Introduction heavy metal pollution

ABSTRACT

Rapidly increasing human population, urbanization, industrialization, and mining activities has become one of the serious environmental issue of today’s world. These activities have added substantial quantities of organic and inorganic pollutants such as xenobiotics (pesticides, pharmaceuticals, petroleum & compounds), toxic and radioactive heavy metals in the environment, which causes hazardous effects on living organisms and impair environmental quality. Coal and mineral mining has resulted forest degradation, biodiversity loss, acid mine drainage, air, water and soil quality deterioration in various parts of the world. Conventional physico-chemical remediation methods are highly expensive and often generate secondary waste. However, bioremediation/phytoremediation of contaminated ecosystems using indigenous microbes and plants or amalgamation of both has been recognized as a cost effective and eco-friendly method of remediation as well as restoration of mine degraded ecosystems. Further, variety of pollutant attenuation mechanisms possessed by microbes and plants makes them more feasible for remediation of contaminated land and water over physico-chemical methods. With respect to their direct roles in remediation processes, microbes and plants use several strategies for dealing with environmental pollutants. Plants and microbes act cooperatively to improve the rates of biodegradation and biostabilization of environmental contaminants. Ecological restoration embraces a broad suite of goals, ranging from amelioration of highly degraded abiotic conditions i.e. toxic pollutant levels and the absence of topsoil on old mine sites, enhancement of key ecosystem functions e.g. production, erosion control, water flow and quality, to the reestablishment of a target biotic community such as rare species, native species, increased biodiversity and eradication of invasive species. In terrestrial ecosystems, plant–microbe interactions are the foundation for effective and sustainable achievement of any of these goals. This chapter aims to emphasize on potential application of microbes and plants to attenuate the organic and inorganic contaminants from the contaminated sites as well as eco-restoration of mine degraded/jhom lands by way of biodegradation and phytoremediation technologies.