Enhanced hexavalent chromium (Cr(VI)) removal from aqueous solution by Fe–Mn oxide-modified cattail biochar: adsorption characteristics and mechanism. Issue 2 (7th February 2020)

• Record Type: Journal Article
• Authors: Wang, Bo; Li, Fayun; Wang, Li
• Is Part Of: Chemistry and ecology. Volume 36:Issue 2(2020)
• Page Start: 138
• Page End: 154
• Publication Date: 2020-02-07
• Subjects: Fe–Mn oxide-modified biochar -- adsorption -- Hexavalent chromium -- mechanism; Pollution -- Environmental aspects -- Periodicals; Ecology -- Periodicals; 577.2
• DOI: 10.1080/02757540.2019.1699537
• Languages: English
• ISSNs: 0275-7540

Abstract

ABSTRACT: In the study, a novel Fe–Mn oxide-modified cattail biochar was synthesised and Cr(VI) adsorption on Fe–Mn oxide-modified biochar in water was investigated. XRF, XRD and FTIR results indicated that Fe and Mn were successfully loaded on the surface of Fe–Mn oxide-modified biochar. Batched experiments showed that Cr(VI) adsorption on Fe–Mn oxide-modified biochar fitted well with the pseudo-second-order kinetics model. The Freundlich isotherm adsorption model could better describe the isothermal adsorption process of Cr(VI) onto Fe–Mn oxide-modified biochar. The maximum saturated adsorption capacity data Qm of Fe–Mn oxide-modified biochar at 20°C, 30°C, and 40°C were respectively 46.43, 52.12, and 59.81 mg·g −1 . The lower pH contributed to the adsorption of Cr(VI) onto Fe–Mn oxide-modified biochar. The effects of coexisting anions on the Cr(VI) removal efficiency were insignificant. Leaching experiments showed that the leakage risk of Mn 2+ during the adsorption process was negligible. The adsorption mechanisms of Cr(VI) onto Fe–Mn oxide-modified biochar mainly involve electrostatic attraction, ligand exchange and complexation. All the results suggested that Fe–Mn oxide-modified biochars could serve as promising adsorbents for Cr(VI) pollution treatment.