• 멤브레인
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• 제19권3호
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• pp.194-202
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• 2009

본 연구에서 처리수를 이용한 주기적인 역세척은 춘천시 공지천의 관형 세라믹 한외여과막에 의한 고도정수처리 시스템에서 막오염을 저감하고 투과선속을 향상시키고자 수행되었다. 일정한 역세척 시간(BT) 15초에서 여과시간 즉, 물 역세척 주기(FT) 2분이 가장 높은 무차원 투과선속(초기 투과선속에 대한 투과선속)과 가장 낮은 막오염 저항값을 보였다. 또한, FT 10분으로 고정한 BT 영향의 결과에서 BT 20초가 가장 낮은 막오염 저항과 가장 높은 무차원 투과선속을 나타내어, 가장 많은 총여과부피 107.3 L를 얻을 수 있었다. 결론적으로 공지천의 정수처리에서 FT 10분과 BT 20초가 최적조건으로 관형 알루미나 정밀여과의 선행 연구결과와 정확히 일치하였다. 한편 관형 세라믹 한외여과 시스템에 의한 오염물질 평균제거율은 탁도 97.0%, 망간법에 의한 COD 32.1%, 암모니아성 질소 28.8%, 총인 54.4%로 나타났다.

• 상하수도학회지
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• 제34권4호
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• pp.239-250
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• 2020

In this study, effects of five raw water quality parameters (turbidity, odor compounds caused by algae, filter clogging caused by algae, pH increase caused by algae, and organic matter) on improvements and operations costs of typical water treatment plant (WTP) were estimated. The raw water quality parameters were assumed the worst possible conditions based on the past data and costs were subsequently estimated. Results showed that new water treatment facilities were needed, such as a selective intake system, an advanced water treatment processes, a dual media filter, a carbonation facility, and a re-chlorination facility depending on water quality. Furthermore, changes needed to be made in WTP operations, such as adding powered activated carbon, increasing the injection of chlorine, adding coagulation aid, increasing the discharge of backwashed water, and increasing the operation time of dewatering facilities. Such findings showed that to reliably produce high-quality tap water and reduce water treatment costs, continuous improvements to the quality of water sources are needed.

• 상하수도학회지
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• 제28권4호
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• pp.397-409
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• 2014

Algal problem in drinking water treatment is being gradually increased by causing deterioration of water supplies therefore, especially taste and odor compounds such as geosmin and 2-MIB occur mainly aesthetic problem by its unpleasant effects resulting in the subsequent onset of complaints from drinking water consumer. Recently, geosmin and 2-MIB are detected frequently at abnormally high concentration level. However, conventional water treatment without advanced water treatment processes such as adsorption and oxidation process, cannot remove these two compounds efficiently. Moreover, it is known that the advanced treatment processes i.e. adsorption and oxidation have also several limits to the removal of geosmin and 2-MIB. Therefore, the purpose of this study was not only to evaluate full scale nanofiltration membrane system with $300m^3/day$ of permeate capacity and 90% of recovery on the removal of geosmin and 2-MIB in spiked natural raw water sources at high feed concentration with a range of approximately 500 to 2,500 ng/L, but also to observe rejection property of the compounds within multi stage NF membrane system. Rejection rate of geosmin and 2-MIB by NF membrane process was 96% that is 4% of passage regardless of the feed water concentration which indicates NF membrane system with an operational values suggested in this research can be employed in drinking water treatment plant to control geosmin and 2-MIB of high concentration. But, according to results of regression analysis in this study it is recommended that feed water concentration of geosmin and 2-MIB would not exceed 220 and 300 ng/L respectively which is not to be perceived in drinking tap water. Also it suggests that the removal rate might be depended on an operating conditions such as feed water characteristics and membrane flux. When each stage of NF membrane system was evaluated relatively higher removal rate was observed at the conditions that is lower flux, higher DOC and TDS, i.e., $2^{nd}$ stage NF membrane systems, possibly due to an interaction mechanisms between compounds and cake layer on the membrane surfaces.

