• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.339-342
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• 2000

A three phase fluidized bed bioreactor including Thiobacillus sp.IW was used to remove hydrogen sulfide and ammonia simultaneously. In this study, hydrogen sulfide was oxidized to sulfate by the microorganism and ammonia was reacted with the sulfate to form ammonium sulfate. Removal efficiency of hydrogen sulfide was almost perfect up to 45 mg/l h of inlet loading rate, whereas that of ammonia was reduced as inlet loading rate increased from 10 mg/1 h.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.40-46
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• 2006

This study was initiated to evaluate the inhibitory effect of selected heavy metals on the growth of Acinetobacter sp. Down as one of the phosphorus accumulating microorganisms (PAO) involved in the enhanced biological phosphorus removal (EBPR) process of the wastewater treatment plant. Acinetobacter sp. was initially selected as a starting model microorganism and was grown under aerobic condition for this experiment. The heavy metals selected and investigated in this study were cadmium (Cd), copper (Cu), mercury (Hg), nickel (Ni), and zinc (Zn). Median $(IC_{50})$ and threshold $(IC_{10})$ inhibitory concentrations for Cd, Cu, Hg, Ni, and Zn were 2.95 and 1.45, 4.92 and 2.53, 0.03 and 0.02, 1.12 and 0.43, 14.84 and 5.46 mg $L^{-1}$, respectively. We demonstrated that most of heavy metals tested in the experiment inhibited the growth of Acinetobacter sp. in the range of predetermined concentrations. Based on the data obtained from the experiment, Hg was the most sensitive to Acinetobacter sp., then Ni, Cd, Cu, and Zn in order.

• Journal of Environmental Science International
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• v.15 no.2
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• pp.169-175
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• 2006

The changes of contaminants and odor corresponding to anaerobic maturation process of piggery slurry were investigated by applying the additives, such as different kinds of complex microorganism products and deodorants containing microorganism activating agents. The pHs during 20-day anaerobic maturation were operated stably without great change regardless of the additives, although they were rather lower in the case that the additives were contained than the case that they were not contained. The effects of removing CODcr, $NH_3-N$, T-N, and T-S in case that the additives were not contained, were not so great during the 20-day operation and so it would be difficult to remove the organic materials and nitrogen ingredients simply with anaerobic maturation process. However, in case of anaerobic maturation process that the additives were contained, their average removal rates were improved with the values of $49\%,\;63.5\%,\;48.5\%,\;and\;30.7\%$ for above each of items, even if the 20-day of short-term maturation period was applied. Especial1y, odor intensity with the additives was lowered continuously during the operation period and it had more than two times of lowering effect compared to that without those.

• Membrane Journal
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• v.11 no.4
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• pp.170-178
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• 2001

PVC microfiltration membrane was prepared by phase immersion method and applied to membrane bioreactor (MBR) contained activated sludge. The hydrophilicity of membrane and the pore size increase with the amount of additive(PVP) ducting the preparation of membrane. Permeation characteristics and the membrane fouling behavior were investigated by varying the internal environment in MBR using the prepared membranes. When there is a sludge bulking in MBR caused by microorganism, membrane fouling was accumulated. The cake layer resistance, R$_{c}$, of membrane increased in the order of CP-0 > CP-1.0 > CP-1.5. Rc increased up to 3.5~7 fold where the sludge bulking occurred in MBR. CP-1.5 seems to be appropriated membrane on the basis of the surface characteristics and the flux. The average flux of all the test membrane was 12(${\pm}$2) L/$m^2$hr whereas the COD removal efficiency was 98.8%. The ratio of bulking sludge and the type and the size of microorganism in operating MBR accelerate the membrane fouling and flux decline. It is concluded that the characteristic of membrane filtration depends on the hydrophilicity of membrane, the internal environment of MBR reactor and the growth factor of sludge.

