• Journal of Environmental Science International
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• v.9 no.4
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• pp.319-323
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• 2000

Nitrate-selective ion exchange resin which have bulky tertiary amine as functional group have been synthesized by the reaction of chloromethylated polystyrene-divinylbenzene copolymer and the corresponding tertiary amine [$NR_3=NE_{t3} 1, N{(C_2 H_4 H_3)}_32]$in ethanol, while commercial resin has $NMe_3$ as functional group. The fundamental properties such as bulk density, water content, appearance index, exchange capacity, effective size, uniformity coefficient of synthesized anion exchange resin (1) have been measured. The ion exchange resin (1) and (2) exhibited the better selectivity for nitrate than sulfate in both batch and continuous column experiments.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.223-229
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• 1986

These studies were investigated ionic balance of leaves from different stalk positions of tobacco plant (cv. NC82) grown on pots supplied with nitrate salts solution in the phytotrone. The results of studies are summerized as follows: 1. In comparision with the leaves along the stalk positions, lower position contained higher proportion of total cation and total anion including organic acid, but their concentration lessened gradually at the upper stalk. The ratio in amounts of inorganic cations and anions in leaf laminae depended on their stalk positon, being more than three times in the fifth, but becoming about 1.3 in the tenth. 2. Inorganic cations in the laminae were mostly $K^+$, $Ca^{{+}{+}}$, and $Mg^{{+}{+}}$, comprising about 80% of total with the first two regardless of their stalk positions. Among these two ions $Ca^{{+}{+}}$ tended to become higher at lower stalks, while $K^+$ was higher in younger and became lower when leaves got older and/or more number of leaves were emerged. 3. Total cations were balanced with inorganic and organic acid anions. Composition of inorganic and organic anions were different along stalk positions, ionic balance was governed by organic acid anions dominantly in older leaves, but by inorganic anions in the younger leaves. 4. The discrepancy in the balance between total cations and anions was more pronounced in the older leaves containing higher amount of cations and organic acids. It was suggested that discrepancy was due to precipitation of oxalate as Ca-salt which was not dissolved in the methylation solution of measurement employed.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.158-164
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• 2001

The purpose of this study was to assess the runoff of nitrogen derived from pig manure under upland condition. Bare and maize cultivated conditions were compared to estimate the effect of plant on the runoff loss of nitrogen and other nutrients by application of pig manure. Soil used in this experiment was sandy loam, and the fermented pig manure was applied at the rate of 0, 50, and $100ton\;ha^{-1}$. The amount of runoff was measured after every rainfall and water samples were analyzed for nitrate and other cations. Runoff was increased with the rainfall, but was depended on the application rate of pig manure at both bare and maize cultivated plots. Concentrations of nitrate in runoff at 0, 50 and $100ton\;ha^{-1}$ application of pig manure were higher at the maize cultivated plots than those at bare plots by 86.9, 42.9, and 33.6%, respectively. However, total mass of nitrate by runoff loss was higher at the bare plot ranging from 1.34 to $3.15kg\;NO_3-N\;ha^{-1}$. The equivalent ratio of nitrate to sum of cations in runoff was higher at the bare plot than that of maize cultivated plots. The concentration of cations in runoff was in the order of K> Mg> Na> Ca.

• Journal of Conservation Science
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• v.7 no.1
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• pp.19-22
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• 1998

The influence of acid rain on the marble cultural properties investigated in two ways : 1) marble samples similar to that of Wongak-sa 10-story pagoda were directly exposed to rain in air at Chongro and Kwanghwamun sites; 2) marble samples under a protective facility were indirectly exposed to rain. The quantity of corrosion products and variations of calcium ion to rain were analyzed. The result shows that the corrosion qantity of the marble samples exposed directly under 1~8 mm rainfall in the Chongno and Kwanghwamun sites were similar, but those were 7.7 times higher than those indoor. Concentration of anions were higher than that of cations among the ion concentration over 40% in the early 1 mm rainfall. Calcium ion was produced over 30%. Because the monuments of marble, limestone and sandstone were affected by acid rain, it may be necessary to establish policies for the conservation on the National Treasures made of these materials.

