The Effect of Apatite II: on the Biodegradation of TNT and Perchlorate in Contaminated Soil Samples

Publication Information:

Martinez, M.N., S.S. Hightower, G.B. Smith, W. Mueller, J.L. Conca and J. Wright, The Effect of Apatite II™: on the Biodegradation of TNT and Perchlorate in Contaminated Soil Samples, Sustainable Range Management-2005. Proceedings of the Conference on Sustainable Range Management, 2005, San Antonio Texas.

Year: 2005

Soil found on military gunnery ranges, old battle field sites, or ammunition repositories poses a hazardous threat to the environment and humans because it may be contaminated with 2,4,6-Trinitroluene (TNT) and perchlorate. The purpose of this research was to investigate the use of microorganisms to degrade TNT and perchlorate, and to examine the biodegradative enhancement with a fishbone-based nutrient source known as Apatite II. Tests consisted of column flow-through experiments in which influent and effluent samples were tested for TNT and perchlorate concentrations. The columns were amended with a combination of Apatite II, and a previously isolated TNT-degrading fungal strain which had the same ribosomal DNA sequence as Penicillium spinulosum (based on 561 nucleotide bases). When 10 ppm TNT was amended over a period of 16 months, HPLC analyses showed that during column flows with a 45-minute retention time, soil-only columns, soil + Apatite columns and soil + Apatite + fungal inoculum resulted in 47%, 69% and 95% of the TNT degraded. When 1 ppm perchlorate was amended to the columns, TNT degradation was unaffected, and perchlorate degradation followed the same trends of TNT degradation: that is, perchlorate degradation was stimulated synergistically by the presence of Apatite and the fungal inoculum. Experimental results clearly indicated that the Apatite II stimulated biodegradation of TNT and perchlorate, especially when combined with the TNT-degrading fungus, and that the Apatite II material maintains biodegradation for lengthy periods of time.