• 해양환경안전학회지
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• 제2권1호
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• pp.67-75
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• 1996

An innovative batch electrolytic system consisted of electrolytic basin, which was equipped with DSA(Dimensionally Stable Anode) type insoluble electrode, Ti/IrO2 anode and H-C metal cathode, and flotation separator was developed for the efficient treatment of shipboard emulsified oily wastewater. The electorod cleance and current density of elecrolytic basin to ensure maximum treatment efficiency of oily wastewater was evaluated as 6 mm, 3 A/dm3, respectively. The electrolytic efficiency of oily wastewater was affected by the operationtemperature, and it means that the temperature controller to ensure the stabiity of the process is required. The conductivity in the electrolytic basin was increased with the percentage of sea water in the oily wastewater, and over 90% of treatment efficiency of oily wastewater could be obtained at 7% of sea water. The oil removal rate was increased according to the increase of the quantity of electricity, and the maximum value of electrilyic rate constant was 288 mgoil/A.min. The information obtained from this study might be used for development of an efficient continuous electrolytic system treating the emulsified oily wastewater.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.772-777
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• 2012

In order to examine the tailorability of advanced sewage treatment of a separated sewer pipe, we observed the quality of leaked water in a reactor. A2C affiliation and MBR affiliation decreased by over 78% in cases of BOD, COD, and SS. SBR affiliation decreased by 79.1% in a case of T-N. Overall, the efficiency of T-N on the above affiliations was low. SS had the high efficiency in MBR affiliation. In the end, examination of water quality improvement showed that the quality was improved from 20% to 90%; hence, it is expected that this treatment can protect the water resources of the Hongcheon River and makes it easier to use the water of the river.

• 한국수자원학회논문집
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• 제52권11호
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• pp.947-950
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• 2019

이 논문의 주요 특징은 초기강우 유입 시 일차 침전지 처리효율을 개선하기 위한 운전제어 전략을 제공하는 것이다. 최근 IoT 기술과 센싱 기술이 발전함에 따라 하수처리시설 운전제어를 위한 기반이 개선되고 있으며, 온라인 측정결과를 활용한 일차침전지 처리효율 개선에 따라 미처리 하수의 하천 유출을 최소화하고, 하수처리시설 운영효율 개선에기여할 수 있다.

• 대한환경공학회지
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• 제32권12호
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• pp.1119-1125
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• 2010

하수 슬러지의 혐기성 소화성을 향상시키기 위한 다양한 전처리 방법이 제시되어 있지만, 대부분 낮은 경제성 등의 문제로 현장 적용에 제한을 받고 있다. 본 연구는 장치의 구성 및 유지관리가 용이한 수리동력학적 캐비테이션 방법을 이용한 venturi cavitation system (VCS)의 전처리 효율을 향상시키기 위한 최적 설계 및 운전조건을 도출하기 위하여 수행하였다. VCS에서 벤츄리의 직렬 연결 개수는 3개일 때 가장 높은 전처리 효율을 나타내었고, 펌프는 흡입방식이 압송방식에 비하여 단위 에너지 투입량 당 1.6배 높은 전처리 효율을 나타내었다. 캐비테이션이 발생하는 조건에서 벤츄리의 목 직경 조합은 전처리 효율에 영향을 주지 않았다. 또한 3개의 벤츄리가 직렬로 연결된 벤츄리를 병렬로 설치할 경우 에너지 투입량 당 전처리 효율이 30% 향상되었다. 병렬 연결 운전조건으로 슬러지를 처리하였을 때, 에너지 소모량 당 가용화 효율은 5.6 mg ${\Delta}SCOD/g$ TS/kWh로 기존의 수리동력학적 전처리장치보다 우수하였다.

• 한국환경과학회지
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• 제12권12호
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• pp.1255-1260
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• 2003

Plasma-photocatalytic oxidation process was applied in the decomposition of Triethylamine(TEA) and Methyl ethyl ketone(MEK). Plasma reactor was made entirely of pyrex glass and consists of 24mm inner diameter, 1,800mm length and discharge electrode of 0.4mm stainless steel. And initial concentrations of TEA and MEK for plasma-photocatalytic oxidation are 100 ppm. Odor gas samples were taken by gas-tight syringe from a glass sampling bulb which was located at reactor inlet and outlet, and TEA and MEK were determined by GC-FID. For plasma process, the decomposition efficiency of TEA and MEK were evaluated by varying different flowrates and decomposition efficiency of TEA and MEK increased considerably with decreasing treatment flowrates. For photocatalytic oxidation process, also the decomposition efficiency of TEA and MEK increased considerably with decreasing treatment flowrates. The decomposition efficiency of MEK was 57.8％, 34.2％, 18.8％ respectively and the decomposition efficiency of TEA was reached all 100％. This result is higher than that of plasma process only, From this study, the results indicate that plasma-photocatalytic oxidation process is ideal for treatment of TEA and MEK.

