Rhodamine B (RB), a synthetically prepared carcinogenic xanthine dye is widely used as a colorant in the textile dyeing, the leather and paint industries, and also as a biological stain in the laboratory [1] and [2]. The discharge of RB into the aquatic environment results in wastewaters with high toxicity, low transparency of light and high content of organic load, which can be consumed by human beings and animals. RB can irritate the skin, eyes and respiratory tract and it is carcinogenic and toxic to the reproductive and nervous system [3] and [4]. Thus, in order to prevent the poisonous impact of RB on ecosystem and public health, RB has to be removed before discharging them into aquatic systems. Currently, several physical or chemical processes such as Fentons reagent, photochemical, electrochemical, membrane filtration and ion exchange are used to treat dye wastewaters [5]. Sorption onto activated carbon is one of the efficient methods to remove RB from effluent and has an advantage over the other methods due to their well-developed porous structure comprised of hydrophobic graphene layers and hydrophilic surface functional groups