Performance Assessment of Bioremediation and Natural Attenuation

Abstract

Bioremediation and monitored natural attenuation are among the most cost-effective approaches to manage soil and groundwater contamination by hazardous organic pollutants. However, these remediation alternatives are not universally applicable and may be marginally effective for recalcitrant pollutants if the necessary microbial catabolic capacity is not present or expressed. Thus, regulatory and public approval of bioremediation and natural attenuation requires documentation of the efficacy of microbial degradation of the target pollutants. Performance assessment generally consists of three components: documented contaminant mass loss, geochemical fingerprints associated with biodegradation, and microcosm studies that show direct evidence of biodegradation. More recently, new molecular and isotope fractionation techniques have emerged to complement existing technologies for the forensic analysis and the demonstration of bioremediation and natural attenuation. This critical review examines the current state-of-art in performance assessment methods and discusses future research directions.

KEYWORDS:

• bioremediation
• monitored natural attenuation
• stable isotope analysis
• chemical fingerprinting
• molecular biological tools

ACKNOWLEDGMENTS

The writing of this paper was supported in part by the Strategic Environmental Research & Development Program (SERDP) through project ER-1365 awarded to Walter Illman. Partial funding was also provided by the U.S. Department of Defense Environmental Security Technology Certification Program (ESTCP-CU-0438) grant provided to Pedro Alvarez. This is an independent product of the authors and do not reflect the views of SERDP or ESTCP. We also thank Mr. Andrew Craig for preparing some of the figures included in this manuscript.