Volatile organic compounds and metals adsorption capacity of wood bark-based activated carbons

This study was conducted to investigate the applicability of wood bark-based activated carbon (AC) for the adsorption of metal ions and volatile organic compounds (VOC) from the atmosphere. Contents of Fe and Al in the AC made with coconut shell, and the bark of larch and cork oak (CSA, LBA and COA, respectively) were higher than those of the unexposed AC and increased with the exposure to various indoor/outdoor spaces when compared to the unexposed AC. However, Fe and Al contents of the exposed AC, which is a coal-based one used as a control (SAA), were lower and scarcely higher than the unexposed SAA. From the results, it is evident that the wood bark-based AC examined in this study is more effective to adsorb metals than SAA. The SEM-EDS analysis exhibited prominent metal-adsorptivity of COA, although its total surface area and pore volume were lower than those of SAA. Total VOC-adsorptivity was the highest in COA followed by CSA, CBA (cypress bark activated carbon), LBA and SAA. In conclusion, wood bark-based AC can be utilized as an effective adsorbent for the removal of metals and VOC from the atmosphere. The optimum AC is COA, an industrial by-product, in view of the techno-economic aspect.

Effects of temperature on volatile organic compounds and odor emissions of polyvinyl chloride laminated MDF

The objective of this study was to investigate odor active compounds of polyvinyl chloride (PVC) laminated medium density fiberboard (MDF) and explore the effect of temperature on total volatile organic compound (TVOC) and odor emissions. A micro thermal extractor was used based on the technology of gas chromatography–mass spectroscopy/olfactometry. The results showed that fruity, sweet, fragrant, and aromatic were the dominant odor impressions of PVC laminated MDF and were primarily concentrated in aromatics. Decoration treatment could effectively prevent the release of some odor compounds from MDF, yet these could add new odor substances. In the test period, the total odor intensity of MDF decreased more rapidly than that of PVC because of the characteristic of exposure. The TVOC from PVC increased when the temperature increased, and the effect was more significant early in the test period. Increasing temperature could accelerate the appearance of some odor active substances. The fastest release of odorant compounds occurred at 40°C. At higher temperature (60°C in this experiment), some substances could be enhanced, causing an increase in TVOC and odor. The temperature contrast between 40°C and 60°C contributed greatly to the release of alkanes, alcohols, esters, and ketones.