• Environmental engineer
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• s.153
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• pp.30-35
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• 1999

본 실험은 준혐기-호기(A/O, anoxic/oxic)순환공정으로서 시간별 주기변화를 통해 영양염류의 제거특성을 비교 검토하였고 이를 토대로 돈사폐수를 고도 처리 할 때 최적 운전주기와 설계인자를 도출하였다. 아울러 돈사폐수의 질소 제거특성을 분석하는 과정에서 폐수의 특성상 질산화 발생이 저해되는 현상을 관찰하였다. 따라서 이것을 규명하기 위해 질산화에 영향을 미치는 인자들을 중심으로 고찰하였다.

• Applied Biological Chemistry
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• v.45 no.1
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• pp.25-29
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• 2002

The kernel of wastewater treatment by activated sludge is elimination of organic substances and maintenance of well-flocculated sludge sedimentation. By the conventional activated sludge treatment, the optimum F/M ratio of soybean wastewater treatment was 0.24 (kg-BOD/kg-MLVSS day) and sludge bulking was generated at 0.48 (kg-BOD/kg-MLVSS day). To improve the treatment capacity and operation quality in higher loading of soybean wastewater, influent pH was constantly controlled by 9.0 using NaOH as a coagulant agent. In this process, higher loading up to 2.88 (kg-BOD/kg-MLVSS day) was possible and SVI was maintained under 150 without bulking. This was equivalent to 7.2 times higher than maximum permissible load of the conventional activated sludge process.

• Environmental engineer
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• v.18 s.191
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• pp.58-61
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• 2002

• Membrane Journal
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• v.7 no.4
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• pp.175-182
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• 1997

Membrane-bioreactor process which combines anaerobic-aerobic bioreactor and membrane process, was used to remove refractory organic susbstances and dye molecule in textile wastewater effectively. Direct feeding of raw feed water to membrane process caused serious fouling on membrane. On the other hand, pretreated feed by bioreactor before the membrane process remarkably reduced the fouling and prolonged the membrane life. Removal efficiency and fouling were more dependent on the material property of the membrane rather than the membrane pore size and structure. Operation mode of hollow fiber membrane module and linear velocity in the hollow fiber influenced the ramoval efficiency and the water flux of the membrane. The combined membrane- bioreactor process was more effective in treating the textile wastewater than each single process.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.04a
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• pp.48-49
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• 1996

산업발달과 도시인구의 집중현상은 물 수요의 급격한 증가를 초래하였고 날로 심각해지는 수질오염 및 수자원의 고갈이라는 어려움에 직면하고 있다. 이러한 요인으로 최근, 폐수 및 하수의 재이용기술 특히, 그 중에서도 막분리공정을 이용한 재 이용에 관심이 집중되고 있으며, 그 적용 또한 확산되고 있다. 특히, 막분리기술 중에서도 한외여과막이나 역삼투막을 이용한 공정이 큰 관심의 대상이 되고 있다. 막분리공정을 이용한 폐수 및 하수의 재이용에 대한 관심은 양호한 처리수질, 장치의 Compact 성, Scale-up의 용이성, 오염된 수자원의 재이용과 효융성이 우수하며, 현재는 경제성 등 몇가지의 문제점을 가지고 있으나, 그에 대한 연구가 활발히 진행되고 있으며 그 적용 또한 매년 증가하고 있는 추세이다. 본 연구에서는 폐수 및 하수 재이용시스템개발을 목적으로 사내에서 발생되는 금속표면처리폐수 및 도금폐수 그리고 호텔오수에 대해서 재이용가능성을 조사하기 위한 연구를 진행하였다. 연구의 목적달성을 위해 UF 및 RO Module를 장착한 Pilot Plant를 개발하여 연구를 진행하였으며, 이를 통하여 최적 폐수 재이용시스템의 개발, 유지관리, 현장적용을 최종 목표로 하였다.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.240.1-240
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• 1979

하천, 호소등의 자정작용(Stream self purification), 즉 미생물에 의한 수중의 유기물의 안정화는, 유기물의 산화분해와 미생물세포의 합성이라는 두가지 대사과정의 조합에 의해 달성된다. 미생물에 의한 폐수처리는, 상술한 자연계의 자정작용을 인공적으로 관리, 운영하는 것이다. 즉, 미생물은 폐수중의 유기영양물을 산화분해하므로써 세포의 합성과 유지에 필요한 energy를 획득하며, 한편 폐수중의 유기물은 산화되어 안정화된다. 이산화반응을 생물학적산화라고 하며, 호기적산화와 혐기적산화의 두가지 형식으로 구별된다. 여기서는 폐수처리에 관여하는 미생물의 분류, 또 폐수처리의 형식으로 호기적산화(산화지, 활성 오이법, 산포처상법 및 회전원판법)와 혐기적산화(Methane발효법)에 대해서 설명한다. 활성오이법 에서 bulking 현상에 대해서도 언급하며, 미생물에 의한 폐수처리의 원리와함께 동력학식의 활성오이법에의 응용에 대해서도 설명한다.

