• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.16-20
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• 2003

Nitrogen(N) and phosphorus(P) in surface streams mainly lead to euthrophication. It aggravates water quality and consequently increases the purification costs. As a resolution of water contamination caused by household drainage through irrigation route by 70% of the 1,300 community residents in Eum-Am Myun, Seo-San city, was implemented biological self-purification method by growing Oenanthe Javanica along the polluted water tunnel. The contaminated water was efficiently purified after passing the dropwort field; DO conc. of effluent water was increased 8.3∼61.9% after through the drop wort field. HRT of experiment system was changed 0.05∼1.50/day. 50% of BOD was eliminated at the range above 12 mg/l of Influent BOD conc. Also, 50% of COD was eliminated at the range above 30 mg/l of Influent COD conc. Finnally, the influent T-N loading at range below 1.5 g/m$^3$/d reduced 50% of Influent T-N conc., and so did influent T-P loading at the range below 0.03 g/m$^3$/dwas reduced 50% of Influent T-P conc.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.58-73
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• 1995

Membrane filtration is a promising technology for efficient solid/liquid separation in water purification. In FY 1991, the Ministry of Health and Welfare, Japanese Government launched a comprehensive research project "MAC 21" for development of membrane technology and its application to public water supply. The project was conducted by the Water Purification Process Association (WPPA), under the supervision of the Institute of Public Health. By the research project from FY 1991 to FY 1993, we confirmed that microfiltration (MF)/ultrafiltration (UF) technology was applicable to water purification and MF/UF was a effective method for the removal of such contaminants as particulate matter and coliforms. The Guideline Committee organized under the Technical Committee prepared a the guidelines on application of membrane system to small-scale public water supplies, based on the results as written above. The guidelines has been published in Dec., 1994 by WPPA.4 by WPPA.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.5
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• pp.329-339
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• 2019

Recently, the advancement of information and communication technology(ICT) is expanding the connectivity through Internet of Things(IoT), and the media of connection is also expanding from wire/cable transmission to broadband wireless communication, which has significantly improved mobility. This hyperconnectivity has become a key element of the fourth industrial revolution, whereas the supervisory control network of purification plants in korea is operated as a communication network separated from the outside, thereby lagging in terms of connectivity. This is considered the best way to ensure security, and thus there is hardly any consideration of establishing alternatives to operate an efficient and stable communication network. Moreover, security for management of a commercialized communication network and network management solution may be accompanied by immense costs, making it more difficult to make new attempts. Therefore, to improve the conditions for the current supervisory control network of purification plants, this study developed a industrial security L2 switch that supports modbus TCP(Transmission Control Protocol) communication and encryption function of the transmission section. As a result, the communication security performance improved significantly, and the cost for implementing the network management system using Historical Trend and information of HMI(Human Machine Interface) could be reduced by approximately KRW 200 million. The results of this study may be applied to systems for gas, electricity and social safety nets that are infrastructure communication networks that are similar to purification plants.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.6
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• pp.644-651
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• 1997

In the water purification plant, chemicals are injected for quick purification of raw water. It is clear that the amount of chemicals intrinsically depends on water quality such as turbidity, temperature, pH and alkalinity. However, the process of chemical reaction to improve water quality (e.g., turbidity) by chemicals is not yet fully clarified nor quantified. The feedback signal in the process of coagulant dosage, which should be measured (through the sensor of the plant) to compute the appropriate amount of chemicals, is also not available. Most traditional methods focus on judging the conditions of purifying reaction and determine the amounts of chemicals through manual operation of field experts using Jar-test data. In this paper, a systematic control strategy is proposed to derive the optimum dosage of coagulant, PAC(Polymerized Aluminium Chloride), using Jar-test results. A neural network model is developed for coagulant dosing and purifying process by means of six input variables (turbidity, temperature, pH, alkalinity of raw water, PAC feed rate, turbidity in flocculation) and one output variable, while considering the relationships to the reaction of coagulation and flocculation. The model is utilized to derive the optimum coagulant dosage (in the sense of minimizing turbidity of water in flocculator). The ability of the proposed control scheme validated through the field test has proved to be of considerable practical value.

