• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.517-527
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• 2014

As sewer flooding frequents due to localized and concentrated stormwater and increased non-permeable surface area after urbanization, building cities with sound water recycle and accordingly efficient management of rainwater is demanded. To do this, the existing sewage (including rainwater) fee imposition system should be philosophically evaluated. This study presents problematic issues of the existing domestic sewage fee imposition system considering the principle of sharing costs on the service of sewage and rainwater collection and treatment. Four methods to improve the existing sewage fee imposition system are suggested: 1) imposing stormwater fee according to Polluter Pays Principle, 2) clarification of the share of public sector, 3) reducing or exempting the sewerage fee for inhabitants reducing urban runoff by constructing their own rainwater management facilities, 4) imposing charge for discharging rainwater to sewers due to new development action. Short, mid, or long term planning for rainwater management is recommended considering the situation of each municipality.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.601-606
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• 2014

Lab scale experiment study was carried out for biological treatment process development in shipboard. SBR(Sequence Batch Reactor) process with BM(Beneficial Microorganisms) was investigated for practical application on shipboard sewage treatment. From the results it was suggested that SBR process with BM might be a suitable process in terms of harmful materials removal. By adding BM to SBR system, the useful species of microorganisms and EPS(Extracellar Polymetric Substances) in sludge was increased. It was found that the biodegrability and harmful organic compounds like VOCs and harmful inorganic compounds like heavy metals. was reduced over 70%. As far as reclamation water is considered, this process is very advantageous to special environments such as cruise ships, because the method of adding BM makes it unnecessary to add other facilities on the SBR system.

• Journal of Environmental Impact Assessment
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• v.28 no.6
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• pp.592-603
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• 2019

This study is about the implementation of low energy sewage management technology through effective control of blower which consumes the most energy in sewage treatment. In calculating the amount of oxygen required for microorganisms, unlike the existing method using the operating index in the bioreactor or TMS data in the discharge port, the CODcr and NH₄⁺-N concentration changes in sewage flowing into the sewage treatment plant were detected in advance before entering the bioreactor and the amount of air was controlled based on this. The pre-sensing was found to have a high correlation compared with conventional products. As a result of blower control, it was possible to save about 9.9% energy more than the manual control. Consequently, this study suggested the possibility of blower's real-time control combined with pre-sensing technology. Also, it is expected that the low energy sewage treatment can be applied to sewage treatment facilities dependent on operation by manpower, and it will contribute to the reduction of greenhouse gas emissions.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.451-456
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• 2014

Lab scale experiment was carried out to study biological wastewater treatment technology developed for shipboard. RCM process using BM(Beneficial Microorganisms) was investigated for practical application on shipboard sewage treatment. RCM process is an environmental friendly treatment system, with minimum production of sludge. In the test, BOD5, CODcr, T-N and T-P were reduced a 96%, 97%, 78% and 81.68% respectively. From the result it was suggested that RCM process with BM might be a suitable process for shipboard sewage treatment, maintenance of useful microorganisms and creating special environment as the SDC tank is circulating in the non-biodegradable organics sludge generated during the wastewater treatment, thus reducing the amount of sludge generated. Therefore, the RCM process does not require additional equipment to strengthen it to meet the marine pollution standards.

• Journal of Korea Water Resources Association
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• v.48 no.9
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• pp.695-709
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• 2015

The inflow of nonpoint pollution sources due to sustainable development and urbanization is gradually increasing and causes a diversity of water pollution. There are lots of difficulties to find a solution as the problems related to variation of hydrological and natural phenomenon. A differentiated method to estimate the nonpoint pollution sources has been proposed using rainfall and characteristics of urbanization and observed data from sewage treatment districts in the study. The types of nonpoint pollution sources on an assumption of combined sewer system have been classified as three types which are inflow of rainfall, bypass of sewage treatments, and combined sewer overflows from a river. Three types for estimation of nonpoint pollution sources applied more accurately to generate a amount of nonpoint pollution loads. This study is expecting a wide application for effective water resource management on TMDL (total maximum delivery load) unit watershed and sewage treatment districts.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.36-37
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• 2010

Lab scale experiment was carried out to study applicability of BM (Beneficial Microorganisms) to the conventional SBR system for the shipboard sewage treatment. BM has been successfully applied to the wastewater treatment by the SBR process and hence this system maintained a stable effluent quality together with an increased treatment efficiency, meeting the requirements of IMO regulations. The SBR system facilitated by BM would be a suitable process for cruise ships in terms of the malodor control, treatment efficiency and operation conveniences.