• Journal of radiological science and technology
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• v.30 no.2
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• pp.167-175
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• 2007

There are some positive effects by the introduction of PACS(Picture Archiving Communication System). This study is to analyze the mutual relation between before and after of the introduction of PACS in terms of the environment effect. It is supposed to cause the reduction of developing and fixing wastewater according to the increase in the rate of a non-film. This study will also show the amount of wastewater. Target places were the department of image medicine(diagnostic radiation) of the general hospitals in Seoul and Gyeonggi-Do, which are equiped with full PACS. The authors examined questionnaires on the number of projection, the number of indirect projection, the amount of the film used, the number of radiation image CD loan, the amount of the developing and fixing solution used, the change of the amount of fixing wastewater. According to the analysis, we analyzed the change of the amount of developing and fixing solution per a film and the change of the amount of developing and fixing wastewater which is supposed to be reduced proportionally by the introduction of PACS. We got conclusion as below after analyzing 8 hospitals except the largest and the least amount of examination, film used, developing and fixing solution and the amount of developing and fixing wastewater in order to decrease the deviation from 10 general hospitals located in Seoul and Gyeonggi-Do. We compared data one year before adopting PACS Versus 3 years after adopting PACS. 1. The frequences of examination increased to 7,357.7 cases per month but the amount of film used decreased to 90%, from 42,774.4 to 4,181.88 after adopting the PACS. 2. 3 years after adopting PACS, monthly average amount of developing solution used decreased to 92% and the monthly average amount of fixing solution decreased to 86%. 3. Monthly average amount of developing solution used per film increased to 1.49 times and fixing solution increased as much as three times. 4. Monthly average wastewater for developing decreased to 88% and wastewater for fixing decreased up to 87%. 5. Monthly average wastewater for developing per film increased to 3.77 times and wastewater for fixing increased to 3.85 times. Although the amount of film used and the amount of developing and fixing wastewater affected by the reduction of the developing and fixing solution became less on the whole by introduction of PACS, they did not decrease proportionally. Moreover the amount of the developing and fixing solution used and the amount of developing and fixing wastewater per a film increased. That means the expectation for an environmental improvement differs from the actual condition.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.241-249
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• 2000

In this study, UV-catalyzed $H_2O_2$ oxidation and $H_2O_2$ oxidation to remove contaminants from photo processing chemicals were investigated at various conditions. Photo processing chemicals contains high concentrations of organic compounds and has very low biodegradability. Hydrogen peroxide is subjected to gradual decomposition as metastable substance. In the process, short-lived and highly reactive hydroxyl radicals are formed. The decomposition can be significantly accelerated by use of appropriate catalyst, such as ultraviolet radiation. The experiments were conducted in a UV-free reflecting reactor in batch and a high-pressure mercury lamp was used as UV source. Mixing, cooling and ventilation of the reactor were operated during experiments. In $UV/H_2O_2$ oxidation and $H_2O_2$ oxidation, the removal efficiencies of $COD_{Cr}$, TOC and chromaticity increased with the increase of $H_2O_2$ dosage and were higher in the controlled pH condition of 3 than in original pH condition of 8. In $UV/H_2O_2$ oxidation under the optimum condition of pH 8 and 1.3 stoichiometric $H_2O_2$ dosage, the removal efficiencies of $COD_{Cr}$, TOC and chromaticity were 47.5%, 75.0% and 91.5% respectively and $BOD/COD_{Cr}$ ratio was significantly increased from 0.04 to 0.21.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.77-79
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• 1994

폐수와 하수처리에서 양질의 재생수를 얻기위하여 고분자막을 이용한 폐수재활용에서 나타나는 공정상 문제점을 고찰하였다. 본 연구에서 사용한 폐수는 처탑공장의 폐수로서 RO막을 이용한 폐수의 재이용공정개발을 목표로하고 있으며, pilot실험을 토대로 폐수의 적용성 검토가 행하여졌다. 사용된 막의 종류는 중공사막형의 막으로서 막내의 층류 흐름의 응용은 투석막, 기체분리, 중금속의 추출등 상당한 관심속에 있다. 여기서 중공사막과 같은 관(Cynlindrical)형의 막 구조에서 물질과 에너지 이동현상은 막분리공정을 이해하는 중요한 물리적고찰로서 막투과도를 높힐수 있을 뿐만 아니라 운전온도에 의해 중공사막 RO막내의 유량변화에 주요한 변수가 될 수 있다.

• Clean Technology
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• v.11 no.2
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• pp.57-67
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• 2005

Epoxy resins are produced by the dehydro condensated reaction with ECH (Epichlorohydrin) and BPA(Bisphenol-A) as raw reactants under sodium hydroxide(NaOH) as a catalyst, and from this reaction, salted water named of brine, which contains ECH derivatives in condition of emulsion as likely as glycidol and polymer resins, is produced as an undesired side product. This brine water is alkaline wastewater and causes process fouling problems by plugging and chemically depositing polymer particles on the surface of inner wall of reactors and pipes, and decreases the biodegradable efficiency in the wastewater process. In this study, the optimization of coagulation and sediment reactions, using inorganic and organic polymer coagulants, were performed to remove the causes occurring the process fouling phenomena. And also, based on this study, the methodologies applicable to the commercial processes including economical analysis were presented.