title: Chemical and microbial remediation of hexavalent chromium from contaminated soil and mining/metallurgical solid waste: a review.
abstract: Chromium is a highly toxic non-essential metal for microorganisms and plants, and its occurrence is rare in nature. Lower to higher chromium containing effluents and solid wastes released by activities such as mining, metal plating, wood preservation, ink manufacture, dyes, pigments, glass and ceramics, tanning and textile industries, and corrosion inhibitors in cooling water, induce pollution and may cause major health hazards. Besides, natural processes (weathering and biochemical) also contribute to the mobility of chromium which enters in to the soil affecting the plant growth and metabolic functions of the living species. Generally, chemical processes are used for Cr- remediation. However, with the inference derived from the diverse Cr-resistance mechanism displayed by microorganisms and the plants including biosorption, diminished accumulation, precipitation, reduction of Cr(VI) to Cr(III), and chromate efflux, bioremediation is emerging as a potential tool to address the problem of Cr(VI) pollution. This review focuses on the chemistry of chromium, its use, and toxicity and mobility in soil, while assessing its concentration in effluents/wastes which becomes the source of pollution. In order to conserve the environment and resources, the chemical/biological remediation processes for Cr(VI) and their efficiency have been summarised in some detail. The interaction of chromium with various microbial/bacterial strains isolated and their reduction capacity towards Cr(VI) are also discussed.
authors: Metal Extraction & Forming Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831 007, Jharkhand, India.
authors: B
authors: B
authors: Dhal
authors: H N
authors: HN
authors: Thatoi
authors: N N
authors: NN
authors: Das
authors: B D
authors: BD
authors: Pandey
mesh_terms: D000327:Adsorption; D002857:Chromium / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D052918:Environmental Restoration and Remediation; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry; D012037:Refuse Disposal; D012987:Soil; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism; D062611:Solid Waste
chemical_list: D007220:Industrial Waste; D012987:Soil; D012989:Soil Pollutants; D062611:Solid Waste; D002857:Chromium; C074702:chromium hexavalent ion; D010100:Oxygen