• 환경영향평가
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• 제14권5호
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• pp.337-346
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• 2005

Pollution load allocation can likely be much controversial, which is essential to formulate the total water pollution load management plan. Existing rules(or guidances) in Korea, can provide no specific criteria for load allocation. Therefore, this paper studied(comprehensively) possible standards how or why to choose any particular allocation method, which was applied in the Gwangju City's load allocation for the satisfaction of set water quality goal. This load allocation is basically focused on the load reduction of domestic wastewater rather than industrial wastewater, because the land-use is strictly regulated and larger sources of pollution are few in the Gwangju City. This paper recommends the city to increase the capacity of sewage treatment plants, promote sewerage maintenance, and set higher effluent standards.

• 상하수도학회지
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• 제29권2호
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• pp.223-231
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• 2015

District Metered Area (DMA) construction is one of the most cost effective alternatives for management of water loss (i.e., water leakage) and energy consumption (i.e., water pressure) in water distribution systems. Therefore, it's being implemented to numerous new and existing water distribution systems worldwide. However, due to the complexity of water distribution systems, especially large-scale and highly looped systems, it is still very difficult to define the optimal boundary of DMAs considering all the aspects of water distribution system management requirements. In this study, a DMA design methodology (or a DMA design model) was developed with Geographic Information Systems (GIS) and hydraulic distribution system model to determine the optimal DMA boundary.

• 상하수도학회지
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• 제22권6호
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• pp.665-672
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• 2008

It is necessary to implement the management plan for the production of safe and high quality drinking water from lake Paldang. To set up the plan, the water quality items such as BOD, T-P, SS and coliform were monitored for ten years, 1997~2006, and the influence of raw water quality on the drinking water treatment process and the treated water quality was also evaluated from 2004 to 2006. In conclusion, water quality items such as turbidity(SS), T-P(eutrophication), pathogens(fecal coliforms, enterovirus, reovirus, giardia, cryptosporidium), DOC(precursor of disinfection by-products), and micro-pollutants(phthalates, VOCs, heavy metals) are should be managed to get safe and high quality drinking water from lake Paldang.

• 상하수도학회지
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• 제23권5호
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• pp.565-572
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• 2009

Hydraulic modeling is widely used to simulate wastewater flow. The simulated models are used to prevent flood and many other problems associated with wastewater flow in planning or rehabilitating sewer systems. In this study, MAKESW (An engineer, South Korea), MOUSE (DHI, Denmark), and SWMM (XPSoftware, USA) are used to for hydraulic modeling of wastewater in C-city, South Korea and E-city, Iraq. These modeling tools produced different results. SWMM comparably overpredicted runoff and peak flow. In using SWMM, use of accurate data with a high confidential level, detail examination over the target basin surface, and the careful selection of a runoff model, which describes Korea's unique hydraulic characteristics are recommended. Modification of existing models through the optimization of variables cannot be achieved at this moment. Setting up an integrated modeling environment is considered to be essential to utilize modeling and further apply the results for various projects. Standardization of GIS database, the criteria for and the scope of model application, and database management systems need to be prepared to expand modeling application.

• 한국물환경학회지
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• 제22권5호
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• pp.913-918
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• 2006

Both raw wastewater and effluent from a rubber products manufacturing factory were found to be toxic to Daphnia magna though the effluent satisfied current water quality standards. Thus, in order to reduce toxicity, advanced oxidation processes (AOPs) such as gamma-ray (${\gamma}-ray$) treatment and ozonation ($O_3$) were applied. A combined ${\gamma}-rays/O_3$ treatment at 20 kGy after coagulation significantly reduced toxicity of raw wastewater, changing 48-h toxic unit (TU) value from 201.21 to 23.92. However, toxicity of treated water was higher than that of effluent (TU = 12.15). This shows limitation of gamma-ray treatment to remove toxicity of raw wastewater. In case of effluent, the combined ${\gamma}-rays/O_3$ treatment at 20 kGy efficiently decomposed toxic compounds down to non toxic level. This work strongly supports the necessity of toxicity reduction evaluation as well as toxicity-based effluent management.

• 한국환경과학회지
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• 제6권3호
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• pp.259-265
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• 1997

This study was conducted to Investigate the treatment of wastewater from acetaldehyde manufacturing plant by activated sludge process with Micrococcus roseus AW-6, Micrococcus roseus AW-22, Microbacterium lacticum AW-38 and Mlcrobacterium nae- vaniformans AW-41. The $COD_{Mn}$ and $BOD_5$ of the wastewater were 5, 260mg/L and 6, 452mg/L, respectively. pH was 1.85. The main organic component in the wastewater was acetic acrid which was contained 67, 600mg/L. Optimum dilution time for activated sludge process was shown 10 times. The specific substrate removal rate(BL) was 1.95day-1 and the nonbiodegradable matters(Sn) were 23.2mg/L. Saturation constant (Ks) and mainmum specific growth rate(qmax) were 1, 640mg/L and 2.33day-1, respectively. Sludge yield coefficient(Y) and endogenous respiration coefficient(kd) were 0.28mg MLVSS/mgCOD and 0.02day-1, respectively. $COD_{cr}$ removal efficiency was 91% for 1.95day of hydraulic retention time.

