• 한국물환경학회지
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• 제24권6호
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• pp.801-805
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• 2008

본 연구에서는 섬유상 재료(PBO)가 고상 추출을 위한 흡착제로 사용되어 분석 과정을 간소화하였다. 두 종류의 PBO섬유(HM, AS)를 이용한 회분식 흡/탈착 실험으로 DEHP 물질의 추출 특성을 평가하였다. 100 mg의 HM 섬유를 20 mL의 수용성 DEHP 용액($50{\mu}g/L$이하)에 주입한 결과, 95%의 DEHP가 흡착되었다. 초기 $50{\mu}g/L$의 DEHP 수용액의 경우, 흡착된 DEHP는 메탄올로 탈착되어 전체 회수율은 92.3%로 나타났다. 따라서 PBO섬유는 알킬프탈레이트 분석을 위한 흡착제로 유용한 것으로 나타났고, 이런 추출 과정은 수중의 SS에 영향을 받지 않았다.

• Environmental Engineering Research
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• 제11권1호
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• pp.1-13
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• 2006

In this study, conventional biofilters packed with flexible synthetic polyurethane (PU) foam carriers were operated to remove toluene from a contaminated air stream. PU foams containing various adsorbents (e.g., zeolite, sepiolite, dolomite and barite) were synthesized for the biofilter media and their adsorption characteristics of toluene were determined. Adsorption capacity of PU-adsorbent foam was in the order of PU-dolomite ${\approx}$ PU-zeolite > PU-sepiolite > PU-barite. During the biofiltration experiment, influent toluene concentration was in the range of 0-160 ppm and EBRT (i.e., empty bed residence time) was 45 seconds. Pressure drop of the biofilter bed was 4-5 mm $H_2O/m$ column height. The maximum removal capacity was in the order of PU-dolomite > PU-zeolite > PU-sepiolite > PU-barite, while the complete removal capacity was in the order of PU-dolomite > PU-sepiolite > PU-zeolite > PU-barite. The better biofiltration performance in PU-dolomite foam was because PU-dolomite foam had lower density and higher porosity than the others providing favorable conditions for microbial growth. The results of biodegradation kinetic analysis showed that PU-dolomite foam had higher maximum removal rate ($V_m\;=\;11.04\;g$ toluene/kg dry material/day) and saturation constant ($K_s\;=\;26.57\;ppm$) than the other PU foams. This supports that PU-dolomite foam was better than the others for biofilteration of toluene.

• 환경위생공학
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• 제16권1호
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• pp.72-90
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• 2001

This study was conducted to evaluate desorption efficiencies accuracy and precision by $CS_2$ and thermal desorption method for polar and non-polar organic solvents collected on activated carbon(AC), activated carbon fiber(ACF), carbosieve SIII, materials tested were Methyl alcohol, n-Hexane, Benzene, Trichloroethylene, Methyl isobutyl ketone and methyl cellosolve acetate and six different concentration levels of samples were made. The results were as follows ; 1. Accuracy on kind adsorbent and desorption method was low. In case of $CS_2$ desorption solvent, Overall B and Overall CV on AC and ACF were 43% and 6.63%, respectively. In case of thermal desorption method, accuracy of thermal desorption method appeared higher than solvent desorption method by AC 18.0%, 3.54%, ACF 2.6%, 2.57%, Carbosieve SIII 13.7% and 1.97%, respectively. 2. In the concentration level III, accuracy of thermal desorption method on adsorbent was in order as follow ; ACF > Carbosieve SIII > AC in the methyl alcohol and Carbosieve SIII > ACF > AC in the rest of them all subject material and Concentration levels showed good precision at EPA recommend standard (${\leq}{\;}30%$) 3. DEs by type of organic solvent adsorbent and desorption method are as follows ; In the case that desorption solvent is $CS_2$, DE of Methyl alcohol is AC 47.5%, DE of all materials is ACF about 50%. In the case of thermal desorption method, DE of Methyl alcohol is AC 82.0%, ACF 97.4%, Carbosieve SIII 86.3%. DE of the later case is prominently improved more than one of former. In particular, Except that DE of EGMEA is ACF 88.5%, DE of the rest of it is more than 95% which is recommend standard MDHS 72. With the result of this study, in order to measure various organic solvent occurring from the working environment, in the case of thermal desorption method, we can get the accurate exposure assessment, reduce the cost, and use ACF as thermal desorption sorbent which available with easy.

