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11.
Youngchul Byun Ian P. Hamilton Xin Tu Dong Nam Shin 《Environmental science and pollution research international》2014,21(13):8052-8058
This study examines gaseous chlorinated species generated from the reaction of sulfur dioxide (SO2) with sodium chlorite powder (NaClO2(s)) to obtain insight into the propensity of this process to enhance NO and Hg0 oxidation. A packed bed reactor containing NaClO2(s) was used and the reaction temperature was set to 130 °C. Initially, we determined that the presence of SO2 enhances the oxidation of NO and Hg0 by reaction with NaClO2(s). We then introduced NO2 into the gas mixture as a radical scavenger and determined that the chlorinated species generated by the reaction of SO2 with NaClO2(s) are OClO, Cl, ClO, and Cl2. Based on these results, we suggest that such gaseous chlorinated ones are responsible for the enhancement of NO and Hg0 oxidation. 相似文献
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Yeon-Hum Yun Young-Jung Wee Hun-Soo Byun Soon-Do Yoon 《Journal of Polymers and the Environment》2008,16(1):12-18
Biodegradable films were successfully prepared by using cornstarch (CS), chemically modified starch (RS4), polyvinyl alcohol
(PVA), glycerol (GL), and citric acid (CA). The physical properties and biodegradability of the films using CS, RS4, and additives
were investigated. The results of the investigation revealed that the RS4-added film was better than the CS-added film in
tensile strength (TS), elongation at break (%E), swelling behavior (SB) and solubility (S). Especially, the RS4/PVA blend film with CA as an additive showed physical properties superior to other films. Furthermore,
when the film was dried at low temperature, the properties of the films clearly improved because the hydrogen bonding was
activated at low temperature. The biodegradation of films was carried out using the enzymatic, microbiological and soil burial
test. The enzyme used in this study was amyloglucosidase (AMG), α-amylase (α-AM) and β-amylase (β-AM). At the enzymatic degradation
test, the GL-added films had an approximately 60% degradation, while the CA-added films were degraded about 25%. The low degradation
value on CA-added film is attributed to low pH of film added CA that deactivated the enzymatic reaction. The microbiological
degradation teat was performed by using Bacillus subtilis and Aspergillus niger. 相似文献
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Modeling heterogeneous ClNO2 formation,chloride availability,and chlorine cycling in Southeast Texas
H. Simon Y. Kimura G. McGaughey D.T. Allen S.S. Brown D. Coffman J. Dibb H.D. Osthoff P. Quinn J.M. Roberts G. Yarwood S. Kemball-Cook D. Byun D. Lee 《Atmospheric environment (Oxford, England : 1994)》2010,44(40):5476-5488
Nitryl Chloride (ClNO2) mixing ratios above 1 ppbv have been measured off the coast of Southeast Texas. ClNO2 formation, the result of heterogeneous N2O5 uptake on chloride-containing aerosols, has a significant impact on oxidant formation for the Houston area. This work reports on the modeling of ClNO2 formation and describes the sensitivity of ClNO2 formation to key parameters. Model sensitivity analyses found that: (1) Chloride availability limits the formation of nitryl chloride at ground level but not aloft; (2) When excess particulate chloride was assumed to be present at ground level through sea salt, ClNO2 concentrations increased in some locations by a factor of 13, as compared to cases where sea salt chloride was assumed to be limited; (3) Inland formation of ClNO2 seems feasible based on chloride availability and could have a large impact on total ClNO2 formed in the region; and (4) ClNO2 formation is quite sensitive to the assumed yield of ClNO2 from N2O5 uptake. These results demonstrate that there is a need for further field studies to better understand the geographic extent of ClNO2 formation and the atmospheric conditions which control partitioning of chloride into the particle phase. In addition, this work examined the role of ClNO2 in the cycling of chlorine between chloride and reactive chlorine radicals. The modeling indicated that the majority of reactive chlorine in Texas along the Gulf coast is cycled through ClNO2, demonstrating the importance of including ClNO2 into photochemical models for this region. 相似文献