Bioremediation and natural attenuation

[...]... responsible for such abiotic natural attenuation mechanisms Bioremediation and Natural Attenuation: Process Fundamentals and Mathematical Models By Pedro J J Alvarez and Walter A Illman Copyright # 2006 John Wiley & Sons, Inc 25 26 Geochemical Attenuation Mechanisms 2.1 CHEMICAL TRANSFORMATION PROCESSES 2.1.1 Hydrolysis Hydrolysis can be defined as the addition of the hydrogen and hydroxyl ions of water... and Table 1.2 summarizes the main sources of groundwater contamination The fact that we are already using about 50% of readily available fresh water makes groundwater protection and cleanup of paramount importance Bioremediation and Natural Attenuation: Process Fundamentals and Mathematical Models By Pedro J J Alvarez and Walter A Illman Copyright # 2006 John Wiley & Sons, Inc 1 2 Introduction to Bioremediation. .. risk-based corrective action (RBCA) In situ bioremediation and monitored natural attenuation are widely accepted as cost-effective cleanup alternatives for sites contaminated with a wide variety of organic pollutants, and the interest in bioaugmentation grows for enhancing the removal of recalcitrant compounds created a bandwagon effect and prompted a major downturn in bioremediation applications In the 1980s,... in bioremediation applications In the 1980s, it became clear that a fundamental understanding of microbiology, microbial ecology, hydrogeology, and geochemistry was needed to successfully 18 Introduction to Bioremediation design and implement bioremediation systems Bioremediation research and the blending of science and engineering to tackle environmental problems boomed in the 1980s, partly stimulated... but more rigorous (and often more costly) numerical modeling (Chapter 6) and analysis is conducted to assess risk (ASTM 1994) Merits and Limitations of Bioremediation 19 Overall, RBCA is intended to be a solution to a resource allocation problem, but its misuse or abuse could lead to an excuse to do nothing RBCA contains the mandates that allow for passive bioremediation (natural attenuation) , which... monitoring and modeling of the contamination However, there is no treatment required if the contamination occurs at a sufficient rate that the plume does not spread Natural attenuation, by no means, is a do- nothing option One has to monitor the site and prove that natural attenuation is actually happening Soil samples have to be taken and analyzed to determine the existence of microbes at the site and the... proliferation and activity of specific microorganisms that can metabolize them Thus, successful bioremediation requires an understanding of site-specific factors that limit desirable biotransformations or 20 Introduction to Bioremediation Table 1.8 Advantages and Disadvantages of Bioremediation Relative to Traditional Remediation Approaches Such as Pump -and- Treat Contaminated Groundwater and Incineration... transportation and liability costs  Organic hazardous wastes can be destroyed (e.g., converted to H2O, CO2, and mineral salts) rather than transferred from one phase to another, thus eliminating long-term liability  Relies on natural biodegradation processes that can be faster and cheaper (at least 10Â less expensive than removal and incineration, or pump and treat)  Minimum land and environmental... Great Lakes and in marine wildlife, and levels on the order of pg/m3 have been detected in human blood and milk (Snyder et al 2003) Oxidized rocket propellants and energetics represent another important class of emerging pollutants and include the rocket propellants NDMA and perchlorate and the military explosive RDX (Figure 1.7) These compounds are increasingly being 12 Introduction to Bioremediation. .. risky technology and continue to select (relatively ineffective) pump -and- treat (P&T) technologies for remediation purposes A 1994 NRC study reports that conventional P&T technologies restored contaminated groundwater to regulatory standards at only 8 of 77 sites Superfund is depleted Poor cleanup record and resource allocation problems stimulate paradigm shift toward natural attenuation and risk-based . protection and cleanup of paramount importance. Bioremediation and Natural Attenuation: Process Fundamentals and Mathematical Models By Pedro J. J. Alvarez and. advantage of natural phenomena, such as bioremediation and natural attenuation. This book aims to provide fundamental biological, chemical, mathematical, and physical