• 한국물환경학회지
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• 제30권5호
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• pp.524-531
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• 2014

Korea has been trying to manage water quality of rivers and lakes in many ways. Ministry of Environment is making continuous efforts of operation control improvement such as strengthening effluent standards in sewage treatment plants and expanding Tele-Monitoring System (TMS). However, evaluation method for operations of sewage treatment plants and establishment system of effluent standards are inadequate. The objective of this study is to evaluate for operations of sewage treatment plants using statistics technique such as frequency analysis, percentile, normal distribution analysis. We used the effluent data (BOD, COD, SS) collected at 299 plants in 2012. The values were very low by comparison with standards. The Data followed a normal distribution. We think that distribution characteristics are closely related with effluent standards, especially T-P and BOD. Statistics technique attempted in this study can be used to evaluate for operations of sewage treatment plants and assess the appropriateness of effluent standards based on TBEL(Technology-based effluent limitation). And, this technique can be used to figure out the overall level of plants, the status of each plant and the favorable treatment process for each item (BOD, COD etc.). Data acquired through this method can be used to improve facilities and operation techniques and decide on a sewerage policy.

• 융합정보논문지
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• 제11권4호
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• pp.122-129
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• 2021

2021년부터 총유기탄소(TOC)가 국내 공공하수처리시설의 새로운 유기물질 기준 지표로 선정됨에 따라, 기존 유기물질 관리지표(DOC, BOD5, CODMn, CODCr)와의 상관성 분석을 통해 TOC의 적용 타당성 평가가 필요하다. 본 연구에서는 500개소 공공하수처리시설을 공정 및 시설용량에 따라 구분하여 유입 및 방류수에 대한 유기물질 관리지표간의 상관성 분석을 실시하였다. 다른 유기물질 관리 지표 대비 유입수와 방류수 내 화학적 산소요구량(CODMn)와 TOC간 농도비와 결정계수(R2)는 상대적으로 높았다. 유기물질 관리지표간의 상관성 결과는 새로이 기준으로 도입된 TOC와 관련된 다양한 연구 수행에 기초자료로 활용될 것으로 기대된다.

• 한국수자원학회논문집
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• 제55권5호
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• pp.357-370
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• 2022

본 연구는 공공하수처리시설의 다양한 운영방식(직영, 공공 위탁, 민간 대행)에 따른 성과의 차이를 분석하고 연구 결과를 토대로 국민에게 가장 효율적이고 높은 수준의 하수처리 서비스를 제공할 수 있는 운영방식과 개선방안을 도출하고자 하는 목적을 가진 연구이다. 이를 위해 경제적 성과지표(하수처리 비용, 하수도 요금)와 사회적 성과지표(수질, 민원 수)를 선정하여 횡단 분석(cross-section data)과 종단 분석(longitudinal analysis)의 방법으로 세 집단 이상의 평균 차이 검증을 일원분산분석(ANOVA)을 통해 실시하였다. 분석 결과 횡단 분석에서의 경제적 성과 차원에서는 운영방식에 따라 차이가 나타나지 않았으나, 사회적 성과 차원에서는 운영방식별로 차이가 나타나는 것을 알 수 있었다. 수질 지표의 경우 공공 위탁에서, 민원 발생 건수에서는 민간 대행에서 직영 대비 우수한 성과를 보이고 있었다. 종단 분석에서는 대부분 성과지표에서 운영방식별로 유의미한 차이가 나타나지 않았다. 따라서 공공서비스의 효율성 제고와 서비스 수준 제고를 위해서는 공공 위탁이나 민간 대행 도입 논리 외에 서비스별 특성에 맞는 다양한 접근이 요구된다고 하겠다. 아울러 향후 지자체가 하수도 위탁을 추진한다면 서비스의 성격과 지자체별 특수성, 서비스 이용자의 니즈 등을 잘 파악하여 추진하는 것이 필요하다.

• 한국물환경학회지
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• 제29권2호
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• pp.276-287
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• 2013

Domestic sewage contains increasingly more pharmaceuticals and personal care products (PPCPs), due to rising use of medicines, health supplement food and daily necessities. And various types of industrial wastewater from pollution sources in treatment areas could flow into the public sewerage treatment plants (PSTPs) in metropolitan areas. The conventional PSTPs are designed to treat suspended solids, biodegradable organics, nitrogen and phosphorous from residential and industrial areas and public facilities. However, toxic, conventional, and non-coventional pollutants from non-domestic sources that discharge into sewer system as well as domestic source with various chemicals could not be treated in the conventional PSTPs and discharged untreated to public basin. In this paper we aim to consider the establishment system of effluent standard of PSTPs in comparison with water quality standard of water environment and wastewater discharge regulation. And also we suggest the necessity of regulations on the pretreatment of industrial wastewater as part of efforts to improve water quality in sewerage systems and to protect public basin.

