Recovery of Chromium (III) from Tannery wastewater

  • M. ALI AWAN Institute of Environmental Science and Engineering (IESE), National University of Sciences & Technology (NUST), Rawalpindi, Pakistan
  • M.A. BAIG Institute of Environmental Science and Engineering (IESE), National University of Sciences & Technology (NUST), Rawalpindi, Pakistan
  • JAVED IQBAL Pakistan Environmental Protection Agency (PEPA), Islamabad, Pakistan
  • M.R. ASLAM Institute of Environmental Science and Engineering (IESE), National University of Sciences & Technology (NUST), Rawalpindi, Pakistan
  • nAVEED IJAZ Institute of Environmental Science and Engineering (IESE), National University of Sciences & Technology (NUST), Rawalpindi, Pakistan

Abstract

Three aqueous oxidants, Hydrogen peroxide, Sodium Hypochlorite and Calcium Hypochlorite were employed independently in oxidizing Chromium (III) containing tannery wastewaters to soluble chromate (CrO42-) under alkaline conditions. The amount of chromate recovered was determined via spectrophotometry. Hydrogen peroxide was potentially a suitable oxidant as it could recover chromate (CrO42-) up to 98% (from synthetic Cr3+ solution) and 88% (from effluent I). The percentage recoveries by the hypochlorites were lower than those by hydrogen peroxide i.e. for NaOCl the recoveries were up to 94% (from synthetic Cr3+ solution) and 67% (from effluent I), similarly for Ca(OCl)2 90% (from synthetic Cr3+ solution) and 49% (from effluent I). For all three oxidants complete (100%) recovery could not be achieved despite different experimental conditions (temperatures and oxidation time). The results clearly indicate that hydrogen peroxide is the most efficient among the three oxidants.

Journal of Applied Sciences and Environmental Management Vol. 7(2) 2003: 5-8

Author Biography

M. ALI AWAN, Institute of Environmental Science and Engineering (IESE), National University of Sciences & Technology (NUST), Rawalpindi, Pakistan
Fax No: 92-51-9271597
Published
2004-03-02
Section
Articles

Journal Identifiers


eISSN: 2659-1502
print ISSN: 1119-8362