Mode of Gypsum Precipitation in Vertical Flow Ponds

Rose, Arthur W.; Morrow, Terry; Dunn, Margaret H.; Denholm, Clifford F.

doi:10.21000/jasmr07010678

Cited by 6 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, performance is highest after start-up, especially if fine limestone is added to the compost layer. For VFW design purposes, a long-term acidity removal rate of 35 g m −2 day −1 has been proposed by Rose and coworkers after an extensive review of more than 30 VFWs in the Appalachian region (Rose 2003(Rose , 2004bRose et al 2004Rose et al , 2007. Watzlaf et al (2000a) reported acidity removal rates for six VFWs ranging from 20 to 62 g m −2 day −1 and that limestone dissolution dominated the neutralization process.…”

Section: Vertical Flow Wetlandsmentioning

confidence: 99%

Review of Passive Systems for Acid Mine Drainage Treatment

et al. 2016

View full text Add to dashboard Cite

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

show abstract

Section: Vertical Flow Wetlandsmentioning

confidence: 99%

Review of Passive Systems for Acid Mine Drainage Treatment

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Prior to "stirring", two trenches (lengthwise and widthwise) were cut in the treatment media to again make observations and to collect samples for analysis. Analytical results of the samples completed under the direction of Dr. Art Rose indicated that a portion of the plugging may be related to amorphous Al precipitates and the formation of gypsum which cemented portions of the limestone aggregate (Rose, 2007). Following the field observations, the media was "stirred-and-fluffed" with the backhoe.…”

Section: System Maintenancementioning

confidence: 99%

Case Study: "The Jennings System" - Over a Decade of Successful Passive Treatment

Denholm¹,

Johnson²,

Taylor³

et al. 2010

ASMR

View full text Add to dashboard Cite

Treatment of drainage from an underground coal mine, abandoned for over 65 years, has been a focus of the Jennings Environmental Education Center (a Pennsylvania State Park) since failure of a mine seal in 1984. Early prototypes of environmentally-friendly technologies or passive treatment components have been installed and monitored since 1989. As Jennings is dedicated to environmental education at various interest levels for the general public and for students of all ages, water monitoring to demonstrate the performance of the system has been imperative. In 1997, a Vertical Flow Pond (VFP) with treatment media consisting of 272 metric tons (300 short tons) of spent mushroom compost mixed with 345 metric tons (380 short tons) [9.52 mm x 1.180 mm (3/8"x16 mesh); >90% CaCO 3 ] of limestone aggregate, a step-down (Bioswale) wetland, and an aerobic wetland/settling pond were installed to treat the acidic, metalladen, raw water which averages 76 Lpm (20 gpm), 3.0 pH, 270 mg/L acidity, 40 mg/L total iron, 15 mg/L total manganese, and 15 mg/L total aluminum. At the time of installation, the predicted optimum life of the VFP treatment media was 7 to 10 years with exhaustion in about 14 years. After over 12 years, however, the system continues to provide successful treatment with limited maintenance. The primary maintenance item has been two, approximately two-day, "stirring" events to address permeability of the treatment media. As a design schematic and analyses from over 200 water monitoring events (depending upon the component), conducted by numerous professionals, students, and volunteers, are publically available online at www.datashed.org, the passive system provides a valuable template for future designs and improvements. The final effluent of the system can be characterized as typically net alkaline with total iron, manganese, and aluminum concentrations of about 1 mg/L or less.

show abstract

“…As the sulfate concentration in the discharges was high (>2000 mg/L) and as research had indicated that gypsum may be a contributor to plugging or fouling (decrease in permeability) of treatment media (Rose, et al, 2007), there was concern about saturation with respect to gypsum with the use of limestone as an alkalinity generator. Several design features, therefore, were included at different locations within the system to try to reduce the likelihood of gypsum precipitation.…”

Section: Inhibiting Gypsum Formationmentioning

confidence: 99%

Low-pH Iron Removal as Part of Multi-Stage Passive Treatment

Denholm¹,

Danehy²,

Busler³

et al. 2010

ASMR

View full text Add to dashboard Cite

Through a contract with the US Army Corps of Engineers, Baltimore District, an innovative passive system to treat drainage from an abandoned underground coal mine was completed in 2008. The discharges can be characterized as highly acidic (pH 2.7, 1400 mg/L acidity) with moderate to high metal concentrations, having average total iron, manganese, and aluminum values of 300 mg/L, 20 mg/L, and 140 mg/L, respectively. The passive system utilizes a variety of treatment components including mixed-media vertical flow ponds, an anoxic limestone drain, a horizontal flow limestone bed, settling ponds, wetlands, etc. Of particular interest is the use of oxidation and precipitation channels to form iron solids at low pH. Preliminary results indicate that on average about 230 mg/L of dissolved iron is being removed at 2.6-3.2 pH. Removal of iron within the channels is expected to decrease operation & maintenance requirements while increasing the overall life of the system. Other design considerations included decreasing the potential for saturation with respect to gypsum, increasing alkalinity through anaerobic decomposition and sulfate reduction in alkaline mine drainage sources, and creating elk habitat. The final system effluent is net alkaline (7.5 pH, 214 mg/L alkalinity, -180 mg/L acidity) with total iron and aluminum less than 1 mg/L and total manganese of about 5 mg/L.

show abstract

Mode of Gypsum Precipitation in Vertical Flow Ponds

Cited by 6 publications

References 11 publications

Review of Passive Systems for Acid Mine Drainage Treatment

Review of Passive Systems for Acid Mine Drainage Treatment

Case Study: "The Jennings System" - Over a Decade of Successful Passive Treatment

Low-pH Iron Removal as Part of Multi-Stage Passive Treatment

Contact Info

Product

Resources

About