• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3352-3358
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• 2021

Aiming at selective adsorption and separation of Y(III) from the Y(III)-Sr(II) group in acid solution, a silica-based TODGA impregnated adsorbent [(TODGA+1-dodecanol)/SiO₂-P-F600] has been prepared. Batch adsorption experiments were conducted under the effect of contact time, acid concentration, solution temperature, and adsorption capacity etc. Chromatography recovery of more than 90% Y(III) was successfully achieved under elution with 0.01 M DTPA solution in nitric acid adsorption system, and 0.1 M HCl solution in hydrochloride adsorption system, respectively.

• 한국지반공학회논문집
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• 제26권9호
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• pp.37-45
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• 2010

본 연구에서는 지하수에 존재하는 비소를 산업 폐기물인 제강 슬래그를 이용하여 제거하고자, 제강 슬래그에 대한 비소의 흡착특성을 규명하였다. 이를 위해 등온흡착 실험과 동적흡착 실험을 수행하였고, 흡착반응 후 용액의 화학적 특성을 분석하였다. 실험 결과, 흡착 실험을 수행한 모든 용액은 염기 상태로 존재하였으며(pH 9이상), 칼슘의 농도가 가장 높았다(30~50mg/L). 등온흡착 실험결과는 Langmuir 모델보다Freundlich 모델에 적용하는 젓이 더 합리적이였으며, 제강 슬래그에 As(V)가 As(III)보다 약 87% 더 많이 흡착되는 것으로 확인됐다. 동적흡착 실험결과의 경우, 유사일차모델보다 유사이차모델을 통해 해석하는 것이 더 적합하였다. 비소의 초기농도가 높을수록 평형 흡착량($q_e$)과 완화시간($t_r$) 이 모두 증가하였으며, As(V)는 As(III)보다 평형 흡착량이 많고 완화시간은 짧은 것을 확인할 수 있었다. 또한, 유사이차모델을 통해 예측된 평형 흡착량이 등온흡착 실험에서 구한 평형 흡착량과 유사해 동적흡착 실험결과로 등온흡착 실험결과를 예측하는 것이 가능함을 확인하였다.

• 분석과학
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• 제5권1호
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• pp.1-5
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• 1992

Amberlite XAD 고분자수지 및 고분자수지 대체흡착제인 rice bran, rice straw 그리고 sawdust에 대한 petroleum oil의 흡착량을 최저 흡착조건에서 뱃치법으로 측정하여 조사하였다. Rice bran과 rice straw에 대한 petroleum oil의 흡착량은 XAD계열수지의 흡착량의 약 50% 정도로 흡착성이 우수하였다. 또한 이들 대체흡착제의 흡착능을 증대시키기 위한 탄화시간은 $200^{\circ}C$, 30분이 최적 조건이었다. Sawdust의 경우에는 30% MeOH 매질에서는 흡착성이 매우 약한 반면 0.5M NaCl 매질에서는 XAD수지 흡착능이 약 1/2에 도달하였다. Rice bran과 rice straw는 외관상의 구조차이와는 관계없이 비슷한 흡착능력을 보였다. 따라서 rice bran과 rice straw들은 XAD계열 수지에 대한 대체흡착제로 충분한 흡착능력을 가지고 있는 것으로 보인다.

• 한국환경과학회지
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• 제24권12호
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• pp.1601-1608
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• 2015

This study evaluates heavy metal(Cu and Cr) adsorption characteristics produced from food waste charcoal extracted in an optimal operation condition after analyzing activated charcoal of iodine adsorption and heavy metals that derived from an activation process of carbide by the developed by-products of food waste treatment facility using the methods from previous studies. As experiment apparatus, this study used a tube-shaped high temp furnace. The mixing ratio of by-products of food waste treatment facility, carbide, and activation component($ZnCl_2$) was 1:1. The experiment was proceeded as adjusting the activation temperature from 400 to $800^{\circ}C$ and activation time from 30 to 120 minutes. The optimal activation condition for iodine absorption was 90 minutes at $700^{\circ}C$ and by using the produced food waste charcoal, this study conducted an experiment on absorption of heavy metals (Cu and Cr) as changing pH of artificial wastewater and stirring time. As a result, pH 7 showed the highest heavy metal decontamination ratio and in terms of stirring time, it revealed balance adsorption after 10 minutes. This result can be particularly applied as basic data for recyclability of high concentration organic waste, by-products of food waste treatment facility, as an food waste charcoal.

