• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.500-505
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• 2007

The objectives of this research were to (1) identify the membrane fouling potential due to different fractions of NOM (2) correlate the physicochemical properties of NOM and membranes with the adsorption of humic substances on membrane (4) find out the effect of membrane physical and chemical washing according to membrane material. The static adsorption test and adsorption test showed that hydrophobic organics adsorbed much more quickly than hydrophilic organics. In case of the effect of membrane properties on the adsorption of organic fractions, the adsorption rate ratio(a) of hydrophobic membrane (0.016, 0.077) was greater than that of hydrophilic membrane (0.010, 0.033) regardless of the kind of organic fractions. This suggests that the UF membrane fouling were occurred mainly by internal pore size decreasing due to adsorption of organic into pore surface for hydrophobic membrane, and by sieving of organics and forming a gel layer on the membrane surface for hydrophilic membrane. In conclusion, the decrease in the pore volume, which was caused by the organic adsorption into the internal pore, was greater with the hydrophobic membrane than with the hydrophilic membrane. In case of the effect of membrane properties on permeate flux, the rate of flux decline for the hydrophobic membrane was significantly greater than that for the hydrophilic membrane.

• Journal of Environmental Science International
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• v.6 no.1
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• pp.61-67
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• 1997

Heavy metal adsorption by microbial cells is an alternative to conventional methods of heavy metal removal and recovery from metal-bearing wastewater The waste Sac-chuomyces cerevisiae is an inexpensive, relatively available source of biomass for heavy metal biosorption. Biosorption was investigated by free and immobilized-S. cerevisiae. The order of biosorption capacity was Pb>Cu>Cd with batch system. The biosorption parameters had been determined for Pb with free , cells according to the Freundlich and Langmuir model. It was found that the data fitted reasonably well to the Freundlich model. The selective uptake of immobilized-S. cerevisiae was observed when all the metal ions were dissolved in a mixed metals solution(Pb, Cu, Cr and Cd). The biosorption of mixed metals solution by immobilized-cell was studied in packed bed reactor. The Pb uptake was Investigated in particular, as it represents one of the most widely distributed heavy metals in water. We also tested the desorption of Pb from immobilized-cell by us- ing HCI, $H_2SO_4$ and EDTA.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.217-229
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• 2000

Adsorption equilibrium experiments for the phenol on granular activated carbon(16~25 mesh) and powder activated carbon(325 mesh) were carried out at $25{\pm}1^{\circ}C$ and the results were expressed with Freundlich isotherm. Adsorption rate experiments were executed in batch adsorption system under the condition that can be neglecting mass transfer resistance at the external surface of the particle. The results were analysed with the Miller's method to evaluate the linear driving force(LDF) adsorption rate constant. Fixed bed adsorption experiments were performed by adopting different flow rates in the activated carbon-phenol system at $25{\pm}1^{\circ}C$. The theoretical breakthrough curves were estimated with the simple constant pattern solution. The adsorption rate constant of LDF model was not a fixed value but variable with adsorption amount. The experimental results were better agreed with the estimation of breakthrough curve using the variable adsorption rate constant than the results estimated using the average fixed adsorption rate constant.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.485-495
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• 2005

This study was conducted to investigate sorption and desorption behaviors of radionuclides (Cobalt and Strontium) in natural soil. Sorption kinetics and isotherms were analyzed to predict sorption behaviors of radionuclides in natural soil and the experimental data were fitted to several sorption models. Desorption experiments were also performed with or without CMCD at constant pH and ion strength conditions. The results showed that $Sr^{2+}$ was more strongly sorbed than $Co^{2+}$ in natural soil. Both $Co^{2+}$ and $Sr^{2+}$ followed a pseudo-second order kinetics and Sips model. The desorption-resistance of $Co^{2+}$ and $Sr^{2+}$ was estimated using a natural surfactant Carboxymethyl-${\beta}$-cyclodextrin(CMCD) or non-desorbing fraction. Desorption of radionuclides was partially irreversible and $Sr^{2+}$ was more resistant than $Co^{2+}$ Addition of CMCD facilitated desorption of $Co^{2+}$ and $Sr^{2+}$ from soil.

