• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.1
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• pp.57-64
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• 2019

We investigated influence of connected influent on the treatability of a wastewater treatment plant (WWTP), recently accepting effluent from a sludge carbonization facility. Based upon the pollutant loading rates (kg/d) of each connected influent, food waste leachate and livestock wastewater contributed to high BOD and COD loadings, while sludge carbonization facility effluent certainly contributed to T-N and $NH_3-N$ loadings. The nitrification rate in aerobic tank decreased to 55% with the carbonization facility effluent entering to the WWTP, while it was 89% with no carbonization facility effluent entering. The sludge carbonization facility effluent may need to be pretreated to reduce T-N and $NH_3-N$ loadings before entering to the WWTP for further treatment.

• Resources Recycling
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• v.11 no.4
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• pp.17-26
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• 2002

As it is not allowed to landfill sludge from 2001 by the act of waste management, new systems of treating sludge are necessary. Life Cycle Assessment, LCA, is a method for evaluating systems in the aspect of environment and also can apply to decision making tools for policy making. The objective of this study is to assess 3 alternatives of landfill: incineration, composting, solidification by applying LCA. This study is done with operation data from incinerator in Kuri, composting facility in Nanjido, solidification facility in Kimpo and electricity and transport data of Korea in 1998 are used. The results of the LCA is that the composting system is most environmental-friendly and the solidification system is least environmental-friendly.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.3
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• pp.195-202
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• 2006

Deterioration of sewer concrete is representative that biochemical corrosion according to the $H_2S$ has growth by inhabit sulfur-oxidzing bacteria because of special environment in sewer. But in case of domestic, fundamentally, sulfur-oxidzing bacteria could moderate development of repair material method is need because of corrosion prevent method is inconsideration with carry out to improve project. In this paper, after development of spread type antibiotic with antibio-metal, antibacterial performance about sulfur-oxidzing bacteria of antibiotic and tested to estimate fundamental properties of bonding strength, abrasion contents, contents of water absorption, contents of air permeability, carbonation depth, chloride ion penetration depth and chemical resistance of spread with antibiotic restorative mortar.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.181-186
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• 1998

The effects of sewage treatment on characteristics of sludge as a composting material were investigated for a year during the initial operation at the full-scale Chunan sewage treatment plant. Due to the shortage of design capacity of belt press, a sludge dewatering unit, non-volatile solids were recirculating and concentrating in the treatment plant, resulting in an increase of MLSS and a decrease in F/M ratio at the activated sludge system. Special attention is required for long term operations since the increase of non-volatile solids in the plant would deteriorates the treatment efficiency. The sewage sludge of the Chunan sewage treatment plant showed 79.5% of water content, 11.6% of organic content, and C/N ratio of 6.1, and contained As 1.8 mg/kg, Cd 27 mg/kg, Hg <0.1 mg/kg, Pb 54 mg/kg, T-Cr 370 mg/kg, and Cu 1,100mg/kg of heavy metals. In order to be used as raw material for optimum composting, the sewage sludge requires bulking agents for moistrure/porosity control and a carbon source for adjusting C/N ratio. However, the sewage sludge is not adequate as a soil conditioner after composing due to a high content of heavy metals. If the sewage sludge has to he used as a soil conditioner after composting, it as required to identify and remove tire industrial wastewater portions in tire influent of the plant since heavy metals in the influent were mostly concentrated in dewatered sludge.

• Journal of Korea Water Resources Association
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• v.55 no.5
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• pp.357-370
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• 2022

This study aims to analyze the differences in performance according to various operation methods (direct management, public consignment, and private agency) of public sewage treatment facilities and derive the most efficient and high level of sewage treatment services to the public based on the research results. To this end, economic performance indicators (sewage treatment cost, sewerage rate) and social performance indicators (water quality, number of civil complaints) were selected, and cross-sectional analysis and longitudinal analysis were used to verify the difference between the averages of three or more groups through one-way ANOVA. As a result of the analysis, cross-sectional analysis, there was no difference in economic performance dimension according to the operating method, but in terms of social performance dimension, it was found that there was a difference according to the operating method. In the case of water quality indicators, the results were superior to those directly managed by public consignment and private agencies in the number of civil complaints. In the longitudinal analysis examining the improvement of performance indicators, there was no significant difference by operation method in most performance indicators. In order to improve the efficiency of public services and improve the service level, various approaches suitable for the characteristics of each service are required in addition to the logic of public consignment or introduction of private agency. In the future, when local governments promote public consignment or private agency, it is necessary to understand and promote the nature of the service, the specificity of each local government, and the needs of service users.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.3
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• pp.68-75
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• 2014

Soluble nitrogen produced from anaerobic digestor is able to have a strong influence on the effluent water quality of municipal wastewater treatment plants during a winter season in particular. The modeling results using the GPS-X simulation software shows that the soluble nitrogen concentration generated from the anaerobic digestor is 214.1 mg/L in the return flow and 6.2 mg/L in the inflow of the primary settler higher than those in nonexistence of the anaerobic digestor, respectively. In the case of using a separation process (flotation thickener) in order to treat the return flow from the sludge treatment system, the soluble nitrogen concentration in the effluent from the separation process and in the inflow of the primary setter could be 6.0 mg/L higher and 0.7 mg/L lower than those of nonexistence of the process, respectively. The modeling results propose the need of the equipments to be able to remove the soluble nitrogen ($NH_3-N$) produced from the digestor in the improvement projects of anaerobic digestor in municipal wastewater treatment plants.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1285-1289
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• 2008

