• KSBB Journal
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• v.25 no.1
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• pp.47-54
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• 2010

The mycelial dispersed growth of Cordyceps sinensis was optimized in submerged batch culture at initial pH of 5.0, 150 rpm, and $25^{\circ}C$. The morphological data showed much more dispersed growth of C. sinenesis at initial pH of 5.0. Also, projected area, main hyphal length and number of tips for the mycelial growth of initial pH 5.0 were higher than those of other initial pHs. The industrial medium for mycelial production of C. sinensis was determined to be molasses of 100 g and crushed brewery yeast of 10 g per liter as carbon and nitrogen sources, respectively. With these culture conditions, the maximum production of mycelia was approximately 30.0 g per liter by batch culture in 5-liter jar fermenter with no controlled pH. This result suggests that large-scale mycelia production of C. sinensis may be possible in submerged batch culture. The hot water extract of mycelia from C. sinensis was mainly composed of 83.0% carbohydrate, 11.8% protein, 1.9% lipid, and 2.4% ash and there were present glucose, mannose, galactose, and arabinose as molar ratio of 8.79 : 2.59 : 1.34 : 1.0 in the carbohydrate, respectively. In the experiment using spleen cell and macrophage, the extract showed potent mitogenic and immuno-stimulating activities and among various components, an important factor that contribute to the immunological activities was turned out to be carbohydrate moiety.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.383-388
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• 2010

Lab scale experiment study was carried out for biological process development on cruise. SBR(Sequence Batch Reactor), MBR(Membrane Bioreactor), and MSBR(Membrane Sequence Batch Reactor) system were investigated for practical application on shipboard sewage treatment. From the results it was suggested that MSBR system might be suitable process for cruise in terms of pollutant removal efficiency, maintenance and special environmental conditions of cruise. About 99% of BOD, 98% of COD and 99% of SS were removed in MSBR system. In addition, about 76% of total nitrogen was reduced and the total phosphorus reduction averaged 59%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1459-1464
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• 2009

Recently demand for large-capacity aluminum heat sinks has been increased as market for high power electricity expands and high-performance electronic products develop. While the brazed heat sinks are in particular preferred, it is almost impossible to manufacture them with an atmospheric continuous furnace due to insufficient heating rate and various thickness of the parent metals. Therefore, a new index batch furnace is developed and the process variables are optimized. Then, brazing efficiency and tensile stress are obtained for brazed parts of the heat sinks. Finally experiment as well as numerical analysis has been performed to compare thermal efficiency of the brazed heat sinks with that of the silicone-bonded heat sinks.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.4
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• pp.470-479
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• 2004

The experimental conditions and relationships between parameters such as organic matter, aeration volume, aeration time, and precipitation time for the effective treatment of domestic wastewater were investigated. With the batch systems, the adsorption amount of unit microbe was measured with the change of MLSS concentration, precipitation time, and aeration amount. Theoretical adsorption amount of microbes was then numerically formulated by use of a SPSS multiple analysis as follows: $$Y=-0.0106(X_1)+0.07310(X_2)+42.705(X_3)+62.700$$ In this study, the amount of organisms to be removed in the range of MLSS concentration 2,000~4,500 mg/l were examined. In order to investigate the optimal condition of nitrification, the upper water in the biosorption stage was used as the initial experiment water. The results showed that the C/N ratio was 1.5 and the reaction time for the optimal nitrification was 1.5 hr. When the adsorption efficiency for microbe biosorption was 66%, the optimum denitrification efficiency was 83.3%. When the optimum parameters obtained from the batch experiment were applied to the lab-scale operation, the total retention time from the flow-in to flow-out was 10 hours and the removal efficiency was 93.8% for $COD_{cr}$ and 80.9% for TN. For the full-scale operation, the total retention time was 9.0 hours and the removal efficiency was 94.4% for BOD, 89.6% for $COD_{cr}$, 88.0% for TN, and 86.2% for TP.

