• 한국지하수토양환경학회지:지하수토양환경
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• 제27권6호
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• pp.11-21
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• 2022

Sorption of phenanthrene (PHE) and pyrene (PYR) in several sorbents, i.e., natural soil, BionSoil^®, Pahokee peat, vermicompost and Devonian Ohio Shale and a surfactant (hexadecyltrimethyl ammonium chloride)-modified montmorillonite (HDTMA-M) were investigated. Pyrene exhibited higher sorption tendency than phenanthrene, as predicted by its higher octanol to water partition coefficient (K_ow). Several sorption models: linear, Freundlich, solubility-normalized Freundlich model, and Polanyi-Manes model (PMM) were used to analyze sorption isotherms. Linear isotherms were observed for natural soil, BionSoil^®, Pahokee peat, vermicompost, while nonlinear Freundlich isotherms fitted for Ohio shale and HDTMA-M. The relationship between sorption model parameters, organic carbon content (f_oc), and elemental C/N ratio was studied. In the binary competitive sorption of phenanthrene and pyrene in natural soil, competition between the solutes caused reduction in the sorption of each solute compared with that in the single-solute system. The ideal adsorbed solution theory (IAST) coupled with the single-solute Freundlich model was not successful in describing the binary competitive sorption equilibria. This was due to the inherent nature of linear sorption of phenanthrene and pyrene in natural soil. The result indicates that the applicability of IAST for the prediction of binary competitive sorption is limited when the sorption isotherms are inherently linear.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.122-126
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• 2002

Contaminant transport in porous media is characterized by solving an advection-dispersion equation(ADE). The ADE can cover equilibrium phenomena of interest, which include sorption, decay, and chemical reactions. Among these phenomena, sorption mechanism is described by several types of sorption isotherm. If we assume the sorption isotherm as linear, the solution of ADE can be easily procured. However, if we consider the sorption isotherm as non-linear isotherm like a Dual Reactive Domain Model (DRDM), the resulting differential equation becomes non-linear. In this case, the solution of ADE cannot be easily acquired by an analytic method. In this paper, we present the numerical analysis of ADE using a DRDM. The results reveal that even if sorption data may be fitted well using linear or non-linear isotherm, the characteristics of contaminant transport of the two cases are different from each other. To be concrete, the retardation of linear isotherm has stronger effect than that of the DRDM. As the non-linearity of sorption isotherm increases, the difference of retardation effects of the two cases becomes larger. For a pulse source, the maximum concentration of the linear model is higher than that of the DRDM, but the plume of the DRDM moves faster than that of the linear model. Behaviors of contaminant transport using the DRDM are consistent with common features of a linear model. For instance, biodegradation effect becomes larger as time goes by The faster the seepage velocity is, the faster the plume of contaminant moves. The plume of the contaminant is distributed evenly over overall domain in the event of high dispersion coefficient.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권1호
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• pp.26-34
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• 2005

토양과 유기화합물의 접촉시간은 흡착과 탈착의 특성에 영향을 미치는 중요한 요소 중의 하나이다. 본 연구에서는 atrazine의 토양 흡착과 탈착에 미치는 접촉시간의 영향을 연구하였다. 등온 흡착실험을 수행하여 토양과 수용액 사이의 분배계수를 구하였고, 탈착에 대한 동력학 실험을 수행하고 three-site desorption모델을 이용, 회기분석 하여 탈착속도 계수들을 추산하였다. atrazine과 토양의 접촉시간은 2일에서부터 8개월까지 변화시켰다. 2일 흡착에 대한 atrazine의 흡착등온 곡선은 거의 선형이었고$(r^2>0.97)$, 흡착분배계수는 토양의 유기탄소 함량과 강한 양의 상관관계를 가졌으며 사용한 모든 토양에서 접촉시간이 길어질수록 증가하였다. 흡착곡선에서의 비선형성은 Houghton muck토양을 제외하고는 접촉시간에 따라 증가하지 않았다. 탈착실험 분석으로부터 접촉시간이 증가함에 따라 equilibrium site분율은 감소하고 non-desorbable site 분율은 증가함을 알 수 있었다. 사용한 모든 토양에서 토양유기탄소 함량으로 표준화한 경우 desorbable sites 에서의 atrazine농도는 접촉시간에 따라 비교적 일정한 것에 비해 non-desorbable site에서의 atrazine농도는 접촉시간이 증가함에 따라 증가하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.277-284
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• 2004

Batch experiments were conducted to investigate the sorption and desorption behaviors of PAHs (naphthalene, phenanthrene and pyrene) in soils. Three different soils montmorillonite KSF (foc =0.14%), masato (foc =0.08%), and diatomite (foc =0.007%) were investigated. The results of sorption-desorption experiment indicate that the sorption affinity of PAHs was in the order of montmorillonite > masato > diatomite. The Freundlich model was well fitted to the sorption and desorption data. Sorption affinity increased as loc increased. Desorption of PAHs from soils was biphasic composed of reversible and irreversible compartments. Desorption-resistance of phenanthrene in soils was also determined. The biphasic desorption model was used to explain desorption-resistance of phenanthrene in soils. The linear term represents reversible sorption fraction and Langmuinian-type term represents desorption-resistant fraction.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.128-131
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• 2001

We evaluated natural attenuation of petroleum hydrocarbons in a shallow aquifer using a modeling study. The studied shallow aquifer was severely contaminated with petroleum hydrocarbons, especially toluene, ethylbenzene and xylenes (i.e, TEX). The exact spill history was not known. Therefor we used a contaminant level in May 1999 (the first sampling date of our integrated study) as an initial contaminant concentration. we calibrated required transport parameters using the contamination levels obtained from groundwater analyses in September of 1999. For fate and transport of the petroleum contaminants, five case 2 with sorption and degradation. case 3 with sorption and degradation (half decay constant compared with case 2), case 4 with degradation but no sorption, and case 5 with sorption but no degradation. For sorption and degradation, a linear sorption isotherm and first order irreversible decay was assumed, respectively and no additional contamination source to groundwater is also assumed.