최근 도시지역의 확대와 고밀도화에 따른 도시근교의 산림, 논밭, 녹지 등이 감소하고, 도로나 건축물 등의 증가로 인해 불투수 유역이 확대되어, 원래 그 토지가 유지하고 있던 보수 유수 기능이 현저히 저하되고 있다. 그 결과 강우 시 표면 유출량의 증가와 유출시간의 단축이 현저하게 되고, 도시하천이나 하수도 유하 능력을 넘는 홍수가 자주 발생하고 있다. 또한 빗물 침투량이 줄어들어, 용천수 고갈, 하천의 평상시 유량감소가 나타나게 된다. 이러한 문제를 해결하기 위해 최근 유역 내에 저류시설과 침투시설 등 유출저감효과를 기대할 수 있는 여러 가지 시설의 활용방안이 꾸준히 모색되고 있다. 본 연구에서는 이러한 내배수 홍수분담시설 중 저류와 침투의 기능을 모두 갖추고 있는 쇄석공극저류시설의 효율성을 분석하였다. 또한 쇄석저류지와 규모와 형태가 유사한 우수저류지와의 비교를 통해 상대적인 효율성을 평가하였다. 그 결과 두 시설이 같은 규모를 가진다고 가정할 때, 우수저류지가 쇄석저류지에 비하여 월등한 유출저감효과를 보이는 것으로 파악되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.499-499
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• 2023

최근 컴퓨터 성능 향상과 새로운 머신러닝 알고리즘 개발됨에 따라, 각 분야별 연구자들이 이를 활용한 연구를 다양하게 수행하고 있으며, 하수처리시설의 경우에는 막대한 양의 운영자료가 축척됨에 따라 머신러닝을 활용한 다양한 연구가 가속화 되고 있다. 기존 하수처리장의 물리학적 모델은 적용된 영향 인자에 여러 가지 가정이 고려되어 모델 정확도가 부정확해지는 경향이 있었으며, 이러한 문제점을 보완하기 위해 하수처리장의 수집된 운영자료 및 머신러닝 기반의 예측 모델을 활용하여 예측 모델 정확도를 향상하는 선행 연구들이 진행되고 있다. A 하수처리장의 부지 내에 설치된 센서를 통하여 운영자료가 중앙제어실 서버에 실시간으로 저장되는 자료를 활용하여 NN (Neural Network), SVM (Support Vector Machine), RF (Random Forest) 등과 같은 다양한 머신러닝 모델을 적용하였고, 하수처리장 운영자료를 적용할 경우 어느 모델이 가장 높은 성능이 나타나는지 인사이트를 도출하고자 하였다. 금회 연구는 A 하수처리장을 대상으로 여러 머신러닝 기반 예측 모델을 개발하고, 각 모델의 예측정확도를 서로 평가함으로써, 머신러닝 모델 최적화를 수행할 수 있었다. 이번 연구에서 도출된 결과를 활용하여 하수처리장 예측 모델 최적화를 진행할 경우, 향후 비교적 짧은 시간에 하수처리장 머신러닝 기반 예측 모델 개발이 가능하다는 점에 의의가 있다.

• Journal of Industrial Technology
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• v.19
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• pp.279-285
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• 1999

An integrated sewer management system was developed for the analysis of sewer flow and for optimal operation of sewer works using ArcView and SWMM. SWMM and ArcView were dynamically linked together using Avenue in order to construct user-friendly management system. The developed system was applied to a residential area in Choonchun city to verify its utilities. All the relevant field data were analyzed on the basis of developed system, and the modeling of sewer flow was implemented using RUNOFF, EXTRAN, TRANSPORT in SWMM. This system is now in the process of connection to the management system of watershed and surface environment in order to develope an integrated environmental management system. Futhermore, this system will be a critical part of overall control system of sewer works including sewer line and wastewater treatment plant. As this system can provide comprehensive prediction of flow and pollution profiles, it could serve as a tool not only for optimal management, but also for decision support system to examine the efficiency of planning and implementation of sewer projects.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.2
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• pp.39-44
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• 2023

This study was conducted to analyze problems related to non-water-soluble sanitary products during the treatment of water regeneration centers in E.T.F. and S.T.F. at a time when the demand and supply of non-water-soluble sanitary products are increasing. As a result, the improvement plan of the W.R.C. should focus on pretreatment facilities. When replacing facilities in the future, various dust removers suitable for the facility's reality will be installed in the pretreatment of S.T.F., and it is proposed to link a bar-racks screen with a comprehensive treatment device or install a comprehensive treatment device for impurities alone in the pretreatment of E.T.F.. In addition, a microscreen screen must be installed on the front end of the excretory treatment unit. to separate non-water-soluble materials, and it is necessary to secure a maintenance space for the excretory treatment unit.