• 한국환경보건학회지
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• 제29권1호
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• pp.28-33
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• 2003

This study was carried out to treat sewage using sand trench combined with septic tank process in rural areas. In order to find optimum parameters, design and operation mode was changed from Run 1 to Run 4. In order to facilitate nitrification and T-P removal, diffuser and iron plate was installed in the 3rd trench of Run 2 period. The septic tank played a role as pre-application process of sand trench system. The removal efficiencies of COD, NH$_4$-N, T-P at steady state were 94.6%, 87.9% and 54.5%, respectively. Addition of diffuser and iron plate in the 3rd trench has increased the removal efficiencies of the NIL-N and T-P. In this system, denitrification were not occurred because of the high DO.

• 한국환경과학회지
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• 제5권2호
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• pp.221-227
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• 1996

The objectives of this study are to examine combustion characteristics of E.V.A. and rubber wastes by fixed-bed incinerator, The results are as follows. Combustion temperature with time rises rapidly, and mass of E.V.A. reduces at short time in E.V.A. combustion. In variation of air-fuel ratio (m), ice ideal values of m of E.V.A. and rubber are 2.5, 1.5 respectively. Mixed-waste combustion is more economic than single E.V.A. combustion, because we can get high combustion efficiency (94.0~99.0%) at 2.0 air-fuel ratio of mixed-waste combustion. Removal efficiencies of SO2 at cooling tower are about 20%. The combustion efficiencies of rubber are over 98.0% according to the experimental conditions.

• 환경위생공학
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• 제12권1호
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• pp.39-48
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• 1997

The study was conducted to know the possibility that the removal efficiency of organic and suspended solids(SS) could be increased by suppling of sea water and the optimum amount of sea water to be supplied treat bleaching waste water by lime coagulation settlement at pulp mill process. When the lime dosage was increased, the removal efficiency of COD and SS in the waste water was increased based on the removal efficiency of COD and SS. The lime dosage and removal efficiency was increased proportionally with the lime concentration of 4,000 mg/l, but the increase of removal efficiency was presented slightly above the 4,000mg/l. It was evaluated that the removal efficiencies of COD and SS could be increased and the requirement of lime dosage could be decreased by the sea water supplement. The removal efficiency of SS was most increased when the sea water supplement was 10% or more in the waste water. The removal efficiencies of COD was the best at 4% sea water excepting the dilution efficiency by sea water supplement.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.423-426
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• 2002

A novel process for $H_2S$ gas treatment has been introduced, based on the combined action of a chemical absorption step and a biological step involving the biocatalytic activity of the bacterium Thiobacillus ferrooxidans. The aim of this study is the development of a process for $H_2S$ elimination from gas streams based on that chemical/biological method. The immobilized biomass reactor/chemical adsorption system is suitable for application of the removal of $H_2S$. A double stage reactor was used for the experimental work. The removal efficiencies of over 99% were observed in the range of inlet $H_2S$ concentration from 200 to 1,000ppm. The novel process showed the stable elimination efficiencies of over 95% under the retention time range from 20 to 40sec at the 1,000ppm of $H_2S$ inlet concentration.

• 한국농공학회지
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• 제35권4호
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• pp.67-75
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• 1993

This study was carried out to investigate the applicability of Solid Contact Process for the improvement of Moving Media Complete Mixing Activated Sludge(MMCMAS) effluents. Laboratory MMCMAS Reactor and MMCMAS/Solid Contact were operated at the hydraulic loading of 122~340 L/m$^2$/d. The conclusions from this study were as follows ; The addition of Solid Contact tank to the MMCMAS reactor has increased the SCOD and SBOD removal efficiencies of 4 to 67% and 2 to 41%, respectively. In addition, the increments of nitrification rates were about 13 to 46%. It was also observed that the addition of Solid Contact tank has greatly increased the organic removal efficiencies at the higher hydraulic loading rates and also decrement of sludge production rates was 0.1 gVSS/gBODrem. It was therefore concluded that the addition of Solid Contact tank could have polished the effluent of MMCMAS at the higher hydraulic loading rates.

• 한국농공학회논문집
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• 제49권2호
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• pp.75-86
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• 2007

This process which has a connection of biofilter and sulfur-limestone has been developed to treat organic substances including BOD, COD and SS etc. and to treat sulfur-limestone is for denitrification.. The whole process consists of chemical reaction tank, sedimentation tank, trickling filter, denitrification tank The trickling filter is equipped with a reactor filled with absorptive filter, and the sulfur denitrification tank is filled with sulfur-limestone mixed media. After setting up practical facilities whose capacity is 60 tons a day, we have observed the removal efficiencies of pollutants through 60 experiments during Summer and Winter seasons. The average concentration of polluted water was BOD for 3.6 mg/L, $COD_{Mn}$ for 11.3 mg/L, SS for 2.8 mg/L, T-N for 8.6 mg/L, and T-P for 0.8 mg/L, and the rate of treatment efficiencies 96.5%, 84.7%, 96.5%, 79.2%, and 80.8%, respectively was found through the experiments. The average treatment efficiency for BOD and $COD_{Mn}$ was 85.0% and 55.7%, respectively and the average removal efficiency for NH4+-N was 84.9% in the trickling filter. The removal efficiency in the denitrification tank is as follows; The removal rate of $NO_3^--N$ was as high as 93.2% within the compass of pH 6.3 to 7.3 through $16.8{\sim}37.0mg/L$ flown into $NO_3^--N$ and $0.1{\sim}8.3mg/L$ outflown. It had observed that this process has implemented highly efficient and advanced treatment without external carbon sources and internal recycle during its process. In conclusion, this process is suitable for a sewerage in a small village due to the merits of low power consumption and easy maintenance.

