Preparation and characterization of activated carbon from groundnut and egg shells as viable precursors for adsorption

O.O.E Onawumi,O.S Bello,A.A Sangoremi

doi:10.4314/jasem.v25i9.24

Abstract

This study was carried out to prepare groundnut shell (GS) and eggshell (ES) into activated carbon (AC) and characterize the AC using Association of Official Analytical Chemists (AOAC) and American Standard for Testing and Materials (ASTM) methods. The AC produced was characterized for: pH, moisture content, volatile matter, ash content, fixed carbon, bulk density and surface area. Surface functional groups and surface morphology were also determined using Fourier Transformed Infrared (FT-IR) and Scanning Electron Microscope (SEM) respectively. The ranges of the following results were achieved for the biomasses: Groundnut shell Activated Carbon (GSAC) and Eggshell Activated Carbon (ESAC) respectively: pH (6.80±0.101−7.80±0.011); moisture content (14.10±0.101−12.90±.110%); volatile matter (9.20±0.112−9.90±0.012%); ash content (8.98±0.111−5.80±0.111%); fixed carbon (67.70±0.010−71.40±110%); bulk density (370.00±0.000−380.00−0.000 g/L); surface area (880.00±0.100−800.00±0.000 m2/g). The agro-wastes have high carbon contents and low inorganic which make them viable adsorbents. FT-IR analysis revealed the presence of oxygen surface complexes such as carbonyls and OH groups on the surface of the ACs in addition to good pore structures from SEM studies revealed that the agro-wastes could be good precursors for ACs production. The overall results showed that the AC produced from the agro-wastes can be optimally used as good and effective adsorbents, thereby ensuring cheaper, readily available and affordable ACs for the treatment of effluent, waste water and used oils.

Highlights

Activated carbons are black solid substances resembling granular or powdered charcoal
The demand for activated carbon is met by importation at high price, whereas there are massive agricultural and industrial wastes which can be used for its production to meet the local demands and for possible exportation
Procurement and preparation of samples: Procurement of agro-waste: The Egg shells were collected from two different eateries: Mr Biggs Igbonna Area and Osun Mall, Fakunle Area, Osogbo, Osun State, while the groundnut shells were collected from the farm settlement at Idi-Osan, Iragbiji, Boripe LGA, Osun State, Nigeria

Summary

Introduction

Activated carbons are black solid substances resembling granular or powdered charcoal They are economically produced by the activation and pyrolysis of renewable, readily available and cheaper carbonaceous precursors which are mainly industrial and agricultural by-products such as bagasse (Boonpoke et al, 2011), rice husk (Boonpoke et al, 2011; Ajala and Ali, 2020), coconut shell (Gawande and Kaware, 2017), sawdust (Alzaydien, 2016; Subramani and Revathi, 2015), empty palm fruit bunch (Hidayat and Sutrisno, 2017), Physic nut waste (Elelu et al, 2019), pruning mulberry shoot (Wang et al.,2010), bamboo stem (Ijaola et al, 2013), chickpea (Ozsin et al, 2019), acorn shell (Saka, 2012). The process produces a porous materials with a large surface area (500-1500 m2/g) (Wang et al, 2010) and a high affinity for organic compounds, chlorine, heavy metals, objectionable tastes and odour in effluent or colour substances from gas or liquid streams (Ajala and Ali, 2020) This is possible as a result of their highly developed pore structure and large internal specific surface area (Mansour et al, 2020; Wan et al, 2010; Hidayat and Sutrisno, 2017). The moisture content was achieved following the method of AOAC, (2019), (ASTM: D 2974-2014, Boadu et al, 2018)

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