• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.107-110
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• 2021

The goal of this study was to investigate moisture sorption characteristics of Lactobacillus brevis-fermented sea tangle Saccharina japonica, Mekabu fucoidan, and these mixture powders. Moisture sorption isotherms of powders were determined at 37℃ using the static gravimetric technique in a water activity (aw) range of 0.11-0.93. Equilibrium moisture content (Xeq) values of the fermented sea tangle powder were almost 3 times when aw<0.7 and increased upto almost 4 times when aw<0.9 higher than mekabu fucoidan powder. In these reason, to improve strong hygroscopic nature of the fermented sea tangle powder, fermented sea tangle and mekabu fucoidan powders were dissolved as ratios of 7:3, 5:5, and 3:7 (w/w) in a distilled water and then freeze dried. Xeq values of mixture powders were around average value of sum of both powders at all aw ranges. All moisture sorption isotherms of powders exhibited typical J-shaped type III. Xeq of mixture powders increased with increasing aw and decreased as increasing proportion of mekabu fucoidan powder. The Peleg model was found to accurately describe moisture sorption isotherms of powders. The results can be used to understand hygroscopic nature of powders, improve shelf life, and retain quality across postharvest processing.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4013-4021
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• 2022

A kind of zirconium phosphate mesoporous coordination polymer Zr-EDTMPA was successfully synthesized and characterized using XRD, FTIR, TGA, EA, SEM-EDS, and N₂ sorption-desorption measurements. The prepared Zr-EDTMPA was first employed for the removal of Co(II) from an aqueous solution, and the effects of pH, contact time, temperature, initial Co(II) concentration, reusability, and sorption mechanism were systematically investigated. The results showed that the Zr-EDTMPA is a zirconium phosphate complex formed by the coordination of EDTMPA to Zr in a molar ratio of 1:1. The sorption of Co(II) by Zr-EDTMPA was a pH-dependent, spontaneous and endothermic process, which was better fitted to the pseudo-second-order kinetic model and Langmuir isotherm model. The Zr-EDTMPA was demonstrated to have excellent reusability and presented a high sorption capacity of 73.0 mg·g^-1 for Co(II) at pH 8.0. The sorption mechanism was mainly attributed to the strong coordination between cobalt and the untapped hydroxyl functional groups on Zr-EDTMPA, which was confirmed by XPS spectra. Therefore, as a candidate sorbent with high sorption capacity and excellent reusability, Zr-EDTMPA has a great potential for the removal of Co(II) from aqueous solutions.

• Journal of Soil and Groundwater Environment
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• v.10 no.1
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• pp.26-34
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• 2005

The effects of soil-chemical contact time (aging) on sorption and desorption of atrazine were studied in soil slurries because aging is an important determinant affecting on the sorption and desorption characteristics of organic contaminants in the environment. Sorption isotherm and desorption kinetic experiments were performed, and soilwater distribution coefficients and desorption rate parameters were evaluated using linear and non-linear sorption equations and a three-site desorption model, respectively. Aging time for sorption of atrazine in sterilized soil slurries ranged from 2 days to 8 months. Atrazine sorption isotherms were nearly linear $(r^2\;>\;0.97)$ and sorption coefficients were strongly correlated to soil organic carbon content. Sorption distribution coefficients $(K_d)$ increased with increasing aging in all soils studied. Sorption non-linearity did not increase with increased aging except for the Houghton muck soil. Desorption profiles were well described by the three-site desorption model. The equilibrium site fraction $(f_{eq})$ decreased and the non-desorbable site fraction $(f_{nd})$ increased as a function of aging time in all soils. In all soils studied, it was found that when normalized to soil organic matter content the concentration of atrazine in desorbable sites was comparatively constant, whereas that in non-desorbable site increased as aging increased.

• Journal of the Korean Ceramic Society
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• v.30 no.4
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• pp.273-278
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• 1993

Using water vapor (de)sorption isotherm, pore structure analyses were performed for hardened cement pastes by a combination of the "MP-method" for the micropores and the "corrected modelless method" for the wide pores. This work was carried out to investigate the pore structure and to understand the microstructural basis of alumina cement developing much higher strength than Portland cement. Alumina cement shows extremely low microporosity and its wide pores are also composed mainlyof pores with very small radii. And the pore structure analysis results are consistent with the high strength property of alumina cement.y of alumina cement.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.96-98
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• 2002

