Performance Of Activated Carbon Fibers Research Articles

Preparation of well-developed mesoporous activated carbon fibers from plant pulp fibers and its adsorption of methylene blue from solution

Well-developed mesoporous plant-based activated carbon fibers (ACFs) with paper structure were prepared from plant pulp fibers (cotton, sisal hemp, manila hemp, softwood and bleached softwood) using phosphoric acid activation at 450°C. The structure and performance of ACFs were studied. Results show that ACFs exhibit high mesoporous rate of 72.8%-82.7%, large specific surface area of 1688–1825 m2/g and average pore size of 2.53–3.31 nm. ACFs show relatively high methylene blue (MB) adsorption capacity with 367.5–490.9 mg/g. SHP-ACFs have the largest MB adsorption capacity, the adsorption equilibrium data follows the Langmuir model and the kinetic data could be described by the pseudo-second-order model.

Effect of Surface Treatment by O3 and Chemical Activation by Alkali Metal on the Performance of ACFs on Adsorption and Desorption of BTX Gases.

In order to investigate the adsorption characteristics of activated carbon fibers (ACFs) with improved surface morphologies towards volatile organic compounds (VOCs), a commercial low-grade ACF was surface modified by successive surface treatment (ST) and chemical activation (CA) process. O3 was used as an ST agent for the formation of oxygen-containing functional groups on the carbon matrix of ACFs. CA was carried out after ST, using a KOH solution. After the successive ST-CA process, Brunauer-Emmett-Teller (BET) surface area and average pore diameter of ACFs were increased from 1483 m2/g to 2743 m2/g and enlarged from 1.931 nm to 2.512 nm, respectively. The successive ST-CA process also resulted in the adsorption capacities of benzene, toluene, and xylene of the ACFs to increase from 0.22 g−Ben./g−ACFs, 0.18 g−Tol./g−ACFs, and 0.19 g−Xyl/g−ACFs up to 0.37 g−Ben./g−ACFs, 0.35 g−Tol./g−ACFs, and 0.38 g−Xyl/g−ACFs, respectively.

Electrokinetic remediation of Pb near the e-waste dismantle site with Fe(NO3)3 as cathode electrolyte

ABSTRACT In this study, Pb-contaminated soil in the e-waste dismantle site was remediated by activated carbon fiber (ACF) enhanced electrokinetic remediation. Experiments were conducted using Fe(NO3)3 as catholyte and citric acid-sodium citrate as anolyte with different conditions: pH value of anolyte, voltage and the electrode gap. At the same time, we set up a group of contrast test without ACF to investigate the adsorption performance of ACF for Pb. Results showed that the highest removal rate of Pb after the remediation was 80.53% at 4 cm from the anode when the electrode gap was 31 cm, pH value was 3 and the voltage was 28 V, and the total removal rate increased significantly with the decrease of the pH value of anolyte and the increase of voltage. Characterization of ACF after reaction showed that ACF effectively adsorbed heavy metal Pb, and the adsorption amount was 1.42 mg/g. Sequential extraction analysis revealed that Pb mainly existed in the forms of organic matter bound and residual in the soil after remediation. These forms are relatively stable and low toxicity, indicating that the remediation has significantly reduced the harm of Pb to the environment.

The adsorption of carbon disulfide on activated carbon fibers

The adsorptive performance of commercial activated carbon fiber(ACF) for CS2 was investigated and a comparison of the adsorptive performance of ACF with activated carbon(AC) and zeolites was made.The effects of the operating parameters such as CS2 concentration,flux,humidity and water content in ACF on the adsorptive performance were investigated.Results indicated that the ACF had a higher adsorption capacity of 46.5% than AC and zeolites did toward CS2.The breakthrough time decreased greatly with flow rate and CS2 concentration.The adsorptive performance deteriorated with increasing humidity and water content in the ACF.The adsorption time was shortened by 28.6% when humidity was increased to 65%.The breakthrough time was decreased by 42.9% when water content in the ACF was increased to 45%.The adsorptive capacity was negligible when water content in the ACF was increased to over 60%.

Removal of Pesticides from Aqueous Solution: Quantitative Relationship Between Activated Carbon Characteristics and Adsorption Properties

The adsorption of pesticides (atrazin, atrazin-desethyl and triflusulfuron-methyl) from aqueous solution is performed by activated carbon fibers (ACF) and granular activated carbons (GAC) in static and dynamic reactors, in order to study the co-influence of adsorbent and adsorbate characteristics on the adsorption mechanisms. First, mono-component adsorption equilibrium is carried out in a batch reactor for a wide range of concentrations (from 5 μg l−1 to 21.4 mg l−1). Classic models, like Freundlich and Langmuir equations, are applied: the maximum adsorption capacities are high, ranging between 63 and 509 mg g−1. The comparison of single-solute isotherms tends to confirm the decisive role of the adsorbent properties in the adsorption capacity of pesticides by the activated carbons: the performance of ACF is significantly higher than that of GAC due to a narrower pore size distribution of fibers in the area of micropores. Furthermore, their small diameter (10 μm compared with 1 mm for grains) enables faster adsorption kinetics because of the larger surface area exposed to the fluid. The influence of adsorbate size is also demonstrated. A multiple linear regression enables the co-influence of adsorbent and adsorbate properties to be quantified, a relationship being assessed between Langmuir maximum adsorption capacity and pesticide molecular weight and adsorbent diameter (R2 = 0.90). Secondly, the adsorption of the three pesticides is studied in a dynamic reactor: in this case, the influence of operating conditions (inlet concentration C0 , flow velocity U0 ) is also taken into account. As the initial concentration or flow velocity decreases, the column performance significantly improves. Both operating factors are included in a multiple linear regression (R2 = 0.91) used to predict saturation adsorption capacity, with molecular weight and particle diameter being again designed as influent explicative variables.

Adsorption onto Fibrous Activated Carbon: Applications to Water Treatment

The adsorption of polluted waters is performed by activated carbon fibers (ACF). This new material is characterized by scanning electronic microscopy. BET surface areas and pore volumes are determined. Adsorption of natural organics (humic substances) and micropollutants (aromatic compounds such as benzene and toluene) is carried out in a batch or dynamic reactor. Classical models are applied and kinetic constants calculated. The results show that the performance of ACF is significantly higher than that of granular activated carbon (GAC) in terms of adsorption velocity and selectivity for micropollutants. These higher performances are due to some ACF physical properties, such as their high BET surface area and micropore volume. Moreover, the micropores are directly connected on the external surface area of fibers, which allows smaller mass transfer resistance. In a dynamic reactor, the breakthrough curves obtained with ACF beds are particularly steep, suggesting a smaller mass transfer resistance than tha...

Adsorption onto activated carbon fibers: Application to water and air treatments

The adsorption of polluted fluids is performed by activated carbon fibers (ACF). The adsorption is carried out in batch and in dynamic reactors. Classic models are applied and kinetic constants are computed. Results show that the performance of ACF is significantly higher than that of granular activated carbon (GAC) in terms of adsorption rate and selectivity for micropollutants. The breakthrough curves obtained with ACF adsorbers are particularly steep, suggesting a smaller mass transfer resistance than with GAC. The adsorption zone in the ACF bed is about 3.4 mm and is not really dependent on the water flow rate within the studied range. Applications are developed in water and air treatments. Examples are given in the micropollutants removal of an aqueous solution. Air loaded with VOC is treated by fibers. Regeneration of this material is performed by heating by the Joule effect or electromagnetic induction. These approaches to water or air treatment processes are successfully put to use.