• 한국물환경학회지
• /
• 제25권4호
• /
• pp.553-559
• /
• 2009

Currently, small scale sewage works are getting increase in Chung Nam Province and it is strongly required for those plants to get the information of optimized procedures and technologies. Most processes for sewage works in Korea were designed for large scale plants, so many difficulties are observed in small scale sewage works. This study was conducted to evaluate the propriety of O&M and construction cost for sewage treatment plants in Chung Nam Province. The treatment results and process stability of 32 public sewage treatment plants were also investigated. It is expected to provide optimum O&M and construction cost for future small scale sewage works and improving projects of existing plants by these results. Pollution problems caused by small scale plants are usually restricted to small areas; however, in view of the high cost per unit population, treatment requirements and alternatives have to be studied carefully. In comparison to larger plants, more pronounced and different boundary conditions such as unstable influent load, per capita costs and a large variety of feasible treatment and disposal systems were considered.

• 수도
• /
• 제24권5호통권86호
• /
• pp.16-28
• /
• 1997

As sewerage works has become one of the major public works in Korea, the employment of advanced and more appropriate sewerage technology has become essential to improve the efficiency of sewerage works. During last 10 years, the Korean Government has made tremendous amount of investment on sewerage works so that treatment plants in 58 cities have treatment capacity which is equivalent to 52.8% of total daily sewage generation in Korea. This remarkable development, however, has heavily depended on one technology, the conventional activated sludge process as more than 95% of the existing plants employ this process, Recently, the Korean Government and local authorities have plans to introduce more appropriate sewage treatment technologies and research and development in this area has become very active. To encourage employing new and appropriate technologies, however, the proper technology evaluation and verification program for new process is needed. The public sector should play a key role in this program since the sewerage works is one of the major public works. In this paper, the technology evaluation and verification programs related with sewerage facilities in the US and Japan are briefly reviewed. The Innovatived and Alternative Technology programs which was operated by US EPA until recently and Environmental Technology Verification(ETV) program which was commenced in 1995 are introduced. The technology verification programs operated in Japan and also in Korea are also reviewed in this paper to propose a future direction for development of the appropriate evaluation and verification system.

• 상하수도학회지
• /
• 제32권6호
• /
• pp.535-550
• /
• 2018

Total organic carbon (TOC) will replace chemical oxygen demand ($COD_{Mn}$) as an effluent water quality standard in public sewage treatment works (PSTWs) from 2021 in Korea. To ensure effective control of TOC in the effluent, investigation was carried out into TOC levels and sewage treatment operation factors in five target PSTWs using anaerobic-anoxic-aerobic ($A_2O$) processes, media, membrane, and sequencing batch reactor (SBR) technologies. TOC removal efficiencies appeared to be 93-96% on average. As a fraction of TOC, biodegradable dissolved organic carbon (BDOC) was reduced from 64% in the influent to 9% in the effluent in these PSTWs. During the investigation, biological treatment processes were applied flexibly for operation factors such as HRT, SRT, MLSS, F/M ratios and BOD volume loads, based on the influent characteristics and design conditions. As a result, we suggest efficient operating conditions in PSTWs by evaluating relationships between TOC removal and operation factors.

• 상하수도학회지
• /
• 제30권6호
• /
• pp.673-682
• /
• 2016

In this study, we investigated influent and effluent water pollutants in 53 Public Sewage Treatment Works (PSTWs) where industrial wastewater or landfill leachate is combined four times for two years from 2014 to 2015. Also, we analyzed the characteristics of heavy metals and volatile organic carbons at influent and effluent of these PSTWs caused by sewage treatment combined with industrial wastewater or landfill leachate. As a result, six heavy metals such as barium, copper, iron, manganese, nickel and zinc, and four volatile organic carbons (VOCs) including phenols, di(2-)ethylhexyl phthalate (DEHP), formaldehyde and toluene were observed above detection limits in most of PSTWs. Also, it was revealed that six heavy metals such as hexavalent chromium, mercury, cadmium, chromium, nickel and selenium, and four VOCs including 1,1-dichloroethylene, vinyl chloride, naphthalene, and epichlorohydrin were observed more frequently according to precipitation. As a result of reviewing the monitoring data on "Water Quality Monitoring Networks" in lower watersheds of PSTWs, both heavy metals and VOCs were below detection limits, indicating that the effluent water had little influence on the watershed. Nevertheless for the better management of influent and effluent pollutants in PSTWs, it is necessary to establish the advanced management plans for water pollutants in PSTWs, which include a list of priority substances management, monitoring plans, and guidelines for industrial wastewater and landfill leachate combined in PSTWs.

• 상하수도학회지
• /
• 제28권6호
• /
• pp.657-668
• /
• 2014

Under Korea's Enforcement Decree of the Framework Act on Environmental Policy amended in 2013, total organic carbon (TOC) is newly added as water quality parameter to assess organic pollution in water and aquatic ecosystem. To meet the TOC requirement and improve quality of effluent discharged into public watershed, it is also necessary to develop standards for TOC in effluent from public sewage treatment works (PSTWs). In this study, we reviewed the characteristics and removal efficiency of TOC in influent and effluent of PSTWs. The study found that phosphorus treatment process removed not only soluble phosphorus but also a portion of TOC remaining after the secondary treatment process. TOC concentration in effluent from PSTWs operated in tandem with industrial wastewater treatment work was higher due to influx of insoluble substances from the industrial wastewater treatment work. In order to lay a foundation for the management of TOC from PSTWs, it is necessary to carry out research on TOC from different perspectives. For example, studies on the generation mechanism of TOC and the impact of TOC on drinking water resources, assessment of effluent qualities through monitoring, and development of measures to control TOC for the preservation of aquatic ecosystem are needed.

