• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1281-1286
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• 2008

Nitrous oxide(N$_2$O) is well known as a greenhouse gas that contributes to the global warming (310 times more per molecule than carbon dioxide) and to the destruction of the ozone layer. The objective of this study is to estimate N$_2$O emission factor using an emission isolation flux chamber from municipal wastewater treatment plants. N$_2$O gas was analysed by GC/ECD with 6 port gas sampling valve. The results of this study were as follows. N$_2$O emission factor of 5-Stage process from Y wastewater treatment plants was lowest as 0.94 g-N$_2$O/kg-TN. And that of other processes were 2.65 g-N$_2$O/kg-TN for Activated sludge process, 9.30 g-N$_2$O/kg-TN for Denipho process, and 26.73 g-N$_2$O/kg-TN for Sequencing Batch Reactor process. We have known that 5-Stage process is most appropriate process to reduce greenhouse for municipal wastewater treatment plants.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.2
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• pp.151-160
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• 2014

Capacitive deionization(CDI) has many advantages over other desalination technologies due to its low energy consumption, less environmental pollution and relative low fouling potential. The objectives of this study are evaluate the performance of CDI which can be used for dissolved salts removal from sewage. To identify ion selectivity of nitrate and phosphate in multiionic solutions and adsorption/desorption performance related to applied potential, a series of laboratory scale experiments were conducted using a CDI unit cell with activated carbon electrodes. The CDI process was able to achieve more than 75 % TDS and $NO_3{^-}$, $NH_4{^+}$ removals, while phosphate removal was 60.8 % and is inversely related in initial TDS and $HCO_3{^-}$ concentration. In continuous operation, increasing the inner cell pressure and reduction of TDS removal ability were investigated which are caused by inorganic scaling and biofouling. However a relative mild cleaning solution(5 % of citric acid for calcium scaling and 500 mg/L of NaOCl for organic fouling) restored the electrochemical adsorption capacity of the CDI unit to its initial level.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.223-228
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• 2000

The purpose of this study is to evaluate the purification capacity of pollutants by column test with the tidal flat sediment. Sediment materials were taken from Chunjangdae tidal flat which located in Chungnam Seochungun. The column tests were conducted on four conditions(R1 : raw sewage filtered by G2 filter, R2 : sterilized sewage after filtered by GF/C filter, R3 : R2 /filtered(membrane) seawater (1:1), R4 : R2 /filtered(membrane) seawater(1:2)). The results of this study may be summarized as followed ; The removed COD by column tests were increased according to increasing the quantity of sewage. During the column tests of 580min, the total removed ammonia nitrogen were 90.1mg for R1, 81.0mg for R2, 27.6mg for R3 and 4.1mg for R4. The result was similar to COD experiment. During the 580min, the total removed total-phosphates were 3.4mg for R1, 4.2mg for R2, 5.6mg for R3 and 2.0mg for R4. The removal efficiency of Pb and Cd for R3 and R4 reactor were higher than R1 and R2 reactor. The remove of heavy metal by the column test was high in sample with seawater. But in the initial 20min, the adsorbed Pb and Cd showed about 3% of the total adsorbed Pb and Cd during 580min.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.1
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• pp.73-83
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• 2010

This study was performed to increase the removal efficiency of the biofilter packed with granular sulfur in municipal wastewater reclamation facility. Constituent units were influent water tank, denitrification tank, BOD reduction tank and outlet. And, the major operation factor is a biofilter packed with submerged granular sulfur. Actual wastewater and synthetic wastewater were used as influent wastewater. Experimental condition was divided into two phases according to the amount of a phosphorus coagulant. Total phosphorus removal efficiency was insignificant at mode I that phosphorus coagulant was not injected. The average influent and effluent total phosphorus concentrations at mode II were 0.5 ~ 1.0 mg/L and 0.27 mg/L, respectively. As for COD and BOD effluent concentrations, COD was 3.0 mg/L and BOD was 1.0 mg/L. Additionally, nitrogen removal rates were high at low influent DO concentration. In conclusion, a new process, biofilter packed with granular sulfur is expected to treat high-rate nitrogen wastewater and expected to be utilized as an alternative of technological innovation for the nitrogen treatment.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.3
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• pp.305-314
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• 2014

