• Journal of environmental and Sanitary engineering
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• v.22 no.4
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• pp.1-9
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• 2007

A wastewater treatment plant, operating process is physico-chemical/biological activated sludge attached sand filtration, was selected to evaluate effluent quality and pollutants removal efficiencies consideration for deriving the technology-based effluent limitation for petroleum refining industry discharge. The results of influent and effluent analysis were as follows: Average effluent quality were 0.076mg/l of copper, 0.084mg/l of lead, 0.036mg/l of zinc, 0.005mg/l of nickel and 0.004mg/l of cadmium, and the range of coefficient of reliability from 0.007 of copper to 1.0 of lead. Also, 95% of reliability, 0.112, 0.15, 0.063, 0.015 and 0.009mg/l, respectively, were remarkably lower than their effluent limitations. And to reach 95% reliability of effluent limitation at cleanness area, designed effluent quality of copper, lead, zinc and cadmium should be 0.268, 0.099, 0.526 and 0.008mg/l, respectively.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.309-313
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• 2007

In Activated Sludge Model, COD fraction of primary settled municipal wastewater was a very important parameter. In this study, the COD fraction was determined using the oxygen utilization rate experiments. Readily biodegradable COD ($S_S$) fraction was observed about 29.7% of influent TCOD. $S_I$, $X_I$, and $X_S$ were analyzed to be 7.6%, 7.3%, and 55.4% of TCOD, respectively. The model used in this study was developed based on ASM3 and modified Bio-P module in order to simulate the existing BNR process. Parameter estimation results showed that $Y_{STO,O2}$, $Y_{STO,NO}$, $Y_{H,O2}$, $Y_{H,NO}$, $Y_{PO4}$, ${\mu}_H$, $b_H$, ${\mu}_A$, $q_{PHA}$, $q_{PP}$ and ${\mu}_{PAO}$ were 0.7, 0.64, 0.61, 0.48, 0.31, 3.9, 0.1, 1.35, 4.98, 1.8 and 0.59, respectively. Using the presented model and the estimated parameters, the simulation of the existing BNR process was successfully conducted.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.42-49
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• 1998

By checking the variations of the raw water quality and MLSS, the effects of the membrane materials on permeable flux and quality of the treated water were investigated in this study. Due to the stability for high variations of MLSS, tubular type membranes were selected. Polysulfone group membranes and polyamide group membranes were tested. The crossflow operation mode was adapted, because membrane fouling problems could be easily controlled by adjusting the linear velocity. Due to the high concentration of the raw water, polyamide group membranes were originally expected to achieve two times higher permeable fluxes. However, difference was only approximately $20l/m^2{\cdot}h$ at $3kgf/cm^2$. It might be resulted from the high concentration of organic materials in the effluent of the RBC process. For the quality of the treated water, polyamide group membranes were slightly less effective. It might be resulted from the fact that polysulfone group membranes had more adsorptive capacities for the organic materials. The effects of temperature on the permeable flux were found to be significant. Despite of the irregular injection of raw water, the quality of the treated water was kept stable.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.3-14
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• 2008

ASM No. 2(Activated sludge model No. 2) is very useful model to analyze the wastewater treatment which removes nitrogen and phosphorus. But, it is difficult to apply ASM No. 2 to control of wastewater treatment since it has 17 material divisions and 46 parameters. So the purpose of this study was the simplification of ASM No. 2 and the provement of simplification model. Firstly ASM No. 2 was simplified with 5 material division and three phases(Anaerobic, aerobic, anoxic phases). The simplified model was proved by R-square using track study data. As a result of provement, the values of R-square in ${NH_4}^+$ were 0.9815 in ASM No. 2 and 0.9250 in simplified model and in ${NO_3}^-$ were 0.8679 in ASM No. 2 and 0.7914 in simplified model and in ${PO_4}^{3-}$ are 0.9745 in ASM No. 2 and 0.9187 in the simplified model when the ability to express the material variation was compared by R-square. So, the simplified model has enough ability to express the variation of ${NH_4}^+$, ${NO_3}^-$ and ${PO_4}^{3-}$.

• Membrane Journal
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• v.17 no.2
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• pp.112-117
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• 2007

The application of membrane bioreactors for the depuration of wastewater coming from the washing of mineral oil storage tanks is described. Microfiltration hollow-fibre membranes were used in the submerged configuration. Filtration tests were carried out with a biomass concentration of about 15 g/L in order to assess the critical flux of the hollow fibre membrane used. Then particular care was taken in carrying out the performance runs in the sub-critical flux region. The reactor performance was very high, with removal efficiencies ranging between 93% and 97% also when the concentration of hydrocarbon was very high. Some kinetic parameters for the COD and the hydrocarbon removal were estimated.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.34-42
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• 1997

A laboratory experiments were performed to investigate the treatment of photographic processing wastewater by chemical oxidation and biological treatment system. The effect of reaction conditions such as hydrogen peroxide dosage, ferrous sulfate dosage and pH on the COD removal in Fenton oxidation were investigated. The optimal dosage of hydrogen peroxide was 2.58 M and 3.87 M for the developing and fixing process wastewater, respectively. The Fenton oxidation was most efficient in the pH range of 3-5 and the optimal condition for initial reaction pH was 5 for a developing process wastewater. With iron powder catalyst, the COD for a developing process wastewater was removed in lower pH than with ferrous sulfate catalyst. The removal efficiency of COD for refractory compounds such as Diethyleneglycol, Benzylalcohol, Hydroxylamine Sulfate, Ammonium Thiosulfate, Ammonium Ferric EDTA and Disodium EDTA in the photogaphic wastewater was found than 90% except Potassium Carbonate. When the photographic processing wastewater after pretreatment by Fenton oxidation was treated with batch activated sludge process, the addition of $KH_2PO_4$ as a phosphorous compound improved the removal efficiency of COD. During the continuous biological treatment of developing and fixing process wastewater after pretreatment by Fenton oxidation, the effluent COD concentration less than 100 mg/l was obtained at 0.425 and 0.25 kgCOD/m$^3$.d, respectively.

