Methylene blue and methyl orange removal from wastewater by magnetic adsorbent based on activated carbon synthesised from watermelon shell

Abstract

The novel magnetic nanocomposites activated carbon (MWMSC) was prepared from activated carbon (AC), produced from watermelon shell through pyrolysis method. The effect of various adsorption parameters such as contact time, pH of the dye solution and MWMSC dose was studied. The optimum conditions were found to be the contact time of 60 and 40 min (MB & MO), pH of 6.0 and 3.0 for MB and MO, adsorbent dose of 100 mg (MB & MO) respectively. The adsorbents were characterized by FTIR, BET, TEM, SEM and EDX analysis techniques. Adsorption isotherms were used to test the experimental data and result is well-fitted to the Langmuir model with a maximum adsorption capacity of MB and MO was 303.30 and 345.70 mg g−1. Adsorption kinetics were well-fitted with the pseudo second-order model. The thermodynamics of the dye adsorption revealed that the adsorption is thermodynamically favourable, spontaneous and exothermic in nature. The method was applicable to real wastewater samples, with 99% removal of MB and MO. The results of this study show that MWMSC is an inexpensive biosorbent that is successfully utilized in removing methylene blue and methyl orange dyes from wastewater.