▎ 摘　　要

Recently, much attention has been given to water pollution as its overall impact is much higher in comparison with air and soil pollution. In this context, dyes are considered as an important and common pollutant in water bodies because of their recalcitrant properties which render them difficult to degrade. Dyes adversely affect flora and fauna by imposing carcinogenic and mutagenic effects on them. In this study, graphene (GR) nanosheets synthesized using modified Hummer's method were used as nanoadsorbent material for the removal of malachite green (MG) from solution. The best suited condition for maximum adsorption was found at pH 8, temperature 313 K, adsorbent dose of 0.5 g/L, and percentage maximum removal of MG was found as 79% with a maximum adsorption capacity of 23.8095 mg/g. The adsorbent was also found to possess a good regenerative property. Equilibrium adsorption data recorded were subjected to Langmuir, Freundlich, Temkin and DR-isotherms and was found to best fit the Langmuir isotherm model. DR model and Delta H degrees analysis revealed that the process under observation was physico-chemisorptions in nature. The kinetics of adsorption was found to follow pseudo-second-order model. The rate constant was determined to increase with a corresponding rise in temperature indicating endothermic character of adsorption which was also supported by the thermodynamic analysis. Hence, it could be concluded that application of GR nanosheets resulted in efficient removal of MG from its aqueous solutions.