Removal of methyl orange and methylene blue from wastewater by magnetic nanocomposites loaded activated carbon synthesised from walnut shell

Abstract

The novel magnetic nanocomposites activated carbon (MWNSC) has been synthesised from activated carbon (AC), produced from walnut shell through pyrolysis method. This adsorbent has been characterized by FTIR, BET, TEM, SEM and EDX analysis techniques. The effects of various adsorption factors such as pH of the dye solution, contact time, and adsorbent dose have been studied. Adsorption isotherms have been employed to test the experimental data, and the results corresponded well to the Langmuir model, with MO and MB having maximal adsorption capacities of 303.30 and 345.70 mg g^-1, respectively. Adsorption kinetics have been studied using pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models, and the experimental results are well-fitted with the pseudo second-order model. According to the dye adsorption's thermodynamics, the process is exothermic, spontaneous, and favourable from a thermodynamic standpoint. The method is applicable to real wastewater samples, with 99 % removal of MO and MB. The outcomes of the present study show that MWNSC is an inexpensive biosorbent that is successfully utilized in removing methyl orange and methylene blue dyes from wastewater.