• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.504-510
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• 2003

This study has been carried out to evaluate the passive treatment systems for acid mine drainage in Korea and to suggest, if possible, the method for the improvement. 35 passive treatment systems in 27 mines have been constructed since 1996. SAPS, being the main process, was combined with more than one of processes such as anaerobic wetland, aerobic wetland, and oxidation pond for the construction of passive treatment system. Problems observed during the operation include the poor sulfate removal ratio, overflow, leakage, unusabless of the whole system, and inefficiency. The reasons of the poor sulfate removal ratio are believed that the low temperature during the winter prohibits the SRB activity and HRT for bacterial sulfate reduction is insufficient. An alternative method In Adit Sulfate Reducing System which enables to keep the temperature constant at about $15^{\circ}C$ was suggested. IASRS is the methods of placing the SAPS inside the adit, which enables the temperature around the system constant can be maintained. The experiments using the laboratory scaled model systems made up of four sections showed high efficiencies in pH control and metal removal ratios, but showed still low sulfate removal ratio of about $23\%$ also with high COD at the beginning of the operation.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.548-552
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• 2001

This study was designed to find optimum conditions of four different factors (ratio of solvent to cholesterol-$\beta$-cyclodextrin complex, mixing speed, mixing temperature, and mixing time) for cholesterol dissociation in cream. Using the ratio of 6 to 1 (solvent to the complex) showed the highest cholesterol dissociation rate (82.50%) when mixed at 100 rpm at $50^{\circ}C$ for 1 h. Mixing speed did not significantly affect the cholesterol dissociation. Also, mixing time appeared to be insignificant. The optimum mixing temperature was $50^{\circ}C$ and mixing at $40^{\circ}C$ resulted in a significantly lower rate, compared with that at $50^{\circ}C$. In a subsequent experiment, using recycled $\beta$-cyclodextrin only showed 75.07% of cholesterol removal in cream, while the mixture of recycled to unused $\beta$-CD with the ratio of 6 to 4 increased cholesterol removal to 95.59%, which is highly close to that of 100% unused $\beta$-CD.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.881-888
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• 2007

In order to investigate the characteristics of the non-biodegradable material, the $BOD_5/COD_{Cr}$ ratio was used. The average ratio of industrial complex's influent wastewater was 2.29~2.96, the effluent ratio was 4.29~19.0. The removal efficiency of $UV_{254}$ by physicochemical treatment was 22.8~94.7% and 5.3~77.2% by biological treatment, respectively. Of the wastewater removal efficiency for each of the items, the $BOD_5$ treatment efficiency was the greatest at 97.3% and the color & TN treatment efficiency was 40~70%. The study of the economical assessment showed that the complex as well as the individual companies spent 722~1,298 won for each ton of treated wastewater. All of the wastewater treatment facilities spent the most money on chemicals needed to treat the wastewater. The total cost for Nylon manufacturing wastewater treatment plant was the greatest while the total cost for cotton manufacturing wastewater treatment plant turned out to the lowest. As respects of removal efficiency and economocal assessment, Polyester A and Cotton manufacturing wastewater treatment plants were better effective than a dyeing industrial complex wastewater treatment plant.

• Journal of environmental and Sanitary engineering
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• v.4 no.1 s.6
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• pp.43-52
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• 1989

A synthetic wastewater composed of powdered baby food and inorganic nutrients was treated by five 3.6L anaerobic reactors in order to test the relationship between solids retention time (SRT) and media surface ratio, and the removal efficiencies of organic substrate. Of the five reactors, four were semi-continuously fed stirred-tank reactors and one continuously-stirred batch reactor. The influent was 7430mg/L in COD, 7120 mg/L $BOD_L$ and 6350mg/L in $BOD_5$, respectively. Operating temperature was $35{\pm}1^{\circ}C$ and pH in the range 6.9 to 7.2. In this experimental study it was found that a linear relationship existed, within the experiment range, between SRT and media surface ratio, and that SRT and removal efficiency increased with increasing media surface ratio. The substrate removal efficiencies were 82.7 to $88.2\%$ in COD, 82.9 to $88.4\%$ in $BOD_L$ and 83.3 to $88.7\%$ in $BOD_5$, respectively.

• Journal of Soil and Groundwater Environment
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• v.8 no.2
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• pp.36-43
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• 2003

Feasibility of micellar-enhanced ultrafiltration far the removal of nitrate was investigated using cationic surfactants, cetylpyridinium chloride and octadecylamine acetate. The removal of nitrate increased as the molar ratio of surfactant increased. With the molar ratio of 3, at least 80% of nitrate was removed, while > 98% of nitrate was removed at the surfactant molar ratio of 10. Octadecylamine acetate showed higher removal efficiency of nitrate and higher rejection of surfactant than cetylpyridinium chloride because of the accessibility of nitrate to surfactant micelles due to head group of surfactant. Octadecylamine acetate turned out to be a better surfactant than cetylpyridinium chloride for micellar-enhanced ultrafiltration to remove nitrate from groundwater.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.3
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• pp.116-121
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• 2004