• Analytical Science and Technology
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• v.7 no.3
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• pp.271-276
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• 1994

A Na-cellulose adsorbent was prepared by treating Sigma S-5504 cellulose with 2M NaOH and examined the adsorption behavior between metal ions and Na-cellulose in aqueous solution with batch method. Considering ion exchange capacity of Na-cellulose, the adsorption ratio of the Na-cellulose to metals charge equivalent indicated that the adsorption result from ion exchanging between metal ions and Na-cellulose. The enthalpy for the metal adsorption on the Na-cellulose was calculated to -18kcal/mol, which value was compared to those of carboxymethylcellulose(CMC) and Dowex 50W-X8, these result suggested that the adsorption on Na-cellulose resulted from ion exchange adsorption.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.367-376
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• 2022

One of biopolymer, β-glucan (BG) chains were crosslinked by citric acid under the heating condition for the adsorption of Pb and Cu ions in the aqueous solution. The variation of functional groups on BG itself and crosslinked β-glucan (CBG) with their surface adsorption characteristics were investigated by FTIR and SEM-EDX. Adsorption kinetic results showed that adsorption of Pb and Cu onto the CBG followed the pseudo-second-order kinetic model and intra-particle diffusion model. The Langmuir adsorption model was depicted better adsorption characteristics than the Freundlich model. The adsorption capacities of Pb and Cu onto the CBG estimated by the Langmuir model were 59.70 and 23.44 mg/g, respectively. This study suggested that CBG may act as an eco-friendly adsorbent for the adsorption of Pb and Cu in the aqueous solution.

• Clean Technology
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• v.16 no.4
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• pp.272-276
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• 2010

Adsorption process for the removal of acetylene, especially 2-butyne, from isoprene was studied with zeolite as an adsorbent. In this work, zeolite 5A was selected to investigate the effects of various regeneration conditions by repeated adsorption experiments. The effect of regeneration temperature and desorption pressure was investigated to identity the optimum regeneration conditions. Repeated adsorption and desorption experiments were carried out for 10 cycles to confirm the efficiency of regeneration process under temperature of 423 K and desorption time of 16 h.

• Journal of the Korean GEO-environmental Society
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• v.12 no.10
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• pp.23-28
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• 2011

This study was conducted to investigate the adsorption characteristics of various surfactants including biosurfactant, SWA 1503, Triton X-100 and sodium dodecyl sulfate(SDS) on soil. The Freundlich adsorption isotherm equation was found to be the best to describe experimental results. The amount of adsorbed surfactant on soil increased as the content of clay increased. The results showed that surfactant was adsorbed mainly on the surface and the pores of soil since the surface area of clay was larger than that of sand. The amount of adsorbed surfactants on soil was as follows: Biosurfactant > SWA 1503 > Triton X-100 > SDS.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.181-183
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• 2008

본 연구는 회분식과 연속식으로 나누어 숯의 농약 흡착 능력을 평가하였다. 실험에 사용된 농약은 Simazine, Diazinon, Fenitrothion, Butachlor, Malathion이다. 회분식 실험 결과에 따르면, 흑탄과 백탄 양을 0.1g, 1g, 10g, 50g씩 증가시킬수록 농약 성분의 제거율이 높아지는 것으로 나타났으며, 흑탄이 백탄 보다 농약 성분을 잘 제거하는 것으로 나타났다. 특히, 1g 주입시 흑탄은 백탄보다 Malathion을 약 15%, Rutachlor을 약 19%, Fenitrothion을 약 25%씩 제거율이 더 높게 나타난 것으로 보아 흡착이 잘된다고 판단된다. 반면에 회분식에서 Diazinon의 제거율은 상대적으로 낮게 나타났나. 연속식 실험에서도 흑탄이 백탄보다 더 높은 제거율을 나타내었으며, 특히 흑탄 칼럼에서는 흡착 시간$(21\sim31hr)$에서 농약 성분의 평균 제거율을 비교해 본 결과, Simazine은 90%, Fenitrothion은 82%, Butachlor은 81%로 나타났으며, 특히 Diazinon의 제거율은 55%로 나타나 상대적으로 흡착이 잘 되지 않는 것으로 나타났다.

• The Journal of Engineering Geology
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• v.12 no.2
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• pp.203-214
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• 2002

The statistical model was introduced to satisfy various experimental condition on the sorption of heavy metals (Pb, Cu, Cd, and Zn) by bentonite. The Box-Behnken model designed statistically was applied to determine relative impact among three variables such as pH, HCO$_3$ contents and heavy metal concentrations on the sorption. The SAS program was used to obtain the statistical solution. The statistical surface response analysis indicates that initial concentration of heavy metals and pH have an important effect on the sorption, and bicarbonate is not a serious variable. The sorption capability about heavy metals of bentonite is in the order of Pb>Cu>Zn>Cd. The precipitation as hydroxyl and carbonate complexes of heavy metals was thermodynamically analyzed as major mechanism of sorption under alkaline pHs and high bicarbonate solution. It was found that there is a little difference between the model prediction on the precipitation of heavy metals and the results of batch sorption experiment. The thermodynamic data of the programs have to revise to obtain the best fit condition between the model prediction and the experimental results.