• Journal of Environmental Science International
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• v.10 no.5
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• pp.359-364
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• 2001

Pseudomanas sp. EL-04J was previously isolated from phenol-acclimated activated sludge. This bacterium was capable of degrading phenol and cometabolizing trichloroethylene (TCE). After precultivation in the mineral salts medium containing phenol as a sole carbon source, Pseudomonas EL-04J degraded 90% of TCE $25 \mu\textrm{M}$ within 20 hours. Thus, phenol-induced Pseudomonas sp. EL-04J cells can bdegrade TCE. Followsing a transient lag period, Pseudomonas sp. EL-04J cells degraded TCE at concentrations of at least $250 \mu\textrm{M}$ with no apparent retardation in rate, but the transformance capacity of such cells was limited and depended on the cell concentration. The degradation rate of TCE followed the Michaelis-Menten kinetic model. The maximum degradation ratio ($V_{max}$) and saturation constant ($K_{m}$) were $7nmo {\ell}/min{\cdot}mg$ cell protein and $11 \mu\textrm{M}$, respectively. Cometabolism of TCE by phenol fed experiment was evaluated in $50m {\ell}$ serum vial that contained $10m {\ell}$ of meneral sals medium supplemented with $10 \mu\textrm{M}$ TCE degradation was inhibited in the initial period of 1 mM phenol addition, but after that time Pseudomonas sp. EL-04J cells degraded TCE and showed cell growth.

• Journal of Environmental Science International
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• v.25 no.8
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• pp.1155-1163
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• 2016

The treatment efficiencies of domestic sewage treatment processes were analysed and assessed to suggest and design a suitable technology for coal seam gas (CSG) water treatment. Two sewage treatment plants (S and G in Busan) were selected. The former operates with standard activated sludge and modified Ludzak Ettinger processes while the later uses the combination of $A_2/O$ and gravity fiber filtration. For both plants, the concentrations of BOD, $COD_{Mn}$, T-N and T-P were about 5.0, 19.0, 5.0, 11.0 and 1.0 ppm, respectively, which satisfy the discharge standards. Therefore, although sewage treatment processes seems to be applicable for CSG water treatment, additional processes to remove total dissolved solids and ionic compounds (i.e. bicarbonate) need to be introduced to produce fit-for-purpose water resources for beneficial use (in accordance with Water ACT 2013). This, for the CSG treatment process design, it is necessary to align the operating conditions with merging methods of combinable unit technology obtained from sewage treatment processes.

• Journal of Environmental Science International
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• v.18 no.6
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• pp.603-608
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• 2009

Activated sludge sewage treatment processes are difficult to be controlled because of their complex and nonlinear behaviour, however, the control of the dissolved oxygen level in the reactors plays an important role in the operation of the facility. For this reason, this study is designed to present a system which accurately measures DO, MLSS, pH and ORP in the aeration tank to alleviate situations above and provide the automatization of a sewage treatment plant (STP) using new DO control system. The automatic control systems must be guaranteed the accuracy. Therefore, the proposed automatic DO control system in this study could be commercial applications in the aeration tanks by means of operating cost analysis and user-friendly for operation and maintenance. We could get accurate data from the lab tank which has water quality checker because there was no vortex and air bubble during the measurement process. Improvement of confidence in the lab tank enabled effective and automatic operation of sewage treatment plants so that operation costs and manpower could be saved. If this result is put in place in every sewage treatment plant nationwide for practical purposes, it is estimated to cost 18.5 million dollars in installing the lab tank and to save 9.8 million dollars in management cost a year, except for cost saved by automation.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1207-1213
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• 2005

In a search for bacteria capable of degrading styrene better than previously isolated strains, bacterium IS-3 was isolated from activated sludge and found to be most closely related to Pseudomonas sp. Styrene degradation by this strain was tested in liquid cultures and polyurethane-packed biofilters. In liquid cultures, the rate of styrene degradation by this bacterium increased from 24.93 to $76.53\;{\mu}mol\;g^{-1}\;DCW\;H^{-1}$ for an initial mass range from 8.7 to $34.8{\mu}mol$. The maximum styrene elimination capacity was 580-635 $g/m^{3}\cdot$h at a space velocity (SV) of 50-200/h. The critical elimination capacities guaranteeing $95\%$ removal of the input styrene were determined to be 635, 170, and 38 $g/m^{3}\cdot$h, respectively, at SVs of 50, 100, and 200/h. Kinetic analysis revealed that the maximum styrene elimination velocity ($V_{m}$) for this biofilter was 1,000 g/m$\cdot$h, and the saturation constant ($K_{m}$) was 454 ppmv. Together, these results suggest that a polyurethane biofilter containing Pseudomonas sp. IS-3 could have potential practical applications for the effective removal of styrene gas.