• 한국토양비료학회지
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• 제49권6호
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• pp.789-794
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• 2016

Continuous excessive application of phosphorus (P) fertilizer and manure in plastic film house soils can lead to an accumulation of P in soils. The understanding of P sorption by soils is important for fertilizer management. In this study, 9 samples were collected for acidic and calcareous soils as non-cultivated soil and plastic film house soils as cultivated soil Phosphorus sorption data of acidic soils fit the Langmuir equations, Freundlich equations in calcareous and plastic film house soils. In calcareous and plastic film house soils, the slope of isotherm adsorption changed abruptly, which could be caused P precipitation with $CaCO_3$. The calculated Langmuir adsorption maximum ($S_{max}$) varied from 217 to 1,250, 139 to 1,429, and $714mg\;kg^{-1}$ for acidic soils, calcareous soils, and plastic film house soils with low available phosphate concentration, respectively. From this result, maximum P adsorption by the Langmuir equation could be regarded as threshold of P concentration to induce the phosphate precipitation in soil. Phosphate-sorption values estimated from one-point isotherm for acidic and calcareous soils as non-cultivated soils were comparable with the $S_{max}$ values calculated from the Langmuir isotherm.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.42-45
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• 2005

Accurate prediction of the fate and transport of contaminants in soils and sediments is very Important to environmental risk assessment and effective remediation of contaminated soils and sediments. The fate and transport of contaminants in subsurface are affected by geosorbents, especially carbonaceous materials including black carbon. Various physical and chemical treatment methods have been developed to separate different kinds of carbonaceous materials from soils and sediments. However, the effects of these separation methods on the properties of remaining carbonaceous materials including sorption capacity and linearity are unclear. The objective of this study is to determine if the chemical and thermal treatment methods previously used to separate different carbonaceous material fractions affect the properties of carbonaceous materials including longer term sorption capacity of hydrophobic organic contaminants. The results indicate that treatments with hydrochloric acid (HCl)/hydrofluoric acid (HF), trifluoroacetic acid (TFA), sodium hydroxide (NaOH) may not affect the sorption capacity of black carbon reference materials such as char and soot, however, treatments with acid dichromate $(K_2Cr_2O_7/H_2SO_4)$ and heat $(375^{\circ}C)$ for 24 hours in sufficient of oxygen) decrease the sorption capacity of them. The results of longer term sorption isotherm indicate that 2 days might be enough for trichloroethene (TCE) to equilibrate apparently with treated black carbon reference materials. The results suggest that acid dichromate and heat treatments may not appropriate method to investigate sorption properties of black carbon in soils and sediments.

• 한국지구과학회지
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• 제43권4호
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• pp.532-538
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• 2022

Under anoxic conditions, this study investigated removal of dissolved As(III) by Si and Al oxides including natural sand, chemically washed sand (silica), alumina, and activated alumina. Despite the similar surface area, natural sand showed greater extents of As(III) sorption than chemically washed sand. This was likely due to the high reactivity of Fe(oxyhydr)oxide impurities on the surface of natural sand. For both sands, As(III) sorption was the greatest at pH 7.1, in agreement with the weakly dissociating tendency of arsenous acid. Also, the least sorption was observed at pH 9.6. At basic pH, elevated silicate, which originated from the dissolution of silica in sands, would compete with As(III) for sorption. Due to the highest surface area, activated alumina was found to quantitatively immobilize the initially added As(III) (6.0×10^-7-2.0×10^-5 M). Alumina showed As(III) sorption compared to or greater than chemically washed sand, although the former had less than 6% of the surface of area the latter. The greater reactivity of alumina than chemically washed sand can be explained by using the shared charge of oxygen.

• 상하수도학회지
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• 제20권5호
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• pp.709-717
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• 2006

This research was conducted to figure out the feasibility of several sorption materials to treat various pollutants in road runoff. In advance of the major feasibility test with various sorption materials, the separation process with $1.2{\mu}m$ filter was conducted and showed that slight portion of pollutants was removed(Orgamic pollutant - 20%, Nutrient salt - 50%, Heavy metals - 0~30%). To remove dissolved pollutants in runoff, various materials were tested through an isotherm sorption experiment. As a result, GAC showed most effective material among them to lessen most contaminants such as organic compounds and nutrients. On the other hand, ion-exchange resin and Zeolite showed limited usefulness on the some heavy metals. Freundlich model was most suitable for the current experiment data, and the amount of adsorbent (GAC) could calculated based on this model.

• 한국환경과학회지
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• 제6권5호
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• pp.531-539
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• 1997

Lead sorption performances by biomass of nonliving, dried marine brown algae Undaria phnaunda, Hlzikia hsyormls. and Sugassum fulvellum used as biosorbent materials were investigated. As the amount of biosorbent materials added was increased, the lead removal by biosorbent materials Increased but the lead biosorption capacities decreased. However, with increasing Initial lead concentration the lead biosorption capacities by the biosorbent materials Increased but lead removal efficiencies decreased. In the range of Initial lead concentration(Co) 10-500 mg/L the lead biosorption capacities and removal efficiencies by the biosorbent materials Increased with increasing pH. Among the biosorbent materials used in this study, the lead biosorption capacities decreased in the following sequence: U. plilnaunda > H. fusiformis > S. fulvellum. The lead biosorption by biosorbent materials were expressed by the Langmuir Isotherm better than the Freundlich Isotherm. The biosorption rate could be expressed by the first order reaction rate equation for initial lead concentration like that rad : 0.288Co for U. phanda, rad = 0.255Co for H. fusiformis, and rad : 0.161Co for S. fulvellum. Key words : Lead, biosorption, biosorbent, Undaria pinnatinda, Hiztkia fusiformis, Sargassum fulvellum, Langmuir isotherm, Freundlich isotherm, biosorption rate.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.164-171
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• 2021