• 펄프종이기술
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• 제37권3호
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• pp.17-22
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• 2005

The cleaning efficiency of papermaking felt which is contaminated with fiber fines and various micro-materials was investigated and compared between the application of enzyme and commercial detergent. It was found that the cleaning efficiency by the treatment of acidic-based detergent was more efficient than that of alkaline-based one in the conventional commercial detergent. it was also observed that the treatment design of first acidic-based detergent treatment to second alkaline-based detergent procedure was better in the cleaning efficiency, compared to alkaline based-to-acidic based one. The cleaning property of felt with enzyme was resulted in good cleaning efficiency, without any addition of surfactant. Especially, the enzyme treatment under alkaline condition (pH 10) showed a better cleaning result than that under acidic condition(pH 5). The addition of nonionic surfactant to the enzyme increased the cleaning efficiency of felt and decreased the cationic demand of wastewater. These results showed more favour than the application of conventional commercial detergent.

• 상하수도학회지
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• 제23권1호
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• pp.39-46
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• 2009

A method to improve water treatment efficiency by coagulant overdosing for high pH raw water at a drinking water treatment plant (WTP) which had no pH adjusting facilities was investigated. Poly aluminum chloride (PACl) was used for coagulant, and turbidity removal efficiency was evaluated as a function of PACl dosage increases. pH and turbidity of supernatant of jar-tester were 7.10 and 0.50 NTU respectively, when the turbidity, pH, alkalinity, water temperature, conductivity of raw water were 1.75 NTU, 9.38, 46.5 mg/L, $6.4^{\circ}C$, $400{\mu}s/cm$, respectively. Turbidity of settled water was reduced from 2.18 NTU to 0.28 NTU (87% reduction) when PACl dosage was increased from 16 mg/L to 45 mg/L at a full scale WTP. This can be attributed to the recovery of coagulant efficiency by pH reduction with the increase of coagulant dose, however coagulation efficiency was reduced with the formation of Al(OH)4- by PACl addition at higher pH. Coagulant overdosing was proven to be a rapid and effective method for high pH raw water, which can be applied at drinking WTP.

• 상하수도학회지
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• 제22권3호
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• pp.367-372
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• 2008

This study configured the conventional $A^2O$ (Anaerobic-Anoxic-Aerobic bioreactor) system which the fixed media immersed into the anoxic reactor(Named PFR system : Plug Flow Reactor) for evaluating the removal efficiency of nitrogen in the wastewater. The experimental equipment was a cylinder which was consist of 4 pleated PE Pipes(Length 330M, Diameter 100mm) including 2 rope shape media. As a result, the average effluent T-N removal efficiency of the conventional $A^2O$ system was 17.9, 40.3, 50.6, 44.6% in each mode, but the average effluent T-N removal efficiency of the PFR system could achieve 38.8, 57.1, 71.8, 65.4% in each mode. It indicated that the PFR system caused to the increasing of C/N ratio that effected to the increasing of the denitrification efficiency. Not only the effective T-N removal efficiency but also the controllable install space will give advantages for retrofitting of the wastewater treatment plant with the conventional treatment system to the PFR system.

• Environmental Analysis Health and Toxicology
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• 제29권
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• pp.15.1-15.7
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• 2014

Objectives This paper tried to review a recent research trend for the environmental exposure of engineered nanomaterials (ENMs) and its removal efficiency in the nanowaste treatment plants. Methods The studies on the predicted environmental concentrations (PEC) of ENMs obtained by exposure modeling and treatment (or removal) efficiency in nanowaste treatment facilities, such as wastewater treatment plant (WTP) and waste incineration plant (WIP) were investigated. The studies on the landfill of nanowastes also were investigated. Results The Swiss Federal Laboratories for Materials Science and Technology group has led the way in developing methods for estimating ENM production and emissions. The PEC values are available for surface water, wastewater treatment plant effluents, biosolids, sediments, soils, and air. Based on the PEC modeling, the major routes for the environmental exposure of the ENMs were found as WTP effluents/sludge. The ENMs entered in the WTP were 90-99% removed and accumulated in the activated sludge and sludge cake. Additionally, the waste ash released from the WIP contain ENMs. Ultimately, landfills are the likely final destination of the disposed sludge or discarded ENMs products. Conclusions Although the removal efficiency of the ENMs using nanowaste treatment facilities is acceptable, the ENMs were accumulated on the sludge and then finally moved to the landfill. Therefore, the monitoring for the ENMs in the environment where the WTP effluent is discharged or biomass disposed is required to increase our knowledge on the fate and transport of the ENMs and to prevent the unintentional exposure (release) in the environment.

• 한국환경과학회지
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• 제13권6호
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• pp.571-579
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• 2004

There is a need to improve the efficiency of the existing sanitary treatment facilities, because the effluent standard becomes more stricter and septic sludge increased. Thus, operating processes of sanitary treatment system in M city changed with installation of additional facilities. Process modifications were as follows: Dilution water was added to the next process after primary aeration tank. Some secondary sedimentation sludge was recycled to primary aerator so that most of the organics were stabilized in primary aeration tank under automatic control of dissolved oxygen. The line of effluent from dewatering process flowing to the activated sludge tank was changed to the primary aerator. The primary sedimentation sludge line was linked to a thickener. Polymer was added to the activated sludge tank. The effluent of primary aerator and aerobic digester was recycled from the 5th to the 1st sector. As consequencies of above process modifications, the improvement of removal efficiency was achieved as BOD 54%, COD 42%, SS 61%, T-N 39%, and T-P 12%, respectively.