• 방사선산업학회지
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• 제18권1호
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• pp.89-93
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• 2024

Accidents at nuclear facilities and nuclear power plants led to leaks of large amounts of radioactive substances. Of the various radioactive nuclides released, ¹³⁷Cs are radioactive substances generated during the fission of uranium. Therefore, due to the high fission yield (6.09%), strong gamma rays, and a relatively long half-life (30 years), a rapid and efficient removal method and a study of adsorbents are needed. Accordingly, an adsorbent was prepared using Prussian blue (PB), a material that selectively adsorbs radioactive cesium. As a result of evaluating the adsorption performance with the prepared adsorbent, it was confirmed that 82% of the removal efficiency was obtained, and most of the cesium was rapidly adsorbed within 10 to 15 minutes. The purpose of this study was to adsorb cesium using the Prussian blue alginate bead and to compare the change in detection efficiency according to the amount of adsorbent added for quantitative evaluation. However, in this case, it is difficult to determine the detection efficiency using a standard source with the same conditions as the measurement sample, so the efficiency change of the HPGe detector according to the different heights of Prussian blue was calculated through MCNP simulation using certified standard materials (1 L, Marinelli beaker) for radioactivity measurement. It is expected to derive a relational equation that can calculate detection efficiency through an efficiency curve according to the volume of Prussian blue, quantitatively evaluate the activity at the same time as the adsorption of radioactive nuclides in actual contaminated water and use it in the field of nuclear facility operation and dismantling in the future.

• 통합자연과학논문집
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• 제6권3호
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• pp.151-157
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• 2013

The ion exchange resins were synthesized from 1-aza-18-crown-6 macrocyclic ligand attached to styrene (2th petroleum in 4th class hazardous material) divinylbenzene (DVB) copolymer with crosslinks of 1%, 6%, and 15% by substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, surface area, and IR-spectrum. The object of this study was to seperate the metal ion absorbed in reinforcement water fire extinguishing agent. As the results of the effects of pH, equilibrium arrival time, and crosslink of synthetic resin on metal ion adsorption for resin adsorbent, the metal ions were showed high adsorption at pH 3 or over and adsorption equilibrium of metal ions was about 2 hours. In addition, adsorption selectivity for the resin in water was the order of Al (III) > Ni (II) > Sm (III) ions, adsorbability of the metal ions was in the crosslinks order of 1%, 6%, and 15%.

• Membrane and Water Treatment
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• 제15권3호
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• pp.131-137
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• 2024

Euryale ferox Salisb. is an important plant resource and valuable tonic in traditional Chinese medicine. The seed of Euryale ferox Salisb. is rich in starch. There are few reports of modification and functional properties of Euryale ferox starch. In present study, the Euryale ferox starch was extracted, carboxymethyl etherified starches were synthesized, the starch-based hydrogels were prepared, and adsorptive properties were investigated. The results of investigation showed that carboxymethyl etherified Euryale ferox starch-based adsorbent has the potential for methylene blue removal. Therefore, Euryale ferox starch has an appealing application prospect in adsorption for scavenging dyes from real complex waste liquid.

