• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.188-192
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• 2002

High concentrations of HCO$_3$$^{[-10]}$ (bicarbonate ion) in hydroponic water lead to high pH and to change in solubility, and consequently inhibition of absorption of available iou. An adequate and practical method is needed to remove HCO$_3$$^{[-10]}$ in the water fur hydroponics. to compare the efficiency of HCO$_3$$^{[-10]}$ removal, the effect of injecting HNO$_3$, H$_3$PO$_4$ or H$_2$SO$_4$ was tested. Acid injection was effective to remove HCO$_3$$^{[-10]}$ Based on the assumption that an equivalent of HCO$_3$$^{[-10]}$ ion is neutralized by an equivalent of acid, KHCO$_3$ was dissolved in a double distilled water at 50, 100, 150, 200 or 250 mg.L$^{[-10]}$ concentration and either HNO$_3$, H$_3$PO$_4$ or H$_2$SO$_4$ was injected at a certain ratio, and the resulting pH change and HCO$_3$$^{[-10]}$ ion removal was measured. According to the results obtained, HCO$_3$$^{[-10]}$ in hydroponic water was titrated, and concentration of the residual HCO$_3$$^{[-10]}$ ion well correlated with the amount of acid injected.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.3
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• pp.149-154
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• 2017

We investigate the availability of $CO_2$ ocean storage by means of chemical conversion of $CO_2$ to the dissolved inorganic carbon (mainly the bicarbonate ion) in seawater. The accelerated weathering of limestone (AWL) technique, which is accelerating the natural $CO_2$ uptake process through the chemical conversion using limestone and seawater, was proposed as an alternative method for reducing energy-related $CO_2$ emission. The method presented in this paper is slightly different from the AWL method. It involves reacting $CO_2$ with seawater and quicklime obtained from alkaline wastes to produce the bicarbonate-rich solution over 100 times more than seawater, which could be released and diluted into the ocean. The released dense bicarbonate-enriched water mass could subside into the deeper layer because of the density flow, and could be sequestrated stably in the ocean.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.234-236
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• 2018

기후변화는 더 이상 피할 수 없는 매우 중요한 문제다. 온실가스 중 큰 비중을 차지하는 이산화탄소 배출을 억제하거나 제거하기 위한 많은 연구들이 진행되고 있다. 최근에는 CCS 중 하나인 지중저장(underground storage)의 대안으로 해양에 이산화탄소를 저장하는 기술인 AWL(Accelerated Weathering of Limestone)을 이용한 해양저장(ocean storage)에 대한 연구가 진행되고 있다. AWL은 이산화탄소를 중탄산이온 형태의 농축수로 만들어 해양에 방류하여 희석 저장시키는 방법으로, 대기 중 재방출이 거의 발생하지 않고 배출된 농축수는 해양의 알칼리도를 높여 해양산성화를 방지할 수 있는 장점이 있다. 금회 연구는 AWL에 의한 방법 중 중탄산이온 농축수의 해양방류 시 이산화탄소 등을 포함하는 용존 무기탄소(DIC, Dissolved Inorganic Carbon)의 거동특성을 파악하기 위한 목적으로 수행하였다. 연구대상 해역은 충분한 수심과 작업효율성이 확보되는 울릉도 부근으로 설정하였으며, 거동특성을 파악하기 위하여 표층방류(surface discharge)와 수중방류(submerged discharge)에 의한 물질확산을 계산할 수 있는 CORMIX모형을 채택하였다. 실험결과, 방류 시점으로부터의 희석률을 고려했을 때, 표층방류 시나리오가 농축수 방류에 가장 적합한 방식이라고 사료된다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.105-109
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• 2008

In our country, limiting nutrient is known as phosphorus in the most lakes. Therefore, the removal of phosphorus is a very important process in sewage treatment. However, many of the sewage treatment plants employ the conventional activated sludge process, known to remove $10{\sim}30%$ of phosphorus. Thus, additional phosphorous removal process will be needed. Oyster shells have been known to remove phosphorus in water. The removal efficiency of phosphorus was highest at smallest size of oyster shells and at the highest pH for batch test. The phosphorous removal rate with various calcium concentrations was increased by increasing calcium concentration. At the 20 mg/l of calcium, more than 90% of phosphorous was removed in two hours. The removal efficiency of phosphorous was increased greatly at 300% of recirculation rate. With 300% of recirculation rate, the removal efficiency reached 80% at pH 11. The negative effects of bicarbonate on crystallization were observed in oyster shells. The effects of bicarbonate on rate constant were also investigated by applying these results to experimental equation. The rate constant was decreased at the inverse logarithm bicarbonate concentration.

