• 한국관개배수논문집
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• 제8권2호
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• pp.105-107
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• 2001

• 환경위생공학
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• 제23권4호
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• pp.55-64
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• 2008

In this study, the management and improvement of public small-scale sewage treatment facilities was investigated. In order to improve the effective management of the operation of small-scale sewage treatment facilities, treatment methods and the problems associated with sewage treatment were carefully addressed based on the data and literature. The investigation results showed that sewer pipes in rural areas should be repaired to prevent sewage from leaking and small-scale operations should be required to have effective management for pollutant loads less than 50%. Also, new methods should be developed for low concentrations of sewage. A law associated with FRP treatment facilities should be established and local governments need to supervise these operations to avoid insufficient and faulty construction. It is recommended that new facilities are built with advanced treatment techniques when the old facility can not comply with nitrogen and phosphorous discharge limits. Moreover, the study shows that nutrient and coliform treatment efficiency improves when abandoned facilities are renovated with the installation of nitrification/denitrification and disinfection processes or another advanced process.

• Environmental Engineering Research
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• 제24권2호
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• pp.202-210
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• 2019

In order to maximize the utilization of sewage sludge, a waste from wastewater treatment facility, the residual sewage sludge generated after lipid and carbohydrate extraction for biodiesel and bioethanol production was used to produce bio-oil by pyrolysis. Thermogravimetric analysis showed that sludge pyrolysis mainly occurred between 200 and $550^{\circ}C$ (with peaks formed around 337.0 and $379.3^{\circ}C$) with the decomposition of the main components (carbohydrate, lipid, and protein). Bio-oil was produced using a micro-tubing reactor, and its yield (wt%, g-bio-oil/g-residual sewage sludge) increased with an increase in the reaction temperature and time. The maximum bio-oil yield of 33.3% was obtained after pyrolysis at $390^{\circ}C$ for 5 min, where the largest amount of energy was introduced into the reactor to break the bonds of organic compounds in the sludge. The main components of bio-oil were found to be trans-2-pentenoic acid and 2-methyl-2-pentenoic acid with the highest selectivity of 28.4% and 12.3%, respectively. The kinetic rate constants indicated that the predominant reaction pathway was sewage sludge to bio-oil ($0.1054min^{-1}$), and subsequently to gas ($0.0541min^{-1}$), rather than the direct conversion of sewage sludge to gas ($0.0318min^{-1}$).

• 한국방재안전학회논문집
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• 제12권3호
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• pp.35-49
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• 2019

현재 한국 내 공공하수처리시설은 2018년 현재 600개 이상 운영 되고 있으며 하수종말처리시설은 법적으로 유입수량이 일일 500톤 이상 설계되어 운영되는 처리시설을 말한다. 마을 하수도는 50톤 이상 500톤 미만 유입되는 소규모 하수처리시설을 의미한다. 그러나 설계유입수량과 수질이 유사한 처리시설은 거의 없다. 이러한 현실은 하수관로의 노후화로 인한 빗물의 유입, 지하수의 침입과 하수관로에 폐수의 무단 투입 등으로 설계유입수량과 수질이 실제 현실과 많이 다른 것은 어쩔 수 없는 현실이다. 본 연구에서는 국내 많은 지역 하수관로 기술진단을 실시한 것 중 대표적 사례 2개소의 하수관로를 선정하여 청천시와 강우시 시간대별 유량 및 BOD 수질분석, 침입수 유량 및 비율 산정을 통해 하수처리시설의 적절한 운영과 하수관로와 그 부속 시설의 노후화 진단평가를 위한 기초자료로 활용하고자 하며, 일일 500톤 이상 공공하수처리시설 유입수 분석을 청천시 주1회 24시간 동안 시간대별 채수 및 분석, 우천시 강우영향일 고려하여 동일시간대 채수 및 분석을 주기적으로 실시하는 것을 제안한다.

• 한국농공학회논문집
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• 제47권3호
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• pp.69-76
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• 2005

An Absorbent Biofilter System (ABS) combined with the recirculation process was investigated for the feasible application in additional removing of organics (BOD, SS) as well as nutrients (TN, TP) from small Community wastewater in Korea. Polyurethane biofilter media with high porosity and large surface area were /used for the aerobic system. A part of treated wastewater was recirculated into the anoxic septic tank to promote removal of nutrients. The concentrations of BOD and SS of treated wastewater satisfied the regulations for small on-site wastewater treatment facility (10 mg/L) during the overall experimental period. The effluent concentrations of BOD and SS were decreased with enhancement of removal efficiencies of 95.7 and $96.7\%$. The nitrogen and phosphorus removal efficiencies by the recirculation increased to $52.9\%\;and\;43.2\%$ in average during the overall experimental period, respectively. With the improvement, these values were increased as much as additional 42 and $18\%$ compared with those of non-recirculation. The rates of nitrification and denitrification were enhanced showing $65\~77\%\;and\;42\~92\%$, respectively. The described process modification is a low cost and effective method of enhancing nitrogen and phosphorus removal, especially on existing systems without changing major design components of a treatment facility.

