• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.89-95
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• 2010

The electrokinetic potential of $CaCO_3$, which takes an important part in aquatic system, has been measured and the variation of total energy between $CaCO_3$ particles with the distance of particles was estimated based on DLVO theory. The electrokinetic potential of particles was observed to increase to positive direction as the charge valence of cations which was added to suspension was increased. Also, the total interaction energy between particles was estimated to be more negative as the charge valence of cation was higher and its concentrations was raised. When a mixture of cations with different charge valences was added, the influence of cation with a higher charge valence was more significant on the total interaction energy between particles. When anion was added to the suspension of $CaCO_3$, the total energy estimated by DLVO theory was examined to move to positive direction and the electrokinetic potential of particles became more negative. Likewise cations, the effect of anions on the electrokinetic potential of particles and total interaction energy between them was observed to be proportional to their charge valence and the influence of the mixture of anions with different charge valence became more remarkable as the mixing ratio of the anion with a higher charge valence was increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.695-698
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• 2000

This paper present the result of the investigation, the distribution of salt contamination with the influence of geographical condition. To get the ESDD data, a conventional brush washing method was adapted, and IC(ion chromatography) was used to measure the quantity of anions, such as Cl$\^$-/ and SO$_4$$\^$2-/. And we make an analysis on the distribution of salt contamination with the increase of distance from shore. With 10 month ESDD data, we seek the 95% ESDD value with interpolation method. With these analyses, we had obtained the formulation concerned with the distance from sea. And could know the composition of contamination.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1782-1784
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• 2000

This paper present the result of the investigation, the distribution of salt contamination with the influence of. geographical condition. To get the ESDD data, a conventional brush washing method was adapted, and IC(ion chromatography) was used to measure the quantity of anions, such as $Cl^-$ and ${SO_{4}}^{2-}$. And we make an analysis on the distribution of salt contamination with the increase of distance from shore. With 10 month ESDD data, we seek the 95% ESDD value with interpolation method. With these analyses, we had obtained the formulation concerned with the distance from sea. And could know the composition of contamination.

• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.458-461
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• 1995

The influence of adding counter-ion such as Na+ on the dimerization of the two sulphonated azo dyes, C.I. Acid Red 14 and C.I. Acid Red 17 in aqueous media has been studied spectrophotometrically. The observed hypochromic effect on increasing the amount of salt has been described. The dye concentration range where the dimerization equilibrium is applicable was chosen. No metachromatic behaviour was observed on changing the dye concentration and the amount of salt. This behaviour was attributed to the ability of the counter-ion to disrupt the structure of water as well as reducing the electrostatic repulsion forces between dye anions which will lead to the increase of aggregation tendency of the dye species.

• The Korean Journal of Physiology
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• v.19 no.1
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• pp.49-59
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• 1985

The effects of anions on net accumulation of $(\rho-aminohippuric\;acid)$(PAH) were studied in rabbit kidney cortical slices. Experiments were carried while varying the major anionic composition of the incubation medium(replacement of $Cl^-$ by isethionate and $SCN^-$). The total replacement of $Cl^-$ with isethionate, $SO_4\;^{2-}$ and $SCN^-$ in the incubation medium decreased the 60-min slice-to-medium concentration(S/M) ratio of PAH to 60%, 40% and 50% of control value, respectively. The degree of inhibition in PAH accumulation by the replacement of isethionate and $SCN^-$ was increased with increasing of both preincubation and incubation time. The influence of isethionate and $SCN^-$ on PAH uptake was fully reversible. Both isethionate and $SCN^-$ increased the apparent Km value significantly with no change on the apparent Vmax value, suggesting a competitive inhibition on PAH uptake. And the inhibitory effect of $SCN^-$ on PAH uptake decreased with increase of pH in the incubation medium while that of isethionate increased with increase of pH. Intracellular water content, intracellular electrolyte concentration and oxygen consumption were not influenced by the replacement of $Cl^-$ with isethionate or $SCN^-$ in the incubation medium. These results suggest that both $isethionate^-$ and $SCN^-$ inhibit the PAH uptake by binding to some site necessary for normal PAH transport without affecting the cellular viability.

• Membrane and Water Treatment
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• v.14 no.1
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• pp.1-10
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• 2023

