• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.37-43
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• 2009

With the economic development of Korea, sewage treatment facilities and waste food treatment facilities have been steadily increased. These facilities have positive effects such as the conservation of the water resources quality and waste food recycling while they also affect the neighborhood life with severe odor problems. Therefore, it was first collected sludge samples from 5 sewage treatment facilities and 5 waste food treatment facilities where the amounts of waste produced from above sites are relatively immense in Busan and estimate the $H_2S$ emission rates. Then it was selected 1 sample which has the highest emission rate of $H_2S$. Using flux chamber and GC/FPD analyses, it was tried to quantify the emitted amount of sulfonic gas concentration under anoxic condition. The sludge sample obtained from Noksan sewage treatment facility has the highest emission rate of $H_2S$. This sample contained 156.18 mg/kg $H_2S$. The odor compounds were analyzed using GC/FPD and the concentrations were converted to odor quotient. Among odor compounds the ratio of $CH_3SH$ (methylmercaptan) for the total odor quotient was 47.3% and considered to be the main odor compound in the sample.

• Journal of Korean Society on Water Environment
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• v.34 no.2
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• pp.216-225
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• 2018

Over the past 40 years, the public sector has continued to invest in the sewage treatment plants (STPs) in Korea. Currently, the domestic sewage treatment rate is over 90% with the enhancement of operating efficiency of the STPs, and water quality of major rivers has been continuously improved. However, COD and T-N indicators are stagnating or slightly worsening, and though advanced treatment facilities are installed in most of the STPs, there is a limit to the removal of nutrients. Since there are a lot of water pollution sources in the vicinity of the watershed because of high population density in Korea, it is essential to reduce the inflow of the nutrients in order to prevent the eutrophication of the rivers and lakes. While the effluent T-P standard in STPs has greatly strengthened since 2012, which results in the considerable investment for the improvement of treatment process in STPs for the last few years, it is necessary to strengthen the T-N standards, as the effluent standard of T-N has been maintained at 20 mg/L since 2002. In this study, based on the analysis of the effluent T-N standard status of major industrialized countries, and the domestic nitrogen load in public waters, the option of appropriate T-N standard level is reviewed, and the required investment costs and the effect of strengthening the standard are estimated.

• Journal of Environmental Impact Assessment
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• v.23 no.4
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• pp.296-314
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• 2014

In recent years, Ministry of Environment (MOE) has been implementing a phased strengthening of the effluent standards for sewage treatment plants. In this regard, a comprehensive system should be developed to help check the appropriateness of such standards by specifying the grounds for standard-setting and investigating the current operation of sewage treatment plants clearly. It is necessary to establish a new standard-setting system for the effluent that is in a closer connection with the environmental criteria and rating systems. In the United States, the federal government provides guidelines on the least provisions and requirements for the Publicly Owned Treatment Works (POTWs). Local governments set the same or stricter guidelines that reflect the characteristics of each state. In Japan, the sewage treatment plants are subject to both the effluent standards and the discharge acceptable limits to pubic waters under the sewerage law. Specific requirements and limits are set in accordance with local government regulations. The European Union imposes sewage treatment plants with different provisions for effluent standards, depending on the sensitivity of public waters to eutrophication. The effluent standards for sewage treatment plants are classified by pollutant loads discharged to receiving waters. MOE also needs to introduce systems for setting new parameter standards on a POTW effluent by applying statistical means and treatment efficiencies or optimal treatment techniques, as seen in the cases of the US National Pollutant Discharge Elimination System (NPDES) or the EU Integrated Pollution Prevention and Control (IPPC).

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.121-128
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• 2006

In this study, the existing MSS facilities were investigated for examination the the present condition of MSS treatment system. There are 23 MSS treatment facilities across the country, In total facilities, 6 facilities have economical problems, and 2 facilities were stopped the operation of establishments for technical problems, and most facilities are suffering from environmental problems, for example, odor and waste water. These kinds of problems play a role as obstacle to treat MSS efficiently. Accordingly, to reform current MSS treatment system, a few adequate measures are required. First a Guide line, which is a manual for establishment of MSS treatment facilities efficiently and environmentally friendly, must be offered from the agencies concerned of the Ministry of Environment to local governments. Second, to devise a plan for MSS treatment, Ministry of Environment and all local governments should devise a long-range policy synthetically not fragmentarily and temporarily.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.486-491
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• 2017

The water discharged from sewage treatment plants has been considered to be useless, due to itslack of economic utility for small hydro power generation. Considering that most sewage treatment facilities have a water head of less than 2 meters and their flow rate is constant, it is necessary to develop a small hydro power generation device capable of maintaining stable power generation and efficiency. This paper presents the development of anintegrated small hydro power generation system and presents its performance evaluation and results. Then, the economics and use of the system for practical applications are suggested. As a result, it is foundthat the generator efficiency is 92%, the electric energy produced is 10kWh and the economic efficiency, as described by the B/C ratio,is 1.0 or more. Particularly, if the operating level of the generation device is maintained at 80% or more of the rated power, it is possible to secure its economic efficiency and, after 23 years, the investment cost will bereturned. The integrated hydro power generation device is expected to have a positive effect not only in terms of the water discharged from the sewage treatment plant, but also in terms of facilities capable of securing similar flow characteristics.

