Efficient biosorption of hexavalent chromium from water by modified arecanut leaf sheath

Bishnu Datt Pant; Deepa Neupane; Dasu Ram Paudel; Prakash Chandra Lohani; Surendra Kumar Gautam; Megh Raj Pokhrel; Bhoj Raj Poudel

doi:10.1016/j.heliyon.2022.e09283

Efficient biosorption of hexavalent chromium from water by modified arecanut leaf sheath

Heliyon. 2022 Apr 19;8(4):e09283. doi: 10.1016/j.heliyon.2022.e09283. eCollection 2022 Apr.

Authors

Bishnu Datt Pant¹, Deepa Neupane¹, Dasu Ram Paudel¹, Prakash Chandra Lohani², Surendra Kumar Gautam¹, Megh Raj Pokhrel³, Bhoj Raj Poudel^{1

3}

Affiliations

¹ Department of Chemistry, Tri-Chandra Multiple Campus, Tribhuvan University, Kathmandu 44600, Nepal.
² Department of Chemistry, Amrit Campus, Tribhuvan University, Kathmandu 44600, Nepal.
³ Central Department of Chemistry, Tribhuvan University, Kathmandu 44618, Nepal.

Abstract

In this work, the excision of hexavalent chromium (Cr(VI)) was studied from an aqueous solution using the chemically modified arecanut leaf sheath (CALS) as a novel bio-adsorbent. The as-prepared adsorbent was characterized by using instrumental methods including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The effect of several factors, including solution pH, contact time, and sorbent dosages were examined to identify the optimum condition for the sorption ability. The optimal pH of Cr(VI) biosorption was 2.0, and equilibrium was reached in 150 min. Adsorption was shown to be pseudo-second-order in kinetic investigations, and the Langmuir isotherm with maximal adsorption efficiency was determined as 109.89 mg/g. The spent biosorbent can be easily regenerated and reused. For the biosorption of oxyanions of chromium, both electrostatic attraction and ligand exchange mechanism play critical roles. From the results, the CALS appears to be a potential low-cost effective sorbent to remove Cr (VI) from water.

Keywords: Adsorption isotherms; Biosorbent; CALS; Cr(VI); Kinetics.