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Neutralization of Alkaline Wastewater with CO2 in a Continuous Flow Jet Loop Reactor (연속흐름형 Jet loop reactor에서 CO2를 이용한 알칼리폐수의 중화)

  • Kang, Dae-Yeop;Kim, Mi-Ran;Lim, Jun-Heok;Lee, Tae-Yoon;Lee, Jea-Keun
    • Korean Chemical Engineering Research
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    • v.54 no.1
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    • pp.101-107
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    • 2016
  • This paper investigates the feasibility of applying the jet loop reactor for the neutralization of alkaline wastewater using carbon dioxide ($CO_2$). In this study, pH changes and $CO_2$ removal characteristics were examined by changing influent flow rate of alkaline wastewater (initial pH=10.1) and influent $CO_2$ flow rates. Influent flow rates of alkaline wastewater ($Q_{L,in}$) ranged between 0.9 and 6.6 L/min, and inlet gas flow rate ($Q_{G,in}$) of 1 and 6 L/min in a lab-scale continuous flow jet loop reactor. The outlet pH of wastewater was maintained at 7.2 when the ratio ($Q_{L,in}/Q_{G,in}$) of $Q_{L,in}$ and $Q_{G,in}$ was 1.1. However, the $CO_2$ removal efficiency and the outlet pH of wastewater were increased when $Q_{L,in}/Q_{G,in}$ ratio was higher than 1.1. Throughout the experiments, the maximum $CO_2$ removal efficiency and the outlet pH of wastewater were 98.06% and 8.43 at the condition when $Q_{G,in}$ and $Q_{L,in}$ were 2 L/min and 4 L/min, respectively.

Prediction of Optimal Leaching Conditions for Green Tea (녹차의 음용을 위한 최적 침출조건 예측)

  • Jang, Moon-Jo;Ha, Hyun-Jung;Yoon, Sung-Ran;Noh, Jung-Eun;Kwon, Joong-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.6
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    • pp.747-753
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    • 2006
  • Tea was known to have different taste and flavor with leaching temperature and time. This study was designed to optimize leaching condition for green tea bag that has been popular to consumers. Soluble solid, total phenolics, and total flavonoid content increased as leaching temperature and time increased. The ranges of maximum leaching condition for these components were $96.1{\sim}99.0^{\circ}C\;and\;5.7{\sim}6.8\;min$. As leaching temperature decreased and leaching time increased, however, electron donating ability (EDA) increased and showed the highest values at $65.3^{\circ}C$ and 7.2 min. The overall acceptability was maximal at $70.2^{\circ}C$ and 3.1min. Based upon the physicochemical and organoleptic properties, it was predicted that the optimal range of leaching conditions for green tea bag was $73{\sim}83^{\circ}C\;for\;5.3{\sim}6.3\;min$.

Simultaneous determinations of anthracycline antibiotics by high performance liquid chromatography coupled with radial-flow electrochemical cell (고성능 액체 크로마토그래피/방사흐름 전기화학전지를 이용한 안트라사이클린계 항생제의 동시 정량)

  • Cho, Yonghee;Hahn, Younghee
    • Analytical Science and Technology
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    • v.20 no.4
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    • pp.308-314
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    • 2007
  • The analytical method of HPLC with the radial-flow electrochemical cell (RFEC) has been developed to determine doxorubicin, epirubicin, nogalamycin, daunorubicin and idarubicin simultaneously by employing a reversed-phase chromatography. Anthracyclines were detected at -0.74 V vs. a Ag/AgCl (0.01 M NaCl) reference electrode, a potential of diffusion current plateau in the mobile phase. At a $V_f$ of 1.0 mL/min doxorubicin, epirubicin, daunorubicin and idarubicin appeared at a retention time ($t_r$) of 6.4 min, 7.4 min, 12.7 min and 18.4 min, respectively, while at a $V_f$ of 0.6 mL/min, doxorubicin, epirubicin, nogalamycin, daunorubicin and idarubicin appeared at a $t_r$ of 9.9 min, 11.5 min, 13.5 min, 19.6 min and 28.7 min, respectively. The linearity between each anthracycline injected ($2.40{\times}10^{-7}M{\sim}1.42{\times}10^{-5}M$) and peak area (charge) was excellent with the square of the correlation coefficient ($R^2$) higher than 0.999. The detection limits were $1.0{\times}10^{-8}M{\sim}1.5{\times}10^{-7}M$ for the five anthracyclines. Within-day precision for the five anthracyclines were in reasonable relative standard deviations less than 3 % ($1.00{\times}10^{-6}M{\sim}1.42{\times}10^{-5}M$) except the lower concentrations less than $0.7{\mu}M$. Solid phase extractions of $1.00{\times}10^{-5}M$ epirubicin, $0.48{\times}10^{-5}M$ nogalamycin and $1.52{\times}10^{-5}M$ daunorubicin from human serum with a $C_{18}$ cartridge resulted in 97 %, 100 % and 90 % of recoveries, respectively.