This volume provides comprehensive up-to-date descriptions of the principles and practices of in situ chemical oxidation (ISCO) for groundwater remediation based on a decade of intensive research, development, and demonstrations, and lessons learned from commercial field applications.

Approximately 85% of the hazardous waste sites in the United States have contaminated ground water. The conventional approach for remediating contaminated ground water has been to extract the contaminated water, treat it above ground, and reinject or discharge the clean water ("pump- and-treat"). The recovered contaminants must be disposed of separately. It is becoming increasingly apparent that pump-and-treat technologies require considerable investment over extended period of time, and often times do not actually clean up the source of the contamination. Current policies and law stress "permanent" remedies over containment. Consequently, there is considerable interest and effort being expended on alternative, innovative treatment technologies for contaminated ground water. This report is one in a series that document recent pilot demonstrations and full-scale applications that either treat soil and ground water in place or increase the solubility and mobility of contaminants to improve their removal by other remediation technologies. It is hoped that this information will allow more regular consideration of new, less costly, and more effective technologies to address the problems associated with hazardous waste sites and petroleum.

This book combines the results of current research with essential background material to provide complete, in-depth coverage of every aspect of in situ and ex situ bioremediation, as well as an extensive overview of the physical and chemical processes currently available for treating petroleum-contaminated soils. Critical information has been collected and assembled under one cover to provide a convenient reference for anyone who must contend with this worldwide problem. Remediation of Petroleum Contaminated Soils: Biological, Physical, and Chemical Processes describes how to optimize the biodegradation of petroleum hydrocarbons in soil-water systems. It reports on the susceptibility of various petroleum components to biodegradation by microorganisms, and considers all groups of microorganisms for their potential contributions. The book also deals with problem areas such as the transport of organisms, oxygen, or nutrients throughout the subsurface, as well as biodegradation of polynuclear aromatic hydrocarbons (PAHs) and nonaqueous phase liquids (NAPLs). In addition, the book presents a variety of methods for monitoring bioremediation. This reference discusses current soil remediation processes and includes many innovative approaches. It also investigates means of controlling volatile organic compounds (VOCs) and leachate, and addresses methods for collecting and treating these secondary waste streams. The expansive coverage of this book will furnish readers with a wide range of options for developing treatment strategies and for customizing procedures for specific requirements.

Federal regulations have required thousands of underground storage tanks (USTs) to be dug up and removed or replaced. The contamination of soil and ground water from leaking USTs has become widespread and has produced an overwhelming number of sites that require remediation. Assessment and Remediation of Petroleum Contaminated Sites presents the broad scope of the remedial process from initial site assessment to closure in an integrated, understandable format. The book guides you effortlessly through regulatory requirements, site assessments and sampling, and remediation methods. RCRA and CERCLA federal regulations are addressed. The chemistry and toxicology of petroleum hydrocarbons in the remediation process are explained, and factors affecting soil remediation are discussed. Environmental assessments, site characterizations, remediation planning, and remediation methods are all covered in detail. The book is an essential guide for environmental consultants, regulatory agency personnel, engineers, and environmental attorneys.

Petroleum hydrocarbon (PHC) contamination poses a serious threat to aquifer systems worldwide. Accidental releases of PHCs due to gasoline spills and leakage from underground storage tanks can often result in PHC subsurface contamination. The main compounds of concern associated with gasoline spills are benzene, toluene, ethylbenzene and xylenes (BTEX), trimethylbenzenes (TMBs) and naphthalene, due to their high mobility and potential human health risks. Sodium persulphate is one of the newest oxidants to gain widespread use for in situ chemical oxidation (ISCO), however its effectiveness in treating PHCs is not fully understood. In this study, the ability to use unactivated sodium persulphate as a remediation tool in treating dissolved and residual BTEX contamination was tested during a bench-scale laboratory study and within a pilot-scale field investigation. In both cases unactivated sodium persulphate was used at a concentration of 100 g/L. A laboratory-scale degradation potential batch test was conducted to assess the efficacy of unactivated sodium persulphate to oxidize petroleum hydrocarbon contaminated groundwater in conjunction with aquifer material from a field site. Data from the control reactions indicated that persulphate was stable for the entire 35-day experimental period and that the decrease in PHC concentrations for most of the samples followed a first-order degradation. The behaviour and ability for sodium persulphate to oxidize dissolved and residual BTEX contamination was further evaluated in a controlled pilot scale field study. 200 kg of sodium persulphate was dissolved in 2000 L of water and injected into the subsurface. Electrical conductivity (EC), pH, sodium, persulphate, sulphate and BTEX concentrations were all monitored throughout the 158-day study period. Field research showed that there was a strong correlation between EC and sodium concentrations. Hence, this relationship allowed for real-time EC measurements to be used to effectively predict the extent of the injectate. Based on the calculated aqueous density of sodium persulphate at a concentration of 100g/L, predicted simulation model results and observed tracer field results, density effects were present and played a very important role in the transport of the injectate. The heterogeneous geology of the site also greatly influenced the transport of the injectate. The majority of the injectate appeared to have flowed out of the layers with higher hydraulic conductivity that intersected the upper and lower portion of the injection well's screen length. The extent of the injected slug in the layers with lower hydraulic conductivity located in the centre portion of the injection well's screen length was less in comparison.