Department of Chemistry, University of Malakand, Pakistan
Key words: Preconcentration, Speciation, Chromium species, Amberlite XAD-7, Diphenylcarbazide
The availability of good quality water is essential for avoiding diseases and improving the quality of life. The increase in both industrial activities and human population has adversely affected several aspects of the environment including the quality of water bodies. Because of the high solubility of heavy metal ions in the aquatic environment, the heavy metals can be adsorbed by living organisms and cause severe health disorders even at relatively low levels. The main aim of the present study was to develop a new solid phase sorbent for speciation and preconcentration of chromium species by functionalizing Amberlite XAD-7 with diphenylcarbazide. FTIR analysis was conducted in order to confirm the successful functionalization. Cr (VI) was preconcentrated using batch method. Hydroxylamine hydrochloride was used as reducing agent to reduce Cr (VI) to Cr (III) and total chromium was determined. Cr (III) was calculated by subtracting the concentration of Cr (VI) from total chromium. Effect of different parameters such as pH, time, and sample volume, shaking time, eluent type, volume and concentration was investigated for maximum sorption as well as recovery of Cr (VI). Quantitative recovery of Cr (VI) 95.8 ± 1.098 was achieved at pH 4 using 10 mL of 2 M HNO3. Kinetic, and thermodynamic studies showed that the sorption of Cr (VI) is second order, endothermic and spontaneous. With good overall properties like good recovery, maximum selectivity and stable application capacity, this newly functionalized XAD-7 resin can be successfully used for the removal of chromium from different aqueous and food samples.
Get the original articles in Source: Indirect speciation of Cr (VI) and Cr (III) in water and food samples using newly synthesized amberlite XAD-7 functionalized resin
Published By: International Network for Natural Sciences