• 한국물환경학회지
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• 제34권2호
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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.

• 수도
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• 제24권5호통권86호
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• pp.29-44
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• 1997

Sewage sludge produced in Korea was 1,275,800 tons (dewatered sludge cake) per year in 1996, which is 3,495 tons per day, 0.303% of 11,526,100 tons per day of sewage treated in 79 sewage treatment plants. Sludge production has been and will be increasing in accordance with construction of new facilities for sewage treatment. Most of the sludge is currently disposed by landfill and ocean dumping, but it is becoming difficult to find suitable sites for landfill, particularly in big cities such as Seoul. In addition, rapid increase of landfill cost is anticipated in a near future. Current trend for sludge disposal in advanced countries is land application. Over the past 10 to 20 years in the United States, sludge management practices have changed significantly, moving from disposal to beneficial use. They use biosolid for utilization instead of sludge for disposal. Under the Clean Water Act of 1972, amended in 1987 by Congress, the U.S. EPA was required to develop regulations for the use and disposal of sewage sludge. The EPA assessed the potential for pollutants in sewage sludge to affect public health and the environment through a number of different routes of exposure. The Agency also assessed the potential risk to human health through contamination of drinking water sources or surface water when sludge is disposed on land. The Final Rules were signed by the EPA Administrator and were published (Federal Register, 1993). These rules state that sewage sludge shall not be applied to land if the concentration of any pollutant in the sludge exceeds the ceiling concentration. In addition, the cumulative loading rate for each pollutant shall not exceed the cumulative pollutant loading rate nor should the concentration of each pollutant in the sludge exceed the monthly average concentration for the pollutant. The annual pollutant loading rate generally applies to applications of sewage sludge on agricultural lands. The most popular beneficial use of sewage sludge is land application. The sludge has to be stabilized for appling to land. One of the stabilization process for sewage sludge is lime stabilization process. The stabilization process is consisted of the stabilizing process and the drying process. Stabilization reactor can be a drum type reactor in which a crossed mixer is equipped. The additive agents are a very reactive mixture of calcium oxide and others. The stabilized sludge is dried in sun drier or rotary kiln.

• 수도
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• 제24권5호통권86호
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• pp.16-28
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• 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.

• 대한환경공학회지
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• 제36권8호
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• pp.549-553
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• 2014

이상 강우 시 하수유입량과 슬러지 계면높이의 변화가 처리효율에 미치는 영향을 실제 처리장에 적용해서 실험한 결과, 유입량이 증가하고, 계면높이가 높아질수록 공공처리장 방류수 수질기준 항목인 $BOD_5$, $COD_{Mn}$, SS, T-N, T-P 처리효율이 감소하였다. 그중 SS는 강우 시 농도변화가 가장 심한 항목으로 0.5배(0.5 Q) 유입 시 슬러지 계면높이 0.5 m에서 74.2%, 1.0 m에서 76.4%, 1.5 m 70.2%, 2.0 m에서 60.7%로 계면높이를 1.0 m로 유지했을 때 처리효율이 가장 높았고, 1.0 Q 유입 시 0.5 m 71.7%, 1.0 m 71.9%, 1.5 m 46.4%, 2.0 m -38.0%로 나타났으며, 2.0 Q~2.0 m 이상과 3.0 Q~1.0 m 이상에서는 sludge rising 현상이 유발되어 공공수역에 악영향을 끼칠 수 있음을 알 수 있었다. 또한 계면높이를 0.5 m로 유지한다 할지라도 유입량이 증가하면 처리효율은 74.2%에서 17.3%로 감소하므로 강우 시 유입량 조절이 가장 중요하고, 계면높이를 1.0 m 이하로 유지하여 운영하여야 공공수역의 수질에 미치는 영향을 최소화 할 수 있다.

• 한국환경보건학회지
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• 제42권4호
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• pp.246-254
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• 2016

Objectives: This study evaluated the odor emission characteristics from fundamental environmental facilities at an industrial complex area in Daegu City. Methods: The odor samples were collected from May 2015 to January 2016 and were analyzed for specified offensive odor substances. The odor quotient and the odor contribution was calculated. Results: Ammonia was detected in all samples monitoring specified odor compounds, followed by hydrogen sulfide and acetaldehyde. According to contribution analysis, hydrogen sulfide shows the highest contribution in all facilities. At wastewater treatment plants A and B and sewage treatment plant F, it was followed by acetaldehyde. At wastewater treatment plant C, it was followed by imethyl sulfide. Conclusion: The major component of odor can be determined by evaluating the degree of contribution to the odor intensity rather than the concentration of the individual odor components. To increase the effectiveness of odor reduction, policies focused on materials with a high odor contribution are needed rather than focusing on high-concentration odor compounds.

• 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.