scholarly journals Preparation of Activated Carbon From Sunflower Straw by H3PO4 Activation and Its Application for Acid Fuchsin Adsorption

Author(s):  
Wende Zhao ◽  
Liping Chen

Abstract In this work, sunflower straw (SS) was used as the raw material, H3PO4 was used as the activator, and the sunflower straw activated carbon (SSAC) was prepared by the one-step activation method under the impregnation ratio of 1:1, 1:2, 1:3, 1:5 (SS/H3PO4, g/g). The adsorption of acid fuchsin (AF) simulated dye wastewater by SSAC prepared under different immersion ratios has been studied. As the impregnation ratio increases, the pore structures of SSAC changed greatly. SSAC3 had the largest specific surface area (1794.01 m2/g), and SSAC4 had the smallest microporosity (0.0527 cm3/g) and the largest pore volume (2.549 cm3/g). The adsorption kinetics of four types of SSAC to AF were more in line with the quasi-second-order adsorption kinetic model. The Langmuir isotherm model was suitable for describing SSAC3 and SSAC4, and the Freundlich isotherm model was suitable for describing SSAC1 and SSAC2. Thermodynamics showed that the adsorption process was spontaneous and endothermic. At 303 K, SSAC4 showed a removal rate of 97.73% for 200 mg/L AF, and the maximum adsorption capacity of 2763.36 mg/g, which was the highest among the four types of SSAC. This study shows that the sunflower straw activated carbon prepared by the H3PO4 one-step activation method is a green and efficient carbon material and has great application potential in the treatment of dye-containing wastewater.

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2741
Author(s):  
Pengcheng Lv ◽  
Ruihong Meng ◽  
Zhongyang Mao ◽  
Min Deng

In this study, the hydrated sodium aluminosilicate material was synthesized by one-step hydrothermal alkaline desilication using fly ash (FA) as raw material. The synthesized materials were characterized by XRD, XRF, FT-IR and SEM. The characterization results showed that the alkali-soluble desilication successfully had synthesized the sodium aluminosilicate crystalline (N-A-S-H) phase of sodalite-type (SOD), and the modified material had good ionic affinity and adsorption capacity. In order to figure out the suitability of SOD as an adsorbent for the removal of ammonium and phosphorus from wastewater, the effects of material dosing, contact time, ambient pH and initial solute concentration on the simultaneous removal of ammonium and phosphorus are investigated by intermittent adsorption tests. Under the optimal adsorption conditions, the removal rate of ammonium was 73.3%, the removal rate of phosphate was 85.8% and the unit adsorption capacity reached 9.15 mg/L and 2.14 mg/L, respectively. Adsorption kinetic studies showed that the adsorption of ammonium and phosphorus by SOD was consistent with a quasi-secondary kinetic model. The adsorption isotherm analysis showed that the equilibrium data were in good agreement with the Langmuir and Freundlich model. According to thermodynamic calculations, the adsorption of ammonium and phosphorus was found to be a heat-absorbing and spontaneous process. Therefore, the preparation of SOD by modified FA has good adsorption properties as adsorbent and has excellent potential for application in the removal of contaminants from wastewater.


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.


2014 ◽  
Vol 26 (4) ◽  
pp. 1058-1062 ◽  
Author(s):  
Tian Huang ◽  
Ye Li ◽  
Jiaxiu Guo ◽  
Lu Fan ◽  
Wenju Jiang

Author(s):  
Xiaorong Kang ◽  
Yali Liu ◽  
Can Yang ◽  
Han Cheng

Abstract Dewatered municipal sludge was used as raw material to prepare activated carbon (SAC), and the SAC was modified by walnut shell and nano-titanium dioxide (MSAC). The results showed that the MSAC had a higher specific surface area (SBET) (279.147 m2/g) and total pore volume (VT) (0.324 cm3/g) than the SAC. Simultaneously, the functional groups such as C-O, C = O, and Ti-O-Ti on the surface of MSAC were enhanced due to modification. These physicochemical properties provided prerequisites for the diffusion and degradation of pollutants in MSAC. Furthermore, the MSAC was applied to adsorb amoxicillin (AMX) from aqueous solution, in batch experiments, the maximum removal rate (88.19%) was observed at an initial AMX concentration of 30 mg/L, MSAC dosage of 5.0 g/L, pH of 8, contact time of 180 min, and temperature of 25 °C. In addition, the adsorption process was well described by the Freundlich isotherm model and pseudo-second-order kinetic model, indicating that the adsorption of AMX onto MSAC was dominated by multilayer chemisorption. Also, the adsorption thermodynamics suggested that the adsorption process of AMX onto MSAC was endothermic, feasible and spontaneous.


2019 ◽  
Vol 79 (3) ◽  
pp. 466-479 ◽  
Author(s):  
Fatemeh Mojoudi ◽  
Amir Hossein Hamidian ◽  
Yu Zhang ◽  
Min Yang

Abstract Novel porous nanocomposite (AC/NC/TGO) was successfully synthesized through the composition of activated carbon, nanoclay and graphene oxide as a Pb(II) adsorbent for the treatment of contaminated aqueous environment. The physicochemical properties and morphology of AC/NC/TGO were examined by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption techniques. Results showed Pb(II) adsorption on the AC/NC/TGO was rapid in the first 20 min and reached equilibrium in 40 min. Kinetic studies showed significant fit to the pseudo second order kinetic model (R2 ≥ 0.9965) giving an equilibrium rate constant (K2) of 0.0017 g mg−1 min−1 for Pb(II) loaded. The experimental adsorption data were better fitted with the Langmuir isotherm model than with the Freundlich isotherm model. Prepared nanocomposite exhibited high values of Brunauer–Emmett–Teller (BET) surface area of 1,296 m2 g−1 and total pore volume of 1.01 cm3 g−1. Maximum adsorption capacity (Qmax = 208 mg g−1) and a relatively high adsorption rate was achieved at pH 5.0 using an adsorbent dose of 0.5 g L−1 and an initial lead concentration of 50 mg L−1. High adsorption capacity, reusability, fast kinetics and simple synthesis method indicate that prepared nanocomposite can be suggested as a high-performance adsorbent for Pb(II) removal from polluted water.


