scholarly journals The Enhanced and Tunable Sustained Release of Pesticides Using Activated Carbon as a Carrier

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4019 ◽  
Author(s):  
Jun Yang ◽  
Wanyu Zang ◽  
Zheng Zhang ◽  
Peng Wang ◽  
Qing Yang
Keyword(s):  
Activated Carbon ◽  
Drug Release ◽  
Sustained Release ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Drug Loading ◽  
Utilization Efficiency ◽  
Physical Analysis

The sustained release of pesticides improves drug utilization efficiency and reduces their adverse effects. Activated carbon (AC) is an excellent adsorbent and promising soil conditioner. It has a rich, porous structure and thus can store and gradually release drugs. In this study, three AC materials with surface areas ranging from 800–2000 m2/g were used and two types of modified activated carbons were prepared, and their capacity as drug carriers was evaluated by using 2,4-Dichlorophenoxyacetic acid sodium (2,4-D sodium) as the model pesticide. The preparations were characterized by scanning electron microscopy, nitrogen physical analysis, and zeta potential. The five preparations showed an enhanced and tunable sustained release of drugs. AC1, with the highest specific surface area, possesses the best drug-loading capacity, reaching 679.18 mg/g, but the lowest drug release rate of 32.31% in 96 h. PDA-AC3 has the lowest specific surface area, showing limited drug-loading ability, 82.94 mg/g, but 100% drug release within 72 h. This study suggests that activated carbon has potent applications in agricultural pest control as an inexpensive, effective, controllable, and safe pesticide carrier.

RSM Optimization for the Production of Activated Carbons from Para-Wood Residue

2016 ◽  
Vol 718 ◽  
pp. 100-104 ◽  
Author(s):  
Pichaya Nitnithiphrut ◽  
Rangsinee Pimsri ◽  
Varinrumpai Seithtanabutara
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Operating Conditions ◽  
Optimal Conditions ◽  
Wood Residue ◽  
Impregnation Ratio ◽  
Rsm Optimization

Para-wood residue was impregnated in 40% wt. of H3PO4 solution for 24 h before carbonization under different temperatures and times. The response surface methodology (RSM) based on Box-Behnken was applied to optimize the operating conditions in producing activated carbon with high specific surface area. The effects of three variables; impregnation ratio, carbonising temperature and time on the specific surface of activated carbons were investigated. The proposed model was almost in accordance with the experimental case with correlation efficient and of 0.9653 and 0.9029, respectively. The optimal conditions were found to be 6%wt. of impregnation ratio and carbonization at 400°C for 67.27 min. The predicted surface area of produced activated carbon under these optimal conditions determined by RSM was 1069.30 m2/g. Experimental validation at these conditions was observed of 978.95 m2/g which closely agreed with the predicted value. This obtained activated carbon structure composed of mesopores and micropores with the average pore diameter of 21.71°A. This study indicated the RSM based on Box-Behnken design was the effectively method to optimize the operating condition and maximize the specific surface area of produced activated carbons.

scholarly journals Effect of Mesopore Development on Butane Working Capacity of Biomass-Derived Activated Carbon for Automobile Canister

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 673
Author(s):  
Byeong-Hoon Lee ◽  
Hye-Min Lee ◽  
Dong Chul Chung ◽  
Byung-Joo Kim
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Volume Fraction ◽  
Activated Carbons ◽  
Total Pore Volume ◽  
Working Capacity ◽  
Activation Time

Kenaf-derived activated carbons (AKC) were prepared by H3PO4 activation for automobile canisters. The microstructural properties of AKC were observed using Raman spectra and X-ray diffraction. The textural properties were studied using N2/77 K adsorption isotherms. Butane working capacity was determined according to the ASTM D5228. From the results, the specific surface area and total pore volume of the AKC was determined to be 1260–1810 m2/g and 0.68–2.77 cm3/g, respectively. As the activation time increased, the butane activity and retentivity of the AKC increased, and were observed to be from 32.34 to 58.81% and from 3.55 to 10.12%, respectively. The mesopore ratio of activated carbon increased with increasing activation time and was observed up to 78% at 973 K. This indicates that butane activity and retentivity could be a function not only of the specific surface area or total pore volume, but also of the mesopore volume fraction in the range of 2.8–3.8 nm and 5.5-6.5 nm of adsorbents, respectively. The AKC exhibit enhanced butane working capacity compared to commercial activated carbon with the high performance of butane working capacity due to its pore structure having a high mesopore ratio.