The europium sorption on Tamusu clay was investigated by batch sorption experiments and spectroscopic study under the condition of strong ionic strength. The results demonstrated that europium sorption on Tamusu clay increased rapidly with pH value, but decreased with the ionic strength of solution increased. The europium sorption also increased in the presence of humic acid, especially at low pH value. The sorption could be fitted by Freundlich isotherm model and the europium sorption on clay was spontaneous and endothermic reaction. Besides, the result indicates that ion exchange was the main process at low pH value, while inner-sphere surface complexation dominated the sorption process at high pH value. The Backscatter electron scanning/Energy Dispersive Spectrometer(BSE/EDS) and the effect of Na for europium sorption results further suggested that europium sorption on Tamusu clay mainly competed with Na at low pH value. Overall, the results in this research were of significance to understand the sorption behavior of europium on the geological media under high ionic strength.

• 대한환경공학회지
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• 제33권8호
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• pp.606-616
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• 2011

본 연구는 흡착제의 흡착특성을 이해하는데 이용되는 각종 흡착모델의 적용성을 평가하는데 목적이 있다. 이를 위해 상용의 음이온교환수지(PA-308)를 이용하여 $NO_3^-$에 대한 흡착특성을 회분식 실험을 통해 조사하였다. 흡착등온과 흡착속도 실험결과는 일반적으로 널리 이용되고 있는 다양한 흡착등온식과 반응속도식을 통해 모델화하였다. 흡착평형실험은 흡착등온식을 적용하는데 있어 실험조건이 미치는 영향을 확인하기 위해 흡착제의 투여량을 일정한 값으로 고정하고 흡착질의 농도변화에 따른 조건과 흡착질의 농도를 일정한 값으로 고정하고 흡착제의 투여량 변화에 따른 조건으로 나누어 수행하였다. 흡착질의 농도를 변화시키는 조건에서의 흡착평형은 Langmuir와 Freundlich 흡착등온식을 결합한 형태의 Sips 흡착등온식과 Redlich-Perterson 흡착등온식에 의해 수식화가 가능하였다. 한편, 흡착제의 무게를 변화시키는 조건에서의 흡착평형은 단층 흡착, 균일표면을 가정하는 Langmuir 흡착등온식과 잘 일치하는 경향을 보였다. 이상의 결과는 $NO_3^-$에 대한 음이온교환수지의 흡착 메커니즘이 흡착실험 조건에 의해 달라질 수 있음을 시사한다.

• 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.

• 한국지반공학회논문집
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• 제24권9호
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• pp.13-21
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• 2008

분배성 추적자 시험법은 LNAPLs(light nonaqueous phase liquids)로 오염된 지반을 조사하는데 아주 유용한 방법이다. 하지만 토양 내 유기물질로 흡착되는 분배성 추적자는 잠재적으로 분배성 추적자 시험법의 정확성에 영향을 끼칠 수 있다. 연구 결과, 추적자의 액상-LNAPL 간 분배 계수는 선형 관계를 보였다. 토양의 흠착능력을 평가하기 위해 흡착 등은 실험을 수행한 결과, Freundlich 흡착 등은 양상과 거의 일치하였고, 추적자의 흡착 정도는 토양 내 유기물질 함량이 증가함에 따라 증가하였다. 또한, 토양 유기물의 흡착능에 따른 잠재적 영향을 판단하고, 추적자 시험법에 의한 LNAPLs 예측의 오차를 수정하기 위해 서로 다른 유기물 함량을 가진 4개의 컬럼 실험을 수행하였다. 컬럼 실험 결과, 오염물질이 없더라도 주문진 표준사와 유기물질이 섞인 컬럼에서는 추적자의 분리 현상이 발생하였다. 오염물질로 케로진을 주입한 이후에 다시 추적자 시험법을 수행하여 파괴곡선을 구한 결과, 토양 유기물질에 대한 추적자의 흡착으로 인해 추적자의 지연계수(R)가 커졌고 LNAPLs의 오염도가 과대평가 되었다. 또한 컬럼 실험 결과를 바탕으로 유기물 함량과 LNAPLs의 예측도 사이의 관계식을 제안하였다.

• 상하수도학회지
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• 제28권1호
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• pp.83-89
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• 2014

The aim of this study is to investigate the sorption/ion exchange of radioactive nuclides such as $Cs^+$ and $Sr^{2+}$ by synthetic Na-micas. In order to prepare Na-micas, two natural micas (phlogopite and biotite) were used as precursor materials. XRD, SEM, and EDS analyses were used to examine material characterization of synthetic Na-micas. Analyses of materials revealed that Na-micas were successfully obtained from natrual micas by K removal treatment. On the other hand, single solute (Cs or Sr) and bi-solute (Cs/Sr) sorption experiments were carried out to determine sorption capacity of Na-micas for Cs and Sr under different pH and ionic strength conditions. Uptake of Cs and Sr by micas in bi-solute system was lower than in single-solute system. Additionally, Langmuir and Langmuir competitive models were applied to describe sorption isotherm of Na-micas. bi-solute system was well described by Langmuir competitive models. For the results obtained in this study, Na-micas could be promising sorbents to treat multi-radioactive species from water and groundwater.