Adsorption of Methylene Blue Onto Activated Carbon Developed From Baobab Fruit Shell by Chemical Activation: Kinetic Equilibrium Studies

Abstract

This article provides results of the usability of baobab fruit shell to produce activated carbons by chemical activation using ZnCl2, H3PO4, and KOH. This study indicated that activated carbon produced from baobab fruit shell fruit can be used as a promising adsorbent for the removal of methylene blue from aqueous solutions. Significant changes on the material surface following the activation process were observed through SEM and FTIR analyses. Scanning electron micrographs of BFS-ACs showed that porous structures were formed during activation, while the FTIR results indicated that the carbons have abundant functional groups on the surface. KOH activation led an activated carbon with a high methylene blue adsorption of 95.54% and maximum adsorption capacity of 113.63 mg/g, which is directly related to the specific surface area of activated carbons. The adsorption isotherm data were fitted to Langmuir and Freundlich adsorption models. The Langmuir isotherm model showed better fit to the equilibrium data than the Freundlich model. The adsorption process was well described by the pseudo-second-order kinetics. The BFS-ACs is an effective and low-cost adsorbent for the removal of MB from an aqueous solution. ABSTRAK: Kajian ini memberi input tentang kebolehgunaan kulit buah baobab bagi menghasilkan karbon teraktifan melalui aktiviti kimia menggunakan ZnCl2, H3PO4, dan KOH. Karbon aktif daripada kulit buah Baobab ini berpotensi sebagai penyerap bagi menyingkir larutan akueus metilin biru. Perubahan ketara pada permukaan bahan diikuti dengan proses pengaktifan dipantau melalui analisis SEM dan FTIR. Imbasan elektron mikrograf BFS-AC menunjukkan struktur porus terhasil semasa proses pengaktifan. Sementara dapatan FTIR menunjukkan karbon mempunyai banyak kumpulan berfungsi pada permukaan. Pengaktifan KOH menghasilkan karbon aktif menggunakan larutan biru metilin yang tinggi sebanyak 95.54% dan kapasiti maksimum penyerapan 113.63 mg/g, iaitu berkadar langsung dengan tumpuan kawasan permukaan karbon aktif berkaitan. Data isoterma penyerapan dibina pada model penyerapan Langmuir dan Freundlich. Model isoterma Langmuir lebih padan pada data keseimbangan berbanding model Freundlich. Proses penyerapan menunjukkan lebih kinetik order-kedua-pseudo. BFS-AC sangat efektif dan penyerap murah bagi membuang MB daripada larutan akues.

Adsorption Performance of Fixed-Bed Columns for the Removal of Phenol Using Baobab Fruit Shell Based Activated Carbon

“…Phenol is regarded as an environmental problem owing to its discharge in wastewater from a variety of industries, including petroleum refineries, petrochemicals, pharmaceuticals, pesticide manufacturing, resins, steel mills, coke manufacturing, paints, dye production, and mine discharge [1]. Currently, about 7.8 million tons of phenol are produced annually around the world, with production rates on the rise [2].…”

“…Commercially available AC is an established and widespread adsorbent for the removal of various pollutants [14]. Despite its extensive use, AC remains an expensive material [1]. Moreover, saturated-AC regeneration is very tedious, difficult, and expensive [14].…”

“…Using lignocellulosic biomass as a raw material for the production of AC provides an alternative to conventional sources and is considered an effective way to discard massive waste quantities and reduce the cost of AC production as well. Lignocellulosic biomasses are cheap, plentiful, renewable, non-toxic, easily accessible, and eco-friendly [1]. Many lignocellulosic biomasses have been utilized as precursors to produce AC for phenol removal from wastewater.…”

“…These biomasses offer an alternative to traditional sources, which may serve as potential precursors to produce AC. As a result, to find a new renewable alternative source for AC, efforts have been made to produce AC from baobab fruit shell (BFS) by chemical activation [1,[23][24][25].…”

Mathematical Modelling and Optimization for Facile Synthesis of Structured Activated Carbon (ACs) from Adansonia kilima (Baobab) Wood Chips Integrating Microwave-Assisted Pyrolysis for the Elimination of Lead (II) Cations from Wastewater Effluents

“…Previously, Adansonia digitata , another kind of Baobab stem powder, and shell were activated using highly concentrated ZnCl 2 to produce ACs using conventional heating [ 41 ]. Adansonia digitata seed hulls, fruit shells, and fibres were also activated using conventional heating using KOH, ZnCl 2 , H 3 PO 4 activation; steam pyrolysis; and two-step conventional pyrolysis, whereby both stages were conducted at a very high temperature of 800–900 °C, respectively [ 42 , 43 , 44 ]. The use of harsh, corrosive chemicals (KOH, ZnCl 2 , H 3 PO 4 ) in the production of ACs is not economically feasible.…”