scholarly journals Thermal analysis as a method for evaluating the quality of regeneration of activated carbon used for purification of glycerin

Surface ◽  
2020 ◽  
Vol 12(27) ◽  
pp. 137-145
Author(s):  
M. V. Borysenko ◽  
◽  
Ya. M. Chubenko ◽  
I. I. Voitko ◽  
T. S. Chorna ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Methylene Blue ◽  
Activated Carbon ◽  
Low Temperature ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Thermal Regeneration

In this work, we investigated granular and powder activated carbons (AC) – initial and waste with adsorbed impurities after purification of technical glycerin and subsequent washing with water. The aim of this work was to quantify the adsorbed impurities in the spent AC using thermal analysis (TA) and to work out the conditions for thermal regeneration of AC. TA of AC samples was carried out in an atmosphere of helium and air; the specific surface area of AC was measured by the method of low-temperature desorption of argon (SAr). It was established by the TA method that water is released in the temperature range of 20 – 170 °C, and glycerin – 170 – 400 °C. Spent AC contains up to 22.8 wt. % H2O and up to 44.6 wt. % C3H5(OH)3. Based on these data, it was proposed to regenerate spent coal by heating at 400 °C in air. In the case of a granular AC sample, the regeneration proceeds completely, while for a powder AC sample, the specific surface area with respect to argon is restored only by 22 %, from the initial 2170 m2/g. The adsorption isotherms of methylene blue (MB) of the initial samples are located higher than for the spent ones, since in the spent ones part of the surface is occupied by adsorbed glycerin. The SMB values calculated from the adsorption of methylene blue in the spent AC samples are strongly overestimated in comparison with SAr. Probably, MB displaces glycerin from the surface or interacts with it to form complexes.

scholarly journals Properties of activated carbon regulated by rapid cooling treatment after pyrolysis

BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 7935-7942
Author(s):  
Bing Wang ◽  
Huiyuan Chen ◽  
Yonggang Li ◽  
Hongyu Si ◽  
Haomin Wei ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Activated Carbons ◽  
Raw Materials ◽  
Average Pore Size ◽  
Process Conditions ◽  
Rapid Cooling

Effects of rapid cooling following pyrolysis were studied relative to the properties of activated carbon using different biomass as the raw materials. Coconut shell-based activated carbon (CSAC), bamboo-based activated carbon (BAC), and straw-based activated carbon (WSAC) were activated via high temperature and subsequently rapidly cooled to below minus 150 °C. The results showed that rapid cooling effectively increased the specific surface area, pore volume, and yield of activated carbons. Compared to natural cooling, rapid cooling increased the specific surface area of CSAC from 1076 m2/g to 1484 m2/g, increased the pore volume from 1.46 mL/g to 1.57 mL/g, decreased the average pore size from 2.25 nm to 2.13 nm, and increased the yield from 27.1% to 31.5%. The variation of the properties of activated carbon after rapid cooling using different raw materials and process conditions were studied using orthogonal experiments.

scholarly journals Modeling and Optimization of Pollutants Removal during Simultaneous Adsorption onto Activated Carbon with Advanced Oxidation in Aqueous Environment

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4220
Author(s):  
Lidia Dąbek ◽  
Anna Picheta-Oleś ◽  
Bartosz Szeląg ◽  
Joanna Szulżyk-Cieplak ◽  
Grzegorz Łagód
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Pollutant Removal ◽  
Phenol Red ◽  
Modeling And Optimization ◽  
Simultaneous Adsorption ◽  
Simultaneous Process

