Modified walnut shell for enhanced adsorption for methylene blue from aqueous solution: Preparation, characterisation, isotherm, kinetics and mechanism study
Year: 2025
Type: article
Abstract: Human and aquatic health is frequently at risk due to methylene blue (MB) dye pollution in aquatic environments. In order to remediate water contaminated with MB dye, a chemically modified walnut shell (CMWS) adsorbent is developed in the present study. The physico-chemical characteristics of modified walnut shell have been investigated using a variety of characterisation techniques, including pHpzc, FTIR, BET, FE-SEM, and EDS. After optimising the impact of the most important parameters, a maximum removal of 85.6% is noted at pH 6. The MB uptake by chemically modified walnut shell is explained by the multilayer layer adsorption onto energetically equivalent sorption sites. The linear Freundlich model yielded a maximal adsorptive capacity of 66.6 mg MB per g CMWS. The kinetic models also showed that the rate depends on the adsorbent's adsorptive capacity. The pseudo-second order model works well for MB adsorption and R2 >0.999. Thermodynamic studies indicated that adsorption is feasible, spontaneous and endothermic in nature. This work suggests that CMWS be investigated further as a possible adsorbent for the removal of MB dye.
Authors: Muskan, Sachin Kumari, Sushila Singh, Bhagya Shree, Indu Rani, Manju
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4411782580