This study explored the feasibility of calcium-rich food waste, Mactra veneriformis shells (MVS), as an adsorbent for phosphate removal, and its removal efficiency was enhanced by the thermal activation process. The CaCO3 in MVS was converted to CaO by thermal activation (>800 ℃), which is more favorable for adsorbing phosphate. Thermal activation did not noticeably influence the specific surface area of MVS. The MVS thermally activated at 800 ℃ (MVS-800), showed the highest phosphate adsorption capacity, was used for further adsorption experiments, including kinetics, equilibrium isotherms, and thermodynamic adsorption. The effects of environmental factors, including pH, competing anions, and adsorbent dosage, were also studied. Phosphate adsorption by MVS-800 reached equilibrium within 48h, and the kinetic adsorption data were well explained by the pseudo-first-order model. The Langmuir model was a better fit for phosphate adsorption by MVS-800 than the Freundlich model, and the maximum adsorption capacity of MVS-800 obtained via the Langmuir model was 188.86 mg/g. Phosphate adsorption is an endothermic and involuntary process. As the pH increased, the phosphate adsorption decreased, and a sharp decrease was observed between pH 7 and 9. The presence of anions had a negative impact on phosphate removal, and their impact followed the decreasing order CO₃^2- > SO₄²- > NO₃^- > Cl^-. The increase in adsorbent dosage increased phosphate removal percentage, and 6.67 g/L of MVS-800 dose achieved 99.9% of phosphate removal. It can be concluded that the thermally treated MVS-800 can be used as an effective adsorbent for removing phosphate.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.150-151
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• 2006

Perfluoroaryl boranes are widely employed as co-catalysts in olefin polymerization processes. Perfluoroaryl diboranes, possessing borane centers in close proximity, are a subclass of this family of compounds that are in theory capable of chelating neutral and anionic bases. The resulting anions are exceptionally weakly coordinating. We have prepared examples of such compounds and studied their coordination behavior with neutral Lewis bases that have the capability to bridge Lewis acid sites in an effort to delineate the kinetic and thermodynamic factors that influence bonding mode. When protic Lewis bases such as alcohols or water are reacted with diboranes, strong Bronsted acids capable of initiating cationic polymerizations under unusual conditions result.

• Corrosion Science and Technology
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• v.3 no.6
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• pp.251-256
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• 2004

Exposure of zinc samples in simulated acid rain solution (SARS) was investigated under a periodic wet-dry conditions using an AC impedance technique. The periodic wet and dry exposure consisted of the immersion of zinc samples in SARS for one hour followed by exposure to 7 hours drying at 60% RH. Phases of the corrosion products were indentified by X-ray diffraction (XRD). The influence of relative humdiity (RH), temperature, and surface inclination on the atmospheric corrosion of zinc is described. The reciprocal of polarization resistance (1/Rp) decreases rapidly during the initial stages then slowly and eventually attains a steady state as exposure time progresses. The average of reciprocal of polarization resistance per cycle, (ARPR) was calculated and found to decrease as number of exposure cycle increases. An increase of temperature enhances the corrsion rate of zinc. The values of ARPR, of a sample inclined at 30 o are lower than those for a sample oriented horizontally. The experiment result shows a pronounced dependence of reciprocal of polarization resistance on RH. Exposure in the presence of carbonate anions gives rise to more protective corrosion products than in nitrate anion solution. The corrosion mechanism during the initial stages of atmospheric zinc corrosion under wet-dry cyclic conditions is suggested.

• Journal of Korean Society of Forest Science
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• v.94 no.2 s.159
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• pp.96-102
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• 2005

This study evaluated the chemical characteristics of rainfall and throughfall in Pinus koraiensis and Larix leptolepis forests. We analyzed pH, EC, and concentrations of cations and anions in rainfall, throughfall and stemflow collected from both forest types in the experimental forests of the central Korea. The concentrations of chemical elements were much higher in throughfall and stemflow than in rainfall for both forest types, and were significantly different among the seasons. Comparing the chemical elements between the P. koraiensis and L. leptolepis plantations, there were not significantly differences in throughfall, but the concentrations of almost elements of stemflow in P. koraiensis were almost lower than those in L. leptolepis. For seasonal inputs to the forest floor, more than half of the total input of $Ca^{2+}$, ${NO_3}^-$and ${SO_4}^{2-}$ was observed in spring. This suggests that air pollutants such as NOx and SOx accompanying calcium-rich aeolian Yellow Sand (Asian dust) from China could have an important influence on nutrient cycles in Korean forests.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.121.1-121.1
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• 2010

We analyzed the temperature and chemical composition of 376 hot springs in Korea. It took about three days for the temperature to stabilize after the pumping test. After the stabilization, in-situ and laboratory analyses of the hot spring water were carried out. The average temperature and TDS were $29.95^{\circ}C$ and 2,071mg/L, respectively. The temperature ranging $25-30^{\circ}C$ were recorded from 70% of hot springs, and $30-35^{\circ}C$ of 15.4%. The maximum temperature was about $78^{\circ}C$. The value of TDS in 79% of the wells was below 1,000 mg/L. 5.5% of the wells, mostly developed near seashore, shows higher values than 10,000mg/L of TDS suggesting the influence of seawater. The hot spring water shows 8.49 of pH representing a weak alkali. For the mineral compositions dissolved in the hot spring in Korea, Na (431 mg/L) and Ca (188 mg/L) are the major cations, and Cl (840 mg/L) and $SO_4$ (213 mg/L) are the major anions.