The paper presents the results of studies on the modeling and optimization of organic pollutant removal from an aqueous solution in the course of simultaneous adsorption onto activated carbons with varied physical characteristics and oxidation using H2O2. The methodology for determining the models used for predicting the sorption and catalytic parameters in the process was presented. The analysis of the influence of the sorption and catalytic parameters of activated carbons as well as the oxidizer dose on the removal dynamics of organic dyes-phenol red and crystal violet-was carried out based on the designated empirical models. The obtained results confirm the influence of specific surface area (S) of the activated carbon and oxidizer dose on the values of the reaction rate constants related to the removal of pollutants from the solution in a simultaneous process. It was observed that the lower the specific surface area of carbon (S), the greater the influence of the oxidizer on the removal of pollutants from the solution. The proposed model, used for optimization of parameters in a simultaneous process, enables to analyze the effect of selected sorbents as well as the type and dose of the applied oxidizer on the pollutant removal efficiency. The practical application of models will enable to optimize the selection of a sorbent and oxidizer used simultaneously for a given group of pollutants and thus reduce the process costs.

scholarly journals Experimental Study on Activated Carbon-MIL-101(Cr) Composites for Ethanol Vapor Adsorption

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3811
Author(s):  
Zhongbao Liu ◽  
Jiayang Gao ◽  
Xin Qi ◽  
Zhi Zhao ◽  
Han Sun
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ethanol Vapor ◽  
Future Application ◽  
Working Fluid ◽  
Relative Pressure ◽  
Adsorption Refrigeration ◽  
Vapor Adsorption

In this study, the hydrothermal method was used to synthesize MIL-101(Cr), and activated carbon (AC) with different content was incorporated in to MIL-101(Cr), thereby obtaining AC-MIL-101(Cr) composite material with a huge specific surface area. The physical properties of MIL-101(Cr) and AC-MIL-101(Cr) were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), nitrogen adsorption and desorption and specific surface area testing, and ethanol vapor adsorption performance testing. The results show that with the increase of activated carbon content, the thermal stability of AC-MIL-101(Cr) is improved. Compared with the pure sample, the BET specific surface area and pore volume of AC-MIL-101(Cr) have increased; In the relative pressure range of 0–0.4, the saturated adsorption capacity of AC-MIL-101(Cr) to ethanol vapor decreases slightly. It is lower than MIL-101(Cr), but its adsorption rate is improved. Therefore, AC-MIL-101(Cr)/ethanol vapor has a good application prospect in adsorption refrigeration systems. The exploration of AC-MIL-101(Cr) composite materials in this paper provides a reference for the future application of carbon-based/MOFS composite adsorbent/ethanol vapor working fluid in adsorption refrigeration.

Increase the Microporosity and CO2 Adsorption of a Commercial Activated Carbon

2015 ◽  
Vol 749 ◽  
pp. 17-21 ◽  
Author(s):  
Joanna Sreńscek Nazzal ◽  
Karolina Glonek ◽  
Jacek Młodzik ◽  
Urszula Narkiewicz ◽  
Antoni W. Morawski ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Materials ◽  
Micropore Volume ◽  
Microporous Carbon ◽  
Microporous Carbons ◽  
Adsorption Capacities

Microporous carbons prepared from commercial activated carbon WG12 by KOH and/or ZnCl2 treatment were examined as adsorbents for CO2 capture. The micropore volume and specific surface area of the resulting carbons varied from 0.52 cm3/g (1374 m2/g) to 0.70 cm3/g (1800 m2/g), respectively. The obtained microporous carbon materials showed high CO2 adsorption capacities at 40 bar pressure reaching 16.4 mmol/g.

Study of the Porous Structure and High Adsorption Capacity of Biomass-Based Activated Carbon Prepared from Aspen Wood by Ferric Nitrate III Activation

2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Mass Ratio ◽  
Aspen Wood ◽  
Surface Functional Groups ◽  
Wood Sawdust

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.

Mesoporous Activated Carbon Filaments

1996 ◽  
Vol 454 ◽  
Author(s):  
Weiming Lu ◽  
D. D. L. Chung
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mesoporous Activated Carbon ◽  
Carbon Filaments

ABSTRACTActivated carbon filaments of diameter ∼0.1 μm, main pore size (BJH) 55 Å, specific surface area 1310 m2/g and yield 36.2% were obtained by activating carbon filaments of diameter ∼ 0.1 urn in C02 + N2 (1:1) at 970°C for 80 min. Prior to this activation, the filaments were surface oxidized by exposure to ozone.

Sign in / Sign up

Export Citation Format

Share Document