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.25-33
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• 2001

The study was performed to examine the influence of sea tide on a tideland composition by Saemankeum reclamation and to evaluate a correlation between the characteristics of physical and the pollution level of heavy metals. Also, it was investigated the characteristics of heavy metal adsorption through a batch experiment and applied to adsorption isotherm equations. In the results, the flow of sea tide occurred to accumulation action and had an effect on the content of heavy metals. It suggests that influence factors for the content of heavy metals in the tidal flat be grain size, cation exchange capacity and organic matter content. Adsorption capacity of heavy metals occurs to 90% adsorption rate for injection concentration within 30 minutes. The flow patterns in Saemankeum area will undergo a change for soil size distribution. In result, this soil size changed will effect the adsorption capacity of heavy metals.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.1
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• pp.33-41
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• 1997

An attempt was made to enhance anaerobic treatment efficiency by adopting the anaerobic sequencing batch reactor(ASBR) process at a thermophilic temperature. Operational characteristics of the ASBR process were studied using laboratory scale reactors and concentrated organic wastewater composed of soluble starch and essential nutrients. Effects of fill to react ratio (F/R) were examined in the Phase I experiment, where the equivalent hydraulic retention time(HRT) was maintained at 5 days with the influent COD of 10g/L. A continuous stirred tank reactor(CSTR) was operated in parallel as a reference. Treatment efficiency was higher for the ASBRs because of continuous accumulation of volatile suspended solids(VSS) compared to the CSTR. However, the rate of gas production and organic removal per unit VSS in the ASBRs was much lower than the CSTR. This was caused by reduced methane fermentation due to accumulation of volatile acids(VA), especially for the case of low F/R, during the fill period. When the F/R was high, maximum VA was low and the VA decreased in short period. Consequently, more stable operation was possible with higher F/R. Effects of hydraulic loading rate on the efficiency was studied in the Phase II experiment, where the organic loading rate was elevated to 3333mg/L-d with the F/R of 0.12. Reduction of organic removal along with rapid increase of VA was observed and the stability of reaction was seriously impaired, when the influent COD was doubled. However, operation of the ASBR was quite stable, when the hydraulic loading rate was doubled and a cycle time was adjusted to 12 hour. It is essential to avoid rapid accumulation of VA during the fill period in order to maintain operational stability of the ASBR.

• Environmental Engineering Research
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• v.25 no.2
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• pp.251-257
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• 2020

This study was performed to verify the possibility of nitrification and denitrification in a single reactor. In batch type experiment, optimal point of experimental conditions could be found by performing the experiments. When supply location of microbubbles was located at half of width of the aeration tank and operating pressure of 0.5 bar, it was possible for zones in the aeration tank to be separated into anoxic and aerobic by controlling air suction rate according to operating pressure of the generator. To be specific, the concentration of dissolved oxygen (DO) in zone 1 and 2 of the aeration tank could be maintained as less than 0.5 mg/L. Also, in the case of concentration of oxygen in zone 3 and 4, the concentration of DO was increased up to 1.7 mg/L due to effects of microbubbles. In continuous flow type experiment based on the results of batch type experiments, the removal efficiency of nitrogen based on T-N was observed as 39.83% at operating pressure of 0.5 bar and 46.51% at operating pressure of 1 bar so it was able to know that sufficient air suction rate should be required for nitrification. Also, denitrification process could be achieved in a single reactor by using ejector type microbubble generator and organic matter and suspended solid could be removed. Therefore, it was possible to verify that zones could be separated into anoxic and aerobic and nitrification and denitrification process could be performed in a single reactor.

• Journal of the Mineralogical Society of Korea
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• v.9 no.1
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• pp.1-6
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• 1996