Furnace slag, a steel industry waste, has been converted into an inexpensive and efficient adsorbent. The product obtained has been utilized for the removal of arsenic from ground water. Kinetic studies have bepn described with the mechanism of adsorption The results from batch studies showed that the As(III) can be removed from the ground water within the pH range 3-7 However the maximum removal was experienced at pH 7.0. Equilibrium was attained within 24 hours. Adsorption data of arsenic correlate well with the Freundlich and Langmuir adsorption models. The maximum sorption capacity as calculated using Freundlich adsorption isotherm was found to be of 0.004 mg g-1 at pH 7 and $25^{\circ}C$.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.3
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• pp.48-54
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• 2009

Resent research on heavy metal biosorption has been focused on its mechanisms and principles. For effective metal removal/recoverythe process design has to be optimized for every type of application. That is most efficiently carried out based on computer simulations by means of mathematical models of the process. Therefore, the study on sorption equilibrium isotherm is important and the methodology wassummarized here involving both one metal and multi-metal systems.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.141-141
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• 1995

The waste biomass of Sacchromyces uvarum, used in fermentation industries to produce ethanol, were studied for their ability to absorb various heavy metal ions. Heavy metal ions studied in this research were Cd, Co, Cr, Cu, Ni and Pb. The order of the sorption capacity was Pb>Cu>Co=Cr=Cd>Ni. The living Sacchromyces uvarum exhibited higher metal-uptake capacity than the dead Sacchromyces uvarum. After we compare the uptake capacity of the Sacchromyces uvarum for individual metal ions with for a mixture of them, the following was observed: in the mixed heavy metal solution the uptake capacity was decreased than the one heavy metal solution. The selective uptake was observed when all . the heavy metal ions were dissolved in a mixed solution. The adsorption isotherm modelling was decribed with the Langmuir and Freundlich model. The results were in good agreement with the Langmuir model.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.527-534
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• 1995

The waste biomass of Sacchromyces uvarum, used in fermentation industries to produce ethanol, were studied for their ability to absorb various heavy metal ions. Heavy metal ions studied in this research were Cd, Co, Cr, Cu, Ni and Pb. The order of the sorption capacity was Pb>Cu>Co=Cr=Cd>Ni. The living Sacchromyces uvarum exhibited higher metal-uptake capacity than the dead Sacchromyces uvarum. After we compare the uptake capacity of the Sacchromyces uvarum for individual metal ions with for a mixture of them, the following was observed: in the mixed heavy metal solution the uptake capacity was decreased than the one heavy metal solution. The selective uptake was observed when all . the heavy metal ions were dissolved in a mixed solution. The adsorption isotherm modelling was decribed with the Langmuir and Freundlich model. The results were in good agreement with the Langmuir model.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.143-148
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• 2005

Plastics and vinyl resin is generally used in the various fields of industry and daily life. Except incineration, most waste has been disposed finally in landfill and the leaching of plasticizer as DEHP(di 2-ethylhexyl phthalaet) has been taken place in the landfill. DEHP had been found. for endocrine disrupter by World Wild Life Fund and Japan. In this study aimed at estimation of capacity of adsorption and measurement of phthalate ester in the residual soil. The residual soil had been gathered from three closed landfill which was under stabilization with sorting and transferring. The Dibutyl phthalate and DEHP had been contained in all residual soil. Especially, resisual soil contained DEHP much more than peripheral soil. In J landfill residual soil, organic matter content, CEC and #200 sieve passing ratio is highest, and Freundlich isotherm sorption coefficient(K) and constant(1/n) is highest.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.1
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• pp.49-57
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• 2013

The present study was conducted to investigate phosphate removal from aqueous solution using industrial wastes, red mud (RM), acid treated red mud (ATRM) and converter furnace steel slag (CFSS). The chemical composition of adsorbents was analyzed using X-ray fluorescence (XRF). Batch experiments and elution experiments using water tank were performed to examine environmental factors that influences on phosphate removal. Kinetic sorption data of RM, ATRM, and CFSS were described well by the pseudo second-order kinetic sorption model, and equilibrium sorption data of all adsorbents obeyed Freundlich isotherm model. The adsorption capacities of adsorbents followed order: ATRM (7.06 mg/g)>RM (4.34 mg/g)>CFSS (1.88 mg/g). Increasing pH from 3 to 11, the amount of adsorbed phosphate on all RM, ATRM, and CFSS were decreased. The presence of sulfate and carbonate decreased the phosphate removal of RM and ATRM but did not influence on the performance of CFSS. The phosphate removal of RM, ATRM, and CFSS was greater in seawater than deionized water, resulting from the presence of cations in seawater. The water tank elution experiments showed that RM capping blocked the elution of phosphate effectively. It was concluded that the adsorbents can be successfully used for the removal of the phosphate from the aqueous solutions.