• 한국의류학회지
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• 제17권1호
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• pp.129-136
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• 1993

Authors have studied the adsorption of anionic surfactant from detergent solutions on cotton fabric during washing process and have measured the concentration of the residual surfactant in rinsing solution. The relations with temperature and pre-soaking time to rinsing process have been studied. The adsorption of sodium dodecylbenzene sulfonate by various textile fibers has also been investigated. The results of this study are; 1. Three times rinsing is sufficient as, without pre-soaking, the concentration of the surfactant on fabric is stable from that time on. 2. The rinsing efficiency increases with temperature; at $25^{\circ}C$, $40^{\circ}C$, and $55^{\circ}C$, the concentrations of surfactant on the fabric after-rinsing are 68, 59, 51 mg/100 g of fiber respectively. 3. The longer the pre-soaking time, the lower the rinsing efficiency is; the 4hrs presoaked fabric shows increased surfactant concentration than the one without-soaking. And the increment is 35.8%. 4. The adsorption of sodium dodecylbenzene sulfonate on fabrics differs greatly with the chemical nature of the fiber; wool, silk and nylon which are thought to be ionic-adsorbants shows greater adsorption. 5. The adsorption of surfactant is more affected by the ionic character than the physical one, and the one with higher crystallinity such as cotton and polyester shows lower value than rayon or acetate.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권2호
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• pp.38-43
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• 2014

In this study, we evaluated the methylene blue (MB) adsorption potential of non-treated and UV-C pretreated bacterial biomass from aqueous solution. The UV-C pretreatment denature the biomass and has increased overall functional groups when compared to non-treated biomass. The biosorbent was exposed to various pH, biomass dose, and contact time. The results showed that the dried and UV-C pretreated biomass effectively removed MB within 30 min. Dried and UV-C pretreated biomass of Bacillus pseudomycoides JH 2-2 showed a adsorption of 858.2 and 1072.4 mg/g at optimum conditions (pH: 9.0, contact time: 30 min, biomass dose: 1 g/L). Similarly, dried and UV-C pretreated biomass of Citrobacter freundii JH 11-2 showed an adsorption 868.3 and 954 mg/g at optimum conditions (pH: 9.0, contact time: 10 min, biomass dose: 1.5 g/L). The changes in the functional groups of UV-C pretreated biomass could be responsible for enhanced adsorption of MB. The results obtained have shown that non-treated and UV-C pretreated biomass has a high adsorption capacity for MB dye and can be used as a low-cost biosorbent in wastewater treatments.

• 한국염색가공학회지
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• 제19권3호
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• pp.26-36
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• 2007

This study was carried out to treat the aqueous solutions containing reactive dyes(RB19, RR120 and RY179) by the Ozone demand flask method and adsorption process using activated carbon fiber(ACF) which are one of the main pollutants in dye wastewater. Ozone oxidation of three kinds of the reactive dyes was examined to investigate the reactivity of dyes with ozone, competition reaction and ozone utilization on various conditions for single- and multi-solute dye solution. Concentration of dyes was decreased continuously with increasing ozone dosage in the single-solute dye solutions. Competition quotient values were calculated to investigate the preferential oxidation of individual dyes in multi-solute dye solutions. Competition quotients(CQi) and values of the overall utilization efficiency, ${\eta}O_3$, were increased at 40mg/l of ozone dosage in multi-solute dye solutions. ACF(A-15) has much larger specific surface area$(1,584m^2/g-ACF)$ in comparison with granular activated carbon adsorbent (F400, $1,125m^2/g-GAC$), which is commonly used, and most of pores were found to be micropores with pore radius of 2nm and below. It was found that RB19 was most easily adsorbed among the dyes in this study. In the case of PCP (p-chlorophenol) and sucrose, which are single component adsorbate, adsorption capacities of ACF(A-15) were in good agreement with the batch adsorption measurement, and saturation time predicted of ACF columns for these components was also well agreed with practically measured time. But in the case of reactive dyes, which have relatively high molecular weight and aggregated with multi-components, adsorption capacities or saturation time predicted were not agreed with practically measured values.

