• Title/Summary/Keyword: Solubility-normalization

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Identification of Tetrachloroethylene Sorption Behaviors in Natural Sorbents Via Sorption Models

  • Al Masud, Md Abdullah;Choi, Jiyeon;Shin, Won Sik
    • Journal of Soil and Groundwater Environment
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    • v.27 no.6
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    • pp.47-57
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    • 2022
  • A number of different methods have been used for modeling the sorption of volatile organic chlorinated compounds such as tetrachloroethylene/perchloroethylene (PCE). In this study, PCE was adsorbed in several natural sorbents, i.e., Pahokee peat, vermicompost, BionSoil®, and natural soil, in the batch experiments. Several sorption models such as linear, Freundlich, solubility-normalized Freundlich model, and Polanyi-Manes model (PMM) were used to analyze sorption isotherms. The relationship between sorption model parameters, organic carbon content (foc), and elemental C/N ratio was studied. The organic carbon normalized partition coefficient values (log Koc = 1.50-3.13) in four different sorbents were less than the logarithm of the octanol-water partition coefficient (log Kow = 3.40) of PCE due to high organic carbon contents. The log Koc decreased linearly with log foc and log C/N ratio, but increased linearly with log O/C, log H/C, and log (N+O)/C ratio. Both log KF,oc or log KF,oc decreased linearly with log foc (R2 = 0.88-0.92) and log C/N ratio (R2 = 0.57-0.76), but increased linearly with log (N+O)/C (R2 = 0.93-0.95). The log qmax,oc decreased linearly as log foc and log C/N increased, whereas it increased with log O/C, log H/C and log (N+O)/C ratios. The log qmax,oc increased linearly with (N+O)/C indicating a strong dependence of qmax,oc on the polarity index. The results showed that PCE sorption behaviors were strongly correlated with the physicochemical properties of soil organic matter (SOM).

A study of distribution characteristics of unidentified particulate components in an urban area (도시환경의 총부유먼지 중 미지성분의 분포 특성에 대한 연구)

  • Kim, Yong-Hyun;Kim, Ki-Hyun;Park, Chan-Koo;Shon, Zang-Ho;Song, Sang-Keun
    • Analytical Science and Technology
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    • v.25 no.2
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    • pp.133-145
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    • 2012
  • The quantitative composition of total suspended particulates (TSP) in the atmosphere is identified to consist mainly of ions, organic carbon (OC), element carbon (EC), and metals. In terms of environmental analysis, the rest of the TSP composition may be defined as unknown fraction (${\Sigma}X$) which is yet difficult to analyze both quantitatively and qualitatively. In this study, the major components of TSP were measured at an urban residential area (Gang Seo) in Seoul, Korea from February to December 2009. These TSP data were analyzed in various respects to explain the relationship between known and unknown constituents. During this study period, TSP was comprised mainly of unknown compounds (48.6%) followed by ions, OC, EC, and metals. The results of this study indicate that the distribution of ${\Sigma}X$ exhibits a strong similarity with ${\Sigma}Anions$, as they both increase with increasing TSP levels. However, if the concentrations of ${\Sigma}X$ and ${\Sigma}Anion$ are normalized against TSP, they exhibit a strong inverse correlation with each other due probably to larges differences in solubility. To establish a better strategy for air quality control in urban atmosphere, more efforts are needed to characterize unidentified proportion of particulate matters.