Abstract

Contamination of water resources by industrial effluents containing heavy metal ions and management of solid waste from agricultural and food industries is a serious issue. This study presents the valorization of waste walnut shells as an effective and environment-friendly biosorbent for sequestrating Cr(VI) from aqueous media. The native walnut shell powder (NWP) was chemically modified with alkali (AWP) and citric acid (CWP) to obtain modified biosorbents with abundant availability of pores as active centers, as confirmed by BET analysis. During batch adsorption studies, the process parameters for Cr(VI) adsorption were optimized at pH 2.0. The adsorption data were fitted to isotherm and kinetic models to compute various adsorption parameters. The adsorption pattern of Cr(VI) was well explained by the Langmuir model suggesting the adsorbate monolayer formation on the surface of the biosorbents. The maximum adsorption capacity, qm, for Cr(VI) was achieved for CWP (75.26 mg/g), followed by AWP (69.56 mg/g) and NWP (64.82 mg/g). Treatment with sodium hydroxide and citric acid improved the adsorption efficiency of the biosorbent by 4.5 and 8.2%, respectively. The endothermic and spontaneous adsorption was observed to trail the pseudo-second-order kinetics under optimized process parameters. Thus, the chemically modified walnut shell powder can be an eco-friendly adsorbent for Cr(VI) from aqueous solutions.

Details

Title
Rapid adsorptive removal of chromium from wastewater using walnut-derived biosorbents
Author
Garg, Rajni 1 ; Garg, Rishav 2 ; Sillanpää, Mika 3 ; Alimuddin 4 ; Khan, Mohammad Amir 2 ; Mubarak, Nabisab Mujawar 5 ; Tan, Yie Hua 6 

 Department of Applied Sciences, Galgotias College of Engineering and Technology, Greater Noida, India (GRID:grid.448824.6) (ISNI:0000 0004 1786 549X) 
 Department of Civil Engineering, Galgotias College of Engineering and Technology, Greater Noida, India (GRID:grid.448824.6) (ISNI:0000 0004 1786 549X) 
 King Saud University, Department of Chemistry, College of Science, Riyadh, Saudi Arabia (GRID:grid.56302.32) (ISNI:0000 0004 1773 5396); University of Johannesburg, Department of Chemical Engineering, School of Mining, Metallurgy and Chemical Engineering, Doornfontein, South Africa (GRID:grid.412988.e) (ISNI:0000 0001 0109 131X); Zhejiang Rongsheng Environmental Protection Paper Co. LTD, Pinghu, People’s Republic of China (GRID:grid.412988.e) 
 Maulana Azad National Urdu University, Physical Sciences Section, School of Sciences, Hyderabad, India (GRID:grid.444448.c) (ISNI:0000 0001 0377 3525) 
 Universiti Teknologi Brunei, Petroleum and Chemical Engineering, Faculty of Engineering, Bandar Seri Begawan, Brunei Darussalam (GRID:grid.454314.3) 
 Curtin University Malaysia, Department of Chemical and Energy Engineering, Faculty of Engineering and Science, Miri, Malaysia (GRID:grid.448987.e) 
Pages
6859
Publication year
2023
Publication date
2023
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2806316576
Copyright
© The Author(s) 2023. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.