STUDY ON ADSORPTIVE REMOVAL OF HEXAVALENT CHROMIUM Cr (VI) IN WATER ENVIRONMENT USING MnO2

Abstract

The present study investigated adsorptive removal of toxic hexavalent chromium Cr(VI) from aqueous
solution using manganese dioxide (MnO2). The MnO2 particles were characterized by X-ray diffraction
(XRD), Fourier transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy
(EDX). Some effective conditions for removal of Cr(VI) using MnO2 were optimized and found to be
adsorption time 120 min, adsorbent mass 0.075 g, and pH 4. Under optimum conditions, maximum removal
of about 100 % was achieved. Adsortion capacity of Cr(VI) increased with increasing ionic strength while
adsorption capacity reached to 72.46 mg/g. Adsorption of Cr(VI) on MnO2 in the absence and in the
presence of antibiotic ciprofloxacin (CFX) decreased with increasing ionic strengths and adsorption
isotherms fit agreed well with Freundlich model, suggesting that adsorption was mainly governed by
electrostatic interaction.