• Journal of Environmental Science International
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• v.15 no.7
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• pp.677-688
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• 2006

Currently, the application of $TiO_2$ photocatalyst has been focused on purification and treatment of wastewater. However, the use of conventional $TiO_2$ slurry photocatalyst results in disadvantage of stirring during the reaction and of separation after the reaction. And the usage of artificial UV lamp has made the cost of photocatalyst treatment system high. Consequently, we studied that solar light/$TiO_2$ film system was designed and developed in order to examine disinfection characteristics of sewage wastewater treatment. The optimum conditions for disinfection such as solar light intensity, characteristic of sewage wastewater, amounts of $TiO_2$ and comparison of solar ligth/$TiO_2$ systems with UV light/$TiO_2$ system was examined. The results are as follows: (1) photocatalytic disinfection process with solar light in the presence of $TiO_2$ film more effectively killed total coliform (TC) than solar light or $TiO_2$ film absorption only. (2) The survival ratio of TC and residual ratio of organic material (BOD, CODcr) decreased with remain resistant material. (3) The survival ratio of TC and residual ratio of organic material (BOD, CODcr) decreased with the increase of amounts of $TiO_2$. (4) TC survival ratio decreased linearly with increasing UV light intensity. (5) The disinfection effect of solar light/$TiO_2$ slurry system decreased more than UV light/$TiO_2$ film systems. (6) The disinfection reaction followed first-order kinetics. We suggest that solar light instead of using artificial UV light was conducted to investigate the applicability of alternative energy source in the disinfection of TC and the degradation of organic material.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.130-138
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• 2020

As of 2017, the sewerage penetration rate of Seoul and metropolitan cities is more than 90%, and the number of domestic sewage treatment plants increased by 25% from 3,064 in 2010 to 4,072 in 2017. Among them, sewage treatment plant operated by SBR system is 585, which is 17% higher than 2010. In order to improve the water quality of the water source and improve the operation of the small sewage facilities, the improvement of the process was studied by applying the modelling to 49 facilities of the sewage treatment plant in Andong Imha dam area with more than 500㎥/day 3 places and 46 places less than 500㎥/day. As an improvement plan for modelling, candidate data were derived by reviewing operation data for 5 years. 49 facilities are operated by 12 types of operating processes. Among them, 1 place mort than 500㎥/day with SBR method and 9 facilities with less than 500㎥/day were selected by dividing 46 sites into 3 types. As a result of applying modelling to more than 500㎥/day, it was possible to improve the quality of discharged water through SRT control and it was found that applying model to sites of small scale treatment plants can improve the removal efficiency of TP by up to 14.4%. As a result, the data of this study could be used to improve and improve the operation of sewage treatment plants and RCSTP(Rural Community Sewage Tratment Plant).

• Journal of Korean Society of Environmental Engineers
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• v.36 no.8
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• pp.549-553
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• 2014

Variation of sewage sludge interface height and flow rate by rainfall were applied to the actual public sewage treatment plant, and the efficiency of sewage treatment was evaluated by measuring $BOD_5$, $COD_{Mn}$, SS, T-N, and T-P. When both flow and interfacial height are increased, the treatment efficiencies in terms of the five water pollutants are decreased. Among them SS is the most critical pollutant in rainfall. When 0.5 Q inflow was applied, the efficiencies were 74.2% at the sludge interface height of 0.5 m, 76.4% at 1.0 m, 70.2% at 1.5 m, and 60.7% at 2.0 m. When 1.0 Q inflow was applied, the efficiencies were 71.7% at the sludge interface height of 0.5 m, 71.9% at 1.0 m, 46.4% at 1.5 m, and -38.0% at 2.0 m. Operation at 2.0 Q~2.0 m and 3.0 Q~1.0 m above the sludge rising phenomenon occurred causing adverse effects on the public bodies. If the flow rate increases, the processing efficiency is reduced from 74.2% to 17.3%, even though the sludge interface height was maintained at 0.5 m, so that the inflow adjustment was most important during rainfall, and the interface height of 1.0 m should be maintained to minimize the adverse effect on public water system.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.115-121
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• 2006

The purpose of this study was to investigate applicability of pretreatment on the existing biological treatment for domestic wastewater reclamation. From Jar Tests, it was found that optimum dosage of coagulant was PAC 0.5mg/L and $FeCl_3$ 180mg/L for urban sewage. In this study, PAC 0.5mg/L was selected considering sludge production and the amount of coagulant required. In a continuous experiment performed with combining chemical coagulation and biological treatment, a considerable removal efficency was obtained in term of BOD, SS, T-N, T-P and ABS. When the raw sewage was supplied into the pre-chamical treatment facility, the removal of BOD and SS was 48.3% and 81.1%. However T-N removal was very low which means T-N consists of $NH_3-N$ mostly. T-P was almost completely recluced by the chemical addition. The effluent BOD & SS was 57~76 and 21~43mg/L, which could reduce the size of biological treatment facility. From the cost estimation pre-chemical treatment could save around half of the area required for biological treatment with post ceagulation.