• Nuclear Engineering and Technology
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• 제50권8호
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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.

• 한국습지학회지
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• 제25권2호
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• pp.91-98
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• 2023

공사 중 발생되는 일부 콘크리트 폐수는 작업자, 관리자, 사용자가 인지하지 못하는 비점오염원의 형태로 우수/오수관를 통해 유입되어 관리가 쉽지 않고 콘크리트 철거시 물과 결합되어 나오는 건설오니들은 일시적으로 소량 유출된다. 이러한 특성 때문에 건설오니는 관리가 되지 않는 상태로 비점오염원의 형태로 하천 및 우수/오수관에 유입되고 있는 실정이다. 본 연구는 도로상 기설치된 콘크리트 옹벽 철거공법에 D.W.S공법(Diamond Wire Saw)을 적용하였고, 이로 인해 발생된 콘크리트 오폐수를 이동식 오수처리 시설을 통해 물리/화학적 처리를 실시하고 제거효율 및 유출수의 폐수배출 허용기준에 만족하는지를 검토하였다. 이에 공사중 이동식 오수처리 시설을 통해 물리/화학적 처리로 BOD 73.5%, SS 89.1%제거를 통한 공사중 오폐수의 유출수 농도 기준을 만족하고자 한다. 또한 공사진행시 이동식 오수처리 시설을 통한 물리화학적 처리 및 공사중 발생되는 오폐수 처리에 대한 환경보전비 산정의 적정성 및 경제성 분석에 대해 검토하고자 한다.

• 한국측량학회지
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• 제24권1호
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• pp.73-78
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• 2006

청주시는 수질오염 방지와 주변 환경보존을 위하여 하수도시설의 체계적인 파악, 효과적인 유지관리, 기존 하수도시설의 개선 등을 목적으로 하수도정비기본계획을 수립하여 시행하고 있다. 지난 5년간의 통계자료를 보면 신설 사업은 매년 전체 시설연장의 약 6%, 개보수 사업은 약 1.5% 정도의 공사가 이루어지고 있는 실정이다. 본 연구는 하수도공사관리시스템을 개발하여 매년 많은 공사가 이루어지고 있는 하수도 공사의 각종 자료관리와 공사비관리, 설계도면 및 사진영상 관리, 공사이력 관리 등 하수도시설을 효율적 관리할 수 있도록 하므로써 하수도 공사의 효용성 및 신뢰성, 그리고 대민 서비스 향상 등을 이루도록 하였다.

• 한국환경과학회지
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• 제18권6호
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• pp.603-608
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• 2009

Activated sludge sewage treatment processes are difficult to be controlled because of their complex and nonlinear behaviour, however, the control of the dissolved oxygen level in the reactors plays an important role in the operation of the facility. For this reason, this study is designed to present a system which accurately measures DO, MLSS, pH and ORP in the aeration tank to alleviate situations above and provide the automatization of a sewage treatment plant (STP) using new DO control system. The automatic control systems must be guaranteed the accuracy. Therefore, the proposed automatic DO control system in this study could be commercial applications in the aeration tanks by means of operating cost analysis and user-friendly for operation and maintenance. We could get accurate data from the lab tank which has water quality checker because there was no vortex and air bubble during the measurement process. Improvement of confidence in the lab tank enabled effective and automatic operation of sewage treatment plants so that operation costs and manpower could be saved. If this result is put in place in every sewage treatment plant nationwide for practical purposes, it is estimated to cost 18.5 million dollars in installing the lab tank and to save 9.8 million dollars in management cost a year, except for cost saved by automation.

• 한국물환경학회지
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• 제23권5호
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• pp.756-760
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• 2007

Most of the sewage treatment plants in Korea are being operated by using the conventional activated sludge process. Recently, as the water criteria have been strict with regard to such main culprits of eutrophication, the existing sewage treatment plants are obliged to upgrade their treatment technology to meet the criteria. Under such circumstances, this study was aimed at analyzing the conditions of an existing sewage treatment plants in Korea, and thereupon, test its treatment performance for the actual sewage water by operating a pilot plant. When the pilot plant was operated with the NPR process at the capacity of $30m^3/day$, the average contents of BOD, $COD_{Mn}$, SS, T-N and T-P in the effluents were 7.0 mg/L, 9.7 mg/L, 5.1 mg/L, 8.0 mg/L and 0.23 mg/L, respectively, which were very stable in general. Accordingly, if the NPR process used for this pilot plant to upgrade the treatment technology for the sewage treatment plat could be adopted, the effluent water quality criteria effective beginning from 2008 would be met.