Characterization of chromium-containing wastes and soils affected by the production of chromium tanning agents

摘要: Wastes of unknown composition derived from the production trivalent chromium (Cr(III)) salts used as tanning agents are deposited in area Kanpur, India. The questions whether these samples chromite ore processing residue (COPR) and Cr occurs its toxic hexavalent form (Cr(VI)) arise. Twenty-one two disposal sites surrounding soils were analyzed, specifically examining their elemental mineralogical composition. Additionally, aqueous eluates with different liquid-to-solid ratios performed analyzed for Cr(VI). classified accordance to sum silicon aluminum calcium contents: uncontaminated, moderately contaminated, highly contaminated material. Highly material exhibited extremely alkaline pH values up 12.5 total contents ranging 65.7 110 g/kg, whereas uncontaminated had comparatively moderate <1 g/kg. In total, seven crystalline phases commonly found COPR identified samples, which five (brownmillerite, hydrocalumite, hydrogarnet, magnesiochromite, periclase) known be able accommodate hydrogarnet hydrocalumite main host Batch tests showed that dissolution controlled Cr(VI) concentrations eluates. Six clearly Cr-contaminated COPR. Leaching resulting contamination water bodies is a key environmental risk arising especially during monsoon season. This situation particular concern local population use Cr(VI)-contaminated not only needs livestock irrigation but also drinking due absence alternative resources.