• Journal of Korean Society of Water and Wastewater
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• v.12 no.1
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• pp.108-114
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• 1998

Experiments on an upgraded RBC were conducted to investigate its removal efficiencies of $NH_4-N$, coliform group and coliphage in the municipal wastewater treatment. A bench scale RBC, made of stainless mesh media with 5mm high surface protrusions, was fed with settled municipal wastewater containing 13-25mg/l of $NH_4-N$ and 40-75mg/l of TOC at the hydraulic loading of $89l/m^2.d$ and $60l/m^2.d$. It was found that the nitrification effectively occured at bulk liquid TOC concentration of less 10mg/l. The coliform group and coliphage were more than 98% and 90%, respectively.

• Journal of Industrial Technology
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• v.36
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• pp.83-88
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• 2016

In this study, a series of experiment was carried to improve dewaterability of the sludge produced in a treatment plant, located in Hongcheon, Gangwondo, which has been treating municipal wastewater and livestock wastewater. Optimum sludge mixing ratio and the amount of sludge conditioner were determined. As sludge conditioners, alum and ferric salt were selected and tested. For the measurement of sludge dewaterability, capillary suction time(CST) and the specific resistance were measured, The specific resistance was detemined by running a series of Buchner Funnel Test. Mixing the two sludges at a 50:50 ratio with the addition of 20 mL alum gave the best results in terms of dewaterability. The moisture content decreased by 2% at this condition.

• International Journal of High-Rise Buildings
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• v.6 no.3
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• pp.271-277
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• 2017

Safety, livability, and efficiency are the three prominent problems of tall buildings, which are also the severe challenges to designers. We proposed the idea of building the sky town to solve these problems, which can be summarized in two sentences, one is tall building multi-storised, and another one is vertical facilities municipal-infrastructurised. The tall building can be horizontally cut into several multi-storey buildings by some large platforms. The platform extends a certain width to block the fire from spreading. Tall buildings are connected together as a group. One of them is a traffic core, which is used for vertical transportation and MEP. It connects to traffic center such as metro, while most of the other tall buildings' cores can be very much released, so as to achieve maximum efficiency of floor usable area and to give good traffic organization. By combining traffic core, platforms, and multi-storey buildings' inner traffic, a transportation network is formed. Finally, we refer to the design of Raffles City Chongqing to make a sketch of sky town.

• Journal of environmental and Sanitary engineering
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• v.14 no.1
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• pp.70-79
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• 1999

A questionary survey was conducted to investigate citizen's attitude to treatment facilities of municipal solid waste in Miryang during 8. June of 1998 and 22 June of 1988. Collection effiencies was 86.7%, as 260 individuals of the 300 individuals. The survey showed that 43.0% of answers recognized seriousness of problem of the waste treatment and 33.1% of respondents concerned about recycle of organic waste. 40.8% of total answers said that they most hated landfill site among waste treatment facilities, and most citizens wanted as much distant as possible from waste treatment facilities. It was investigated that the greater part of respondents wanted the greatest compensation. About 58% of respondents was opposed to complete waste treatment facilities. 36.2$ among answers wanted establishment of waste treatment facilities in an industrial complex or an industrial area. The majority of respondents was willing to increase recycle rate and recognized seriousness of landfill site security. The majority of citizens do not trust environmental administration of Miryang City and they think that democracy and open of administration need for overcome MINBY.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.528-535
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• 2000

Solid waste incinerator is expected to become widely used in Korea. The incineration of solid waste produces large quantities of bottom and fly ash, which has been disposed of primary by landfilling. However, as landfills become undesirable other disposal method are being sought. In this study, an experimental research is conducted to determine the geotechnical properties of municipal solid waste incinerator fly ash(MSWIF) in order to evaluate the feasibility of using the material for geotechnical applications. Basic pysicochemical characteristics, moisture-density relationship, strength, permeability, and leaching characteristics are examined. The results of MSWIF are compared to other MSWIF and coal fly ash which are used as construction material. In addition, the effectiveness of cement stabilization is investigated using various mix ratios. The result of stabilized mixes are compared to the unstabilized material. Cement stabilization is found to be very effective in reducing permeability, increasing strength, and immobilizing heavy metals. This results indicate that MSWIF with cement stabilization may be used effectively for geotechnical application.

• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.27-35
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• 2006

This study was carried out to investigate the removal of nitrogen and phosphorus in municipal sewage depending on existence of biological coated media in BCM reactor. The reactor with biological coated media is the process combining $A_2/O$ process. The removal efficiencies for $COD_{Mn},\; BOD_5,\;SS$, T-N and T-P were $78\%,\;90.5\%,\;92.3\%,\;61.9\%,\;60.2\%$, respectively. The specific nitrification rate$(mgNO_3-N/gMLSS{\cdot}d)$ of Contact aeration basin was 52.2 and the specific denitrification rate$(mgNO_3N/gMLSS{\cdot}d)$ in anoxic basin was 95.1. Also, phosphorus release$(mgPO_4-P/gMLSS{\cdot}d)$ in Anaerobic basin was 71.8 and Phosphorus uptake$(mgPO_4-P/gMLSS{\cdot}d)$ in contact aeration was 27.1.

• Journal of environmental and Sanitary engineering
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• v.10 no.3
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• pp.29-34
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• 1995

This study was on the characteristics and heating values analysis of municipal solid wastes according to the volume- rate garbage collection system in Busan. Each waste sample was analyzed to obtain physical composition, proximate analysis, heating value, chemical composition. And the heating value were compared with those of the past waste collection system. The average physical composition of A.P.T. area was food waste 54.0~65.7% , while that of common residence was food waste 57.9~61.2% . The density of solid waste were largely different for site and the highest densities of waste was $399.6kg/m^{3}$ from Market. The low heating value of waste from residence site was 996.9kca1/kg~1, 238.1 kcal/kg which was lower than 1, 000kcal/kg~1, 800kca1/kg of the past wastes. These difference was mainly due to the difference of moisture content and the amount of vegetables.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.3
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• pp.231-239
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• 2000

Water treatment processes produce sludges resulting from water clarification. Sludge production amount increases each year and its treatment and disposal is growing to social problems according to water demand increase. Water treatment plant sludges can be modified to soil cover in sanitary landfill site through the lime treatment. Compression strength of $1.0kg/cm^2$ or more is recommended for soil cover material in municipal landfilling site. Compression and shear strength properties of modified sludges showed material property improvement applicable for soil cover alternatives. Solidification effect of the modified sludge was observed through the scanning electron microscope. Extraction tests for hazardous components in sludges revealed that extraction levels of cadmium, copper, and lead were below the regulated criteria. When adding 10% calcium hydroxide to water treatment plant sludges, the modified sludges can reach material properties for cover soil after 28 days solidification reaction.

• Journal of the Korean Society for Railway
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• v.8 no.4
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• pp.385-390
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• 2005

In Korea, about 60 percent of railroad accidents are associated with highway-rail grade crossings numbering 1,657 nationwide, which the railroad system operates. To reduce the number of accidents, the authority formulated methods to improve or eliminate grade crossings. However, the improvement programs have made progress in slow time due to the institute inertia and the lack of funds from the municipal government, which shares the cost of improvement of grade crossings. Thus, this study analyses the institute system of the grade crossings, proposes modifications, and suggests financing methods to improve the grade crossings and to lower the number of accidents. Presently, the grade crossings safety perspective is directed towards road conditions and so a new perspective, which includes safety from the train perspective and to finance in review of railway system and to allocate the cost between the central government and the municipal governments. is discussed.

• Journal of Environmental Health Sciences
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• v.27 no.3
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• pp.81-85
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• 2001

The aim of this study was to evaluate on the removal effect of total nitrogen and posphorus in municipal wastewater by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process using influent as a Carbon Source. CNR(Cilium Nutrient Romoval) is the process combining $A^2$/O process with cilium media of H2L corporation. The removal efficiencies for BOD$_{5}$, T-N and T-P were 81.1%, 61.4%, 61.4%, respectively. The removal efficiency of nitrogen and posphorus were low by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process.s.