Bioremediation of Hazardous Wastes—A Review

Intensive industrialization generates hazardous wastes comprising organics, inorganics, heavy metals, and munitions that need to be tackled in a safe manner. Commonly employed physicochemical technologies have paved the way to ecofriendly bioremediation processes. Bioremediation uses natural as well as recombinant microorganisms to break down toxic and hazardous substances by aerobic and anaerobic means. They can be applied on site (in situ) or off site (ex situ), mediated by mixed microbial consortia and/or pure microbial strains and. plants (phytoremediation) or even natural attenuation. They include several processes—bioventing, biosparging, biostimulation, bioaugmentation, bioleaching, fungal bioremediation, and biosorption. Bioremediation also encompasses ex situ engineered methods like bioreactors and enzyme catalyzed breakdown. The success of bioremediation is governed by three important factors—availability of microbes, accessibility of contaminants, and a conducive environment. This review discusses various bioremediation technologies, listing the advantages as well as disadvantages and field application, if any.