• Korean Journal of Veterinary Service
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• v.13 no.2
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• pp.130-140
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• 1990

A field test using Nophazin (drying off period therapeutics) was done from May, 1989 to October, 1989. 299 quarters of 75 cows from 28 herds were tested. The results were summarized as follows. 1. At the day 7 after parturition, CMT-was 81.60%, clots were removed perfectly, removal rate of hard, hot, pain was 99.6%, only one hard 0.35% was maintained. Recovery rate of general symptoms was 100%. 2. Recovery rate in Nophazin treatment was 100% in Micro-coccus SPP, Corynebacterium SPP, and unisolated, 97.06% in Enterobacterid SPP, 95.58% in Staphylococcus SPP, 91.67% in other Bacilli, 89.19% in Streptococcus SPP, Overall recovery rate was 95.32%, And fungi did not react. 3. The ratio of isolated microorganisms was Staphylococcus SPP 49.8%, Streptococcus SPP 16.3%, Enterobacteria SPP 15.0%, Micrococcus SPP 7.9% Corynebacterium SPP 4.4%, Pseudomonas SPP 2.6%, Bacilli 2.6% and Fungi 1.3%. 4. The range of sensitivity of each microorganism to therapeutics is as follow : Staphylococcus SPP 61.1∼94.7%, Streptococcus SPP 51.4∼91.9%, Micrococcus SPP 44.4∼94.4%, Corynebacterium SPP 70∼80%, Enterobacteria SPP 11.8∼88.2%, and other Gram negative bacilli 8.3∼83.3%. Overall sensitivity was in the range of 50.4∼92.0%, Microorganisms showed the highest sensitivity (80∼94.7%) to Nophazin. 5. New intramammary infection rate was 3.96% (9 strains) at paturition, 8.37% (19 strains) at the day 7 after paturition. Persistent organism wits 6.17% .(14 strains). 6. There was no side effect of Nophazin treatment.

• Journal of Environmental Impact Assessment
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• v.30 no.1
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• pp.35-48
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• 2021

In this study, the assessment of field applicability of in-situ remediation of nitrate-contaminated groundwater located in Yesan-gun was performed. Zero-valent iron/bio composite media injected PRB (Permeable Reactive Barrier) and monitoring well were installed in the contaminated groundwater site and monitored main remediation indicators during the PRB operation. Nitrate, nitrite, ammonia, Fe ion, TOC, and turbidity were analyzed and the diversity and population of microorganism in the PRB installed site were investigated for the verification of effect of injected PRB. In the study site where is an agricultural area, a river flows from west to east that forms a river boundary and the southern area has an impermeable sector. It was found that nitrate flows into the river, which is similar as groundwater flow. Simulation result for the fate of nitrate in groundwater showed steady state of nitrate arrived after 3~5 years passed. However, it is just to consider current conditions with no additional input of contaminant source, if additional input of contaminant source occurs contamination dispersion and time for steady state are expected to be increased. The monitoring results showed that Fe ion, TOC and turbidity in groundwater were not clearly changed in concentration after PRB installation, which indicates adaptability of the injected PRB for remediation of groundwater with no additional harmful effect to water quality. The concentration of nitrate maintained less than 5mg/L until 42 days after PRB installation and recovered its initial concentration after 84 days passed and showed termination of reactivity of injected zero-valent iron/bio composite media for removal nitrate. Nitrite and ammonia ions found after installation of PRB indicates reductive removal of nitrate. And the outstanding increase of microorganism diversity and population of Betaproteobacteria Class which includes denitrification microorganism explains biologically reductive removal of nitrate in injected PRB.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.3
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• pp.5-14
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• 2018

This study investigated the effect of concentrate of membrane filtration of sewage reuse facilities on bioreactor's microorganisms in sewage treatment facility, and concentrate was analyzed, oxygen uptake rate and continuous activated sludge experiment were performed. As a results, the concentration of organic matter and TP concentration in concentrate was closely related to the concentration of SS and the concentration of ionic substances in concentrate was higher in order of $Cl^-$ > $Na^+$ > $Ca^{2+}$ > $K^+$ > $Mg^{2+}$ > $F^-$. And the analysis value of analytical items was greatly fluctuated according to sampling time of concentrate. Result of OUR test according to the mixing ratio of concentrate to sewage, it was found that the concentrate acts as an organic matter in the activated sludge microorganism and it increases with the increase of the concentrate mixing ratio. As a result of continuous activated sludge experiment, MLSS concentration, organic removal efficiency and TN removal efficiency gradually decreased with increasing concentrate mixing ratio. Based on the experimental results, expected mixing ratio of concentrate to affect the treatment efficiency of activated sludge is 25%.

