Efficient adsorption to hexavalent chromium by iron oxalate modified D301: Characterization, performance and mechanisms

• Published in: Chinese journal of chemical engineering 2021-05, Vol.33 (5), p.61-69
• Main Authors: Jia, Dongmei, Cai, Huamin, Duan, Yongzheng, Xia, Jiangbao, Guo, Jia
• Format: Article
• Language: English
• Subjects: Adsorption; Chromium; D301; Iron oxalate
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/j.cjche.2020.06.031

Chromium is a common harmful pollutant with high toxicity and low bearing capacity of soil and water. Excellent salinity resistance, a wide pH range, and high regeneration capacity were essential for qualified adsorbents used in removing hexavalent chromium (Cr(VI)) from polluted water. Herein, iron oxalate modified weak basic resin (IO@D301) for the removal of Cr(VI) was prepared by the impregnation method. The IO@D301 was characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Owing to abundant amine, carboxyl groups and iron ions existing on the surface, IO@D301 possesses high adsorption and salinity resistance capacity for Cr(VI). The maximum adsorption capacity of IO301 towards Cr(VI) reached 201.30 mg·g−1 at 293 K and a pH of 5. The adsorption equilibrium was well fitted by the Freundlich model, and the adsorption process was described by the pseudo-first-order kinetics model as spontaneous and exothermic. The mechanism may be identified as electrostatic attraction, coordination, and reduction, which was confirmed by FT-IR and X-ray photoelectron spectroscopy. Mechanism of chromium adsorption onto IO@D301 adsorbent. [Display omitted] •Iron oxalate modified weak basic resin (IO@D301) was used to removal hexavalent chromium from polluted water.•The adsorption performance of IO@D301 to hexavalent chromium was excellent.•The mechanism of hexavalent chromium removal by IO@D301 was probed.