• Journal of the Korean earth science society
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• v.21 no.1
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• pp.81-92
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• 2000

The purpose of this study is to elucidate the characteristic of this study is of attitudinal variation of water quality for nine representative springs in the Halla mountain region. The evolutional processes of the spring water also have been studied. Results of hydrogeochemical analyses show that Gwaneumsa spring is very high in pH. The spring waters from Yungsil, Namguksunwon, Sungpanark Oremok and Gwaneumsa which springs situated lower than 1000m in altitude are relatively high concentrations in chloride, sulphate, nitrate nitrogen and sodium ions, indicating that they are affected by surrounding pollution sources. The concentrations of bicarbonate, sulphate and hydrogen ions in spring waters increase when the precipitation increases, whereas the concentrations of nitrate nitrogen, chloride and calcium ions decrease with increasing amounts of precipitation. The magnesium, sodium and electrical conductivity are nearly independent of the precipitation. The spring waters in the Halla mountain region belong to the groups of sodium or potassium type and bicarbonate type, except the Baegrogdam and Wiseorm spring water.

• Clean Technology
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• v.20 no.4
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• pp.383-389
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• 2014

$CO_2$ absorption processes have a good potential for large scale capture of $CO_2$ but a large amount of absorbing solution has to be regenerated, undesirably increasing the consumption of energy such as sensible heat and latent heat of vaporization. In this study, a cooling crystallization process which would separate the $CO_2$-rich potassium bicarbonate crystals from $CO_2$-lean water was developed to reduce the energy penalty. Sterically hindered alkanolamine additives were used to enhance the $CO_2$ removal efficiency and their antisolvent effect on the crystallization was found in a continuous cooling crystallizer. The production yields of crystals were increased in the sequence of 2-amino-2-methyl-1-propanol (AMP) < 2-amino-2-methyl-1,3-propanediol (AMPD) < 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD), which are related to the number of hydroxyl groups in the additive molecules. Using $^{13}carbon$ nuclear magnetic resonance, the additives favored the formation of bicarbonate ions by steric hindrance effect and increased the supersaturation of $KHCO_3$. It is shown that the additives increase the mean size of crystals and crystal growth rate by increasing supersaturation. The additives are promising for enhancing the $CO_2$ removal efficiency and reducing the regeneration energy cost of $CO_2$ absorbing solution by promoting $KHCO_3$ crystallization.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.147-157
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• 2004

The production of $^{14}C$ occurs in the Moderator(MOD), Primary Heat Transport System (PHTS), Annulus Gas System(AGS) and Fuel in the CANDU reactor. Among the four systems, The MOD system is the largest contributor to $^{14}C$ production(approximately 94.8%). $^{14}C$ is distributed of $^{14}CO_2$, $H_2^{14}CO_3$, $H^{14}{CO_3}^-$ and $^{14}{CO_3}^{2-}$ species as a function of the pH of water. Of these species, $H_2^{14}CO_3$ and $H^{14}{CO_3}^-$ form are predominant because the pH of MOD system is ＞ 5. In this paper, adsorption-desorption characteristics of bicarbonate ion (${HCO_3}^-$) by IRN 150 resin was investigated. ${HCO_3}^-$ ion existed in neutral condition(app. pH 7)was reacted with ion exchange resin (IRN-150) and saturated with it. Then $NaNO_3$ and $Na_3PO_4$ solutions selected as extraction materials were used to make an investigation into feasibility of ${HCO_3}^-$ extraction from resin saturated with ${HCO_3}^-$. Desorption of $CO^{2+}$ and $Cs^+$ ion by $Na^+$ ion was not occurred, and desorption of ${HCO_3}^-$ ion by ${NO_3}^-$ and ${PO_4}^{3-}$ was occurred slowly. Also, the status of ion exchange which is used in Wolsong NPPs and generation of spent resin yearly were surveyed.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.149-156
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• 2014

