Adsorption/desorption characteristics of low-concentration semi-volatile organic compounds in vapor phase on activated carbon

2022 ◽  
Vol 305 ◽  
pp. 114360
Author(s):  
Xiuwei Ma ◽  
Linjun Yang ◽  
Yong Hou ◽  
Lei Zhou
Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 372 ◽  
Author(s):  
Lipei Fu ◽  
Jiahui Zhu ◽  
Weiqiu Huang ◽  
Jie Fang ◽  
Xianhang Sun ◽  
...  

Carbon-silica composites with nanoporous structures were synthesized for the adsorption of volatile organic compounds (VOCs), taking tetraethyl orthosilicate (TEOS) as the silicon source and activated carbon powder as the carbon source. The preparation conditions were as follows: the pH of the reaction system was 5.5, the hydrophobic modification time was 50 h, and the dosage of activated carbon was 2 wt%. Infrared spectrum analysis showed that the activated carbon was dispersed in the pores of aerogel to form the carbon-silica composites material. The static adsorption experiments, dynamic adsorption-desorption experiments, and regeneration experiments show that the prepared carbon-silica composites have microporous and mesoporous structures, the adsorption capacity for n-hexane is better than that of conventional hydrophobic silica gel, and the desorption performance is better than that of activated carbon. It still has a high retention rate of adsorption capacity after multiple adsorption-desorption cycles. The prepared carbon-silica composites material has good industrial application prospects in oil vapor recovery, providing a new alternative for solving organic waste gas pollution.


Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1207
Author(s):  
Aled D. Roberts ◽  
Jet-Sing M. Lee ◽  
Adrián Magaz ◽  
Martin W. Smith ◽  
Michael Dennis ◽  
...  

Fabrics comprised of porous fibres could provide effective passive protection against chemical and biological (CB) threats whilst maintaining high air permeability (breathability). Here, we fabricate hierarchically porous fibres consisting of regenerated silk fibroin (RSF) and activated-carbon (AC) prepared through two fibre spinning techniques in combination with ice-templating—namely cryogenic solution blow spinning (Cryo-SBS) and cryogenic wet-spinning (Cryo-WS). The Cryo-WS RSF fibres had exceptionally small macropores (as low as 0.1 µm) and high specific surface areas (SSAs) of up to 79 m2·g−1. The incorporation of AC could further increase the SSA to 210 m2·g−1 (25 wt.% loading) whilst also increasing adsorption capacity for volatile organic compounds (VOCs).


2021 ◽  
Vol 13 (12) ◽  
pp. 6570
Author(s):  
Asma Akter Parlin ◽  
Monami Kondo ◽  
Noriaki Watanabe ◽  
Kengo Nakamura ◽  
Mizuki Yamada ◽  
...  

The quantitative understanding of the transport behavior of volatile organic compounds (VOCs) in near-surface soils is highly important in light of the potential impacts of soil VOC emissions on the air quality and climate. Previous studies have suggested that temperature changes affect the transport behavior; however, the effects are not well understood. Indeed, much larger changes in the VOC flux under in situ dynamic temperatures than those expected from the temperature dependence of the diffusion coefficients of VOCs in the air have been suggested but rarely investigated experimentally. Here, we present the results of a set of experiments on the upward vertical vapor-phase diffusive transport of benzene and trichloroethylene (TCE) in sandy soils with water contents ranging from an air-dried value to 10 wt% during sinusoidal temperature variation between 20 and 30 °C. In all experiments, the flux from the soil surface was correlated with the temperature, as expected. However, the changes in flux under wet conditions were unexpectedly large and increased with increasing water content; they were also larger for TCE, the volatility of which depended more strongly on the temperature. Additionally, the larger flux changes were accompanied by a recently discovered water-induced inverse correlation between temperature and flux into the overlying soil. These results demonstrated that the flux changes of VOCs under dynamic temperatures could be increased by volatilization-dissolution interactions of VOCs with water. Future extensive studies on this newly discovered phenomenon would contribute to a better understanding of the impacts of soil VOC emissions on the air quality and climate.


2014 ◽  
Vol 88 ◽  
pp. 423-428 ◽  
Author(s):  
Ikuo Ueta ◽  
Emi Liana Samsudin ◽  
Ayako Mizuguchi ◽  
Hayato Takeuchi ◽  
Takumi Shinki ◽  
...  

2019 ◽  
Vol 19 (11) ◽  
pp. 7315-7319 ◽  
Author(s):  
Yi-Xin Wang ◽  
Hong Tao ◽  
Min-Nan Chen ◽  
Ling-Shao ◽  
Guang-Feng Shang ◽  
...  

In this study, a new type of molecular sieve/polyacrylonitrile fiber (M-PAN) was prepared by electrospinning to adsorb atmospheric volatile organic compounds (VOCs). The suitable content of molecular sieve in nanocomposites was also determined for achieving maximum VOCs adsorption capacity. SEM, TEM and N2 adsorption/desorption analyzer were performed for characterization of the surface morphology, structural properties, surface area and pore size. A part of molecular sieve is exposed on the fiber surface where VOCs can be adsorbed efficiently in a short time. Acetone was used as a challenge pollutant to evaluate the adsorption of VOCs at different recycling times and types of electrospinning nanofibers. The adsorption capacity of 6M-PAN (60% weight of molecular sieve) nanofiber reached 58.2 μg g−1 and the reused nanofibers nearly had the same adsorption capacity as the newly prepared nanofibers after several times of recirculation.


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