9 - Degradation of energetic compounds by fungi

Summary

Introduction

Energetic compounds have important roles in military and civilian applications, and their production represents a considerable portion of the chemical manufacturing industry. Soils and waters at a significant number of sites worldwide have become contaminated with energetic organonitro compounds as a result of manufacturing and decommissioning of ordnance (Rosenblatt et al, 1991). Kaplan (1990) describes hazardous energetic organonitro compounds as a class of synthetic chemical characterized by the presence of a nitroaromatic, nitrate ester or nitramine functional group or moiety. The relative toxicity, mutagenicity and recalcitrance of these compounds in the environment has led to intensive research for innovative technologies to treat contaminated wastes, soils and waters (Kaplan, 1990, 1992; Rosenblatt et al, 1991).

Technologies have been developed to reduce or remove hazardous energetic organonitro compounds from particular waste streams and from the environment in general. Physical treatment technologies include activated carbon absorption, air stripping, filtration and incineration. Chemical treatment technologies include solvent extraction, surfactant precipitation and neutralization (Kaplan, 1990). Biological treatment technologies include denitrification (Kaplan, 1990), batch and continuous fermentation systems (Funk et al, 1995a,b; Razo-Flores et al, 1997; Lenke et al, 1998) and composting (Isbister et al, 1984; Williams, Ziegen-fuss & Sisk, 1992; Funk et al, 1995b; Emery & Faessler, 1997; Tuomi, Coover & Stroo, 1997; Lenke et al, 1998). A biological approach is often desirable because of its relatively low cost compared with chemical or physical treatment technologies and the innocuous nature of the typical by-products, carbon dioxide and water.