Author(s):  
Mohamed A. Elsayed ◽  
O.A. Zalat

This study illustrates the preparation of activated carbon (AC) from Corn Cob (CC) via microwave assisted K2CO3 activation. The effect of operational parameters including chemical impregnation ratio (0.25-1.25), microwave power (90 – 800 W) and irradiation time (1 – 9 min) on the carbon yield and adsorption capability of derived Corn Cob Activated Carbon (CCAC) were investigated. The results indicated that the optimum conditions were as follows: microwave power of 600W, microwave radiation time of 5 min and the impregnation ratio of K2CO3 was 0.75 g/g. The optimum conditions resulted in CCAC with a maximum adsorption capacity of 275.32 mg/g for MB and carbon yield of 27.09%. The BET surface area, Langmuir surface area and total pore volume were determined to be 765 m2/g, 834 m2/g and 0.43 cm3/g, respectively.


Author(s):  
С.А.А. Ахмед ◽  
Е.С. Гогина

Адсорбция фенола на активированном угле считается одной из наиболее эффективных систем очистки сточных вод. В связи с этим изучена эффективность двух промышленных активированных углей российского производства для очистки сточных вод от фенола. Образцы включают порошкообразный активированный уголь (производимый из березового угля) и дробленый активированный уголь (производимый из скорлупы кокосового ореха). Исследование проведено в условиях изменения pH, влияния времени контакта и различных начальных концентраций фенола на процесс адсорбции. Исследование дополнительно расширено для выяснения кинетики адсорбции и модели изотерм Ленгмюра и Фрейндлиха. Результаты показали, что активированный уголь сохраняет максимальную адсорбционную способность в широком диапазоне pH – от 2 до 9. Это доказывает применимость угля для удаления фенола из различных сточных вод. Механизм адсорбции с использованием обоих образцов активированных углей следовал псевдовторому порядку и соответствовал модели изотермы Ленгмюра. Максимальная адсорбционная способность составила 185,19 и 172,41 мг/г для порошкообразного и дробленого угля соответственно, что свидетельствует о высокой эффективности удаления фенола из сточных вод. The adsorption of phenol on activated carbon is considered one of the most efficient wastewater treatment systems. In this regard, the effectiveness of two Russian manufactured industrial activated carbon types in removing phenol from wastewater has been studied. The samples included powdered activated carbon (made from birch charcoal) and crushed activated carbon (made from coconut shells). The study was carried out under the conditions of pH variation and the effect of contact time and different initial concentrations of phenol on the adsorption process. The study was further expanded to clarify the adsorption kinetics and the Langmuir and Freundlich isotherm model. The results showed that activated carbon retained the maximum adsorption capacity over a wide pH range of 2 to 9. This fact proves the usability of coal for removing phenol from various wastewater types. The adsorption mechanism using both activated carbon samples followed the pseudo-second order and corresponded to the Langmuir isotherm model. The maximum adsorption capacity was 185.19 and 172.41 mg/g for powdered and crushed coal, respectively, suggesting a high efficiency of phenol removal from wastewater.


RSC Advances ◽  
2020 ◽  
Vol 10 (24) ◽  
pp. 14262-14273 ◽  
Author(s):  
Hongyan Li ◽  
Lianxin Liu ◽  
Jianguo Cui ◽  
Jiali Cui ◽  
Fang Wang ◽  
...  

Edible fungus residue as an efficient and low-cost precursor was used to produce Edible Fungus residue Activated Carbon (EFAC) using the zinc chloride activation method at a 1 : 2 impregnation ratio and 600 °C activation for 3 hours.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2453
Author(s):  
Ri-si Wang ◽  
Ya Li ◽  
Xi-xiang Shuai ◽  
Rui-hong Liang ◽  
Jun Chen ◽  
...  

The development of effective heavy metal adsorbents has always been the goal of environmentalists. Pectin/activated carbon microspheres (P/ACs) were prepared through simple gelation without chemical crosslinking and utilized for adsorption of Pb2+. Scanning electron microscopy (SEM) revealed that the addition of activated carbon increased the porosity of the microsphere. Texture profile analysis showed good mechanical strength of P/ACs compared with original pectin microspheres. Kinetic studies found that the adsorption process followed a pseudo-second-order model, and the adsorption rate was controlled by film diffusion. Adsorption isotherms were described well by a Langmuir isotherm model, and the maximum adsorption capacity was estimated to be 279.33 mg/g. The P/ACs with the highest activated carbon (P/AC2:3) maintained a removal rate over 95.5% after 10 adsorption/desorption cycles. SEM-energy-dispersive X-ray spectrum and XPS analysis suggested a potential mechanism of adsorption are ion exchange between Pb2+ and Ca2+, electronic adsorption, formation of complexes, and physical adsorption of P/ACs. All the above results indicated the P/ACs may be a good candidate for the adsorption of Pb2+.


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