Department of Mechanical Engineering, Incheon National University, Songdo 1(il)-dong, Yeonsu-gu, Incheon, Republic of Korea. Electronic address:
Published: February 2018
AI Article Synopsis
Article Abstract
Volatile organic compound (VOC) gases can cause harm to the human body with exposure over the long term even at very low concentrations (ppmv levels); thus, effective absorbents for VOC gas removal are an important issue. In this study, accordingly, graphene-based adsorbents with microsized pores were used as adsorbents to remove toluene and acetaldehyde gases at low concentrations (30ppm). Sufficient amounts of the adsorbents were prepared for use on filters and were loaded uniformly at 0.1-0.5g on a 50×50mm area, to evaluate their adsorption features with low gas concentrations. The morphology and chemical composition of the adsorbents were characterized using scanning electron microscopy, N adsorption-desorption isotherms, X-ray photoelectron spectroscopy, and Raman spectroscopy. Microwave irradiation and heat treatment near 800°C under KOH activation resulted in enlargement of the pristine graphene surface and its specific surface area; maximum volume capacities of 3510m/g and 630m/g were observed for toluene and acetaldehyde gas. The high removal efficiency for toluene (98%) versus acetaldehyde (30%) gas was attributed to π-π interactions between the pristine graphene surface and toluene molecules.
Emissions of volatile organic compounds (VOCs) such as benzene, toluene, xylene, styrene, hexane, tetrachloroethylene, acetone, acetaldehyde, formaldehyde, isopropanol, etc., increase dramatically with accelerated industrialization and economic growth. Most VOCs cause serious environmental pollution and threaten human health due to their toxic and carcinogenic nature.
Seven different types of industrial boilers in Sichuan Province were selected to determine the VOC emission components and the source profiles of VOCs containing 115 components were established using Teflon sampling and GC-MS/FID analysis. The ozone formation potential （OFP） and emission factors of VOCs from different types of industrial boilers were analyzed. The results showed that the VOC components emitted from different types of industrial boilers were different.
An online gas chromatograph （GC5000） was used to monitor the volatile organic compounds （VOCs） in the atmospheric environment of Zhengzhou City during the ozone campaign period from May to September of 2022. The relationship between O and its precursors as well as meteorology was analyzed and the pollution characteristics of VOCs during the O exceeding and non-exceeding the standard days were compared and explored. Different VOC activity evaluation methods of OFP and were utilized to compare and analyze the key active components and species and the ratio analysis （RA） and positive matrix factorization （PMF） analysis models were used to study the apportionment contribution of VOCs.
Unlike many commercial sweeteners for which sweetness dose-response curves have been constructed, honey's sweetness has yet to be quantified. Honey differs from most commercial sweeteners in that it has a robust aroma; this aroma may impact its perceived sweetness. This study quantified the sweetness intensity and the impact of aroma on the perceived sweetness of four different honey varieties (clover, wildflower, alfalfa, and orange) compared to sucrose.
An air quality monitoring campaign in Luanda, Angola, in June 2023 examined gaseous pollutants at 25 locations, finding that traffic-heavy areas had higher levels of benzene, toluene, SO, and NO, but these were within WHO guidelines.
* Ozone levels were notably higher than in other African regions, with heavy traffic areas showing a strong potential for ozone formation, primarily from compounds like m,p-xylene and toluene.
* Despite moderate risk for non-cancer diseases across most sites, the Mulenvos landfill showed a high hazard quotient, and overall cancer risks exceeded acceptable levels, primarily driven by naphthalene exposure.*