• 한국환경과학회지
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• 제29권8호
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• pp.827-835
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• 2020

Zeolite material having XRD peaks of Na-A zeolite in the 2θ range of 7.18 to 34.18 can be synthesized from the waste catalyst using a fusion/hydrothermal method. The adsorption rate of Mn ions by a commercial Na-A zeolite and the synthesized zeolitic material increased as the adsorption temperature increased in the range of 10 ~ 40℃. The adsorption of Mn ion were very rapid in the first 30 min and then reached to the equilibrium state after approximately 60 min. The adsorption kinetics of Mn ions by the commercial Na-A zeolite and the zeolitic material were found to be well fitted to the pseudo-2^nd order kinetic model. Equilibrium data by the commercial Na-A zeolite and the zeolitic material fit the Langmuir, Koble-Corrigan, and Redlich-Peterson isotherm models well rather than Freundlich isotherm model. The removal capacity of the Mn ions by the commercial Na-A zeolite and the zeolitic material obtained from the Langmuir model was 135.2 mg/g and 128.9 mg/g at 30℃, respectively. The adsorption capacity of Mn ions by the synthesized zeolitic material was almost similar to that of commercial Na-A zeolite. The synthesized zeolitic material could be applied as an economically feasible commercial adsorbent.

• Carbon letters
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• 제14권1호
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• pp.27-33
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• 2013

An increase in population initiating rapid industrialization was found to consequently increase the effluents and domestic wastewater into the aquatic ecosystem. In this research the potentialities of Sambucus nigra L. (SNL) plant in the remediation of water, contaminated with methylene blue (MB), a basic dye were investigated. SNL was chemically impregnated with $KHCO_3$. Operating variables studied were pH, amount of adsorbent and contact time. In general, pH did not have any significant effect on colour removal and the highest adsorption capacity was obtained in 0.035 g MB/g-activated carbon. The Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption models were applied to describe the equilibrium isotherms. The adsorption isotherm data were fitted to the Temkin isotherm. The mass transfer property of the sorption process was studied using Lagergren pseudo-first-order and chemisorption pseudo-second-order kinetic models. The sorption process obeyed the pseudo-second-order kinetic model. The surface area, pores volume and diameter were assessed by the Brunauer-Emmett-Teller and Barrett-Joyner-Halenda methods. The results were compared to those from activated carbon (Merck) and an actual sample. The results indicate that SNL can be employed as a natural and eco-friendly adsorbent material for the removal of dye MB from aqueous solutions.

• Advances in environmental research
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• 제4권2호
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• pp.119-133
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• 2015

Water pollution means that the physical, chemical and biological properties of water are changing. In this study, adsorption was chosen as the treatment method because it is an eco-friendly and low cost approach. Magnetite is a magnetic material that can synthesize chemical precipitation. Magnetite was used for the removal of copper in artificial water samples. For this purpose, metal removal from water dependent on the pH, initial concentration of metal, amount of adsorbent and effect of sorption time were investigated. Magnetite was characterized using XRD, SEM and particle size distribution. The copper ions were determined by atomic absorption spectrometry. The adsorption of copper on the magnetite was studied in a batch process, with different aqueous solutions of Cu (II) at concentrations ranging from 10 to $50mg\;l^{-1}$. Optimum conditions for using magnetite were found to be concentration of $10mg\;L^{-1}$, pH: 4.5, contact time: 40 min. Optimum adsorbent was found to be 0.3 gr. Furthermore, adsorption isotherm data were analyzed using the Langmuir and Freundlich equations. The adsorption data fitted well with the Freundlich ($r^2=0.9701$) and Langmuir isotherm ($r^2=0.9711$) equations. Kinetic and equilibrium aspects of the adsorption process were studied. The time-dependent Cu (II) adsorption data were described well by a pseudo-second-order kinetic model.

• 한국응용과학기술학회지
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• 제24권1호
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• pp.92-97
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• 2007

The present paper deals with gaseous carbon dioxide separation by a commercial adsorbent: X-type zeolite. Experimental work was carried out at an ambient condition focusing on how well meeting to the national guideline. A few types of reactor and material were examined, and practical capability was found in a granular bed type reactor with the flow of 2.5 CMM. An optimum design of reactor and adsorbent could provide the required concentration, less than 2500 ppm, for the continuous operation up to 10 hours. More work including automatic regeneration is now underworking.