Bisphenol A Removal from Aqueous Solution Using Waste Agarwood Activated Carbon: Kinetic and Isotherm Investigation of Adsorption Process

Abstract

Presently, it is difficult to prepare inexpensive water pollutant adsorbents of
promising efficiency based on natural source-derived activated carbons (AC). This work
investigated the properties of agarwood-synthesised AC (agar AC) of high potential.
Displaying an expansive surface area, this carbon was examined in terms of its kinetics and
isotherms associated with adsorption of bisphenol A. The preparation of agar AC involved a
three-stage process of chemical activation, comprising carbonisation, treatment with
sulphuric acid and activation, with agarwood branch serving as precursors. The highest
BET surface area of the synthesised agar AC was 1092 m2/g, while the highest absorptivity
of the activated carbon under conditions of 50°C, three hours, pH 7 and 1 wt. % carbon
dosage was 430 mg/L. Exhibiting an endothermic and spontaneous character, adsorption
was observed to comply with the pseudo-second-order with Langmuir and Freundlich
adsorption isotherms. In the context of water purification, bisphenol A adsorption could be
adequately and inexpensively achieved with this agar AC, which can also be used again
following a renewal with great effectiveness of extraction.