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This review provides a snapshot of papers published in 2015 relevant to the topic of mine drainage generation and control options. The review is broken into 3 sections: Generation, Prediction and Prevention and Treatment Options. The first section, mine drainage generation, focuses on the characterization of mine drainage and the environmental impacts. As such, it is broken into three subsections focused on microbiological characterization, physiochemical characterization and environmental impacts. The second section of the review is divided into two subsections focused on either the prediction or prevention of acid mine drainage. The final section focuses on treatment options for mine drainage and waste sludge. The third section contains subsections on passive treatment, biological treatment, physiochemical treatment and a new subsection on beneficial uses for mine drainage and treatment wastes. [ABSTRACT FROM AUTHOR]

Mine drainage from the mining of mineral resources (coal, metals, oil sand, or industrial minerals) remains as a persistent environmental problem. This review summarizes the scientific literature published in 2014 on the technical issues related to mine drainage or mine water in active and abandoned coal/hard rock mining sites or waste spoil piles. Also included in this review is the water from oil sand operations. This review is divided into the four sections: 1) mine drainage characterization, 2) prediction and environmental impact, 3) treatment technologies, 4) oil sand water. Many papers presented in this review address more than one aspect and different sections should not be regarded as being mutuallyexclusive or all-inclusive. [ABSTRACT FROM AUTHOR]

Globally, mine drainage is a persistent environmental problem facing the mining industry. This review covers the literature published in 2013 on topics relating to acid mine drainage (AMD) or acid rock drainage (ARD) due to the presence of sulfide bearing minerals in active and abandoned coal/hard rock mining sites or waste spoil piles. This review is divided into the four sections: 1) mine drainage characterization, 2) mine drainage treatment 3) modeling and simulation, and 4) environmental aspect. Many papers presented in this review address more than one important topic and different sections presented in this review should not be regarded as being mutually-exclusive or all-inclusive. [ABSTRACT FROM AUTHOR]

A review of the literature published in 2012 on topics relating to acid mine drainage (AMD) or acid rock drainage (ARD) due to the presence of sulfide bearing minerals in active and abandoned coal/hard rock mining sites or waste spoil piles is presented. This review is divided into the following sections: 1) Characterization and Assessment, 2) Protection, Prevention and Restoration, 3) Toxicity Assessment, 4) Fate and Transport, 5) Biological Characterization, and 6) Treatment Technologies. Due to the complexity of the minerals and mine drainage, many papers presented in this review address more than one important topic, indicating that they can be categorized into more than one section. Therefore, the different sections presented in this review should not be regarded as being mutually-exclusive or all-inclusive. [ABSTRACT FROM AUTHOR]

Highway construction in mountainous areas can result in sedimentation of streams, negatively impacting stream habitat, water quality, and biotic communities. We assessed the impacts of construction of a segment of Corridor H, a four-lane highway, in the Lost River watershed, West Virginia, by monitoring benthic macroinvertebrate communities and water quality, before, during, and after highway construction and prior to highway use at upstream and downstream sites from 1997 through 2007. Data analysis of temporal impacts of highway construction followed a Before-After-Control-Impact (BACI) study design. Highway construction impacts included an increase in stream sedimentation during the construction phase. This was indicated by an increase in turbidity and total suspended solids. Benthic macroinvertebrate metrics indicated a community more tolerant during and after construction than in the period before construction. The percent of Chironomidae and the Hilsenhoff Biotic Index (HBI) increased, while percent of Ephemeroptera, Plecoptera, and Trichoptera (EPT) decreased. Our 10-year study addressed short-term impacts of highway construction and found that impacts were relatively minimal. A recovery of the number of EPT taxa collected after construction indicated that the benthic macroinvertebrate community may be recovering from impacts of highway construction. However, this study only addressed a period of 3 years before, 3 years during, and 4 years post construction. Inferences cannot be made concerning the long-term impacts of the highway, highway traffic, runoff, and other factors associated with highway use. Continual monitoring of the watershed is necessary to determine if the highway has a continual impact on stream habitat, water quality, and biotic integrity. [ABSTRACT FROM AUTHOR]

Adsorption tests of Congo Red, a commercial azo dye, by acid mine drainage (AMD) sludge were carried out at different pH, temperature, dye concentration, contact time, and adsorbent dosage. Precoat filtration was conducted to test if the dye could be removed during continuous filtration by a precoated AMD sludge layer. Adsorption of Congo Red onto AMD sludge followed the Langmuir isotherm model with a maximum adsorption capacity of 389.1 mg/g. Based on thermodynamic studies, adsorption was found to be exothermic, and an increase in temperature led to a decline in dye removal. Dye removal decreased with an increasing pH. Through metal leaching tests, it was observed that most metals associated with AMD sludge remained insoluble when adsorption occurred at pH 6–10. A rather rapid process was observed for the adsorption of Congo Red onto AMD sludge with more than 80% adsorption taking place within 5 min. Adsorption kinetics followed pseudo-second-order model. Precoat filtration continuously removed Congo Red from aqueous solution with success, and dye removal mechanism via precoat filtration was adsorption. The adsorption and precoat filtration studies showed dye removal could be a beneficial use of AMD sludge prior to its final disposal. [ABSTRACT FROM AUTHOR]

A major problem in the active treatment of acid mine drainage (AMD) is the generation of large volumes of sludge through pH neutralization and subsequent metal precipitation. The sludge typically contains a low concentration of solids, resulting in associated handling and disposal difficulties. Anhydrous ammonia is one reagent commonly used to neutralize AMD due to its quick reaction rate, easy implementation, and relatively low chemical and operational costs. However, very limited information is available in the literature related to the detailed characterization and dewaterability of ammonia-treated AMD sludge. In this study, sludge was collected from an AMD treatment facility where ammonia neutralization was used. The sludge characteristics included high pH and alkalinity, high total Fe and Al, elevated sulfate, and low solids content (0.72 ± 0.24%). Coagulants and flocculants were not effective in reducing the settled sludge volume. Based on filtration tests, ammonia-treated AMD sludge demonstrated relatively good dewaterability in terms of specific resistance to filtration ( SRF). Sludge cake containing 4.5–6.3% solids were obtained using vacuum filtration at a vacuum of 50.8 kPa (15-inch Hg). The appropriate immersion time was 60 s for a vacuum filter, and sludge cakes of 6.2% solids and a yield of 3.04 kg/m2h were achieved. Overall, the belt filter press showed the best performance in improving total solids content in the sludge cakes, where concentrations of ∼10% solids were achieved. [ABSTRACT FROM AUTHOR]

The large volumes of sludge produced through the active treatment of acid mine drainage (AMD) require further processing and final disposal. AMD sludge typically contains a heterogeneous mixture of iron, aluminum, magnesium, and calcium oxides/hydroxides that are of little to no practical value. However, purified iron and aluminum hydroxides have potential commercial value. Based on the solubility of the major dissolved metals, a two-step selective precipitation process was developed to recover high purity iron and aluminum as separate hydroxide products through the manipulation of current AMD treatment operations. The recommended pH for iron precipitation was pH 3.5–4.0 with precipitate purity >93.4% and iron recovery >98.6%. AMD water after iron removal was used as source water for aluminum recovery. Aluminum precipitated best at pH 6.0–7.0 with aluminum recovery >97.2% and precipitate purity >92.1%. [ABSTRACT FROM AUTHOR]