• Textile Coloration and Finishing
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• v.26 no.1
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• pp.7-12
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• 2014

Nowdays, fluorescent rhodamine chemosensors have attracted a worldwide interest due to its ability to selectively detect heavy and transition metal cations. Due to the importance in environmental and biological toxic effects, the developments of fluorescent chemosensors have been received considerable attention in recent. Especially, a rhodamine-based chemosensor probes have been proved to be useful by exhibiting the efficient "off-on" fluorescence switching toward selected metal cations. This fluorophore can undergo the transformation from non-fluorescent and colorless spirolactam derivative to fluorescent ring-open form. In this study, a new fluorescent chemosensor was synthesized using rhodamine B through two-step procedures, and its selectivity and related optical property were characterized. Selectivity and sensitivity was found toward $Cu^{2+}$ guest molecules and then related optical properties of rhodamine B based fluorescent chemosensor compound were characterized using discussed. In addition, computational calculation was used to determine the HOMO/LUMO values.

• Journal of Environmental Science International
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• v.10 no.4
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• pp.305-310
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• 2001

pH($H_2O$), pH(KCI), CEC(cation exchange capacity), O.M.(organic matter) and exchangeable cations(K, Na, Ca, Mg) of paddy soil, upland soil and forest soil in Kumi city were investigated for the purpose of knowing soil acidification and the correlation between soil acidification and leaching of inorganic salts. The mean pH($H_2O$) values of paddy soil were 5.23(surface soil) and 5.69(subsoil) and 4.74(subsoil). The were 6.37(surface soil) and 6.11(subsoil), and those of forest soil were 4.67(surface soil) and 4.74(subsoil). The mean pH(KCl) values of paddy soil were 4.59(surface soil) and 4.98(subsoil) were 5.48(surface soil) and 5.04(subsoil), and those of forest soil were 3.82(surface soil) and 3.89(subsoil). The acidification of forest soil was more rapid than that of paddy soil and upland soil/ The total mean amounts of exchangeable cations(K, Na, Ca, Mg) in paddy soils were 6.14me/100g(surface soil) and 5.64me/100g(subsoil), and those in upland soils were 6.86me/100g(surface soil) and 6.65me/100g(subsoil), and those in forest soils were 4.06me/100g(surface soil) and 3.34me/100g(subsoil). The contents of inorganic salts in forest soil were much less than those of paddy soil and upland soil. The correlation coefficients(r) between pH($H_2O$) values and the total amounts of exchangeable cations in soils were $0.6635^{**}$(surface soil) and $0.6946^{**}$(subsoil), and those between pH(KCl) values and exchangeable cations in soils were 0.6629(surface soil) and $0.5675^{**}$(subsoil). The correlation between soil acidification and leaching of inorganic salts in soil was positively significant at 1% level.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.161-169
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• 2000

In this study, the temporal changes in the chemical characteristics of soil in a reclaimed coastal area, the Shihwa Industrial Complex in the West Coast in Kyung-Gi Province, and the correlations between chemical components were investigated to provide useful information needed for introducing vegetation in the area. The sites were filled with mountain forest soils from 1987 to 1996, and developed into various landuses such as neighbourhood parks, children's parks, buffer greens, pedestrian roads and others. The correlation analyses shoed that pH, organic matter(OM) and available P205 had not been closely related to other chemical parameters such as various cations electro-conductivity(EC) and cation exchange capacity(CEC): especially, pH showed a very low correlation with other factors. The EC turned out to have positive relationships with cations, especially with Na+ ions. There seemed to be fairly good correlations between cations except Ca++ ion. The relation between cations and OM was inconclusive possible because the OM contents in the soils were too low for the analysis. The OM seemed to increase slowly with time and the EC decreased slowly. The salinity and CEC in the original soils decreased rapidly possibly because of leaching. It is believed that there were some external disturbances such as rainfall which had affected the soil properties. The soils sampled in dry season showed a very high salinity. From this it is possible to assume that the rainfall would affect the sol properties significantly. So it is necessary to continue further studies to investigate the impacts of external disturbances such as rainfall on vertical soil profile and temporal variations as well as to delineate correlations between parameters with external disturbances controlled.

