Preparation, characterization and evaluation of adsorptive properties of orange peel based activated carbon via microwave induced K2CO3 activation
Graphical abstract
Highlights
► Highlight the renewable use of orange peel. ► Evaluate the effects of impregnation ratio, microwave power and radiation time. ► Short activation time of 6 min and low chemical impregnation ratio of 1.25. ► High BET and Langmuir surface area of 1104 and 1661 m2/g. ► Monolayer adsorption capacity of 382.75 mg/g and carbon yield of 80.99%.
Introduction
Orange, specifically known as Citrus sinensis, is one of the most favored subtropical fruits in the world. The fruit is globose, subglobose and oblate, with a width from 6.5 to 9.5 cm. The outer epicarp is orange when ripe, while the inner mesocarp is white, spongy and non-aromatic (Morton, 1987). Orange fruit is primarily eaten fresh and available as food complements in desserts, salads, gelatins, fruit cocktail, jam or juice combinations in the citrus processing industries (Armando et al., 2001). According to the Food and Agriculture Organization (FAO), the annual production of orange fruit in 2010 is projected at 64 million MT, translating to approximately 32 million MT of peels as the byproducts (Spreen, 2010).
Traditionally, orange peels (OPs) were processed to obtain the volatile and nonvolatile fractions of essential oils and flavoring in the carbonated drinks, ice creams, cakes, air-fresheners, perfumes and cosmetic products (Li et al., 2008). Besides, OPs have been reported to have germicidal, antioxidant and anti-carcinogenic properties as a remedy against breast and colon cancer, stomach upset, skin inflammation, muscle pain, and ringworm infections (Spreen, 2000). However, the application of these extracted constituents is limited due the overall demands for these value-added products are relatively insignificant. Therefore, it is necessary to find a rapid and easy route towards upgrading of the citrus processing biomass.
In this sense, the present work is aimed at evaluating the viability of microwave irradiation for preparation of activated carbon from OP via K2CO3 activation. The significant influences of microwave power, radiation time and chemical impregnation ratio on the carbon yield and adsorption capacity were investigated systematically. Structural, functional and surface chemistry of the prepared adsorbent was performed. Moreover, the adsorption equilibrium, isotherms, kinetics and thermodynamics were outlined.
Section snippets
Adsorbate
Methylene blue (MB), a monovalent cationic pollutant (Supplementary Fig. 1) difficult to be degraded in natural environment was selected as the model adsorbate in the present study. A stock solution of 500 mg/L was prepared by dissolving an appropriate quantity of MB in double distilled water and then diluted to the desired concentrations.
Preparation of activated carbon
Orange peel (OP), a by-product collected from the local restaurant, was the precursor used in the present study. The raw precursor was washed exhaustively with
Effect of chemical impregnation ratio
Effect of chemical impregnation ratio (IR) on the carbon yield and adsorption equilibrium of MB was evaluated at the microwave input power of 360 W and irradiation time of 5 min (Fig. 1a). It can be clearly observed that carbon yield increased from 72.45% to 85.14% with increasing IR from 0.25 to 1.25. Beyond the value, further increase in IR showed a gradually decrease of carbon yield. Similarly, augmenting IR from 0.25 to 1.25 illustrated an enhancement of adsorption uptake from 56.52 to 171.15
Conclusion
The results showed that orange peel is a potential raw precursor for preparation of high quality activated carbon. Integration of microwave heating has promoted porosity development in a short heating period. The optimum condition for preparation of OPAC has been identified at IR of 1.25, heating power of 600 W and irradiation time of 6 min. The adsorption behavior could be favorably described by Langmuir isotherm model, while the adsorption kinetic was well fitted to the pseudo-second-order
Acknowledgements
The authors acknowledge the financial support provided by Universiti Sains Malaysia under the Research University (RU) Scheme (Project No. 1001/PJKIMIA/814072) and RU-PRGS grant scheme (Project 465 No. 8043030).
References (33)
- et al.
Preparation and characterization of activated carbon from palm shell by chemical activation with K2CO3
Bioresour. Technol.
(2007) - et al.
The use of piassava fibers (Attalea funifera) in the preparation of activated carbon
Bioresour. Technol.
(2010) - et al.
Adsorption kinetics of a basic dye from aqueous solutions onto apricot stone activated carbon
Bioresour. Technol.
(2008) - et al.
Preparation of activated carbons from cotton stalk by microwave assisted KOH and K2CO3 activation
Chem. Eng. J.
(2010) - et al.
Bio-separation, speciation and determination of chromium in water using partially pyrolyzed olive pomace sorbent
Bioresour. Technol.
(2011) - et al.
Effectiveness of Cupressus sempervirens cones as biosorbent for the removal of basic dyes from aqueous solutions in batch and dynamic modes
Bioresour. Technol.
(2010) - et al.
Insights into the modeling of adsorption isotherm systems
Chem. Eng. J.
(2010) - et al.
Microwave assisted thermal treatment of defective coffee beans press cake for the production of adsorbents
Bioresour. Technol.
(2010) - et al.
Preparation and characterization of activated carbon produced from rice straw by (NH4)2HPO4 activation
Bioresour. Technol.
(2011) - et al.
Equilibrium and a two-stage batch adsorber design for reactive or disperse dye removal to minimize adsorbent amount
Bioresour. Technol.
(2011)
Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue
Appl. Surf. Sci.
Mechanisms of the alkali metal catalyzed gasification of carbon
Fuel
Activated carbons from sisal waste by chemical activation with K2CO3: kinetics of paracetamol and ibuprofen removal from aqueous solution
Bioresour. Technol.
Influences of pyrolysis condition and acid treatment on properties of durian peel-based activated carbon
Bioresour. Technol.
Activated carbons from waste biomass: an alternative use for biodiesel production solid residues
Bioresour. Technol.
Preparation of high surface area activated carbon from coconut shells using microwave heating
Bioresour. Technol.
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