• Journal of Ocean Engineering and Technology
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• v.20 no.4 s.71
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• pp.58-63
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• 2006

When the costal zone surrounded by a breakwater has a narrow vertical opening, currents in the vicinity of a narrow entrance can result in a jet flow, coinciding with the tide. Such a Tidal-Jet Generator(TJG) can change the water mass distribution and transport processes in the domain of influence of the jet. Also, it can decrease the residual time of them. In the present study, the water purification utilizing tidal jets in the coastal zone over constant bathymetry are estimated numerically, using a finite-difference numerical scheme, named the NS-MAC-TIDE method, which isbased on the fully 3D Navier-stokes(NS) equations. The shear velocity near the inlet of the TJG are predicted from the flow field simulation, and are assessed qualitatively with the development of scouring or sediment that is caused by the change of diffusion or sweeping flowup from the seabed of sediment particles. Finally, through solving a transport equation of concentration, the residual time related on mass transport processes and the flushing mechanism for water purification are investigated.

• 수도
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• v.22 no.3 s.73
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• pp.120-131
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• 1995

• Journal of the Korean Ceramic Society
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• v.54 no.2
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• pp.114-120
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• 2017

In underdeveloped countries, many people suffer from water shortage due to the absence of water supply service. Although water purifiers have provided support in such situations, it is not easy to maintain water filters without a continuous supply of consumable filters. To obtain a sustainable drinking water source, appropriate technology of water treatment is necessary. Herein, a low cost water purification system was developed using natural raw materials. A non-electric water treatment system was developed using filtration through an Onggi filter, which is a type of Korean traditional earthenware with a microporous surface. The porosity and flux of the prepared Onggi filter were 29.06% and 31.63 LMH, respectively. After purification of water with total dissolved solids of 10.4 mg/L and turbidity of 100 NTU, the total dissolved solids and turbidity of the water treated using the Onggi filter decreased by 12% and 99.8%, respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.4
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• pp.87-95
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• 2000

A vegetation purification system was applied to improve water quality of Masan Reservoir in Korea, which was composed of constructed wetlands in series. Five different kinds of macrophytes were planted in each wetland. The system was operated with the condition of low concentrations and high hydraulic loadings. Removal efficiencies(%) of chemical oxygen demand(COD) , total nitrogen(T-N) and total phosphorus(T-P) in this system were 9.0, 12.8, 20.1% , respectively. and removal rates(g/$m^2$/d) were 1.9(COD), 0.34(T-N) and 0.05(T-P) . Comparing this system with other wetlands operated at low hydraulic loadings, average removal efficiencies were low but removal rates were relatively high. Accordingly, this system could be applied to imporve reservoir water quality, because removal rates are more important than removal efficiencies in case of reservoir water quality improvement . However, the removal efficiencies and rates of this system are less than those of the hydroponic biofilter method which is a kind of a constructed wetland and utilize root zones of emergent macrophytes for trapping pollutants. Therefore, it is recommended that this system should be modified to utilize root zones of emergent macrophytes enough to improve reservoir water quality more efficiently.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.75-81
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• 2011

This study performed field examinations of a zero discharge and reuse system developed by Hong and Choi(2009). The system installed one of villages located in Hyoryeong-myeon, Gunwee-gun for the experiments. The zero discharge and reuse system consists of anoxic, FES (Ferrous Electricity System), Oxic, Cralifier processes for water treatments. The main feature of the system is to remove phosphorous by using Fe-ionizing module within the FES process. The water purification performances of the system were evaluated, while any defects for using the system were investigated through the field monitoring. It was found that the removal capacities of T-P, T-N, and BOD of the system meet the required water quality with outstanding performance from T-P by obtaining the results of over 90 % removal rates. The efficiency of T-P removal rate of the system found to be greatly influenced by whether using an automatic washing system to the Fe-ionizing module and conducting replacement of iron plate within a proper period.

• Journal of Korean Society of societal Security
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• v.3 no.2
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• pp.47-55
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• 2010

It was developing of portable hybrid water purification system for clean water production in the disaster area. because there are no way to supply a drinking water to the victims of calamity. currently, the government has been supplying bottled water to victims. but it is a limit to the reserves. It is composed of a filter, a feed pump, a solar-cell, a controller, and a case and is possible supplying a drinking water not to limit time and a place. Field test was carried out to developed portable water purification system and the purified water was satisfied a criterion for a drinking water.