• 상하수도학회지
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• 제31권5호
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• pp.431-440
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• 2017

The small-scale sewage treatement system with $A^2/O$ process was applied to evaluate applicability for Mongolian sewage, It was designed to have 10 m3/d flowrate and installed in Ulaanbaatar, Mongolia. During over 6month operation BOD, COD, TN, TP removal efficiency were measured and operation condition was optimized. In addition, MLSS concentration its internal circulation rate and DO were adjusted properly. BOD, COD showed average 88 perecent of removal and TN and TP achieved 81 percent and 88 percent removal efficency, respectively. Maxium influent concentration of BOD, COD, TN and TP was 214 mg/L, 300 mg/L, 24.3 mg/L and 5 mg/L respectively, which were decreased to 4.1 mg/L, 5.6 mg/L, 1.3 mg/L and 0.15 mg/L by the test system. This study show possibility tham small-scale sewage treatment system could be a useful system for scattered sewage wastewater treatment.

• 상하수도학회지
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• 제19권4호
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• pp.462-472
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• 2005

This study was carried out to suggest the plans for installation of rural sewage treatment facilities through the analysis of these facilities installed in Chungchongnam-do Province. About 5% of all installation was carried out by the department of wastewater and related environment problems and the other case was carried out by the department of construction or residence. In wastewater caused by 250 and 300 persons, facilities capacity do not exceed about $50m^3/d$, caused by 2,500 and 3,000 persons, $500m^3/d$. Advanced sewage treatment process were first needed in the discharge area where affected the water environment greatly. However, in carrying out the water quality pollutant of the total amount management system in the other areas, they should be driven only over the scale of pollutant quota object facilities standard. Rural sewage must be included in the special accounts according to the regulations of local government, and sewage treatment cost should be collected to manage. Installation type uses integrating joint treatment method in case the distance among villages is short or one treatment facility independently.

• 한국환경농학회지
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• 제19권5호
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• pp.426-432
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• 2000

Field experiment was performed from August 1996 to December 1999 to examine the feasibility of constructed wetland system for sewage treatment in rural areas. A pilot system was installed in Konkuk University and the effluent of septic tank for school building was used as an influent to the wetland treatment basin. The system was composed of sand and reed, and operated continuously including winter time. Average removal rate of about 70% was observed for BOD, COD, and SS, about 50% for T-P, and about 25% for T-N. The reason for poor T-N removal might be due to high loading rate and short retention time. The system demonstrated satisfactory effluent concentration and stable performance in growing season. And it also worked adequately in wintertime even below $10^{\circ}C$ without freezing, and removal was still significant. The amount removed in BOD, COD, and SS was almost the same as in the growing season, and the amount removed in nutrients was about half of the one in growing season. Overall performance of the experimental system was compared with existing data base (NADB, 1994), and it was within the range of general system performance. As study period increased, removal rates for BOD, COD, SS, and T-P were consistently maintained and even enhanced, but removal rate for T-N decreased slightly. Wetland system was thought to be a feasible alternative for sewage treatment in rural area considering its low cost and low maintenance requirement. However, the effluent of the experimental wetland system often exceeded current effluent water quality standards, therefore, further treatment could be required if the effluent should be discharged to public waters. Wetland system of interest locates in rural area and is a part of rural ecosystem, therefore, ultimate disposal of reclaimed sewage for agricultural purpose or subsequent land treatment might be available and further research in this matter is recommended.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.1170-1177
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• 2006

We apply VRP(Vehicle Routing Problem) to sludge collection system in this study. Sewage stores of villages are located in each village around a multipurpose dam. Sludge which is produced in sewage store of village is transported from the sewage store of village to the sewage treatment plants by the special purpose vehicle such as the tank lorry. In this paper, we propose sludge collection strategies which allocate each sewage store of village to sewage treatment plants and decide the schedule of sludge collection in order to collect sludge efficiently. The strategies aim to decrease transportation cost with deciding proposed vehicle routing and scheduling the sludge collection. When we decide route of vehicles, we consider the collection time in sewage store of village, distance between sewage store of villages and vehicle information as average velocity of vehicle, operation time of vehicle driver. We also develop the SCMS(Sludge Collection Management System) based on windows system with real data which is used in certain circumstance. And we experiment to figure out vehicle route and transportation cost throughout changing input data.

