• Coupled systems mechanics
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• v.5 no.1
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• pp.21-39
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• 2016

Wastewater process models are the essential tools for understanding relevant aspects of wastewater treatment system. Wastewater process modeling provides more options for upgrades and better understanding of new plant design, as well as improvements of operational controls. The software packages (BioWin, GPS-X, Aqua designer, etc) solve a series of simulated equations simultaneously in order to propose several solutions for a specific facility. Research and implementation of wastewater process modeling in combination with computational fluid dynamics enable testing for improvements of flow characteristics for WWTP and at the same time exam biological, physical, and chemical characteristics of the flow. Application of WWTP models requires broad knowledge of the process and expertise in modeling. Therefore, an efficient and good modeling practice requires both experience and set of proper guidelines as a background.

• Journal of the Korean Applied Science and Technology
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• v.23 no.2
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• pp.130-136
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• 2006

Theoretical total nitrogen removal efficiency and reactor volume ratio in oxic-anoxic-oxic system can be found by influent water quality in this study. The influent water quality items for calculation were ammonia, nitrite, nitrate, alkalinity, and COD which can affect nitrification and denitrification reaction. Total nitrogen removal efficiency depends on influent allocation ratio. The total nitrogen removal follows the equation of 1/(1+b). Optimal reactor volume ratio for maximum TN removal efficiency was expressed by those influent water quality and nitrification/denitrification rate constants. It was possible to expect optimal reactor volume ratio by the calculation with the standard deviation of ${\pm}14.2$.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.137-141
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• 1998

A chemical has been aging in soil environment is more less bioavailable than freshly added chemical. The amount of bioavailability of the aged chemical is different by bacterial strains. The difference could be depend on physiochemical properties of each strain. Phenanthrene was employed as an aged chemical. Seven bacteria were isolated from activated sludge and petroleum disposed soil. These strains were able to degrade phenanthrene and to grow using phenanthrene as a sole carbon source. According to the result of materialization and chemical extraction experiment, the bioavailable amount of aged phenanthrene which has been aged in Lima loam is different by each bacteria. Several physiochemical properties of each strain were tested to certify correlation with their different amount of bioavailability.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.98-101
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• 2003

The pilot scale experiment was performed to investigate phosphorus and nitrogen removal from sewage by intermittently activated sludge process combined with the electrochemical interaction (Localized Corrosion) of aluminum and silver. The average T-N removal rate for HRT of 24hr was 57.4%. It was possible to remove P in sewage to under 1 mg/L with a short HRT of 12 hr using Al and Ag plate but often required additional A1 plate supplement during the operation.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_1
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• pp.41-45
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• 2001

Pseudomonas aeruginosa EMS1, isolated from activated sludge, was able to grow an produce a biosurfactant on 4.5 % soybean oil, used as the source of energy and carbon. Pseudomonas aeruginosa EMS1 was cultivated at 3$0^{\circ}C$ in a reciprocal shaking incubator, and the highest biosurfactant production was observed after 3 days. Furthermore, Pseudomonas aeruginosa EMS1 was also able to use whey as a co-substrate for biosurfactant production and growth

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.516-519
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• 2000

Lab-scale biofilter was studied for the simultaneous removal of ammonia and hydrogen sulfide in gas mixtures. Compost and polyurethane foam were used as packing materials (50 : 50) and activated sludge from a wastewater treatment plant was innoculated initially. When tested under varying inlet concentrations and empty bed residence time(EBRT), up to 80 ppmv of ammonia and 40 ppmv of hydrogen sulfide could be removed completely at an EBRT of 30 sec. The pH was found to be the key factor governing the biofilter performance.

• Journal of Environmental Science International
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• v.9 no.2
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• pp.173-176
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• 2000

This study was carried out to investigate the filtration characteristics of membrane modules according to hollow fiber dispersion for direct solid-liquid separation of activated sludge. 2 bundle, 4 bundle, and 10 bundle, and 10 bundle module used in this experiment according to hollow fiber dispersion was manufactured at laboratory and permeate flux and transmembrane pressure(TMP) of each module were observed under a suction pressure of 0.5kgf/c$m^2$. As the hollow fibers were dispersed, permeate flux was increased and TMP was decreased. Permeate flux and TMP of each module was 15.0 $\ell$/$m^2$.h and 31.8 cmHg for 2 bundle, 16.0 $\ell$/$m^2$ .h and 17.4 cmHg for 4 bundle, and 20.4 $\ell$/m2 .h and 31.8 cmHg for 10 bundle. In conclusion, the membrane fouling is expected to be decrease by maintaining lower TMP with hollow fiber dispersion.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.366-369
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• 2002

Subsurface biobarrier technology has potential applications to contain contaminated groundwater and/or to degrade toxic pollutants in groundwater. Most biobarrier studies were conducted under aerobic condition, however there were several obstacles to make aerobic condition. Thus, In this study, we examined biobarrier formation under denitrifying condition by using nitrate as an electron acceptor. Experiments were performed with a sand column inoculated with activated sludge from the nearby WWTP. The substrate medium was pumped to the sand column in an upflow mode. During the low substrate loading rate period, the extent of reduction rate in hydraulic conductivity was found similar throughout the column, and permeability became relatively stable after couple of days. However, during the high substrate loading rate period, the column demonstrated a gradient of permeability reduction, with the greatest reduction in sections nearest the column inlet. Rapid growth of microorganisms near the column inlet resulted in the unbalanced reduction of hydraulic conductivity throughout the sand column. As a result, at this denitrifying condition the thickness of biobarrier could be controlled by adjusting the medium conditions of microbial growth.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.3
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• pp.1-8
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• 1994

In the general process of design for aerobic digestion, the design for field plant of which inflow pattern is continuous inflow is performed using the results from lab scale batch reactor. However, the recent researchers reported that the general designs were performed as over-estimated, Therefore, in this study, laboratory batch experiments were carried out at $20^{\circ}C$ and pH 7.5 on the aerobic digestion of waste activated sludge at different solid levels. This treatise could consider the negligence about effective digestion periods the usage of VSS as solid concentration, and the effect of initial solid concentration of solid degration rate coefficient($k_d$) as reasons of the overestimated design, and showed the scheme of how to design for aerobic digestion from batch experiment.

• Journal of Food Hygiene and Safety
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• v.9 no.4
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• pp.205-211
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• 1994

From 120 soil and activated sludge, the strains able to grow on benzoate and m-Toluate have been isolated after selective enrichment which were later identified as Psudomonas sp. according to its morphological and biochemical characteristics. Ben-2 strain contained two plasmid DNA having about 120 Kb and below 2.0 Kb by agarose gel electrophoresis. Form the comparative investigation of catechol 1,2-oxygenase and catechol 2,3-oxygenase activities in Ben-2 strain and its cured strain, Ben-2 strain has both of these two enzymes while cured strain has catechol 1,2-oxygenase only.