• 한국토양비료학회지
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• 제37권6호
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• pp.365-370
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• 2004

토양의 규산흡착 지표인 C-type slope에 영향하는 토양 특성을 탐색하고자, 모재가 상이한 8개 토양에 대하여 pH 5, 6, 7 및 8의 4개 수준에서 등온흡착실험을 하였다. 등온흡착실험결과 규산흡착량은 같은 평형농도에서 pH 증가에 따라 큰 폭으로 증가하였다. 같은 pH조건에서 규산흡착량은 평형농도의 증가에 따라 직선적으로 증가하였으며, 규산의 등온흡착형태는 C-type이었다. 등온흡착의 직선회귀 기울기인 C-tyre slope는 모든 토양에서 pH 증가에 따라 지수 함수적으로 증가하였다. Log(C-type slope)는 pH가 높아짐에 따라 모든 토양에서 고도의 유의성이 있게 직선적으로 증가하였으며, 토양별 직선회귀 기울기가 사촌통과 종곡통 외에는 0.29-0.34 범위로 유사하였다. 각 토양의 pH 변화에 따른 Log(C-type slope)의 직선회귀 기울기들은 대부분 토양특성들과 상관관계를 보이지 않았다. pH 7에서의 Log(C-type slope)와는 $Fe_o$ (oxalate 추출 Fe)만이 유의성이 있는 상관관계가 있었으며, 다중회귀 분석 결과도 여러 가지 토양특성들 중에서 $Fe_o$만이 유의성이 있는 기여도를 나타내었다.

• Environmental Engineering Research
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• 제21권4호
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• pp.384-392
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• 2016

The aim of this study was to investigate the removal efficiency of $17{\alpha}$-methyltestosterone (MT) from aqueous solution by Salvinia cucullata Roxb. ex Bory in an active plant-based reactor with a specific focus on linear regression analysis for the sorption phenomena of MT onto the plant roots. A high performance liquid chromatographic method using UV detection (245 nm) was used to analyse the samples. The batch experiments of the active plant reactor (APR) were established to investigate the ability of Salvinia cucullata to remove MT from the liquid phase. The results revealed that 40% and 60% removal of MT from the liquid phase was observed at 5 min. and at 4 h, respectively. Salvinia cucullata can effectively remove MT from the aqueous solution in APRs. Kinetic studies revealed that the sorption phenomena of MT by Salvinia is best described using a linearized pseudo - second order model. Based on the kinetic parameters, it is likely that during the first 4 h of the contact (t = 0 to t = 4 h) sorption is the major driving mechanism of the disappearance of MT from aqueous solutions. However, at higher MT concentrations, diffusivity of MT has a significant effect on the migration of MT from the bulk stream to the root surface. The isotherm analysis revealed that the sorption kinetics favourably followed pseudo second-order. The results of isotherm analysis have indicated that the sorption of MT onto the root surfaces of Salvinia cucullata was favourable and almost irreversible.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.191-194
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• 2005

Characteristics of sorption and desorption in soils affect chemical fate, soil-remediation time, and selection of remediation technology. The sorption and desorption behavior of atrazine and naphthalene on soils was studied. Six soils collected at Gwangju area were used as sorbents and the organic matter contents ranged from 1.28 to 5.21%. Sorption and desorption experiments were conducted and sorption distribution coefficients(Kd) of atrazine and naphthalene were nearly linear$(R^2=0.93{\sim}0.97)$. Desorption parameters were evaluated using three site desorption model included equilibrium, nonequilibrium and nondesorption sites. Non-desorbable site fraction for atrazine was evaluated, but for naphthalene it was not enumerated during the experimental period. Through the series dilution desorption experiments, non-desorpbable sites were observed for both chemicals.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.894-900
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• 2021

This paper examines sorption of Pd(II) onto illite, MX-80 bentonite, and Queenston shale in Na-Ca-Cl solutions of varying ionic strength (IS) from 0.01 to 6.0 mol/L (M) and pH_c ranging from 3 to 9 under atmospheric conditions. A 2-site protolysis non-electrostatic surface complexation and cation exchange model was applied to the Pd sorption onto illite and MX-80 using PHREEQC, and the model results were compared to the experimental ones obtained in this work. Surface complexation and cation exchange constants were estimated for both illite and MX-80 through the optimization process to bring the predicted distribution coefficients from the model into alignment with the experimentally derived values. These optimized surface complexation constants were compared to existing linear free energy relationships (LFER).

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.339-339
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• 2006

In this study, the microvoids in glassy polymers were investigated by Xe sorption and $^{129}Xe$ NMR measurements. Xe sorption isotherms of glassy polymers have been successfully interpreted by the dual-mode sorption model. $^{129}Xe$ NMR chemical shift of the $^{129}Xe$ in the samples show nonlinear low-field shift with increasing sorption amount of Xe because of a fast exchange of Xe atoms between Henry and Langmuir sites, whereas it has showed linear shift against sorption amount of Xe into the Langmuir site. From this Xe-density dependence of the $^{129}Xe$ NMR chemical shift, it has been able to estimate mean size of the microvoids in glassy polymer. It is confirmed that there is correlation between ${C_H}'$ and volume or number of microvoids. From these findings, it is demonstrated that $^{129}Xe$ NMR spectroscopy is a powerful technique to determine the mean size and number of microvoids in glassy polymers.