• Journal of the Korea Institute of Building Construction
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• v.6 no.2 s.20
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• pp.65-72
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• 2006

The amount of water demand at large buildings is increasing with the concentration of population to city and a rise in the standard of living in the city area. In this reason the Water Shortage is expected and a problem of water pollution by the city sewerage is increasing. One of method of saving city water demand and city sewer is applying recycling water system witch make used water reuse by purification of water. The application of recycling water system witch make used performed since the application of Lotte World Complex. But the popularization of this system is not activated because of cost problem and feeling of people to the water recycled. So in this study, provide application method for recycling water system by propose the estimation method of optimal sizing of recycling water system.

• KIEAE Journal
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• v.2 no.3
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• pp.25-32
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• 2002

The demand for water in a city area has enormously increased due to the concentration of population and improvement of the living quality. In this reason, the water shortage and the pollution by city sewage seem to be inevitable. For saving city water and meeting the demands from the city, the wastewater recycling system can be used, which makes used water reusable by a certain purification process. In Korea, the application of a wastewater recycling system to the buildings has continuously been adopted since its first appearance at the Lotte World Complex in 1989. However, the system has not been in fashion because of its high cost and users' negative attitude against recycled water. A research based on literature review and a case study for a recycling water system was carried out and an estimation and evaluation model was proposed. The results from the present study suggest that the optimal size of the recycling water system should be designed within 30-40% of total water demand in a building. Also, it was found that economic benefits could be expected within the payback period of 5.3 years by securing the operation rate over 70%.

• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.123-131
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• 2014

Whole amount of waste water, approximately 921.6 liter, for cleaning a ready mixed concrete truck should be used to produce concrete as a mixing water or cleaning water. Recycling water for concrete mixing contains solids, which cause decrease in slump, air and compressive strengths, so it may influence on poor concrete quality. Therefore, it has been maintained to use recycling water with less than 3 percent of solids. Since no evaluation system has been constructed to directly reflect on variability of recycling water from ready mixed concrete plants, it is necessary to develop "Automatic recycling solid measuring system" for quality controls in real time. In this research, sensors measuring waste water concentration in ultrasonic and inductance methods were developed, and automatic system using the sensors were established. The accuracy of measurement sensors developed for recycling water based on various conditions of concentration was proved, and application limits were evaluated. Also, concentration of recycling water using sensors developed from ready mixed concrete plant was measured, and curing method verified the accuracy of the sensors. Moreover, measurement sensors for recycling water in various locations were installed to evaluate the effects on measuring method and spots. The automatic measuring system for recycling water concentration, which is developed in the research, will contribute to improve concrete quality safety through reliable solids maintenance.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.2
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• pp.32-40
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• 2001

It is desirable to reduce the amounts of fresh water and reuse the recycled water in papermaking process. In an attempt to improve the efficiency of recycling water refining treatment and to enhance the productivity of OCC recycling mill, up flow anaerobic sludge blanket(UASB) reactor was developed and introduced to Korea recently. In order to maximize the operating efficiency and minimize the adverse side effects it is imperative to estimate and evaluate the total effects of new system, UASB on the whole OCC recycling process. This study was carried out with a view to investigate the effects of the high temperature and alkalinity of process water on the quality ad productivity of testliner of OCC recycling mill which is equipped with UASB reactor and almost closed. Another object of this study was searching for the best available use of UASB treated process water. The results were as follows; Reuse of UASB treated water characterized with high temp and alkalinity was useful to improve the strength and drainage properties of recycled OCC owing to its good points of promoting OCC disintegration and reducing the calcium hardness of process water. However, it might not be avoidable to induce the increase of dissolved solids in process water in accordance with direct introducing of UASB treated water into the former stage of OCC stock preparation. So it would be advisable to adopt the UASB treated water in the stage of clean, screened OCC stock.

