Environmental Bioremediation Technologies (Electronic book text)

The rapid expansion and increasing sophistication of various industries in the past century has remarkably increased the amount and complexity of toxic waste effluents, which may be bioremediated by suitable plants & microbes, either natural occurring or tailor-made for the specific purpose. This technology is termed as bioremediation. Bioremediation is an eco- friendly, cost-effective and natural technology targeted to remove heavy metals, radionuclides, xenobiotic compounds, organic waste, pesticides etc. from contaminated sites or industrial discharges through biological means. Since this technology is used in in-situ conditions, it does not physically disturb the site unlike conventional methods i.e. chemical or mechanical methods. In this technology, higher plants or microbes are used alone or in combination for phytoextraction of heavy metals from metal contaminated sites. Through microbial interventions, either the metals are immobilized or mobilized through redox conversions at contaminated sites. If mobilized, metal accumulating plants are put in place to accumulate metals in their body. Thenafter, metal-loaded plants are harvested and incernated to reduce the volume of waste and then disposed off as hazardous materials or used for recovery of precious metals, if possible. In case of immobilization, metals are no longer available to be toxic to organisms.