Microporous activated carbon prepared from yarn processing sludge via composite chemical activation for excellent adsorptive removal of malachite green

Abstract

A highly microporous activated carbon from yarn sludge (YSAC) was developed via composite activation using KI and KOH. The activated carbons were characterized for elemental composition, textural properties, morphology, and surface chemistry. YSAC exhibits a high specific surface of 1037 m2/g, which yields a malachite green (MG) capacity of 498 mg/g. YSAC is primarily negatively charged with the highest total acidic groups of 1.56 mmol/g. MG adsorption by YSAC could be described as monolayer coverage onto homogeneous structure, where the transport is controlled by film diffusion. From the thermodynamics viewpoint, the adsorption is endothermic and spontaneous.