The objective of this research was to investigate the influence of bicarbonate ($HCO_3{^-}$) concentrations in nutrient solution on the growth and physiological disorders in mother plants and occurrence of daughter plants in propagation of 'Seolhyang' strawberry (Fragaria ${\times}$ ananassa Duch.). To achieve this, the mother plants were transplanted to coir dust + perlite (7:3, v/v) medium and Hoagland solution was modified to contain 60, 90 (control), 120, 180, and $240mg{\cdot}L^{-1}$ of $HCO_3{^-}$. The symptoms of Fe, Zn and B deficiencies appeared on the mother plants in the $HCO_3{^-}$ of $240mg{\cdot}L^{-1}$ from the 60th day after treatment. The symptoms spread to all plants in the $240mg{\cdot}L^{-1}$ $HCO_3{^-}$ including daughter plants at 90 days after treatment. The$HCO_3{^-}$ concentrations higher than $120mg{\cdot}L^{-1}$ suppressed the growth of mother plants such as leaf number, chlorophyll content, fresh weight and other growth parameters. While the mother plants in $60mg{\cdot}L^{-1}$ $HCO_3{^-}$ produced 23 daughter plants, while mother plants in $240mg{\cdot}L^{-1}$ $HCO_3{^-}$ produced 13 daughter plants. The final pH 126 days after treatment in the $HCO_3{^-}$ of 60, 90, 120, 180 and $240mg{\cdot}L^{-1}$ were 5.4, 5.8, 7.3, 7.9, and 8.3, respectively. The elevation of $HCO_3{^-}$ concentrations in nutrient solution resulted in the decrease of Fe, Mn, Zn and Cu contents of above ground tissue 126 days after treatment. These results indicate that the $HCO_3{^-}$ concentrations higher than $120mg{\cdot}L^{-1}$ inhibited the growth of mother plants and occurrence of daughter plants in vegetative propagation of 'Seolhyang' strawberry.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.65-72
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• 2013

This study was conducted to investigate the influences of bicarbonate ($HCO_3^-$) concentrations in irrigation solution on growth of lettuce and change in chemical properties of root media. The blue leaf and red leaf lettuces with two true leaf stages were transplanted into 10 cm diameter plastic pots filled with perlite. The five treatments were made by dissolving $NaHCO_3$ into irrigation solution to reach 30, 70, 110, 150 and $180mg{\cdot}L^{-1}$ $HCO_3^-$. The crops were fed with fertilizer solution contained $HCO_3^-$ with various concentrations and controlled to $100mg{\cdot}L^{-1}$ in nitrogen concentration. The pH in soil solution of root media 10 weeks after transplant of blue lettuces were 7.04 and 7.10 in the treatments of 30 and $70mg{\cdot}L^{-1}$ of $HCO_3^-$, respectively. But those rose gradually after week 3 and finally reached 7.39, 7.48 and 7.56 at week 10 in the treatments of 110, 150 and $180mg{\cdot}L^{-1}\;HCO_3^-$, respectively. The pH in the treatments of 30 and $70mg{\cdot}L^{-1}\;HCO_3^-$ in cultivation of red leaf lettuce were around 6.65 during week 4 to week 8, but this rose abruptly and reached 6.92 and 7.01 at week 10, respectively. Those in the treatments of 110, 150, and $180mg{\cdot}L^{-1}\;HCO_3^-$ rose gradually and finally reached to 7.49, 7.53, and 7.58, respectively. The EC rose gradually after week 2 in all treatments of blue and red leaf lettuces. The change of macro ion concentrations in both blue and red leaf lettuces showed similar trends. The concentrations of $PO_4-P$, $Ca^{2+}$ and $Mg^{2+}$ increased gradually in all treatments of $HCO_3^-$ during cultivation of blue and red leaf lettuces. As the concentrations of $HCO_3^-$ in irrigation solution were elevated, the concentrations of $PO_4-P$, $Ca^{2+}$ and $Mg^{2+}$ became higher and that of ${SO_4}^{-2}$ became lower in soil solution of root media. The main reason of concentration changes were that $HCO_3^-$ influenced pH and the pH changes also affect the activities of the ions in soil solution of root media.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.2
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• pp.207-213
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• 2016

This study is focused on manganese (Mn(II)) removal by potassium permanganate ($KMnO_4$) in surface water. The effects of bicarbonate on Mn(II) indicated that bicarbonate could remove Mn(II), but it was not effectively. When 0.5 mg/L of Mn(II) was dissolved in tap water, the addition of $KMnO_4$ as much as $KMnO_4$ to Mn(II) ratio is 0.67 satisfied the drinking water regulation for Mn (i.e. 0.05 mg/L), and the main mechanism was oxidation. On the other hand, when the same Mn(II) concentration was dissolved in surface water, the addition of $KMnO_4$, which was the molar ratio of $KMnO_4/Mn(II)$ ranged 0.67 to 0.84 was needed for the regulation satisfaction, and the dominant mechanisms were both oxidation and adsorption. Unlike Mn(II) in tap water, the increasing the reaction time increased Mn(II) removal when $KMnO_4$ was overdosed. Finally, the optimum conditions for the removals of 0.5 - 2.0 mg/L Mn(II) in surface water were both $KMnO_4$ to Mn(II) ratio is 0.67 - 0.84 and the reaction time of 15 min. This indicated that the addition of $KMnO_4$ was the one of convenient and effective methods to remove Mn(II).