Chapter 11 - In situ bioremediation of heavy metal contaminated soil

Abstract

Due to ongoing urbanization and industrialization environmental pollution has become a dominant aspect of society. Of the many pollutants present in the environment heavy metals are of serious concern as they are highly toxic in nature and result in health issues. Soil contaminated with heavy metals causes its accumulation in the plants and thereby reaches the human body as they pass through the food chain. Hence removal of heavy metals from soil is of utmost importance to eliminate the problems of toxicity. The use of plant and microbe-mediated approaches for heavy metal remediation is effective and eco-friendly. Microorganisms acquire inherent biological mechanisms which permit them to survive under heavy metal stress conditions and aid in the removal of metals from the environment. In situ bioremediation process aims to use the microorganisms for their multiple functions of enhancing soil fertility, improving the growth of plants, and heavy metal elimination from the soil at the same time. Several bioremediation methods have been developed by many scientists, some of which involve uptake of pollutants and others which involve the conversion of harmful complex pollutants into harmless forms by oxidation, fixation, etc. This chapter discusses the toxic effects of heavy metal pollution and the mechanisms used by microbes and plants for remediation of contaminated soil. Recent advances in heavy metal removal by using various in situ microbial strategies as well as their prospects and limitations are also discussed.