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1355-1363
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• 2018

Many radionuclides exist in normal environment and artificial radionuclides also can be detected. The radionuclides ($^{131}I$) are widely used for labeling compounds and radiation therapy. In Korea, the radionuclide ($^{131}I$) is produced at the Radioisotope Production Facility (RIPF) at the Korea Atomic Energy Research Institute in Daejeon. The residents around the RIPF assume that $^{131}I$ detected in environmental samples is produced from RIPF. To ensure the safety of the residents, the radioactive concentration of $^{131}I$ near the RIPF was investigated by monitoring environmental samples along the Gap River. The selected geographical places are near the nuclear installation, another possible location for $^{131}I$ detection, and downstream of the Gap River. The first selected places are the "front gate of KAERI", and the "Donghwa bridge". The second selected place is the sewage treatment plant. Therefore, the Wonchon bridge is selected for the upstream of the plant and the sewage treatment plant is selected for the downstream of the plant. The last selected places are the downstream where the two paths converged, which is Yongshin bridge (in front of the cogeneration plant). In these places, environmental samples, including sediment, fish, surface water, and aquatic plants, were collected. In this study, the radioactive iodine ($^{131}I$) detection along the Gap River will be investigated.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.5
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• pp.557-564
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• 2009

A combined sewer system can quickly drain both storm water and sewage, improve the living environment and resolve flood measures. A combined sewer system is much superior to separate sewer system in reduction of the non-point source pollutant load. However, during rainfall. it is impossible in time, space and economic terms to cope with the entire volume of storm water. A sewage system that exceeds the capacity of the sewer facilities drain into the river mixed with storm-water. In addition, high concentration of CSOs by first-flush increase pollution load and reduce treatment efficiency in sewage treatment plant. The aim of this study was to develope a processing unit for the removal of high CSOs concentrations in relation to water quality during rainfall events in a combined sewer. The most suitable operational design for processing facilities under various conditions was also determined. With a designed discharge of 19.89 m/min, the removal efficiency was good, without excessive overflow, but it was less effective in relation to underflow, and decreased with decreasing particle size and specific gravity. It was necessary to lessen radius of vortex separator for increasing inlet velocity in optimum range for efficient performance, and removal efficiency was considered to high because of rotation increases through enlargement of comparing height of vortex separator in diameter. By distribution of influent particle size, the actual turbulent flow and experimental results was a little different from the theoretical removal efficiency due to turbulent effect in device.

• Journal of Environmental Impact Assessment
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• v.11 no.1
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• pp.25-36
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• 2002

The purpose of this study is to assess the environmental carrying capacity of Chongju City for the environmental management and the urban growth management. The urban environmental carrying capacity assessment of the city by the index of ecological footprint(EF), shows that the ecosystem of the city has been overloaded and most of the deficiencies has come from outside of the city. The EF index, the area of land per capita required for production and consumption in the city, was 1.731 ha per capita in 1989 and 1.901 ha per capita in 1999. On the other side, the ecologically productive land is 0.0175 ha per capita. It means that every citizen owes 1.88 ha per capita to the ecosystem in 1999. The land consumption of the city has increased by 0.1705 ha per capita during the last 10 years. The capacity of infrastructure and the service supply estimated by the Onishi model does not exceed the demand of the city in 1999. But the rapidly increasing population and fast urban growth need the expansion of the capacity. The water supply capacity of the city appears to be sufficient in 1999, but the water supply demand will increase in the future. The capacity of sewage treatment facilities seems to be sufficient, but the higher level of sewage treatment facilities should be adopted for the improvement of water quality as the generation of sewage will increase and its characteristics will also make the wastewater treatment difficult. Due to the decrease of solid waste generated, the land fill capacity for solid waste disposal is not insufficient at present, but the capacity will be saturated in the near future. Therefore, the scientific management system of solid wastes should be introduced. The air quality of the city meets both the national air quality standard and WHO recommendation standard, but the strong regulation and control of automobile emission gas such as CO, $CO_2$, NOx and HC is required for clean air.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.3
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• pp.177-190
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• 2019

The purpose of this study was to analyze the effects of sewerage facilities through I/I analysis by rainfall by selecting areas where storm overflow diverging chamber is remained due to the non-maintenance drainage equipment when the sewerage system was reconstructed as a separate sewer system. Research has shown that wet weather flow(WWF) increased from 106.2% to 154.8% compared to dry weather flow(DWF) in intercepting sewers, and that the WWF increased from 122.4% to 257.6% in comparison to DWF in storm overflow diverging chamber. As a result, owing to storm overflow diverging chamber of partially separate sewer system with untreated tributary of sewage treatment plant, rainfall-derived infiltration/inflow(RDII) has been analyzed 2.7 times higher than the areas without storm overflow diverging chamber. Meanwhile, infiltration quantity of this study area was relatively higher than that of other study areas. Therefore, it is necessary to reduce infiltration quantity through sewer pipe maintenance nearby river. Drainage equipment maintenance should be performed not to operate storm overflow diverging chamber in order to handle the appropriate sewage treatment plant capacity for rainfall because it is also expected that RDII due to rain will occur after maintenance. In conclusion, it is necessary to recognize aRDII(allowance of rainfall-derived infiltration/inflow) and to be reflected it on sewage treatment plant capacity because aRDII can occur even after maintenance to the complete separate sewer system.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.8
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• pp.884-891
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• 2007