Inhibition of iron-oxidizing bacteria in wastes from coal and hard-rock mines using the anti-bacterial agent

The production of acid mine drainage (AMD) is catalyzed by iron-oxidizing bacteria primarily of the species Thiobacillus ferrooxidans. By inhibiting these bacteria, the production of AMD can be greatly reduced. One compound found to be effective in the inhibition of T. ferrooxidans is nitrapyrine. N-Serve, a product of Dow Chemical, Inc., is the commercially available form of nitrapyrine. This compound has been widely used in agriculture for nitrification inhibition. The purpose of this study was to determine the effectiveness of N-Serve in reducing the production of AMD under simulated field conditions. A column study was completed using a coal mine waste and a hard-rock mine waste. Eight columns containing 7kg of rock were established for each substrate. Three doses of NServe (22% nitrapyrine) were applied once at the beginning of this study: a high dose 2200 mg/kg, a medium dose 220 mg/kg, and a low dose 22 mg/kg. Duplicate columns were included for each N-Serve dose including two untreated columns to serve as a control for each substrate. Beginning the week after treatment, the columns were leached once a week for 29 weeks with deionized, distilled water (equivalent to 2.5 cm precipitation). Only the highest NServe dose produced a column leachate of significantly better quality than that of the controls. The acidity in the high-dose coal mine columns averaged less than 50 percent of the acidity in the control effluent from week 6 through the end of the study. A monolithic controlled release system utilizing acrylonitrile rubber was successfully developed and tested for use with nitrapyrine. This formulation should withstand the rigors of the environment and with minor modification could produce a variety of release rates.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Environmental Sciences and Engineering

Department dc:contributor.department

Environmental Sciences and Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1990

Author dc:creator

• Strobel, Philip Scott

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-04252009-040826

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/42234