• Korean Journal of Microbiology
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• v.47 no.1
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• pp.66-73
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• 2011

Bacterial density distributions of gut microbes in the digestive organs of Harmonia axyridis collected from three different sources (JK, CK, and CJ) were $6.0{\times}10^4$ CFU/gut under aerobic culture condition and $8.0{\times}10^6$ CFU/gut under anaerobic culture condition. Seven colony types were observed under aerobic condition and three types of similarity were detected under anaerobic condition. In total, 116 strains, including 34 strains under aerobic condition, were isolated from the digestive organs of H. axyridis. Based on the analysis of the 16S rRNA gene sequence, aerobic gut microbes were assigned to the Proteobacteria, Actinobacteria, Firmicutes, and Deinococcus-Thermus. A large number of isolates belonged to the genus Bacillus and Staphylococcus of the Firmicutes commonly found in H. axyridis from different sites. Anaerobic gut microbes were found to be similar according to colony morphological, phylogenetic analysis using ARDRA. Eighty-two anaerobic gut microbes were clustered into 17 different ARDRA types according to HaeIII. Representative anaerobic gut microbes in each ARDRA group were divided into five species of ${\gamma}$-Proteobacteria based on 16S rRNA gene sequence analysis; Hafnia alvei, Enterobacter ludwigii, Enterobacter kobei, Pseudomonas oryzihabitans and Pseudomonas koreensis. Phylogenetic analysis indicated that about 70% of the isolates belonged to ${\gamma}$-Proteobacteria, suggesting predominance of gut microbes.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.3
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• pp.19-25
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• 1994

In this research, characteristics of nitrification and denitrification using the microorganism attached on sponge and plates were examined. The denitrification and nitrification performance were investigated under the anaerobic and aerobic condition for about 2 months. Because the basins of denitrification and nitrification were connected in series, wastewater was flowed from denitrification basin to nitrification one. The 90% of influent flowrate was returned from nitrification basin to denitrification one. Most of organic material was removed in nitrification basin, wherease the only exact amount of organics required in denitrification process was removed in denitrification one. This experiment resulted in that heterotrophic bacteria existing in aerobic basin governed the removal efficiency of organic compounds. In case the influent BOD concentration into nitrification basin was 80mg/l, it did not affect to accumulation of nitrifying bacteria, the balance of heterotrophic bacteria was proved to be an important factor in nitrification/denitrification method such as anaerobic and aerobic cycling type.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.680-688
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• 2004

A sequencing batch reactor (SBR) was operated to investigate the degradation and removal of non-ionic surfactant, nonylphenol ethoxylates (NPEOs) in wastewater using lab scale experimental apparatus. About 5mg/L of NPEO was introduced and only < 0.1mg/L of NPEOs and nonylphenol(NP) in total was detected in treated effluent. In the effluent, long chain ethoxylates (NPEO12-15) were not detected, but short chain ethoxylates (NPEO1,2) were in relatively high concentration. NPEOs in the mixed liquor disappeared more rapidly in anaerobic condition than in aerobic condition.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.495-500
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• 1992

Photosynthetic bacteria which can utilize ferulate as a sole carbon source for their metabolic activities were isolated from soils by liquid enrichment culture technique. The strain P-1 was selected by the highest capability of degrading ferulate in aerobic and anaerobic conditions. The strain P-1 was rod-shaped with its motility, strained gram negatively and could not utilize sulfur compounds. This strain has the bacteriochlorophyll a group I carotenoid and membrane structures like lamellae. As the results of physiological, morphological and cultural charactderistics, the isolate was identified as Rhodopseudomonas plaustris, one of the purple nonsulfer bacteria. The strain P-1 utilized 2mM/day in aerobic condition and 0.86 mM/day in anaerobic condition.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.532-535
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• 2003

Indigenous bacterial mediation of As in contaminated sediment after biostimulation with a variety of carbon sources was investigated under aerobic and anaerobic conditions. Under the aerobic condition with lactate supply, indigenous bacteria increased the amount of total As extracted from the sediment and most dissolved As existed as As(V). Under the anaerobic, glucose-supplied condition, dissolved As diminished with time likely due to production of As sulfide(s) and subsequent precipitation, which resulted from bacterial reduction of ${SO_4}^{2-}$. The results implied that bacterial natural attenuation of As in subsurface has a potential to be practically applied.