• Carbon letters
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• 제12권3호
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• pp.152-161
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• 2011

Activated carbon was prepared from pre-carbonized petroleum coke. Textural properties were determined from studies of the adsorption of nitrogen at 77 K and the surface chemistry was obtained using the Fourier-transform infrared spectrometer technique and the Boehm titration process. The adsorption of three aromatic compounds, namely phenol (P), p-nitrophenol (PNP) and benzoic acid (BA) onto APC in aqueous solution was studied in a batch system with respect to contact time, pH, initial concentration of solutes and temperature. Active carbon APC obtained was found to possess a high surface area and a predominantly microporous structure; it also had an acidic surface character. The experimental data fitted the pseudo-second-order kinetic model well; also, the intraparticle diffusion was the only controlling process in determining the adsorption of the three pollutants investigated. The adsorption data fit well with the Langmuir and Freundlich models. The uptake of the three pollutants was found to be strongly dependent on the pH value and the temperature of the solution. Most of the experiments were conducted at pH 7; the $pH_{(PZC)}$ of the active carbon under study was 5.0; the surface of the active carbon was negatively charged. The thermodynamic parameters evaluated for APC revealed that the adsorption of P was spontaneous and exothermic in nature, while PNP and BA showed no-spontaneity of the adsorption process and that process was endothermic in nature.

• 한국환경과학회지
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• 제22권11호
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• pp.1433-1441
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• 2013

The adsorption ability of wood-based activated carbon to adsorb methylene blue (MB) and crystal violet (CV) from aqueous solution has been investigated. Adsorption studies were carried out on the batch experiment at different initial MB and CV concentrations (MB=150 mg/L~400 mg/L, CV=50 mg/L~350 mg/L), contact time, and temperature. The results showed that the MB and CV adsorption process followed the pseudo-second-order kinetic and intraparticle diffusion was the rate-limiting step. Adsorption equilibrium data of the adsorption process fitted very well to both Langmuir and Freundlich model. The maximum adsorption capacity ($q_m$) by Langmuir constant was 416.7 mg/g for MB and 462.4 mg/g for CV. The thermodynamic parameters such as ${\Delta}H^{\circ}$, ${\Delta}S^{\circ}$ and ${\Delta}G^{\circ}$ were evaluated. The MB and CV adsorption process was found to be endothermic for the two dyes.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2753-2759
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• 2013

The aim of the present study is to explore the possibility of utilizing fly ash and loess, as alternative to activated carbon, for the adsorption of diazinon in water. Batch adsorption experiment was performed to evaluate the influences of various factors like initial concentration, contact time and temperature on the adsorption of diazinon. The adsorption data shows that fly ash is not effective for the adsorption of diazinon. The equilibrium data for both activated carbon and loess were fitted well to the Freundlich isotherm model. The pseudo-second-order kinetic model appeared to be the better-fitting model because it has higher $R^2$ compared to the pseudo-first-order kinetic model. The thermodynamic parameters such as free energy (${\Delta}G$), the enthalpy (${\Delta}H$) and the entropy (${\Delta}S$) were calculated. Contrary to loess, the ${\Delta}G$ values of activated carbon were negative at the studied temperatures. It indicates that the adsorption of diazinon by activated carbon is a favorable and spontaneous process. The positive ${\Delta}H$ values of activated carbon and loess suggest that the diazinon adsorption process is endothermic in nature. In addition, the positive ${\Delta}S$ values show that increased randomness occurs at the solid/solution surface during the adsorption of diazinon.