• Textile Coloration and Finishing
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• v.26 no.3
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• pp.272-276
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• 2014

The functional materials have been developed as a promising research topic toward the end uses for organic materials and applications. In this study, fluorescein based dye was synthesized by three step reaction. We have designed and synthesized the colorimetric dye through the reactions of fluorescein and methoxy group and ethylene diamine and squaric acid. The structure of the non-fluorescent spirolactam was elucidated by $^1H$-NMR, LC-Mass and FT-IR analyzes. Further studies are in progress to understand the effects of various substituent during the recognition process and to develop fluorescein based sensors for cations or anions.

• Journal of Radiation Industry
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• v.18 no.3
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• pp.167-171
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• 2024

Technetium-99 (⁹⁹Tc) is recognized as a critical concern in the disposal of spent nuclear fuel due to its long half-life and remarkable stability, existing predominantly as TcO₄^- in the natural environment. The anionic form of technetium is highly soluble and mobile, posing significant environmental risks from the viewpoint of nuclear waste management. Thus, developing efficient and cost-effective sorbents for aqueous Tc(VII) is essential for mitigating relevant contamination. In the present work, the adsorption characteristics of Re(VII), a chemical analog of Tc(VII), were investigated using the clay mineral bentonite, modified with two different organic cations: hexadecylpyridinium (HDPy) and hexadecyltrimethylammonium (HDTMA). Sorption experiments were conducted at a liquid-to-solid ratio of 1 g/L with Re(VII) solutions prepared at concentrations from 10^-4 mol/L to 10^-6 mol/L. The sorption ratio and distribution coefficients were determined with samples collected at reaction times of 10, 50, 100, and 500 minutes after 0.45 ㎛ syringe filtration. In parallel, the modified bentonite samples were further analyzed using the X-ray diffraction (XRD) method to understand the adsorption mechanism of Re(VII) onto the target minerals. According to the quantification analysis results, a rapid equilibrium reaction of aqueous Re(VII) for all modified bentonite samples was identified. Moreover, near-complete adsorption of Re(VII) was observed when the bentonite was modified at 200-400% of its cation exchange capacity (CEC) for both organic cations. For cases of lower modification, the HDTMA-modified bentonite showed relatively higher adsorption efficiency compared with the one modified with HDPy. This result was inferred to be due to the difference in inter-layer spacing based on the characteristics of the organic cations. It is expected that the results obtained through this study will serve as a preliminary case for the synthesis of adsorbents for the retardation of highly mobile anionic radionuclides, such as I and Tc, in the natural environment.

• Journal of Animal Environmental Science
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• v.15 no.3
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• pp.289-296
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• 2009

The effects of the processing mixture of pig manure and various organic wastes on the growth, cast production of earthworm, and conversion of organic matter to earthworm tissues by vermicomposting. The substances used in this experiments were sawdust, rice hull, coffee waste, brewery waste, litters, turfgrass cutting residues, rice bran, vegetable wastes and rice straw and were mixed with pig manure at a ratios of 50:50 (v/v), and pig manure 100% (control), respectively. The highest values of growth parameters, cast production and conversion efficiency of organic matter to earthworm tissues were obtained at the mixtures of pig manure with coffee waste, it may due to the favourable diet conditions to process with pig manure by vermicomposting. But, all of the earthworm died in the pig manure 100% (control) and pig manure with vegetable wastes treatments by vermicomposting was impossible in this experiment. The vermicast contained a higher values of total nitrogen, available phosphorus, exchangeable cations and cation exchange capacity than their parent materials with increased availability of nutrients and improved physicochemical properties.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.53-58
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• 2001

Sulfonated poly(phenylene sulfide) (SPPS) polymers were prepared by sulfonation of poly[methyl[4-(phenylthio) phenyl]sulfonium trifluoromethanesulfonate] (PPST) with fumic sulfonic acid (10% $SO_3-H_2SO_4$) and demethylation with aqueous NaOH solution. The equilibrium constants of ion exchange reactions between alkali metal cations ($Li^+,\;Na^+,\;and\;K^+$) and SPPS ion exchanger in organic solvents such as tetrahydrofuran (THF) and dioxane were measured. The equilibrium constants of ion exchange reactions increased as the polarity of the solvent increased, and the reaction temperature decreased. The equilibrium constants of the ion exchange reaction ($K_{eq}$) also increased in the order of $Li^+,\;Na^+,\;and\;K^+$. To elucidate the spontaneity of the exchange reaction in organic solvents, the enthalpy, entropy, and Gibbs free energy were calculated. The enthalpy of reaction ranged from -0.88 to -1.33 kcal/mol, entropy ranged from 1.42 to 4.41 cal/Kmol, and Gibbs free energy ranged from -1.03 to -2.55 kcal/mol. Therefore, the exchange reactions were spontaneous because the Gibbs free energies were negative. The SPPS ion exchanger and alkali metal ion bounding each other produced good ion exchange capability in organic solvents.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.63-74
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• 2012