• Journal of Environmental Science International
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• v.12 no.1
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• pp.55-61
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• 2003

This study was carried out to obtain the operating characteristics of SMMIAR process for biological nitrogenㆍphosphorus removal. SMMIAR was operated at HLR(Hydraulic loading rate) of 39.6, 52.8, 63.4 and 79.2 $\ell$/$m^2$/d respectively and the operating parameters such as intermittent aeration time ratio of aerobic/anoxic, DO and microorganism concentration were changed to confirm the optimum operating condition. The concentrations of the wastewater BOD, TN(Total nitrogen) and TP(Total phosphorus) were 150, 30 and 7.5mg/$\ell$ respectively. Achieving better removal efficiencies of BOD, TN and TP up to 90, 85.4 and 95.4% respectively, we must keep in operation condition of SMMIAR by 0.75 of time ratio of aerobic/anoxic and by minimum 45 minutes of oxic period simultaneously.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.409-410
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• 2006

• Journal of Korean Society of Water and Wastewater
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• v.21 no.4
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• pp.409-420
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• 2007

ASM No. 1 is a very useful model to analyze wastewater treatment system removing organic carbon and nitrogen material. But it isn't adequate to control the wastewater treatment system with real time since it has many material divisions and parameters. So, the purpose of this study is the simplification of ASM No. 1 to control the wastewater treatment system. ASM No. 1 was changed with the model which has 3 material divisions(COD, $NH_4{^+}$, $NO_3{^-}$) and two phases(Aerobic and Anoxic condition). SBR was running with two phases(Phase I and II). Phase II running 20 minutes with aerobic time was used for deciding model parameters and Phase I running 12 minutes with aerobic time was used for proving the simplified model. The simplified model was compared with ASM No. 1 using data of Phase I and II. As a result of model comparison, the simplified model has enough ability to express the variation of $NH_4{^+}$ compound.

• Environmental Engineering Research
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• v.20 no.4
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• pp.377-382
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• 2015

The high concentration of nitrogen and phosphorus in wastewater incorporated with the ability to use carbon dioxide as the carbon source make the microalgae become more attractive in wastewater treatment process. This study evaluates the optimal conditions for the digestion of settelable solids from the recirculating aquaculture system to produce the biomass of the green microalga Scenedesmus sp. After solids separation, aerobic digestion of settleable solids under disperse condition produced nitrate as the final product of consequently ammonification and nitrification processes. With the optimal digestion procedure, nitrate concentration during aerobic digestion in 2000 mL vessel increased from $9.63{\pm}0.65mg\;N/L$ to $58.66{\pm}0.06mg\;N/L$ in 10 days. Thereafter, cultivation of Scenedesmus sp. was performed in 1000 mL Duran bottle with air bubbling. The highest Scenedesmus sp. specific growth rate of $0.321{\pm}0.01/d$ was obtained in treatment using liquid fraction after aerobic digestion as the whole culture medium for Scenedesmus sp. cultivation. With this study, digestion of $8,800{\pm}128.12mg\;dry\;weight/L$ of settleable solids from fish pond finally produced $1,235{\pm}21mg\;dry\;weight/L$ of Scenedesmus sp. biomass.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.2
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• pp.179-182
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• 2008

The KIDEA process, occurred in single reactor, is operated by three consequential steps, i.e., aerobic, settling, and discharge while introducing wastewater into the bottom of reactor continuously. It could accomplish biological oxidation (BOD), nitrification, denitrification (T-N), phosphate removal (T-P), and solid separation (SS) through the operational mode mentioned. Especially, this system has removed the T-P by wasting certain amount of sludge at the end of aeration phase during 5~10 minutes and not returned the activated sludge into the reactor, that is, no RAS (Return Activated Sludge). All running mode and instrumentation were controlled by the PLC equipment automatically. In this study, therefore, we have evaluated T-P removal efficiency and moisture content (MC) performance under the different excess sludge wasting mode. T-P track study and MC with TS concentration were analyzed during aerobic and settling phase. It has revealed that there was no significant difference of released T-P concentration between the first case which waste the sludge at the end of aerobic phase (0.2mg/L) and the second case which waste the sludge at 40 min of settling phase (0.25mg/L). Also, dewatering duration and MC have decreased 1.7% when TS concentration was increased from 0.31% to 0.5% during aerobic condition. Hence, it has concluded the system performance was less influenced by the operation time change of PLC program.