Bioremediation

Bioremediation is one of the most promising technological approaches to the problem of hazardous waste. This process relies on microorganisms such as bacteria or fungi to transform hazardous chemicals into less toxic or nontoxic substances. There are several reasons why such biological transformation is often more attractive than direct chemical or physical treatment. Microorganisms typically: directly degrade contaminants rather than merely transferring them from one medium to another, employ metabolic degradation pathways that can terminate with benign waste products (e.g., carbon dioxide and water), derive the food energy necessary to degrade contaminants from the contaminants themselves, can be used in situ to minimize disturbance of the cleanup site. For these reasons, microorganisms can be effective, economical, and nondisruptive tools for eliminating hazardous chemicals. Until recent years, however, the use of bioremediation was limited by the lack of a thorough understanding of biodegradation processes, their appropriate applications, their control and enhancement in environmental matrices, and the engineering techniques required for broad application of the technology.