• 한국물환경학회지
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• 제25권5호
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• pp.674-681
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• 2009

Characteristics of organic matters (OM) in wastewater and the removal efficiencies were investigated using the influent and the effluent samples collected from 21 wastewater treatment plants. The OM characteristics investigated included biodegradability, humic content, specific UV absorbance (SUVA), the distribution percentage of refractory OM (R-OM), and synchronous fluorescence spectra. The types of wastewater (sewage, livestock waste/night soils, industrial waste) were easily distinguished by comparing the synchronous fluorescence spectra of the influent wastewater. The prominent peak of protein-like fluorescence (PLF) was observed for livestock waste/night soils whereas sewage exhibited a unique fluorescence peak at a wavelength of 370 nm. Irrespective of the wastewater types, the distribution percentage of R-OM increased from the influent to the effluent. Livestock waste/night soils showed the highest removal efficiency among all the three types of wastewater. There was no statistical difference of the removal efficiency between a traditional activated sludge and biological advanced treatment processes. Removal efficiency based on dissolved organic carbon DOC presented good correlations with the distribution percentage of R-OM and fulvic-like fluorescence (FLF) of the influent. The prediction for DOC removal efficiency was improved by using multiple regression analyses based on some selected OM characteristics and mixed liquid suspended solid (MLSS).

• 한국환경과학회지
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• 제25권11호
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• pp.1493-1498
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• 2016

The efficiencies of Gang-Byeon sewage treatment facilities, which are based on GPS-X modelling, were analysed and used to design recycle water treatment processes. The effluent of an aeration tank contained total kjeldahl nitrogen (TKN) of 1.8 mg/L with both C-1 and C-2 conditions, confirming that most ammonia nitrogen ($NH_3{^+}-N$) was converted to nitrate nitrogen ($NO_3{^-}-N$). The concentrations of $NH_3{^+}-N$ and $NO_3{^-}-N$ were found to be 222.5 and 227.2 mg/L, respectively, with C-1 conditions and 212.2 and 80.4 mg/L with C-2 conditions. Although C-2 conditions with higher organic matter yielded a slightly higher nitrogen removal efficiency, sufficient denitrification was not observed to meet the discharge standards. For the total nitrogen (T-N) removal efficiency, the final effluent concentrations of T-N were 293.8 mg/L with biochemical oxygen demand (BOD) of 2,500 mg/L, being about 1.5 times lower than that (445.3 mg/L) with BOD of 2,000 mg/L. Therefore, an external carbon source to increase the C/N ratio was required to get sufficient denitrification. During the winter period with temperature less than $10^{\circ}C$, the denitrification efficiency was dropped rapidly even with a high TKN concentration (1,500 mg/L). This indicates that unit reactors (anoxic/aerobic tanks) for winter need to be installed to increase the hydraulic retention time. Thus, to enhance nitrification and denitrification efficiencies, flexible operations with seasons are recommended for nitrification/anoxic/denitrification tanks.

• 한국물환경학회지
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• 제22권6호
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• pp.996-1003
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• 2006

The absorption characteristics of powdered activated carbon doped by transition-metal nanoparticles were investigated to enhance the remove efficiencies of $TCOD_{Mn}$ and Color from the flexo-inks wastewater. According to the adsorption dynamics of PAC and MPAC, the optimal dosage of activated-carbon adsorbents was 3 g/L under the reaction conditions of pH6.0, 30 mill of reaction time, 240 rpm of mixing intensity. The removal efficiencies by the optimal dosages were maximized as 19% $TCOD_{Mn}$, 57% Color for PAC and 88% $TCOD_{Mn}$, 95% Color for MPAC. Freundlich indexes of isotherm absorption were estimated as follows: i) For PAC, k=-8.11, 1/n=2.98, r=0.91 in the raw water, and k=0.14, b/n=0.75, r=0.96 in the biological treatment water, ii) For MPAC, k=2.69, 1/n=0.21, r=0.80 in the raw water, and k=0.74, 1/n=1.17, r=0.95 in the biological treatment water. MPAC (Powdered activated carbon doped by transition-metal nanoaprticles) was very effective in the removal of organics from the raw water and biological treatment water, as Freundlich indexes of 1/n for both types of water were estimated less than 2.0.

• 한국물환경학회지
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• 제20권6호
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• pp.610-614
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• 2004

The objective of this study was to remove organics and color in livestock wastewater using coagulation and Fenton oxidation process. After coagulation process as $1^{st}$ treatment, organics in $1^{st}$ treatment water were removed by using OH radical produced in Fenton oxidation process. Removal efficiencies of $COD_{Mn}$ and color were 87.2% and 95.7% separately. At that time, the ratio of $Fe^{2+}/H_2O_2$ was 0.8~1.0, and range of reaction pH was effective at the pH of 3.5~3.8. The Reaction time of 120min more than 60min or 90min was sufficient in Fenton process. Removal efficiency of organics was higher two- or multi-stage treatment than one-stage treatment.