Treatability tests were conducted to study the feasibility of EMMC process as a recycling-water treatment system in high density seawater aquaculture farm. To study the effect of organic and ammonia nitrogen loading rate on system performance, hydraulic retention time was reduced gradually from 12hr to 10min. The conclusions are can be summarized as follows. When the system HRT was reduced from 12hr to 2hr gradually, there was little noticeable change(reduction) in ammonia nitrogen removal efficiencies. However, removal efficiencies were decreased dramatically when the system was operated under the HRT of less than 2hr. In case of organics(COD), there was no dramatic change in removal efficiencies depending on HRT reduction. COD removal efficiencies were maintained successfully higher than 9％ when the system was operated at tile HRT of 10 min. System performances depending on media packing ratio in the reactors were also evaluated. There were little differences in each reactor performances depending on media packing ratio in reactor when the reactors were operated under the HRT of longer than 1hr. However, differences in reactor performances were considerably evident when the reactors were operated under the HRT of shorter than 1hr. When comparing reactor performance among 25％, 50％,7 5％ packed reactor, it can be judged that media packing ratio more than 50％ plays no significant role in increasing reactor performance. For this reason, packing the media less than 50％ is more reasonable way in view of economic. Such a tendency shown in COD removal efficiencies well agreed with the variation of ammonia-nitrogen removal efficiencies according to the media packing ratio in reactors at each HRT. Difference in effluent ammonia-nitrogen concentration between 50％ media packing reactor and 75％ media packing reactor was negligible. When comparing with the results of 25％ packing reactor, difference was not so great.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.343-346
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• 2000

This study was carried out to investigate the effects of influent $NH_4^{\;+}-N$ load, C/N ratio and superficial air velocity on the nitrogen removal efficiencies. Laboratory scale upflow biological aerated filter(BAF) was consisted of an anoxic-aerobic filter packed with porous ceramic media and operated with synthetic wastewater. BAFs requires less energy and space for the system when compared to conventional activated sludge process. The influent C/N ratios were varied from 0 to 1 by adjusting acetate. Various superficial air velocity had been applied to investigate aeration effect on nitrogen removal. The BAF reactor showed more than 90% average $NH_4^{\;+}-N$ removal efficiencies at $NH_4^{\;+}-N$ loading in the range of $0.26{\sim}1.33$ kg $NH_4^{\;+}-N/m^3{\cdot}d$ and 62% average T-N removal efficiencies at the C/N ratio of 1. Moreover, average T-N removal efficiencies increased as the superficial air velocity increased, because of the increase $NH_4^{\;+}-N$ removal efficiencies.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.45-52
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• 2013

In this study, we had analyzed the ammonia removal efficiency in sea animal-culturing aquarium water using hypochlorous acid (HOCl) which is very reactive, no harm to human, and with no formation of toxic trihalomethane. The amount of hypochlorous acid for the removal of ammonia varied with the concentration of ammonia in samples, with 90% of removal efficiency for 30 minute reaction time in the sea water where the ratio of hypochloous acid to ammonia (w/w) is about 8.5 ~ 9.0, and 100% removal in the sample with the ratio of 9.8 ~ 10.1. The removal efficiency with the time was shown to be 90% within 10 minute in the ratio of 9.0 ~ 10.0. These results will effectively be used for the proper management and protection of sea animals in large aquarium through water clarification with hypochlorous acid by calculating the right amount and reaction time.

• Journal of Environmental Science International
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• v.25 no.4
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• pp.517-524
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• 2016

In order to treat groundwater containing high levels of nitrate, nitrate reduction by nano sized zero-valent iron (nZVI) was studied using batch experiments. Compared to nitrate removal efficiencies at different mass ratios of $nitrate/Fe^0$, the removal efficiency at the mass ratio of 0.02% was the highest(54.59%). To enhance nitrate removal efficiency, surface modification of nZVI was performed using metallic catalysis such as Pd, Ni and Cu. Nitrate removal efficiency by Cu-nZVI (at $catalyst/Fe^0$ mass ratio of 0.1%) was 66.34%. It showed that the removal efficiency of Cu-nZVI was greater than that of the other catalysts. The observed rate constant ($k_{obs}$) of nitrate reduction by Cu-nZVI was estimated to $0.7501min^{-1}$ at the Cu/Fe mass ratio of 0.1%. On the other hand, TEM images showed that the average particle sizes of synthetic nZVI and Cu-nZVI were 40~60 and 80~100 nm, respectively. The results imply that catalyst effects may be more important than particle size effects in the enhancement of nitrate reduction by nZVI.

• Journal of Korean Medical classics
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• v.28 no.1
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• pp.55-69
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• 2015

Objectives : I hope this prescription configuration analysis among Liuhejian's and Lidongyuan's books and "Hejijufang" would explain the differences among Liuhejian's and Lidongyuan's theories against Hejijufang. Methods : I have searched for frequently used herbs combinations in the books and compared each features with others. And then I'd like to find out similar prescription by comparing composition ratio of configuring herbs. Conclusions : (1) In the composition ratio of configuring each of herbs Liuhejian's composition ratio of configuring herbs is higher than "Hejijufang" and Lidongyuan's prescriptions. (2) Lidongyuan's tendencies are about 'stimulate qi', 'removal of fever', 'removal of damp' and 'supplement of yin'. Liuhejian's tendencies are about 'removal of fever' and 'removal of wind'. Tendencies of "Hejijufan" are about 'heat up inside' and 'supplement of blood'. As I compared Lidongyuan's prescriptions with Liuhejian's, Lidongyuan's tendencies are about 'raising yang', 'supplement of qi', 'stimulation qi' and 'promotion of digestion'. Liuhejian's tendencies are about 'removal of fever' and 'removal of wind'. (3) I could prove that Liuhejian and Lidongyuan had created new theories against tendency of Hejijufang.