In Situ Biodegradation of Nitroaromatic Compounds in Soil


Book Description

Nitroaromatic compounds, particularly nitrotoluenes used as explosives and nitroaromatic herbicides such as dinoseb, are serious environmental contaminants at industrial locations nationwide. Research performed during the 1970s (15,18) generally indicated that complete biomineralization of 2,4,6-trinitrotoluene (TNT) and similar highly nitrated compounds did not occur. Biological reductions (R-NO2-R-NO-R-NHOH-R-NH2) and polymerization reactions appeared to occur, but actual degradation of aromatic nuclei was not observed. However, this work involved studies of aerobic systems such as activated sludge and thermophilic composts, and pure culture studies of aerobic fungi and bacteria such as pseudomonads. Pure cultures of some anaerobic bacteria such as Veillonella alcalescens (35) were examined, with similar results. Boopathy and Kulpa (2) recently isolated a Desulfovibrio that used TNT as a sole source of nitrogen, producing toluene as-an end product. A Pseudomonas that produced dinitrotoluene-, mononitrotoluene, and toluene from TNT, perhaps by hydride additions was isolated by Duque et al. (10). These are still incomplete degradations of the parent molecule. Since the Desulfovibrio strain required obligately anaerobic conditions.




Augmentation to in Situ Biodegradation of Nitroaromatic Compounds in Soil


Book Description

We have determined that an organism able to degrade both RDX and TNT in a pure culture is a strain of Clostridium bifermentans. The consortium from which this organism is derived also degrades these compounds, and we suspect that C. bifermentans is also the responsible organism within that consortium. The bioconversion of RDX and TNT occurs under anaerobic conditions both in the consortium and in pure culture without the need of an added reductant. The presence of co-metabolites speeded these biotransformations.




Biodegradation of Nitroaromatic Compounds and Explosives


Book Description

Filled with practical applications and research, Biodegradation of Nitroaromatic Compounds and Explosives presents an international perspective on environmental contamination from explosives. It covers biodegradation strategies for DNT and a wide variety of other nitroaromatic compounds of environmental significance and makes the information access




Biodegradation of Nitroaromatic Compounds


Book Description

During the past five years increased awareness of environmental contamination by nitroaromatic compounds has led to a dramatic increase in research on their biodegradation. The resulting discoveries have markedly extended our understanding of degradation mecha nisms and pathways in bacteria and fungi. Futhermore, this new basic knowledge promises the development of field applications of biodegradation systems for nitroaromatic com pounds. In May of 1994, an International Symposium on the Biodegradation of Nitro aromatic Compounds was held in Las Vegas, Nevada. This symposium brought together the scientists at the frontiers of research into the biodegradation of nitro aromatic compounds. The invited speakers were asked to review their area of expertise and write a critical, comprehensive synthesis of their work and related work by others. This book is the result of their efforts. The emphasis of the reviews is on basic research in biodegradation and biotransfor mation. Therefore, the reactions of nitroaromatic compounds in plants, animals, bacteria, fungi, soil, and even nonbiological systems are considered. The goal of the work is to provide the reader with an appreciation of the tremendous range of possibilities for metabolism of aromatic nitro compounds and the experimental approaches used to understand them. This volume should be of interest to biochemists, microbiologists, engineers, toxicologists, and anyone interested in the behavior of synthetic chemicals in the environment or in living systems. Furthermore, a variety of commercial applications can be envisioned for some of the reactions described here.







Bioremediation of Nitroaromatic and Haloaromatic Compounds


Book Description

Sites contaminated with explosive compounds, pesticides, herbicides, PCBs, and other aromatic compounds present formidable technical, regulatory, and financial challenges. The application of bioremediation technologies to such sites offers the promise of cost-effective site remediation that can serve as a key component of a well-formulated strategy for achieving site closure. This volume presents the results of bench-, pilot-, and field-scale projects focused on the use of biological approaches to remediating problem compounds, such as RDX, HMX, TNT, DDT, 2, 4-D, nitro- and chlorobenzenes, nitroaniline, chloroaniline, hexachlorobenzene, PCPs, PCBs, and dichlorophenol in soils and groundwater.




Biological Remediation of Explosive Residues


Book Description

Microbial degradation, Phytoremediation, Remediation, Explosive residues, Biotransformation, Mineralization, Degradative Enzymes, Degradation Pathways, Energetics, Soil contamination, Water contamination.




In Situ Bioremediation and Natural Attenuation of Dinitrotoluenes and Trinitrotoluene


Book Description

Contamination of soils and groundwater with nitroaromatic compounds such as 2,4,6-trinitrotoluene (TNT) and dinitrotoluenes (DNTs) has drawn considerable attention due to widely distributed contamination sites and substantial efforts for cleanup. Two isomers of DNT, specifically 2,6-dinitrotoluene (2,6-DNT) and 2,4-dinitrotoluene (2,4-DNT), occur as soil and groundwater contaminants at former TNT production sites. The discovery of bacteria that use DNT isomers as electron donors has encouraged bioremediation at contaminated sites. Current work is extending the existing engineered bioremediation to naturally occurring in situ biodegradation and focuses on the application of natural attenuation (NA) as a remediation strategy for residual DNT at contaminated sites. More specifically this research evaluated factors influencing in situ bioremediation of DNTs and TNT in surface soils, vadose zones, and saturated medium. Applications involving surface soils and vadose zones investigated the potential of water infiltration to promote in situ bioremediation. Studies in saturated media were more applicable to NA. Factors that were also considered in studies conduced included: 1) the presence and distribution of degrading microbes in field soils (Barksdale, WI); 2) the dissolution and bioavailability of contaminants in historically contaminated soils; and 3) the effect of mixtures of contaminants (i.e., DNTs and TNT) on biodegradation processes.




Soil Bioremediation


Book Description

SOIL BIOREMEDIATION A practical guide to the environmentally sustainable bioremediation of soil Soil Bioremediation: An Approach Towards Sustainable Technology provides the first comprehensive discussion of sustainable and effective techniques for soil bioremediation involving microbes. Presenting established and updated research on emerging trends in bioremediation, this book provides contributions from both experimental and numerical researchers who provide reports on significant field trials. Soil Bioremediation instructs the reader on several different environmentally friendly bioremediation techniques, including: Bio-sorption Bio-augmentation Bio-stimulation Emphasizing molecular approaches and biosynthetic pathways of microbes, this one-of-a-kind reference focuses heavily on the role of microbes in the degradation and removal of xenobiotic substances from the environment and presents a unique management and conservation perspective in the field of environmental microbiology. Soil Bioremediation is perfect for undergraduate students in the fields of environmental science, microbiology, limnology, freshwater ecology and microbial biotechnology. It is also invaluable for researchers and scientists working in the areas of environmental science, environmental microbiology, and waste management.