Development of Slow-Release Chemical Oxidation Methods for Environmental Remediation

Chemical oxidation (chemox) is an emerging method used for treating subsurface water and soil. In chemox, highly reactive liquids or gases are injected into a contaminated zone where the oxidants rapidly react to oxidize and breakdown subsurface contaminants to less toxic byproducts. Examples of oxidants used in chemox include ozone gas, Fenton's Reagent, and crystalline permanganate or persulfate dissolved in water. Despite the effectiveness of chemical oxidation, there are drawbacks to current chemox technologies. These drawbacks include the need (1) to inject very strong gases or copious volumes of chemox liquids into the ground, (2) to reapply the oxidants into the subsurface to fully clean sites due to side reactions occurring with natural organic matter or plugging of the subsurface system with chemox precipitates, (3) to prevent explosion hazards caused by the rapid reactions, and (4) to protect workers from the health and safety hazards associated with use of these chemicals. A novel approach to improving chemical oxidation treatment is to develop slow-release, or controlled release systems, to deliver chemical oxidants for water and soil remediation. This paper addresses the development of slow-release oxidant prototypes which are able to delay the release of a chemical oxidants which can be used for various applications in water treatment.