scholarly journals Adsorption of methylene blue onto betel nut husk-based activated carbon prepared by sodium hydroxide activation process

2020 ◽  
Vol 82 (9) ◽  
pp. 1932-1949
Author(s):  
Mondira Bardhan ◽  
Tamanna Mamun Novera ◽  
Mumtahina Tabassum ◽  
Md. Azharul Islam ◽  
Ali H. Jawad ◽  
...  

Abstract In this study, activated carbon (AC) was prepared from agro-waste betel nut husks (BNH) through the chemical activation method. Different characterization techniques described the physicochemical nature of betel nut husks activated carbon (BNH-AC) through Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and pH point of zero charge. Later, the produced AC was used for methylene blue (MB) adsorption via numerous batch experimental parameters: initial concentrations of MB dye (25–250 mg/L), contact time (0.5–24 hours) and initial pH (2–12). Dye adsorption isotherms were also assessed at three temperatures where the maximum adsorption capacity (381.6 mg/g) was found at 30 °C. The adsorption equilibrium data were best suited to the non-linear form of the Freundlich isotherm model. Additionally, non-linear pseudo-second-order kinetic model was better fitted with the experimental value as well. Steady motion of solute particles from the boundary layer to the BNH-AC's surface was the possible reaction dynamics concerning MB adsorption. Thermodynamic study revealed that the adsorption process was spontaneous and exothermic in nature. Saline water emerged as an efficient eluent for the desorption of adsorbed dye on AC. Therefore, the BNH-AC is a very promising and cost-effective adsorbent for MB dye treatment and has high adsorption capacity.

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1377 ◽  
Author(s):  
Ruoke Ma ◽  
Xianxian Qin ◽  
Zhigao Liu ◽  
Yunlin Fu

Activated carbon fiber was prepared from liquefied wood by chemical activation with ZnCl2 (Z-LWACF) at different impregnation ratios, with a particular focus on its adsorption property, kinetic and isotherm. The characterization and properties of Z-LWACFs were investigated by nitrogen adsorption/desorption, X-ray photoelectron spectroscopy (XPS), methylene blue (MB) and iodine adsorption. Two activation process methods were employed to prepare Z-LWACF and contrasted with others fibers. The results showed that the Z-LWACF obtained by one-step ZnCl2 activation present higher yields and specific surface area than others fibers. Besides, the change of MB adsorption value at different impregnation ratios was consistent with pore structure distribution above 1.5 nm pore size, indicating that larger micropores (1.5 to 2 nm) and mesopores played a major role in the MB adsorption by Z-LWACF. The kinetics of MB adsorption process was found to follow the pseudo-second-order kinetic model and the adsorption rate was controlled by chemisorption. It was also found that MB adsroption by Z-LWACF belonged to monolayer adsorption and Z-LWACF was easy to adsorb MB.


2021 ◽  
Vol 22 (2) ◽  
pp. 31-49
Author(s):  
Radhia Nedjai ◽  
Ma’an Fahmi Rashid Alkhatib ◽  
Md Zahangir Alam ◽  
Nassereldeen Ahmed Kabbashi

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.


2020 ◽  
Vol 5 (3) ◽  
pp. 221
Author(s):  
Muhammad Azam ◽  
Muhammad Anas ◽  
Erniwati Erniwati

This study aims to determine the effect of variation of activation temperature of activated carbon from sugar palm bunches of chemically activatied with the activation agent of potassium silicate (K2SiO3) on the adsorption capacity of iodine and methylene blue. Activated carbon from bunches of sugar palmacquired in four steps: preparationsteps, carbonizationstepsusing the pyrolysis reactor with temperature of 300 oC - 400 oC for 8 hours and chemical activation using of potassium silicate (K2SiO3) activator in weight ratio of 2: 1 and physical activation using the electric furnace for 30 minutes with temperature variation of600 oC, 650 oC, 700 oC, 750 oC and 800 oC. The iodine and methyleneblue adsorption testedby Titrimetric method and Spectrophotometry methodrespectively. The results of the adsorption of iodine and methylene blue activated carbon from sugar palm bunches increased from 240.55 mg/g and 63.14 mg/g at a temperature of 600 oC to achieve the highest adsorption capacity of 325.80 mg/g and 73.59 mg/g at temperature of 700 oC and decreased by 257.54 mg/g and 52.03 mg/g at a temperature of 800 oCrespectively.However, it does not meet to Indonesia standard (Standard Nasional Indonesia/SNI), which is 750 mg/g and 120 mg/g respectively.


