title: Temporal changes and depth wise variations in pit pond hydrochemistry contaminated with industrial effluents with special emphasis on metal distribution in water-sediment system.
abstract: The investigation showed pronounced temporal and vertical variations of pit lake-water chemistry contaminated with industrial effluents. An intermixing layer of few meters at a depth of 5-8 m usually separates an upper oxic epilimnion with alkaline pH from deeper sub-oxic/anoxic zone with relatively lower pH. Metal concentrations were in higher magnitude at anoxic zone in comparison to surface layer. Most of the parameters including metals showed higher concentrations during summer, while least concentrations were observed during monsoon. In shallow sediments, metals were mainly in insoluble-residual form, while redox metals were fractionated as oxihydroxide-reducible form. Geoaccumulation of metals in bottom sediments were Fe>Cr>Pb>Cu>Cd>Mn>Zn. Toxicity assessment showed that pit pond water is highly contaminated (C(d)=7.52) and moderate pollution load (PLI=2.272) in shallow sediments, with metal evaluation index (HEI) value of 11.08 and 15.91 respectively.
authors.affiliation: Department of Environmental Science, The University of Burdwan, Golapbag 713104, West Bengal, India.
authors.forename: S
authors.initials: S
authors.lastname: Gupta
authors.forename: S
authors.initials: S
authors.lastname: Nayek
authors.forename: R N
authors.initials: RN
authors.lastname: Saha
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water / Q000032:analysis* / Q000737:chemistry; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry; D015386:Hazardous Substances / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D008670:Metals / Q000032:analysis*; D012621:Seasons; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D015386:Hazardous Substances; D007220:Industrial Waste; D008670:Metals; D014874:Water Pollutants, Chemical