A pilot plant (Q=5 $m^3/d$) study was implemented for small and medium sized personal wastewater treatment plant effluent to evaluate MBR and A/O processes utilizing self-sufficient energy composed of wind and solar energy. The removal efficiencies of BOD, SS, turbidity and color were sufficient for legal water quality standards for gray water. However, those of nitrogen and phosphorus could not meet legal regulations which suggested that further removal of those contaminants were needed for reuse of the treated water. Self-sufficient energy rate was 100 % for the pilot plant due to excessive design capacity. In this research, wind and solar energy system was applied considering geological characteristics, which significantly improved energy self-sufficiency. Substantial improvement on energy self-sufficiency can be obtained by optimized investment and operation at a full scale wastewater treatment plant.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.535-539
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• 2006

GIS-based integrated management system was developed for the treated wastewater to be reused as agricultural water. The major scopes of this research includes developing different types of system such as connecting data of wastewater treatment plants to data of hydraulic structures and paddy field ; separating spatial data into the watershed boundary and the agricultural water boundary ; and estimating applicable site for reuse. This system can enable to provide more scientific support to manage information of effluent and agricultural data utilizing GIS techniques.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1959-1963
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• 2006

As an alternative water resources development, wastewater reuse for agricultural and instream uses are expected to be fond of the limelight. In order to find the feasible reuse system scheme for reclaimed water in real field, existing reuse sites were investigated for water quantity, quality, and irrigation scheme. From the results, most of sites supplied reclaimed water with a request of the users(farmers) and reuse techniques for agricultural use were to be needed in the sites which supplied over yearly $1.0{\times}10^6$ ton as agricultural water.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.89-92
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• 2002

Among 172 wastewater treatment plants, eighty eight plats are found to be qualified for potential wastewater resources applicable to agricultural irrigation. The total effluent capacities are 4,042 thousand tonnes per day, which may be used to irrigated paddy fields of $156\;km^2$. Preliminary surveys have been made to inquire farmers and water managers about their preference for wastewater reuse. All of them expressed their willingness to accept the wastewater reuse. The surveyed water managers suggested microbiological treatments be made and exclusive prove for safety of wastewater irrigation be prerequisite to the practices. Further surveys with experts and water managers throughout the nation are needed before any conclusions are made.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.1
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• pp.17-24
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• 2020

This study analyzes economic feasibility by looking at the case of wastewater reclamation and reuse system of Osan, the only place currently operated in Korea, exploiting wastewater uniquely reused as industrial water. Furthermore, this paper examines the problem in wastewater recycling and present the method to expand the potential of using reclaimed water. Method to activate the reuse of wastewater as industrial water. First, it is required to provide self-governing body and demander with diverse information on this project so that they correctly recognize the reuse of wastewater as industrial water. Second, law should be amended so that the water quality requirement of reused water can be given in the national level to supply industrial water depending on right standard. Third, financial support should be expanded in diverse parts so that more private investment advantageous to investor can be made, for instance, BTL, BTO.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.5
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• pp.223-230
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• 2007

Plasticity of clay bodies containing bottom ashes(BA) and small portion of other wastes was investigated. Plasticity indices of clay bodies using Atterberg limits were measured. It was confirmed that the plasticity indices could be applicable in actual forming process by extrusion. The forming possible compositions were found by changing the contents of water, bottom ash, stone dust, and sewage sludge. The relationship between the plasticity and physical properties of the aggregate green body was also investigated. The compositions for extrusion forming can be expected by measured the plasticity indices and these results were confirmed by real extrusion process. There is also strong relationship between the plasticity indices and the property of aggregate green body.