• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.3
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• pp.64-71
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• 1997

Floating aquatic plant system using water hyacinth was applied to examine feasibility as a wastewater treatment system for the industrial complex in rural area. The wastewater from the industrial complex does not likely contain toxic pollutants because the industries which generate wastewater with toxic compounds are not allowed to move in. Pilot plant was installed at Baeksuk Nongkong Danzi in Chunahn-City, Chunchungnam - Do , and field study was performed during summer and fall of 1996. Hydraulic loading rate was 0. $0.19m^3/m^2$.day. The effluent concentration of DO was higher than influent, and it implies that 0.6m depth reactor was reaerated enough to increase DO level. The influent concentration of BOD varied significantly from less than 30 to 120mg/${\ell}$ during the study period, however, effluent concentrations were generally lower than the water quality standard and removal efficiency was up to 85%. The influent concentration of COD also showed wide variation from less than 40 to 160mg/${\ell}$ and effluent concentration was higher than water quality standard when influent concentration was over l00mg/${\ell}$. The influent concentrations of T-N and T-P were lower than water quality standard and no further treatment was required, and these compounds were also removed in the system. Although some improvement and refinement are still required, overall* the floating aquatic plant system was proved to be feasible to apply to treat wastewater from industrial complex in rural area.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.203-206
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• 2001

Finding the optimal solution in the river water quality management system is very hard with the non-linearity of the water quality model. Many suggested methods for that using the linear programming, non-linear programming and dynamic programming, are failed to give an optimal solution of sufficient accuracy and satisfaction. We studied a method to find a solution optimizing the river water quality management in the aspect of the efficiency and the cost of the waste water treatment facilities satisfying the water Quality goals. In the suggested method, we use the QUAL2E water quality model and the genetic algorithm. A brief result of the project to optimize the water quality management in the Youngsan river is presented.

• Water for future
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• v.41 no.10
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• pp.59-64
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• 2008

• Journal of Korean Society of Water and Wastewater
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• v.22 no.4
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• pp.445-448
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• 2008

The application of the membrane filtration process has been increased for the drinking water treatment system because of excellent quality of treated water compared with the sand filtration process. The selection of suitable pre-treatment processes and optimum flux according to the characteristics of raw water are important factors for the design of membrane processes. In this study, the most efficient pre-treatment processes for drinking water was selected by investigating the effects of pre-treatment processes on the operational stability of the membrane filtration process. Both lab-scale and pilot-scale experiments were conducted. In the lab-scale test, the effect of pre-treatment processes on the stability of the membrane filtration process was investigated indirectly by comparing the performance of membrane flux for raw water, pre-treated water, and membrane permeated water. In the pilot-scale test, the usefulness of prefiltration processes was assessed by comparing the performance of single membrane process and hybrid coagulation-membrane process. The results indicated that the coagulation process contributed to the stabilization of trans-membrane pressure (TMP) by removing contaminants on membranes, though the pre-filtration process had little effect on the TMP.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.2
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• pp.24-30
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• 2014

In this paper, a new remote terminal unit(hereafter RTU) is proposed to manage a wide range of applications and a variety of sensors (eg, pressure, water quality, temperature and humidity sensors, the amount of pollutants, $CO_2$, etc.) to monitor and control the facility such as water treatment plant, intake and effluent pumping station, water tank and distribution network. Fault status of local sensor devices and network are alerted by using the embedded fault handling capabilities of the RTU in the system and also sent to the fault handling server, by which fault can be easily monitored to users. The developed system was applied to one of K-water branch offices in Geoje city and improved its reliability and stability for controlling and monitoring water facility.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.54-64
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• 2002

This study evaluated advanced water treatment (AWT) system in Korea. There are currently 16 plants operating with AWT. However, no attempt has been made to evaluate AWT system. This study selected one water treatment plant with AWT (pre-ozonation ＋ BAC). Using the operation data from 1995 to 2001 and pilot study results, the post-evaluation of the AWT system has been conducted. The study found that AWT improved water qualities of organic, ammonia, and turbidity, as expected. However, the extent of the improvement was generally short of the pilot study expectations. Pre-ozonation failed to decrease coagulant consumption. The dosage increased rather than decreased. AWT was, however, successful to decrease chlorine consumption. The chlorine reduction was related to the change in raw water characteristics and AWT introduction. Pre-ozonation failed to decrease coagulant consumption. The dosage increased rather than decreased. AWT was, however, successful to decrease chlorine consumption. The chlorine reduction was related to the change in raw water characteristics and AWT introduction, Both operation of pre-ozonation and reduced ammonia loading were responsible for the reduction. AWT increased the operation cost. Maintenance, raw water, and power cost increased, while labor and chemical cost decreased. Manpower reduction resulting form automation caused the decrease of labor cost. The reduction of chlorine consumption caused the decrease of chemical cost.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.5
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• pp.659-666
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• 2011

