Bioremediation in urban pollution mitigation: Theoretical background and applications to groundwaters

This chapter briefly introduces the theory of bioremediation, which applies to both solid and aqueous media, and then discusses the application of this important technology to the in situ biological treatment of groundwater. It examines both oxidative and reductive mechanisms relating to both organic and inorganic contaminants. The chapter summarizes the main requirements for bioremediation. Oxygen releasing compounds can provide electron acceptors via substances introduced into the subsurface layer which decompose to release O². The most commonly used electron acceptor in the absence of oxygen is nitrate. The removal of nitrate and perchlorate are examples of reductive anaerobic degradation, which is far less common than oxidative bioremediation. Permeable reactive barriers work by directing groundwater under the influence of the hydraulic gradient through a zone where remedial processes are optimised.