• KSBB Journal
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• v.19 no.2
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• pp.154-158
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• 2004

Recycled packed-bed reactor emploring immobilized microorganism was suggested in this paper for efficient denitrification. In the batch reactor, the effects of initial oxidation-reduction potential and nitrate concentration on denitrification were investigated. As the initial oxidation-reduction potential was decresed to -70 mV from ＋40 mV, the removal rate of nitrate was increased to 3.33 from 1.25 m9 NO$_3$$\^$-/-N/min under the experimental conditions. As the initial nitrate-N concentraion was increased to 200 mg/l, the removal rate of nitrate was proportional to the concentration of nitrate. When the concentration of nitrate-N was 400 mg/min, nitrite was detected, and when the initial nitrate-N concentration was reached at 1,000 mg/l, it took longer time for the complete nitrate removal. In order to decrease the initial oxidation-reduction potential and the nitrate-N concentration in the feed stream, the effluent was recycled to the influent stream in the packed-bed reactor. In the case of recycling, the initial oxidation-reduction potential was decreased to 30 mV from 150 mV, and the initial nitrate concentration could be decreased to 85 from 120 mg NO$_3$$\^$-/-N/l. As the result of recycling, the removal rate of nitrate was increased to 91.7% from 49.2%.

• Journal of the Korean GEO-environmental Society
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• v.17 no.11
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• pp.35-43
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• 2016

In this study, by using a Effective Microorganisms Brewing Cycle, it confirmed the purification effect of pollutants that are adsorbed on the basins stench removal and retarding soil. On the basis of on-site application test, a soil decontamination system will be suggested. Using a Effective Microorganisms Brewing Cycle, the odor concentration is reduced 2.5 times than that of natural purification treatment method. It was measured and found that the quality of the pore water discharged from the soil is improved. In addition, it was found that a composite of copper and lead with the fermentation microorganisms adsorbed on soil particles from the surface of the stirred experiments lagoon mixed soil is reduced to 65% and 66%, respectively, The TPH organic component was confirmed that the reduction effect of 85%. Restoration of reservoir contaminated soils using the effective microorganism brewing cycle needs to be more developed and implemented as a long-term purification system. This study may be a good reference of developing more complete microorganism brewing system which will efficiently reduce the odor and soil contamination based on optimal stirring and mixing ratio of the compound solutions and contaminated soils in reservoir.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.824-830
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• 2013

As a result of the sensory test for Bechamel Sauce being prepared by varying the amount of frozen-dry mugwort, the moisture content was the highest at 83.56% in the control group and the lowest at 76.18% in the one containing 20% of mugwort. The pH level decreased significantly (p>0.001) as the addition of specimen increased. In case of color, the brightness (L) and redness (a) were highest at 81.54 and -0.85 within the control group, and the yellowness (b) was highest at 35.82 for the one containing 20% of mugwort. The viscosity was the lowest at 64.45 cp for the control group and 138.45 cp for the Bechamel Sauce containing 20% of mugwort. Reduced sugar was significantly increased (p>0.001) with the addition of specimen. The results of change in the total number of bacteria showed that there was no microorganism until the third day of storage. On the fifth day, the groups with up to 10% mugwort showed $1.6{\times}10^2$ CFU/ml microorganisms and the groups containing 15% and 20% of mugwort were free of microorganisms. All groups contained microorganisms on the seventh day of storage, but the groups with greater mugwort contents showed smaller number of microorganisms on the fifth and tenth days. Taking into acoount the DPPH free radical removal of brown sauce containing mugwort, the removal increased with greater mugwort content. In terms of preference test, the color was 3.5 for the control group without the mugwort and the taste was highest at 5.1 with 10% of mugwort. The group containing 15% of mugwort received the highest score (4.6) for the after taste and the viscosity was the lowest at 2.7 for the group containing 20% of mugwort. Overall acceptability was the highest at 5.3 for the group containing 10% of mugwort and the lowest for the group containing 20% of mugwort.