• 웰빙융합연구
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• 제6권3호
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• pp.33-36
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• 2023

Purpose: Since the food wastewater contains a high concentration of nitrogen, it is very important to find a way to efficiently remove it. Research design, data and methodology: A total of four experiments were conducted under different conditions to remove ammonia nitrogen present in the food wastewater. The experiment was designed by adding sodium hypochlorite to the raw food wastewater and varying conditions such as pH control, aeration/precipitation, and stirring. Results: The ammonia nitrogen removal rate in Experiment 1 was about 12% (sodium hypochlorite added), ammonia nitrogen increased about 4.7% in Experiment 2 (sodium hypochlorite added after aeration/precipitation in a bioreaction tank, stirring), and decreased about 52.5% (sodium hypochlorite added after controlling and stirring). Conclusions: When the concentration of sodium hypochlorite was high, ammonia nitrogen was best removed, and the pH was adjusted to 12, and sodium hypochlorite was added after stirring, and the removal was the second best. If the method of this study is further studied and developed, it can be basic data for ammonia nitrogen removal in the future.

• 한국물환경학회지
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• 제30권6호
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• pp.585-595
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• 2014

The temporal trends of the prioritized toxic water pollutants generated and discharged from the industrial facilities in the Geum-River basin, Korea were analyzed with the results of the nationwide Water Pollution Source Survey conducted in 2001 - 2012. The statistical results indicated rapid increase in the volume of raw toxic wastewaters whereas the amount of each toxic pollutant kept fluctuating for 12 years. Serious discrepancies in the survey data of the same type of industries demonstrated a low reliability of the survey result, which stemmed from several error factors. A unit-load for each type of industrial facility was devised to estimate the amount of prioritized toxic water pollutant based on the total volume of industrial wastewater generated from the same type of industrial facilities. The supplementary measures with an effective permit issuance policy and adding survey parameters of terminal wastewater treatment plants to use them as references to the Water Pollution Source Survey were suggested as means to minimize the errors associated with the false reports from the industries.

• 생태와환경
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• 제49권3호
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• pp.187-196
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• 2016

본 연구는 감조하천과 연결된 하수처리장 방류구에서 발생하는 거품의 형성기작 해석과 저감기술의 실험적용을 위하여 2015년 3월부터 2016년 7월까지 수행하였다. 거품은 방류구와 하천 수면 사이의 낙차에 의한 공기연행과 거품확산방지막에 의한 내부축적이 원인이었다. 특히 썰물 때와 방류량이 많을 때에 거품성장이 가장 활발하였다. 이를 해결하기 위하여 방류수로와 방류구에 각각 미세스크린 망과 수중방류 인공수로장치를 각각 설치한 후 실험하였다. 거품 저감효과는 각각 약 85.0~92.0%, 70.7~85.6% 범위였다. 또한, 거품뿐만 아니라 소음 등 부가적인 문제점도 해결할 수 있었고, 무엇보다도 민원예방에 기여할 것으로 본다. 본 연구는 단일 하수처리장을 대상으로 하였으나, 국내 다른 하수처리장의 유사한 사례에도 응용될 수 있을 것으로 사료된다.

• 상하수도학회지
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• 제31권2호
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• pp.141-148
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• 2017

The waterworks company is in charge of managing water facilities buried underground, and the management has been centered on manholes. However, since there is no standard management manual, it has been impossible to introduce and operate a systemized managing tool by water service providers and managers, and manhole management has been carried out by individual data recording personnel for each water service provider. When the management is carried out individually, the data to be shared by other waterworks managers tend to be privatized, and consequently, it may become a big obstacle to proceed with many civil works such as emergency leak repair, road excavation, replacement of old buildings. This report introduces RFID (Radio Frequency Identification) system which is based on the magnetic field capable of IOT. It also describes the necessity of leveraging the system for smart managing of pipe management record that has been done by hand writing. The RFID system includes RFID marker, data reader, portable computer operating program, and data base server operating program. In this system, the data is managed with a single communication device, and it would be possible to share the information on the underground facilities and water treatment facilities. This RFID technology is expected to provide water service providers with opportunities to develop more scientific and modernized underground facilities information systems.