• 상하수도학회지
• /
• 제29권4호
• /
• pp.493-502
• /
• 2015

In accordance with the Watershed Sewer System Maintenance Plan enforced on February 2, 2013, the different compliance concentration of effluent limit be applied to effluent discharged from public sewage treatment works(PSTWs) in each watershed on the basis of water quality thereof. With the introduction of watershed sewer system, it is necessary to set the compliance concentration of effluent limit for PSTWs situated in the watershed, by region and PSTW size, to achieve water quality criteria for regional watersheds or target water quality under TMDL program. Watershed Environmental Agencies establish the Watershed Sewer System Maintenance Plan and set the compliance concentrations of effluent limit for PSTWs under the plan. The agencies plan to apply tougher effluent BOD concentration limits in Class I to IV areas. Effluent BOD concentration limits will be toughened from 5~10 mg/L to 3 mg/L in class II~III areas, from 10mg/L to 5mg/L in class IV areas. Uniform application of effluent BOD concentration limits to PSTWs in the watershed sewer system need to be complemented considering type of sewage treatment technology employed and watershed characteristics. Therefore, this study presents method to determine the compliance concentration of effluent limit from PSTWs in the watershed.

• 수도
• /
• 제24권5호통권86호
• /
• pp.5-15
• /
• 1997

This year the Ministry of Environment(MOE) made a fifth amendment to the Sewerage Act, which was enacted in August 1966. The first objective of this amendment is to introduce small public sewerage system that is designed to treat wastewater produced in rural areas. Before small public sewerage system was introduced to the Act through this amendment, only urban areas were covered by public sewerage system. Because small sewerage system was introduced, wastewater generated in urban areas as well as rural areas can now be treated by public sewage treatment plants. In addition to this, some authorities on sewerage affairs were moved from the MOE to local governments by this amendment in order to enhance the power and responsibility of local governments in relation to sewerage affairs. Also, this amendment enabled local governments to entrust the authority to establish and manage sewage treatment plants to private companies, and enabled the MOE to organize an advisory committee on sewerage to review economic and technical aspects ofsewage treatment plants. This amendment went into effect September 8, 1997.

• 상하수도학회지
• /
• 제30권4호
• /
• pp.427-440
• /
• 2016

Various kinds of processes are used in the Public Sewage Treatment Works(PSTWs) in order to achieve water quality criteria and TMDL in the watershed. The performance of the existing processes at PSTWs depends on influent characteristics, effluent quality target, amount of sludge production, power cost and other factors. In present, the Selection Guideline for the Available Treatment Process of PSTWs is used for a process decision in the country. But there are some problems regarding redundancy of assessment factors and complexity of assessment procedure in the guideline. In this study, we did a test application of AHP for process selection of PSTWs, which propose is to simplify assessment factors such as pollutant removal amount, sludge generation, electricity consumption, stability of operation, convenience of maintenance, easiness of existing process application, installation cost, and operating cost concerning of environmental factors, technical factors and economical factors. According to the study, the PSTWs selection procedure guideline can be improved using application of AHP method.

• 환경영향평가
• /
• 제24권4호
• /
• pp.386-395
• /
• 2015

유역의 수질환경기준(중권역 목표기준) 또는 수질오염총량관리 목표수질을 달성하기 위하여 유역내 지역별 시설규모별 하수처리장에 대한 방류수 수질 준수농도(안)을 설정하는 것이 필요하다. 공공하수처리시설에서 하수처리기술은 혐기-무산소-호기 하수처리법에서부터 다양한 처리기술이 적용되고 있으며, 운영관리에 따라 효율의 차이가 나는 등 다양한 요인에 따라 처리효율이 달라질 수 있다. 또한 처리효율뿐만 아니라 전력 등 에너지 소요비용도 고려하여 각 유역환경 조건에 맞는 적합한 처리기술을 적용하는 것이 필요하다. 본 연구에서는 유역하수도정비계획 수립 시 공공하수처리시설에 적용하는데 필요한 최적처리기술을 평가하기 위해 미국과 유럽의 산업계 배출수 처리시설에 대한 최적처리기술 평가 방법을 검토하여 우리나라 공공하수처리시설의 운영관리에 적합한 최적처리기술 평가지침의 평가항목을 제시하였다.

• 환경영향평가
• /
• 제23권5호
• /
• pp.406-416
• /
• 2014

2011년말 저갈수기 북한강수계에서 수돗물 이취미 발생의 한 원인으로 의암호에서 조류 발생에 영양염류의 과다와 기상요인에 의한 것으로 보고 있으며, 특히 춘천지역의 생활하수에서 기인하는 영양염류를 중심으로 춘천시 공공하수처리시설의 방류수에서 배출하는 영양염류의 기여율 및 의암호 조류 발생과의 관계를 살펴보고 그 영향을 분석하고자 하였다. 의암호 수체 내 영양염류가 부영양화 수준으로 이미 존재하고 있고, 겨울철임에도 체류시간, 수온 등 환경요인은 조류 성장에 적합한 여건을 갖추고 있다. 의암호 수계에서 인처리시설 도입으로 하수처리장의 총인 부하량은 약 43% 저감하였고, 의암호 조류 농도(Chlorophyll-a)는 약 7% 정도 개선되었다. 반면, 인처리시설 도입에 따른 하수처리장의 질소 처리효율에는 거의 변화가 없는 것으로 나타났다. 이러한 문제를 좀더 효율적으로 해결하기 위해서는 의암호 상류지역에 대한 유역관리 대책을 수립하는것이 필요하며, 춘천지역 하수처리장의 질소 처리를 위한 운영 관리 개선 방안을 마련하는 것이 필요하다고 판단되었다.