• 제어로봇시스템학회논문지
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• 제17권6호
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• pp.602-609
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• 2011

In this paper, we standardized the water operation system picture, process control logic, realtime database and system configuration. All aspects, including monitoring & controlling processes, symbols such as pumps, valves and pipes were standardized. As a result we have developed a specialized Integrated water operation system, iWater. We have developed a variety of advanced application programs that are essential for water treatment systems, such as IWS (Integrated Warning system), MBO(modbus opc)/LSE(LS ethernet) driver, video monitoring, self diagnosis system, network monitoring, etc. IWS prevents water supply accidents by using a variety of alarms and warning messages. Drivers have the flexibility to communicate with other 3rd party systems. We expect that iWater will eliminate any concerns regarding water-related issues while also promoting the production and fair distribution of clean water.

• Journal of Advanced Marine Engineering and Technology
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• 제34권3호
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• pp.383-390
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• 2010

This study is currently giving priority to developing the ship's ballast water treatment system using ozone (Ozone BWTS). The Ozone BWTS was tested in a full scale land-based mobile barge to evaluate performance according to the IMO G8 Guidelines. Test cycles using the mobile-barge were conducted in seawater and brackish water in the vicinity of the Port of Busan and Nakdong River, Republic of Korea. All tests were conducted according to the requirements of the G8 Guidelines. Test results show that the Ozone BWTS meets the Ballast Water Performance Standard contained in Regulation D-2 of the IMO Ballast Water Management Convention, as well as all of the operational, safety, and environmental testing requirements of the G8 Guidelines, as required for type approval of IMO. The study results show that the Ozone BWTS is capable of meeting the Ballast Water Performance Standard under Regulation D-2 of the International Convention for the Control and Management of Ships’ Ballast Water and Sediments, and also the more stringent standards being proposed under US legislation.

• 한국물환경학회지
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• 제25권2호
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• pp.227-234
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• 2009

In this research, a retrofitting process, which consists of a pretreatment system (coagulation) for dye wastewater combined with a biological nutrient system (MLE process using media), for a sewage treatment plant that has to treat dye wastewater efficiently with domestic wastewater were developed and a pilot plant was operated for verifying adoptability and performance of the developed advanced process for dye wastewater. From the results of the pilot plant operation, BOD 52.9%, $COD_{Cr}$ 55.9%, and color 71.3% were removed in pretreatment of coagulation process and the biodegradability of dye wastewater was improved to $0.32{\sim}0.59BOD/COD_{Cr}$ of the coagulated wastewater from $0.29{\sim}0.43BOD/COD_{Cr}$ of the raw dye wastewater. The final effluent concentrations were BOD of 8 mg/L, $COD_{Cr}$ of 43 mg/L, $COD_{Mn}$ of 18 mg/L, T-N of 8 mg/L, and T-P of 1.3 mg/L, respectively. Color was removed from 1655 to 468 unit by coagulation and then to 123 unit by MLE process. The HPLC analysis of aromatic amines in wastewater showed that decolorization was achieved by cometabolism while aromatic amines were produced by cleavage of azo bonds under anaerobic conditions and these products were removed in an aerobic tank subsequently. Nitrification rates of attached and suspended microorganisms were evaluated comparatively and the acclimating conditions of bacteria on media were validated by the scanning electron microscope.

• 상하수도학회지
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• 제26권2호
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• pp.209-218
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• 2012

Recently, as reinforced water quality standards for wastewater has been announced, more efficient and more powerful wastewater treatment processes are required rather than the existing activated sludge process. In order to meet this demands, we evaluate Task 1-4 about lab scale $A_{2}O$　process using biofilm media. Task 1, 2, and 3 use 'Module A' which has 4 partitions (Anoxic/Anerobic/Oxic/Oxic). Task 4 uses 'Module B' which has 2 partitions including a denitrification reactor with an Inclined plug flow reactor (IPFR) and a nitrification reactor with biofilm media. The denitrification reactor of Module B is designed to be upward flow using IPFR. The result of evaluating at each Task has shown that attached growth system has better capacity of removal efficiency for organic matter and nitrogen with the exception of phosphorus.　Task 4 which has the most outstanding removal efficiency has 90.5% of $BOD_{5}$ removal efficiency, 97.8% of ${NH_4}^{+}-N$ removal efficiency, 65% of T-N removal efficiency and 92% of T-P removal efficiency with additional chemical phosphorus removal system operated at HRT 9hr, Qi:Qir 1:2, and BOD/T-N ratio 2.7.

