Graphene oxide based carbon composite as adsorbent for Hg removal: Preparation, characterization, kinetics and isotherm studies

The presence of Hg in the aqueous media is known to cause severe health issues in both humans and animals. Many technologies and especially adsorbents have been applied for its removal. In this study, a graphene oxide-carbon composite (GO-CC) as a new adsorbent was prepared by sol gel procedure and characterized using field emission scanning electron microscopy, BET and EDX. The effects of different variables including solution pH, contact time, adsorbent dose and GO ratio in adsorbent matrix on the removal capacity of Hg were studied. The isotherm data correlated well with the Langmuir isotherm model. Further analysis recommended that the Hg2+ adsorption process is governed by the intra-particle and external mass transfer, in which the film diffusion was the rate restrictive step. The presented composite has maximum absorption capacity, q(max) of 68.8 mg.g(-1), which is comparable with carbon based adsorbent reported in the previous publications. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.