Although DAF(Dissolved Air Flotation) has been successfully accepted for water and wastewater treatment, the fundamental characteristics of the process have not been fully investigated. Water is saturated with compressed air to dissolve the air into the water at high pressure in saturation tank. Then the water containing dissolved air is released into a floatation tank at a lower pressure, generating micro-bubbles that rise gently through the water and carry the suspended matter to the surface. This study investigated the removal of sewage using automatic mixture type DAF pump and non-powered flotation tank. Characteristics of two devices were compared and analyzed with samples. The results showed that the PAC exhibited higher performance than other coagulants. When air dosage was 2.5ml/l/min, treatment was stable in operation. In the DAF pump with a pressure of 4 atm., the average size of bubbles was 36.2${\mu}m$. Removal efficiency of SS was 80%. At this time removal efficiency of COD was about 80%, of T-N was 30% and T-P was 70% in stable operation. It was concluded that DAF pump system with micro bubble performed higher efficiencies compared to general DAF system for treating wastewater.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.1
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• pp.55-65
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• 2018

It is necessary to develop a mobile water production system in order to provide stable water supply in case of disasters such as floods or earthquakes. In this study, we developed a modular mobile water production system capable of producing water for various uses such as domestic water and drinking water while improving applicability in various raw water sources. The water production system consists of three stages of filtration (sand filtration - activated carbon filtration - pressure filtration) to produce domestic water and an additional reverse osmosis process to produce drinking water. In laboratory and field experiments, the domestic water production system showed excellent treatment efficiency for particulate matter, but showed limitations in the treatment of dissolved substances such as dissolved organic matter. In addition, ultraviolet irradiation was considered as additional disinfection step, because it does not form precipitates of manganese oxides after disinfection. Reverse osmosis process was added to increase the removal efficiency of dissolved substances and the treated water satisfied drinking water quality standards. Fluorescence analysis of dissolved organic matter showed that the fulvic acid-like substances in raw water was successfully removed in the reverse osmosis process. The mobile water production system developed in this study is expected to be used not only in water supply in case of disaster, but also widely used in islands and rural area.

• Journal of Soil and Groundwater Environment
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• v.14 no.1
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• pp.61-67
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• 2009

A non-discharged system of sequentially physico-chemical water treatment was used to treat the contaminated water produced from washing system of soils according to full-scale soil washing. After washing the TPH contaminated soils, the remaining concentrations of COD$_{Mn}$, SS, and n-hexane were analyzed for each compartment to estimate the treatment efficiencies of non-discharged system. Three times of sampling events were conducted for 4 different compartments (sediment tank, flocculation tank, oil/water separator, and process-water tank). In addition, soil washing efficiencies and concentrations of each parameter (COD$_{Mn}$, SS, and n-hexane) for process-water tank were analyzed for about 8 months. As results, the average efficiency of soil washing was high to have 95.9%, regardless of the condition of TPH contamination level for soils, as well as the concentrations of COD$_{Mn}$, SS, and n-hexane in the process-water tank were below the regulation limits of the Water Environmental Conserveation Act. Accordingly, the full-scale washing treatment system in this study could make the washing water 100% recycled which lead the system to be environmentally-friendly and economical.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.3-12
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• 2018

The objective of this study was to evaluate the radius of influence of effluent of water treatment system developed for the purpose of improvement of reservoir water quality using fluorescent dye (Rhodamine-WT) tracer experiment and 3-D numerical model. The tracer experiment was carried out in a medium-sized agricultural reservoir with a storage capacity of $227,000m^3$ and an average depth of 1.6 m. A guideline with a total length of 160 m was installed at intervals of 10 m in the horizontal direction from the discharge part, and a Rhodamine measurement sensor (YSI 6130, measurement range $0-200{\mu}g/L$) was used to measure concentration changes in time, distance, and depth. Experimental design was established in advance through Jet theory and the diffusion process was simulated using ELCOM, a three dimensional hydraulic dynamics model. As a result of the study, the direct effect radius of the jet emitted from the applied water treatment system was about 50-70 m, and the radius of physical effect by the advection diffusion was judged to be 100-120 m. The numerical simulations of effluent advection-diffusion of the water treatment system using ELCOM showed very similar results to those of the impact radius analysis using the tracer experiment and jet flow empirical equations. The results provide valuable information on the spatial extent of the water quality improvement devices installed in the reservoir and the facility layout design.