Robert L. P. Kleinmann

Bio: Robert L. P. Kleinmann is an academic researcher from United States Department of Energy. The author has contributed to research in topics: Drainage & Coal mining. The author has an hindex of 3, co-authored 3 publications receiving 392 citations.

Review of Passive Systems for Acid Mine Drainage Treatment

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 up-gradient of the AMD. Most passive treatment systems employ multiple methods, often in series, to promote 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.

The Passive Treatment of Coal Mine Drainage

Abstract: Passive treatment of mine water uses chemical and biological processes to decrease metal concentrations and neutralize acidity. Compared to conventional chemical treatment, passive methods generally require more land area, but use less costly reagents, and require less operational attention and maintenance. Currently, the three most common types of passive technologies are aerobic ponds and wetlands, anoxic limestone drains (ALDs), and reducing and alkalinity-producing systems (RAPS). Aerobic wetlands promote mixed oxidation and hydrolysis reactions, and are effective when the raw mine water is net alkaline. Anoxic limestone drains generate bicarbonate alkalinity and can be used to convert water that is net acidic into net-alkaline water for treatment in aerobic ponds and wetlands. RAPS promote reducing conditions and limestone dissolution. They extend the concept of ALDs by pre-treating the water before it contacts the limestone, to eliminate dissolved oxygen and reduce dissolved ferric iron to ferrous iron. These systems can generally be used to treat more acidic water than ALDs, and can better treat water with significant aluminum concentrations. In passive treatment systems, rates of metal and acidity removal and alkalinity generation have been developed empirically. Aerobic wetlands remove iron from alkaline water at rates of 10 to 20 g m &2 d &1. Anoxic limestone drains add 150 to 300 mg/L of alkalinity in about 15 hours of contact, imparting 5 to 20 mg/L of alkalinity per hour of contact. Reducing and alkalinity-producing systems add 15 to 60 g m &2 d &1 of alkalinity, depending on influent water quality and contact time. Selection and sizing criteria for the design of passive treatment systems are presented in this report.

Treatment of Mine Drainage by Anoxic Limestone Drains and Constructed Wetlands

Abstract: As contaminated mine drainage flows into receiving streams, rivers, and lakes, its toxic characteristics decrease naturally as a result of chemical and biological reactions and by dilution with uncontaminated water. During the last decade, the possibility that these processes might be used to treat mine water passively has developed from an experimental concept to full-scale implementation at hundreds of sites. Ideally, passive treatment systems require no input of chemicals and very little operation and maintenance. However, passive treatment systems use contaminant removal processes that are slower than that of conventional treatment and thus require longer retention times and larger areas in order to achieve similar results.

The Evolving Nature of Semi-passive Mine Water Treatment

Abstract: Abstract Passive mine water treatment technologies were originally developed to treat small flows of water with low to moderate acidity and metal loadings. Gradually, semi-passive adaptations and refinements, such as occasionally adding amendments to enhance treatment processes, have allowed passive systems to be used at a greater range of mine sites. This paper addresses the largely unwritten history of semi-passive water treatment and its potential future.

Review of Passive Systems for Acid Mine Drainage Treatment

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 up-gradient of the AMD. Most passive treatment systems employ multiple methods, often in series, to promote 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.