactors use sulfate and iron reducing bacteria to process sulfate into hydrogen sulfide. Hydrogen sulfide then reduces metals ions to metal sulfides . When the pH of the ARD is <3, the bacteria can no longer metabolize the sulfate and iron compounds.…”

Section: Introductionmentioning

confidence: 99%

Acid Rock Drainage Treatment Using Membrane Distillation: Impacts of Chemical-Free Pretreatment on Scale Formation, Pore Wetting, and Product Water Quality

Hull

Zodrow

2017

Environ. Sci. Technol.

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Acid rock drainage (ARD) is a metal-rich wastewater that forms upon oxidation of sulfidic minerals. Although ARD impacts >12,000 miles of rivers in the U.S. and has an estimated cleanup cost of $32-$72 billion, the low pH and high metal concentrations in ARD make rapid, high volume treatment without chemical addition difficult. This research focuses on a novel method of ARD treatment, membrane distillation (MD). In MD, heated ARD is separated from a cooled distillate by a hydrophobic, water-excluding membrane. Because water only passes through the membrane in the vapor phase, nonvolatile sulfate and heavy metals are retained in the concentrate stream. A preliminary in silico analysis using an electrolyte thermodynamic model indicated that MD of 10 different mine wastes yields product water containing no contaminants at concentrations >0.2 ppm. MD tests of synthetic ARD used a ∼34 °C temperature difference, operated at 80% recovery, and produced an initial flux of 38.4 ± 1.1 L·m·h. This flux decreased slightly after scaling by iron oxyhydroxide; however, membranes maintained >99% dissolved solids rejection. Both flux decline and membrane scale formation decreased after a chemical-free, thermal precipitation pretreatment. These results indicate that MD can purify contaminated, acidic wastewater using low-grade heat sources, such as geothermal energy, without chemical addition.

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Advances in Development of Bioreactors Applicable to the Treatment of Ard

Cited by 4 publications

References 1 publication

Review of Passive Systems for Acid Mine Drainage Treatment

Review of Passive Systems for Acid Mine Drainage Treatment

Advances in Development of Bioreactors Applications for the Treatment of Acid Mine Waters

Acid Rock Drainage Treatment Using Membrane Distillation: Impacts of Chemical-Free Pretreatment on Scale Formation, Pore Wetting, and Product Water Quality

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