• 상하수도학회지
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• 제29권4호
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• pp.511-517
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• 2015

Korea's modern waterworks began with construction of DDukdo water treatment plant in 1908 and has been growing rapidly along with the country's economic development. As a result, water supply rates have reached 98.5% based on 2013. Despite multilateral efforts for high-quality water supply, such as introduction of advanced water treatment process, expansion of waterworks infrastructure and so on, distrust for drinking tap water has been continuing and domestic consumption rate of tap water is in around 5% level and extremely poor comparing to advanced countries such as the United States(56%), Japan(52%), etc. Recently, the water management has been facing the new phase due to water environmental degradation caused by climate change, aging facilities, etc. Therefore, K-water has converted water management paradigm from the "clean and safe water" to the "healthy water" and been pushing the Smart Water City(SWC) Pilot Project in order to develop and spread new water supply models for consumers to believe and drink tap water through systematic water quality and quantity management combining ICT in the whole water supply process. The SWC pilot projects in Pa-ju city and Go-ryeong county were an opportunity to check the likelihood of the "smart water management" as the answer to future water management. It is needed to examine the necessity of smart water management introduction and nationwide SWC expansion in order to improve water welfare for people and resolve domestic & foreign water problems.

• Advances in environmental research
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• 제1권2호
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• pp.125-142
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• 2012

Clean development mechanism (CDM) validity study was conducted to suggest better and more adaptable CDM scenario on water treatment plant (WTP). Potential four scenarios for CDM project; improvement of intake pumping efficiency, hydro power plant construction, solar panel construction and system optimization of mechanical mixing process were evaluated on S-WTP in Korea. Net present value (NPV) of each scenario was estimated based on sensitivity analysis with the variable factors to investigate the CDM validity percentile. Hydro power plant construction was the best option for CDM business with 97.76% validity and $1,127,069 mean profit by 9,813 $tonsCO_2e$/yr reduction. CDM validity on improvement of intake pumping efficiency was 90.2% with $124,305 mean profit by huge amount of $CO_2$ mitigation (10,347 $tonsCO_2e$/yr). System optimization of mechanical mixing process reduced 15% of energy consumption (3,184 $tonsCO_2e$/yr) and its CDM validity and mean profit was 77.25% and $23,942, respectively. Solar panel construction could make the effect of 14,094 $tonsCO_2$ mitigation annually and its CDM validity and mean profit was 64.68% and $228,487, respectively.

• 멤브레인
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• 제1권1호
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• pp.78-95
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• 1991

미국 캘리포니아주 Orange County에 위치한 Water Factory 21(WF-21)은 생물학적 처리공정을 거친 도시하수를 재생하여, 이 재생수를 지하수지층으로 유입되는 해수의 침투를 막기 위한 Reinjection System에 이용하고 있다. 장치 구성 공정은 Lime처리, Air Stripping, 사여과, 활성탄처리, 역삼투막 및 염소처리 등으로 이루어지며, 이에 대한 각 처리공정의 효율성에 대하여 실험을 실시하였다. 3년간의 장기간에 걸친 실험결과로부터, 도시하수에 대한 RO Membrane 처리수는 음료 수질 기준에 적합한 고수질의 물을 생성할 수 있음을 입증했다. Pilot Plant 실험에선 Lime Clarifier만으로 전처리를 실시하여 성공적인 결과를 얻었으며, 또한 저압 (250 psi)이 적용된 새로운 Membrane을 사용하여 에너지 절약을 통한 비용 절감 효과에 대한 실험도 상당한 가능성을 보여주었다.