Facile Synthesis of NaOH-modified Fishbone Charcoal (FBC) with Remarkable Adsorption towards Methylene Blue

Abstract

This study has demonstrated the preparation of NaOH-FBC and investigated its potential application as an adsorbent to remove MB from aqueous solution. Adsorption Experiments of MB removal were carried out based on the parameters of initial pH, initial MB concentration, temperature and contact time. Results showed that the specific surface area of the NaOH-FBC reached up to 61.13m²/g. The experimental adsorption data were analyzed with Langmuir and Freundlich isotherm models. The kinetic adsorption models were also studied. By fitting the Langmuir adsorption isotherm model, the q_max of the NaOH-FBC was highly achieved as 605.82±9.09 mg/g, compared to 70.42±1.34 mg/g produced by the untreated FBC. The MB adsorption process using the untreated FBC was a non-spontaneous and endothermic process, which was well fitted with the pseudo-first-order kinetic model and Freundlich adsorption isotherm model. However, the MB adsorption process of the NaOH-FBC was a spontaneous and endothermic process, which was in accordance with the pseudo-second-order kinetic model and Freundlich adsorption isotherm model. Furthermore, with the increase of pH, temperature and contact time, the adsorption capacity of MB onto the FBC and NaOH-FBC were both increased. The adsorption results suggest the efficiency and potential of NaOH-FBC as a MB adsorbent.