Chemical and Microbiological Treatment of Acid Mine Drainage for the Removal of Iron and AcidityEPA Grant Number: U914731
Title: Chemical and Microbiological Treatment of Acid Mine Drainage for the Removal of Iron and Acidity
Investigators: Diz, Harry R.
Institution: Virginia Polytechnic Institute and State University
EPA Project Officer: Michaud, Jayne
Project Period: January 1, 1995 through January 1, 1996
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1995) Recipients Lists
Research Category: Fellowship - Waste Treatment , Hazardous Waste/Remediation , Academic Fellowships
The main objective of this research project is to implement the design of a process (patent pending) to remove iron from acid mine drainage (AMD) without the formation of metal hydroxide sludge.
The system includes the oxidation of ferrous iron in a packed bed bioreactor, the precipitation of iron within a fluidized bed, the removal of manganese and heavy metals (Cu, Ni, Zn) in a trickling filter at high (> 9) pH, with final neutralization in a carbonate bed. This technique avoids the generation of iron oxyhydroxide sludge. Heavy metals were removed both in the fluidized bed reactor as well as in the trickling filter. Oxidation at pH > 9 caused manganese to precipitate (96 percent removal); removals of copper, nickel, and zinc were due primarily to sorption onto oxide surfaces. Removals averaged 97 percent for copper, 70 percent for nickel, and 94 percent for zinc. The treatment strategy produced an effluent relatively free of iron (< 3 mg/L), without the formation of iron sludge and may be suitable for AMD seeps, drainage from acidic tailings ponds, active mine effluent, and acidic iron-rich industrial wastewater.