• 환경위생공학
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• 제15권3호
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• pp.50-56
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• 2000

In this study, sewage were treated with operating Two-step Aeration System and conventional activated sludge process together in a condition. At the same HRT 8hr of Two-step Aeration System and Activated Sludge Process, BOD treatment efficiency of 1st sedimentation basin effluent 36.9% by Two-step Aeration system was 12.3% higher than 24.65 by Activated Sludge Process and the COD treatment efficiency 39.8% by two-step Aeration System was 11.6.3% higher than 28.2% by Activated Sludge Process. BOD and COD treatment efficiencies of 2nd sedimentation basin effluent were 88.1% and 85.6% Two-step Aeration System and were 83.8% and 82.3% Activated Sludge Process. In the first treatment, as BOD was relatively removed a lot, F/M ratio 0.17, $0.21{\cdot}BOD/kg{\cdot}MLSS.d$ was maintained by Activated Sludge Process. Therefore it was proved that organic matter treatment efficiency by Two-step Aeration System os Higher than by Activated Sludge Process in a aeration time 8hr. $NH_4^{+}-N$ treatment efficiencies were 55.5% by Two-step Aeration System and 39.75 by Activated sludge Process. $NO_3^{-}-N$ concentration in 2nd. sedimentation basin effluent were 3.33% by Two-step Aeration System and 2.36% by Activated Sludge Process. From this result, Two-step Aeration System was proved more advantageous treatment process for nitrification than Activated Sludge Process. The fluctuation range of BOD, COD and SS concentration in 2nd sedimentation basin effluent $16~33mg/{\ell}$, $15~23mg/{\ell}$ and $14~22mg/{\ell}$ by Two-step Aeration System was smaller than $16~57mg/{\ell}$, $15~25mg/{\ell}$ by Activated sludge Process. Overall the fluctuation range in 2nd sediment basin effluent by was smaller than by Activated Sludge Process. As a result, it is possible for this Two-step Aeration with no facility investment and a little of operation condition change in a conventional sewage treatment plant to get stability and nitrification of treatment water quality.

• 환경위생공학
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• 제21권3호
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• pp.27-36
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• 2006

For the last 20 years, China has transformed itself from a rural economy into an industrial giant, averaging over 8 % annual growth of GDP. Unfortunately, this rapid growth has taken a significant toll on its natural resource base as well, particularly water resources. These problems have been exacerbated by a low level of sewage treatment technology and by the operating and maintenance (O&M). In case of urban areas, most big cities in China have a well functioning sewage system comprised of sewers and sewage treatment plants (STPs). Nevertheless, the existing STPs are still not capable of properly treating the sewage, both quantitatively and qualitatively. The rural areas in China cover a large land, with two-third of the nation's population. The low educational and poor economic states make it hard to process self-protection and management. In the surveyed area in Henan, there was no STPs put into use as of 2004, and the sewer lines are not well organized. The big issue for the currently planned STPs is the collection system not included in the plans.

• 대한공간정보학회지
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• 제5권1호
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• pp.103-118
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• 1997

최근 하수처리업무는 도시인구의 증가 및 하수처리기준의 강화로 인해 대부분의 도시에서 하수처리 시설의 신설 및 증설문제가 대두되고 있다. 본 연구는 하수처리시설의 증설에 대비하여 중요시설의 유지관리에 필수적인 도형 및 속성정보의 효율적인 관리를 위한 자료관리 Library 개발하는데 목적이 있다. 본 연구에서는 하수처리장 유지관리에 필요한 도형 및 속성정보의 자료관리 Library를 개발하였으며, 청주시환경사업소를 대상으로 하수처리시설의 유지관리업무의 현황을 분석하고 데이터베이스 설계를 수행하여 이를 토대로 하수처리장 유지관리에 적합한 시스템을 개발하였다. 하수처리장 유지관리시스템은 도형정보와 속성정보를 조작하기 위한 기본기능과 하수처리 관련업무를 처리하기 위한 응용기능으로 나누어 개발하였으며, 본 연구를 통해 개발된 시스템이 하수처리장의 효율적인 유지관리에 기여할 수 있음을 알 수 있었다.

