CHEMICAL ENGINEERING TRANSACTIONS VOL. 72, 2019 A publication of The Italian Association of Chemical Engineering Online at www.aidic.it/cet Guest Editors: Jeng Shiun Lim, Azizul Azri Mustaffa, Nur Nabila Abdul Hamid, Jiří Jaromír Klemeš Copyright © 2019, AIDIC Servizi S.r.l. ISBN 978-88-95608-69-3; ISSN 2283-9216 Rubber Seed Shell Based Activated Carbon by Physical Activation for Phenol Removal Koh Zhe Yan a , Muhammad Abbas Ahmad Zaini b, *, Agus Arsad c , Noor Shawal Nasri c a School of Chemical & Energy Engineering, Faculty of Engineeringm Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia b Centre of Lipids Engineering & Applied Research (CLEAR), Ibnu-Sina Institute for Scientific & Industrial Research, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia c UTM-MPRC Institute for Oil & Gas, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia abbas@cheme.utm.my This work was aimed at evaluating the characteristics of activated carbons derived from rubber seed shell through physical activation using CO2 for phenol removal. Two activated carbons were obtained at different retention times of 30 min (AC1) and 90 min (AC2) at fixed temperature of 900 °C. Activated carbons were characterized for specific surface area, surface functional groups and morphology. The values of specific surface area were recorded as 852 m 2 /g and 606 m 2 /g for AC2 and AC1. AC2 shows a higher phenol removal capacity of 302 mg/g than AC1 (112 mg/g) that is directly related to the specific surface area of activated carbons. The equilibrium data fitted well to the Langmuir isotherm, suggesting monolayer coverage of phenol molecules on the homogeneous surface of activated carbons. The kinetics data obeyed pseudo-first-order model, indicating the external diffusion as the rate-limiting step in adsorption. 1. Introduction The demand for phenol-related products has resulted in the manufacturing of phenol in large scale. One of the major products is phenolic resin that is produced through polymerization reaction of formaldehyde with phenol. The use of large amount of phenol in processing may eventually result in the chemical to find its ways to the environment (Dabrowski et al., 2005). Phenol is toxic and has high bio-accumulation rate due to its lipophilic character (Gad and Saad, 2008). The presence of phenol in water bodies, consequently renders serious pollution that may as well affects the aquatic creatures (Gad and Saad, 2008), food chain and public health (Lin et al., 2011). Hence, the effluent laden with phenol should be treated prior to its release to the environment. Malaysia is the leading country in the world that produces nearly 46 % of the world natural rubber (MREPC, 2016). As a result, large amount of rubber tree seed is produced over the season. The crop residue has trivial commercial value and is commonly left on the field to decompose or burnt together with dry leaves, which consequently, could lead to other environmental issues. Therefore, sustainable solutions are sought to utilize the material so as to minimize its related consequences to the environment. A promising approach is to convert the crop residue into activated carbon for environmental protection, especially in water and wastewater treatment. Activated carbon has long been recognized as adsorbent that can remove various contaminants such as phenol (Kilic et al., 2011), lead (II) (Zaini et al., 2009), copper (II) (Zaini et al., 2010), reactive orange (Lin-Zhi and Zaini, 2017a), congo red (Shu-Hui and Zaini, 2017a), etc. from water. The process in which the solute molecules are attracted to the surface of activated carbon for the removal to take place is generally known as adsorption (Zaini et al., 2016a). Generally, activated carbon can be produced from carbonaceous materials such as palm kernel shell (Garcia et al., 2018), empty fruit bunch (Zaini and Shaid, 2016), textile sludge (Shu-Hui and Zaini, 2017b), castor seed (Lin-Zhi and Zaini, 2017b), etc. As such, rubber seed shell is also seen as a promising feedstock candidate that is cheap and abundantly available in the country to manufacture activated carbon. To date, there is still limited literature available to unlock the potential of rubber seed shell as activated carbon, hence worth to be further explored so as to enrich the body of present knowledge. DOI: 10.3303/CET1972026 Paper Received: 30 March 2018; Revised: 05 August 2018; Accepted: 28 October 2018 Please cite this article as: Yan K.Z., Ahmad Zaini M.A., Arsad A., Nasri N.S., 2019, Rubber seed shell based activated carbon by physical activation for phenol removal, Chemical Engineering Transactions, 72, 151-156 DOI:10.3303/CET1972026 151