This experiment was carried out to investigate the effect of different stocking rate on growth, cast production and conversion efficiency of organic matter to tissues of earthworm. The carbon and nitrogen ratio (C/N) of tested Korean cow manure was 25.1, it was estimated an adequate ratio as feed for earthworms. The different stocking rates were 1:8(S-1), 1:16(S-2), 1:32(S-3) 1:64(S-4) 1:128(S-5) and 1:256 (S-6) as the ratios of earthworm fresh weight to biomass of Korean cow manure, respectively. A stocking rate of 1:32(S-3) was obtained a significantly highest values of increasing rate and conversion efficiency of organic matter to earthworm tissues. The mean values of increasin g rate of fresh weight and conversion efficiency of organic matter to earthworm tissues were 10.63 mg/day and 6.65% at the ratio of 1:32(S-3) with a rearing volume was $56.6cm^3$. A stocking rate of 1:8(S-1) was obtained a highest ratio of vermicasts, but showed a negative values of increasing rate and conversion efficiency of organic matter to earthworm tissues, it may due to severely food competition between individuals during the rearing periods. The pH, total nitrogen, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with stocking rate. Especially, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with rearing progressed. Vermicasts have the potential for improving plant growth when amended to container medium and soil according to increased availability of nutrients and improved physicochemical properties.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.399-407
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• 2013

Organic grape was generally produced in rainshield or plastic greenhouse culture while most of fruits were produced in open field. But little attention has been given to soil properties with different culture facilities in organic grape cultivation. This study was conducted to investigate soil physico-chemical properties of organic grapes farms with different culture facilities and soil management practices. Organic fertilizer was main resource to manage soil at organic grapes farms. Organic grapes farms were applied with total amount of organic fertilizer at one time, either at basal or additional fertilization, whereas conventional grapes farms applied with split fertilization. Bulk density and penetration resistance of soil were lower at both rainshield and green manure-applied plastic greenhouse cultures than those at clean plastic greenhouse culture. Especially, in plastic greenhouse, sod culture with natural weed after green manure application was more effective than general sod culture in improving physical properties of the rhizosphere. The contents of organic matter, available phosphate and exchangeable potassium tended to increase in the soils applied with green manure, and the difference of soil chemical properties were significant between rainshield and plastic greenhouse cultures. The optimum soil management was required in plastic greenhouse because pH, available phosphate and exchangeable cations reached over optimum range. Consequently, the ground cover management is the key factor to affect the chemical properties as well as soil physical properties extensively in plastic greenhouse. It is found that sod culture with natural weed after green manure application resulted in enhancement of utilization efficiency of nitrogen, phosphoric acid and potassium in soil in comparison with general sod culture.

• Journal of Environmental Science International
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• v.5 no.2
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• pp.243-252
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• 1996

In order to investigate the effects of pH and organic matter content on cadmium adsorption and exchangeable cations desorption in soils, the adsorption isotherms of cadmium and the desorption isotherms of calcium and magnesium on four New jersey soils at four pH values were plotted, and the cadmium partition coefficients (Kd) were also calculated. The slopes of cadmium adsorption isotherms dramatically increased with increasing solution pH. Judging from Langmuir adsorption equations, the maximum adsorption quantities(b) of cadmium at high pH values were much greater than those at low pH values for the same soil. The partition coefficients increased greatly with increasing solution pH. The slopes of regression equations between partition coefficients and pH values were steep in the order of the organic matter content of the soils. The correlation coefficients (r2) between partition coefficient and organic matter content for soils. The correlation coefficients (r2) between partition coefficient and organic matter content for $1\times10^{-4}$M increased from 0.3027 at pH 4.0 to 0.9964 at pH 8.5 and from 0.2093 at pH4.0 at 0.9657 at pH 8.5 for$2\times10^{-4}$M ${Cd(NO_3)}_2$. The desorption quantities of calcium and magnesium decreased with increasing solution pH and increased with- increasing cadmium adsorption.