REVIEW AND RESEARCH NEEDS OF ACTIVE TREATMENT OF ACID MINE DRAINAGE BY ION EXCHANGE

Acid mine drainage (AMD), characterized by low pH and high concentrations of sulfate and heavy metals, is an important and widespread environmental problem related to the mining industry. Active treatments have received much attention lately as promising method for AMD treatment. They offer advantages such as high metal removal at low pH, stable sludge, and recovery of metals. Ion Exchange is the desired mechanism of contaminant removal; however, many mechanisms including adsorption reverse osmosis of metal occur in active treatments. The efficiency of active treatment is high. The most important component is the selection of resins and operating parameters. The performance of field ion exchangers can also be limited by AMD load and metal toxicity. Several studies conducted to find the best-suited resin are reviewed. Moreover, critical parameters for design and long-term operation are discussed. Additional work needs to be done to properly assess the long-term efficiency of Ion exchanger and the metal removal mechanisms.