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Chapter Two: Chromium Contamination And Its Risk Assessment In Complex Environmental Settings, Girish Choppala, Nanthi Bolan, Jin Hee Park
Chapter Two: Chromium Contamination And Its Risk Assessment In Complex Environmental Settings, Girish Choppala, Nanthi Bolan, Jin Hee Park
Dr Girish Choppala
Chromium reaches the soil environment through waste disposal emanating from a number of industrial activities, including coal-fired power production, electroplating, leather tanning, timber treatment, pulp production, and mineral ore and petroleum refining. Of the heavy metals, chromium (Cr) is a major pollutant, poses a great threat to flora and fauna and persists for long time. The most abundant species of Cr—Cr(III) and Cr(VI)—have very different properties. The toxicity, mobility, and bioavailability of Cr mainly depend on its speciation. In the natural environment, Cr(III) is most immobile, less soluble and stable, whereas Cr(VI) is highly mobile, soluble and bioavailable. Redox reactions …
Chemodynamics Of Chromium Reduction In Soils: Implications To Bioavailability, Girish Choppala, Nanthi Bolan, Belaji Seshadri
Chemodynamics Of Chromium Reduction In Soils: Implications To Bioavailability, Girish Choppala, Nanthi Bolan, Belaji Seshadri
Dr Girish Choppala
Chromium toxicity in soils can be mitigated by reduction of Cr(VI) to Cr(III) which is influenced by the presence of free Cr(VI) species in soil solution, and the supply of protons and electrons. In this study, the effects of Cr(VI) adsorption (i.e. availability of free Cr(VI) species in soil solution), soil pH (i.e. supply of protons) and three electron donor carbon sources [black carbon (BC), chicken manure biochar (CMB) and cow manure (CM)] on the reduction of Cr(VI) to Cr(III) in soils were investigated. The results indicated that the rate of Cr(VI) reduction decreased with an increase in Cr(VI) adsorption …