• 한국물환경학회지
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• 제16권4호
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• pp.513-521
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• 2000

Intermittently aerated activated sludge process was applied as a water reuse process of $70m^3/day$ for the upgrade of organic, nitrogen and phosphorus removal efficiency and clarifier performance. After application of the intermittently aeration, removal efficiency of BOD, SS, T-N and T-P were achieved 95%, 90%, 80% and 60%, respectively. Removal efficiencies in intermittently aerated process were considerably increased. comparing to those of continuously aerated activated sludge process. Also sludge rising problem in clarifier was improved. Average concentration of supplied reusing water were BOD 5 mg/L, turbidity 4 NTU and after chlorination, residual chlorine 0.4 mg/L, coliform 0 MPN/100mL. Intermittently aerated activated sludge process could be one of the best alternative process for the retrofit of conventional activated sludge process for the removal of nutrient in water reuse system.

• KSBB Journal
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• 제21권1호
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• pp.28-33
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• 2006

제올라이트로 충진된 수평 흐름 갈대 여과상에 실제하수를 간헐적으로 주입하면서 처리효율을 조사하였다. 여과상 표면적 $m^2$당 1일 314 L의 하수가 6시간마다 10분 동안 간헐적으로 주입되었다. 처리수의 pH는 원수보다 감소하였으며, 용존산소 농도는 원수보다 증가하였다. 수평 흐름 여과상에서 각 항목별 연중 평균 처리효율은 SS $88.5%,\;COD_{cr},\;86.1%,\;COD_{Mn}\;81.0%,\;T-N\;48.6%,\;NH_4^+-N\;97.1%$, T-P 42.8%이었다. 수평 흐름 여과상에서 처리수 중 T-N의 대부분은 $NO_3^--N$이었으며 $NO_2^--N$의 농도는 0.10 mg/L 이하이었다. 처리효율의 계절적 차이는 없었다.

• 한국물환경학회지
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• 제34권2호
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• pp.216-225
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• 2018

Over the past 40 years, the public sector has continued to invest in the sewage treatment plants (STPs) in Korea. Currently, the domestic sewage treatment rate is over 90% with the enhancement of operating efficiency of the STPs, and water quality of major rivers has been continuously improved. However, COD and T-N indicators are stagnating or slightly worsening, and though advanced treatment facilities are installed in most of the STPs, there is a limit to the removal of nutrients. Since there are a lot of water pollution sources in the vicinity of the watershed because of high population density in Korea, it is essential to reduce the inflow of the nutrients in order to prevent the eutrophication of the rivers and lakes. While the effluent T-P standard in STPs has greatly strengthened since 2012, which results in the considerable investment for the improvement of treatment process in STPs for the last few years, it is necessary to strengthen the T-N standards, as the effluent standard of T-N has been maintained at 20 mg/L since 2002. In this study, based on the analysis of the effluent T-N standard status of major industrialized countries, and the domestic nitrogen load in public waters, the option of appropriate T-N standard level is reviewed, and the required investment costs and the effect of strengthening the standard are estimated.

• 환경위생공학
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• 제17권2호
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• pp.40-47
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• 2002

In this study, water hyacinth plants(Eichhornia crassipes), water parsley(Oenanthe javanica) and Lemna paucicostate were used to treat contaminants such as COD, T-N and T-P in far m·fishing village wastewater. The results were as follows : In the batch system experiment, water hyacinth was showed at the high removal efficiency in the 173∼412kgCOD/ha·day concentration that is rather than 260mg/1 of the high concentration. The next is Oenanthe javanica, Lemna. Oenanthe javanica was showed the high removal efficiency in the 96∼173kgCOD/ha·day concentration that is less than 260mg/1 of the low concentration.