• Membrane Journal
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• v.19 no.4
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• pp.317-323
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• 2009

In this study the nanofiltration (NF) membrane treatment of a nitric acid waste solutions containing $Pb^{+2}$ heavy metal ion discharging from the etching processes of an electronics and semiconductors industry has been studied for the purpose of recycling of nitric acid etching solutions. Three kinds of NF membranes (General Electric Co. Duraslick NF-4040 membrane, Dow Co. Filmtec LP-4040 membrane and Koch Co. SelRO MPS-34 4040 membrane) were tested for their separation efficiency (total rejection) of $Pb^{+2}$ ion and membrane stability in nitric acid solution. NF experiments were carried out with a dead-end membrane filtration laboratory system. The membrane permeate flux was increased with the increasing storage time in nitric acid solution and lowering pH of acid solution because of the enhancing of NF membrane damage by nitric acid. The membrane stability in nitric acid solution was more superior in the order of Filmtec LP-4040 < Duraslick NF-4040 < SelRO MPS-34 4040 membrane. The total rejection of Pb+2 ion was decreased with the increasing storage time in nitric acid solution and lowering the pH of acid solution. The total rejection of $Pb^{+2}$ ion after 4 months NF treatment was decreased from 95% initial value to 20% in the case of Duraslick NF-4040 membrane, from 85% initial value to 65% in the case of SelRO MPS-34 4040 membrane and from 90% initial value to 10% in the case of Filmtec LP-4040 membrane. These results showed that SelRO MPS-34 4040 NF membrane was more suitable for the treatment of an acidic etching waste solutions containing heavy metal ions.

• Journal of the Korean Chemical Society
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• v.31 no.3
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• pp.231-235
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• 1987

In 10M chloride (4M HCl + 6M LiCl) solution, cobalt, but not nickel, formed complex anion (${CoCl_3}^-$), and this anion was extracted by a liquid anion exchanger with Amberlite LA-2. The ion exchange capacity was 2.175meq of cobalt complex per unit ml of Amberlite LA-2. Upon eluting the resin with 0.4M nitric acid, the cobalt complex was stripped and transfered into eluate quantitatively. By using this separation method in the chloride solution dissolved with 50mg of cobalt (II) and 500mg of nikel(II), recovery of cobalt were 99.6 percent.

• Journal of the Korean Chemical Society
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• v.25 no.4
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• pp.253-262
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• 1981

The AgI/ PV${\cdot}$THF membrane electrode could be used as an indicator electrode in the potentiometric titration of single halide and mixture halide solutions with the standard solution of silver nitrate. The errors in the stepwise titrations of mixture halide solutions were considerably large, but by addition of flocculating agent, such as $NaNO_3$ or $Ba(NO_3)_2$, in the sample solution, the errors were greatly reduced. Also, the effects of gelatin, filter paper and temperature on the titration errors were examined.

• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.124-132
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• 2007

This work investigated a fabrication way of stable platinized Ti electrode and evaluated the electrochemical characteristics of the Sn-modified platinized Ti electrode in nitrate solution. A Pt electro-plating way to form some open special clearances within the Pt coating layer on etched Ti substrate was very important to remove effectively the residual contaminate due to plating solution out of the fabricated electrode surface and to maximize the actual electrode surface area contacting solution. Both boiling and electro-cleaning processes of the fabricated electrode was essential to obtain a stable platinized-Pt electrode with reproducible and stable surface property which was necessary for the correct evaluation of Sn coverage on the electrode. The electro-cleaning caused a morphology change of the platinized Ti electrode surface with some downy hair-like polyps formed during the deposition disappearing, which made the electrode stable. The Sn-modified platinized Ti electrode in this work showed the best electro-activity for nitrate reduction, when it was fabricated through the Pt electro-plating of about 30 minutes.

• Analytical Science and Technology
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• v.13 no.3
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• pp.304-308
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• 2000

The iodide was recovered from a simulated spent fuel to the sodium bisulfite aqueous solution. It was discussed that the trace iodide (below 1 ppm) was determined without the matrix effect of 0.1 M sodium bisulfite and 1 mM $HNO_3$ in aqueous solution by ion chromatography with UV detection. AS4A-SC (DIONEX) column and UV-absorption spectrophotometer were used. The UV-absorption spectra of sodium bisulfite, nitric acid and iodide were obtained, and then 230 nm was selected as an absorption wavelength for iodide determination. 0.1 M NaCl eluent was optimum condition. In this condition the calibration curve of iodide was obtained on the range of about 0-1,000 ppb. The linear coefficient was 0.99993 and the detection limit was 5 ppb. The relative standard deviation was 1.26%.

• Analytical Science and Technology
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• v.13 no.2
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• pp.151-157
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• 2000

Effects of acids and pre-reductants in the analysis of arsenic have been studied by hydride generation-atomic absorption spectrometry. The analytical results were strongly dependent on the acid concentrations. All the pre-reductants was very effective to observe the arsenic signal at strong acid concentrations (3 M-5 M). However, at the low acid condition (${\leq}0.1M$), L-cysteine only showed a reasonable effect on the absorption signal. When the sample was treated with the nitric acid, absorption signal was unstable and was also decreased. Although interference effects were observed from metal ions such as $Cr^{6+}$ and $Br^{5+}$ at low acid condition, the generation of hydride could be increased by the strong acid condition.