Woolastonite from Susan occurs as intercalations in limestone beds of Lower Paleozoic Joseon Supergroup. It is a thermal metamorphic product of impure limestone. Electron microprobe analysis shows that it is considerably pure wollastonite. It has triclinic cell with a=7.932$\AA$, b=7.328$\AA$, c=7.069$\AA$, $\alpha$=89.995$^{\circ}$, $\beta$=$95.255^{\circ}$, and $ \Upsilon=103.367^{\circ}$.Dissolution behaviors of wollastonite have been studied conducting three different dissolution experiments; two different reactions with HC1 (one batch and one re-initialization experiment) and one traction with distilled water. In the batch type powder wollastonite-HCl reaction, pH of solution rapidly increases in the early stage and then its rate of increase slows down to reach plateau resulting in parabolic relationship with time. It is represented by the early rapid rise and fall in pH giving a sharp pH-edge and succeeding slow rise in the re-initialization experiment. The early rapid rise in pH is due to the rapid sorption of H- in solution to oxygens on the reactive surface of wollastonite and the fall in pH means that all reactive surface sites are occupied by H- ions and no more H- adsorption occurs. The slow rise in pH following the pH- edge is due to the dissolution of wollastonite as evidenced by the correlation of pH variation and cation concentration. Dissolution of powder wollastonite in HCl shows linear trend with time. Si is dissolved predominantly over Ca at a constant rate. Ca is dissolved predominantly in the very early stage. Dissolution rate of coarse-grained wollastonite fragments in distilled water is parabolic with times howing a rapid reaction in the early stage and a slow reaction in the advanced stage. The Ca/Si ratio in solution is high in the case of coarse-grained wollastonite fragment as compared with powder wollastonite. The coarse-grained wollastonite fragment-water (acid) reaction resulted in the solution with an elevated constant pH value (alkaline) giving an important significance on the environmental view point.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.575-584
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• 2007

The adsorption capability of iron phthalocyanine derivatives were investigated by means of X-ray diffractometor (XRD), IR (infrared) spectroscopy, scanning electron microscopy (SEM) and temperature programmed desorption (TPD). According to TPD results, iron phthalocyanine derivatives showed two desorption peaks at low temperature ($100{\sim}150^{\circ}C$) and high temperature ($350{\sim}400^{\circ}C$) indicating that there were two kinds of acidities. Tetracarboxylic iron phthalocyanine (Fe-TCPC) have a stronger desorption peak (chemical adsorption) at the high temperature and a weaker desorption peak (physical adsorption) at the low temperature than iron phthalocyanine (Fe-PC). The specific surface areas of Fe-TCPC and Fe-PC were $26.46\;m^2/g\;and\;11.77\;m^2/g$, respectively. The pore volumes of Fe-TCPC and Fe-PC were $0.14\;cm^3/g\;and\;0.06\;cm^3/g$, respectively. The adsorption capability of triethyl amine calculated by breakthrough curve at 220 ppm of equilibrium concentration was 29.2 mmoL/g for Fe-TCPC and 0.8 mmoL/g for Fe-PC. The removal efficiency of dimethyl sulfide of Fe-TCPC and Fe-PC in batch experiment of 225 ppm of initial concentration were 44.9% and 28.9%, respectively. The removal efficiency of trimethyl amine of Fe-TCPC and Fe-PC in batch experiment of 118 ppm of initial concentration were approximately 100.0% and 33.9%, respectively.

• KSBB Journal
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• v.19 no.3
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• pp.236-240
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• 2004

Korean wastewaters have higher nitrogen concentrations than typical wastewaters of other countries. Most treatment processes such as activated sludge processes will need to supplement extra carbon sources for a complete removal of remaining nitrogen after the initial wastewater treatment, Because of these difficult matters, we have searched wastewater treatment methods that require no additional carbon sources. Wastewater treatment by microalgae in photobioreactors, using a green eukaryotic microalgae, Chlorella kessleri, showed a promising results and thus was selected to study further. This system is not intended to replace the conventional system but is to assist the existing biological treatment systems as a supplemental nitrogen removal process. Thus the secondary treated livestock wastewater was tested. Column type photobioreactors developed in our laboratory were used. When aerated with 5% CO$_2$ balanced with air at 1 vvm and illuminated at 100 ${\mu}$mol/㎡/s under 25$^{\circ}C$ and PH 7-8 by CO$_2$ buffering effect, the maximum nitrogen removal rate was 2.6 mg/L/hr. The results confirmed a possibility of microalgal wastewater treatment system as a secondary system to remove extra nitrogen sources. Based on these experimental results, the size of the optimal microalgal wastewater system was calculated. For the wastewater whose initial nitrogen concentration of 150 mg/L, the optimal batch system was found to be a 2 stage system with a combined retention time of 4.6 day. From the continuous experiments, nitrogen removal rates were examined under different dilution rates and 2 stage system was also found to be the optimal system. The combined retention time for the continuous system was 3.5 days. It is expected that conventional biological wastewater treatment systems followed by microalgal systems would reliably decrease the nitrogen concentration below the government criteria even for the livestock wastewater with low C/N ratio.