• Journal of environmental and Sanitary engineering
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• v.23 no.4
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• pp.13-21
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• 2008

With the rise in membrane applications, residuals management has become a growing challenge for membrane system. The primary residuals of MF/UF (microfiltration/ultrafiltration) system results from the wastes generated during backwashing. Many regulatory agencies, utilities, and water process engineers are unfamiliar with the characteristics and methods for treatment and disposal of membrane residuals. Therefore, this study was performed to investigate the backwash residuals water quality from the pressurized system with and without pre-coagulation, and to suggest approaches for the backwash residuals treatment. Pressurized MF system was installed at Guui water intake pumping station and operated with raw water taken from the Han River. We compared performances with and without the recycling backwash residuals at flux conditions, 50 LMH and 90 LMH with and without pre-treatment (coagulation). Based on the results, recycling of backwash residuals in pressurized system with pre-coagulation showed applicability of backwash residuals managements. Moreover, the recovery rate also increased up to over 99%.

• The Plant Pathology Journal
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• v.19 no.6
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• pp.280-283
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• 2003

A soybean-sprout rot epidemic occurred in a mass production soybean sprout factory in 2000 and 2001 in Korea, which caused up to 20% production loss. Among the causal pathogenic bacteria and fungi, Pythium deliense was found to be the dominant pathogen of severe root and hypocotyls rot, particularly in recirculating water system. An average of 90% of the isolated fungi from the rotted sprout on potato dextrose agar were Pythium sp. The fungal density of Pythium in the sampled water was monitored in the recycled water system for 1 year using a selective medium (com meal agar with Pimaricin, 10 mg； Rifampicin, 10 mg； and Ampicillin, 100 mg per 1 liter). The drained water from the soybean-sprout cultivation always had a certain amount of fungus in it. The removal of Pythium from the recycling water system must be thorough, safe, and environment friendly. However, the pathogen in the water was easily found even after ozone and chlorine treatments, which were devised on the recycling system for the removal of microorganisms. 5-$\mu\textrm{m}$ pore size filter was applied and was able to successfully control the disease. As the sprout industry increasingly shifts into mass production, the demand for water will increase continuously. Recycling water for sprout production is eco-friendly. However, a process must be devised to be able to first decompose organic matters before Pythium zoospores are filtered.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.4
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• pp.1-7
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• 1999

This study was carried out to simulate the change of various properties of recycled water when zero-discharge system was applied to a KOCC recycling process. contaminants such as chemical oxygen demand, anionic trash, and calcium hardness were gradually increased in the process water as the recycling was repeated . Especially, the increase of anionic trash and COD were closely related to the starch derived from corrugating adhesive in KOCC. Four kinds of water were compared in the preparation of handsheet to evaluate the performance of retention program. Waters used in this work were laboratory tab water, process water from Dong-II mill and the same one treated by UASB process, and closed white water prepared by KRICT. The result revealed that one the major factors fro reducing a retention power was the anioni trash accumulated in the recycled water.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.581-590
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• 2013

A research was performed for zero discharge system of waste water which is produced from energy recovery process of waste and biomass. Leachate and all kinds of waste water should be separated and integrated into three categories in addition to converting existing leachate treatment facility into waste water treatment facility as well as introducing a management system of reverse osmosis membrane facility and bioreactor landfill. Following these conditions to better water treatment process, it was likely to produce over 3,000 tons of low-grade recycling water and 2,000 tons of high-grade recycling water per day when zero discharge system of waste water is applied starting from 2016. Economical efficiency was also surveyed in total treatment fee. Present system costs 18,129 million won per year, and suggested zero discharge system would cost 15,789 million won per year.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1232-1237
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• 2009

Recently, we often encounter water shortage problem due to drought during dry season. Although we have built dams and expanded our tap water system greatly to meet the increasing demand of water, this approach has its inherent limitation including environmental destruction in the course of the dam construction. Therefore, this paper is aimed to analyze the water recycling models developed in other countries and modify them to fit into our system. Also the water recycling system in Busan municipal area was analyzed to propose an alternative method for reusing the recycled water from wastewater treatment area.

• Journal of Environmental Science International
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• v.12 no.9
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• pp.911-919
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• 2003

When the city water was heated for the optimum use of unused energy, the energy flows and losses were calculated and evaluated to improve the value of heated water systems at dwelling side. To obtain this purpose, it was simulated on heat flows under two conditions like with heat pumps or not and calculated the energy sayings. Furthermore, recycling water system was suggested for enhancing the value of heated water system. From this results, the energy flows without heat pumps showed that it was 3-4 percents of heat losses from pipes, 62 percents of energy savings from hot water uses and 34 percents of unutilized heat. When the heated water system adopt the recycling water system at dwelling side, it was improved 12 percents of total energy sayings.