Author(s):  
Nawwarah Mokti ◽  
Azry Borhan ◽  
Siti Nur Azella Zaine ◽  
Hayyiratul Fatimah Mohd Zaid

The use of an activating agent in chemical activation of activated carbon (AC) production is very important as it will help to open the pore structure of AC as adsorbents and could enhance its performance for adsorption capacity. In this study, a pyridinium-based ionic liquid (IL), 1-butylpyridinium bis(trifluoromethylsulfonyl) imide, [C4Py][Tf2N] has been synthesized by using anion exchange reaction and was characterized using few analyses such as 1H-NMR, 13C-NMR and FTIR. Low-cost AC was synthesized by chemical activation process in which rubber seed shell (RSS) and ionic liquid [C4Py][Tf2N] were employed as the precursor and activating agent, respectively. AC has been prepared with different IL concentration (1% and 10%) at 500°C and 800°C for 2 hours. Sample AC2 shows the highest SBET and VT which are 392.8927 m2/g and 0.2059 cm3/g respectively. The surface morphology of synthesized AC can be clearly seen through FESEM analysis. A high concentration of IL in sample AC10 contributed to blockage of pores by the IL. On the other hand, the performance of synthesized AC for CO2 adsorption capacity also studied by using static volumetric technique at 1 bar and 25°C. Sample AC2 contributed the highest CO2 uptakes which is 50.783 cm3/g. This current work shows that the use of low concentration IL as an activating agent has the potential to produce porous AC, which offers low-cost, green technology as well as promising application towards CO2 capture.


2019 ◽  
Vol 6 (9) ◽  
pp. 190523 ◽  
Author(s):  
Lu Luo ◽  
Xi Wu ◽  
Zeliang Li ◽  
Yalan Zhou ◽  
Tingting Chen ◽  
...  

Activated carbon (AC) was successfully prepared from low-cost forestry fir bark (FB) waste using KOH activation method. Morphology and texture properties of ACFB were studied by scanning and high-resolution transmission electron microscopies (SEM and HRTEM), respectively. The resulting fir bark-based activated carbon (ACFB) demonstrated high surface area (1552 m 2 g −1 ) and pore volume (0.84 cm 3 g −1 ), both of which reflect excellent potential adsorption properties of ACFB towards methylene blue (MB). The effect of various factors, such as pH, initial concentration, adsorbent content as well as adsorption duration, was studied individually. Adsorption isotherms of MB were fitted using all three nonlinear models (Freundlich, Langmuir and Tempkin). The best fitting of MB adsorption results was obtained using Freundlich and Temkin. Experimental results showed that kinetics of MB adsorption by our ACFB adsorbent followed pseudo-second-order model. The maximum adsorption capacity obtained was 330 mg g −1 , which indicated that FB is an excellent raw material for low-cost production of AC suitable for cationic dye removal.


2017 ◽  
Vol 75 (10) ◽  
pp. 2390-2402 ◽  
Author(s):  
Bellington Mudyawabikwa ◽  
Henry H. Mungondori ◽  
Lilian Tichagwa ◽  
David M. Katwire

The aim of this study was to prepare activated carbon from tobacco stalks using microwave heating. The prepared activated carbon was applied as an adsorbent in methylene blue (MB) removal from water. The optimum conditions for activated carbon preparation were a radiation power of 280 W for a period of 6 minutes after the impregnation of the precursor material with 30% ZnCl2 for 24 hours. The activated carbon yield and iodine number were 49.43% and 1,264.51 mg/g respectively. The activated carbon also had a point of zero charge of 5.81 with an adsorption capacity of 123.45 mg/g for MB. The optimum conditions for MB adsorption were a pH of 6.5 with an adsorbent dosage of 0.2 g/50 mL at 25 °C. The MB adsorption kinetics followed the pseudo second order kinetic model with the intra-particle diffusion model suggesting a two-step adsorption mechanism. The adsorption data also fitted well within the Langmuir adsorption isotherm model. Tobacco stalks can successfully be turned into an economically important product.