• 환경영향평가
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• 제23권4호
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• pp.296-314
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• 2014

우리나라의 공공하수처리시설 방류수 수질기준을 마련하는데 있어 기준설정 근거를 명확히 하는 것과 하수처리시설의 운영조사를 근거로 적정성 여부를 검토할 수 있는 종합적인 기준설정 체계를 마련할 필요가 있다. 미국은 연방정부가 POTW에 대한 최소한의 항목과 기준의 가이드라인을 제시하며, 지방정부는 국가 가이드라인과 동일하거나 주별 특성을 반영하여 보다 엄격한 가이드라인을 제시하도록 하고 있다. 일본의 경우 하수도법상 방류수 수질기준에서 하수처리시설 구조 기술상의 기준을 만족하여야 하고 방류수 수질기준과 공공수역으로의 배수기준을 동시에 적용하도록 하고 있으며 이에 대한 세부항목 및 기준은 지자체 조례로 규정하고 있다. 유럽의 경우 하수처리시설 방류수 수질기준은 공공수역에 대한 부영양화의 민감성에 따라 수질기준 항목을 차등하여 적용하고, 수계로 배출되는 오염물질 부하량에 따라 수질기준을 차등하여 적용하고 있다. 우리나라도 공공하수처리시설 방류수 수질기준 설정 시 미국 국가오염물질배출삭감제도 또는 유럽 통합환경관리제도에서와 같이 통계적 평균값 및 처리효율 또는 최적처리기술을 적용한 방류수 수질기준을 설정하는 체계를 도입하는 것이 필요하다.

• 한국농공학회지
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• 제45권7호
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• pp.70-82
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• 2003

A pilot study was performed from July 1998 to December 2002, including winter performance, to examine seasonal performance of a constructed wetland and subsequent pond system for treatment of sewage in small communities of Korea. Pond was operated as a intermittent-discharge pond during winter period, and continuous flow system during growing season; its effects was evaluated from December 2001 to April 2003. The subsurface flow (SSF) wetland was satisfactory for treating sewage with good removal efficiency even during the winter period. The wetland effluent concentrations of $BOD_5$ and TSS were often higher in winter than in the growing season, but this was explained by the higher loading rates, rather than lower removal efficiency. The relatively poor-quality wetland effluent was further polished during winter in the pond. The upper layer of the pond water column became remarkably clear immediately after ice melt. In the growing season, ponds could be operated as a continuous flow system to remove nutrients and pathogens, and the effluent of pond could be reused as a supplemental irrigation water without risk of infection by sewage-borne pathogens as well as causing adverse effect on growth and yield. Overall, the wetland system was found to be adequate for treating sewage with stable removal efficiency, and the intermittent-discharge pond was found to be effective for further polishing if necessary. Therefore, the combination of a wetland and subsequent pond system and reuse of effluent as crop irrigation water is recommended as a practical alternative to treat sewage in Korean small communities, and partial discharge of pond water in March is suggested.

• 한국산업융합학회 논문집
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• 제2권2호
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• pp.23-33
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• 1999

After studying several methods of the application a device of a treated sewage in anticipation of the future shortage of the duty of water, we could have some conclusion as the following : Advanced treatment systems arc essential prerequisites in reusing a treated sewage. And in a short term, the application of reusing a treated sewage should go first to new building areas near the sewage but for the long run, it should cover the whole area of Taegu, it is desirable that the pipe line networks which include dual water systems as well as water supply should be spread throughout the whole city. The city authorities have to make every effort to step up publicity activities on this plan to all the citizens and building owners to steadily carry out this project and encourage private constructors to participate with the help of SOC. And for the long run, it is desirable that the application of reusing a treated sewage should be obligatory.