2017 ◽  
Vol 6 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Farida Hanum ◽  
Rikardo Jgst Gultom ◽  
Maradona Simanjuntak

Durian is a kind of tropical fruits which can grow well in Indonesia. Durian is containing 60-75% shell. Durian shell could be a potential alternative to activated carbon because it contains 57.42% carbon. The aim of this research is to know the effect of contact time and  stirring speed to activated carbon adsorption capacity from durian shell with KOH and NaOH as activators. FTIR (Fourier Transform Infra Red) analysis showed the activation process effects on  absorption intensity  wavelength region and resulted in formation of C = C aromatic tape, so that the nature of the charcoal becomes more polar compared with the initial condition. Analysis using spectrophotometer UV-Vis to determine  absorbance and  final concentration of each variation of contact time and stirring speed. The results showed that the maximum adsorption capacity obtained by activation of KOH and NaOH on stirring speed of 150 rpm and a contact time of 90 minutes is equal to 3.92 mg / g and 3.8 mg / g respectively. The maximum surface area obtained by activation of KOH and NaOH during the stirring speed 130 rpm and a contact time of 120 minutes is equal to 1785.263 m2 / g and 1730.332 m2 / g respectively. The maximum surface area obtained from this research has met the standards of commercial activated carbon surface area was between 800-1800 m2/ g. Modeling pseudo second order presents a more representative adsorption data, a second order equation is based on the assumption that adsorption step is chemosorption.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3054
Author(s):  
Yiming Zhou ◽  
Te Li ◽  
Juanli Shen ◽  
Yu Meng ◽  
Shuhua Tong ◽  
...  

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.


Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2554
Author(s):  
Panlong Dong ◽  
Hailin Liu ◽  
Shengrui Xu ◽  
Changpo Chen ◽  
Suling Feng ◽  
...  

To remove the pollutant methylene blue (MB) from water, a sheet-like skeleton carbon derived from shaddock peels (SPACs) was prepared by NaOH activation followed by a calcination procedure under nitrogen protection in this study. Characterization results demonstrated that the as-prepared SPACs displayed a hierarchically porous structure assembled with a thin sheet-like carbon layer, and the surface area of SPAC-8 (activated by 8 g NaOH) was up to 782.2 m2/g. The as-prepared carbon material presented an ultra-fast and efficient adsorption capacity towards MB due to its macro-mesoporous structure, high surface area, and abundant functional groups. SPAC-8 showed ultrafast and efficient removal capacity for MB dye. Adsorption equilibrium was reached within 1 min with a removal efficiency of 99.6% at an initial concentration of 100 mg/g under batch adsorption model conditions. The maximum adsorption capacity for MB was up to 432.5 mg/g. A pseudo-second-order kinetic model and a Langmuir isotherm model described the adsorption process well, which suggested that adsorption rate depended on chemisorption and the adsorption process was controlled by a monolayer adsorption, respectively. Furthermore, column adsorption experiments showed that 96.58% of MB was removed after passing through a SPAC-8 packed column with a flow rate of 20 mL/min, initial concentration of 50 mg/L, and adsorbent dosage of 5 mg. The as-prepared adsorbent displays potential value in practical applications for dye removal due to its ultrafast and efficient adsorption capacity.


RSC Advances ◽  
2016 ◽  
Vol 6 (14) ◽  
pp. 11631-11636 ◽  
Author(s):  
Xiu-Qing Qiao ◽  
Fu-Chao Hu ◽  
Feng-Yu Tian ◽  
Dong-Fang Hou ◽  
Dong-Sheng Li

MoS2 ultrathin nanosheets display excellent adsorption ability towards methylene blue, with a maximum adsorption capacity of 146.43 mg g−1 in 300 seconds. Moreover, the adsorbent can be resued by washing with deionized water.


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