• 한국물환경학회지
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• 제25권2호
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• pp.322-328
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• 2009

The advantage of simultaneous nitrification and denitrification (SND) is to reduce requirement of oxygen as well as tank volume. The fludized media was used in the oxic (aerobic) tank of Membrane-BNR to enhance the efficiency of SND. Nowadays, the interest of applying membrane to the wastewater treatment plant has been increased, which is proved by a lot of research published about the MBR. The Membrane-BNR, consisted of total 5 reactors might be called the compact process by using the fludized media and having short HRT of 6.5 hr. It could attain the further removal of not only the organics but also nutrients such as T-N and T-P. The mode A and B were identified with or without the step feed of influent. The mode A was classified with 3 modes according to the different DO concentration in the fludized media aerobic reactor, and the mode B with step feed was operated with the optimum DO condition. The step-feed was capable of improving TN removal efficiency under the domestic wastewater with the low ratio C/N. On the other hand, the efficiency of SND with the 1.0~1.5 mg/L DO in the oxic media tank was better than the one with below 1.0 mg/L, on which the nitrification did not happen enough, and with above 3.5 mg/L, on which the reduction of anoxic area in the tank happened. It means that the profitable nitrification should be performed prior to the denitrification step. The removal efficiency of nitrogen by SND was about 20% among of total denitrified nitrogen. And some organic carbon consumed could be reduced by the endogeneous denitrification.

• 환경위생공학
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• 제15권3호
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• pp.31-36
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• 2000

Conventional membrane systems was difficults to treatment for the swine waste water. Technological advances in membrane filtration systems have created opportunity for the swine wastewater to treat effluent streams in order to meet stricter environmental constraints. "Vibratory Shear Enhanced Processing(VSEP)" developed by new logic international makes it possible to filter effluent streams without the fouling problem exhibited by conventional membrane systems. Various kinds of waste water occurred to and swine wastewater experiment with "VSEP" set up conventional reverse osmosis membrane (ACM-4, ESPA, BW-30). The results were as followes : Treatment efficiency for the input COD(From $332mg/{\ell}$ to $4,968mg/{\ell}$) was 98%. Treatment efficiency for the input SS(From $140mg/{\ell}$ to $4,040mg/{\ell}$) was 100%(All together). Treatment efficiency for the input T-N(From $155mg/{\ell}$ to $934mg/{\ell}$) was 97%~99.8%. Treatment efficiency for the input T-P(From $28.6mg/{\ell}$ to $132mg/{\ell}$) was 99.7% and up. ESPA membrane excels three types of reverse osmosis membranes applied VSEP in removal efficiency.

• 한국물환경학회지
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• 제28권1호
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• pp.94-101
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• 2012

The performance data for eight years from a free-surface-flow constructed wetland system receiving agricultural tailwater were used to analyze denitrification rate and nitrogen treatment characteristics according to season and wetland design. Seasonal difference between growing season (March~November) and winter season (December~February) was shown in the concentration of all nitrogen species. Seasonal nitrogen treatment has similar trend with temperature and measured denitrification rate. The highest denitrification rate was measured in July, but treatment efficiency was most higher in May and June. Nitrogen absorption of vegetation could affect to these wetland performances, therefore dense population of wetland vegetation might be helpful. According to design of wetland, at least 25~50 m of wetland length was needed to decrease effluent T-N concentration to background concentration in growing season. In winter season, wetland needed much longer distance to reduce T-N concentration. Mass removal rate was continuously high through whole year because runoff coefficient was low in winter season. Applicability of constructed wetland was observed for the total maximum daily load that control T-N load.

• 대한화학회지
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• 제56권6호
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• pp.700-705
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• 2012

본 연구는 수중에 있는 질소와 인의 흡착 제거를 위해서 활성탄뿐 아니라 황토와 비산재의 이용 가능성을 탐구하는 것이다. 여기서 우리는 각 흡착제에 대한 흡착효율과 Freundlich 상수 k와 1/n 값을 조사하였다. 비산재는 수중에 있는 총질소와 총인에 대하여 전혀 흡착능력을 보이지 않았다. 황토에 의한 수중으로부터의 총질소의 흡착은 일어나지 않았다. 그러나 24시간의 반응시간과 실온에서 총인에 대하여 대략 57.5%의 흡착효율을 보였다. 활성탄은 총질소에 대해서 매우 효과적인 흡착제라는 것을 보여 주었다. 활성탄의 Freundlich 상수 1/n 값을 통해서 활성탄이 황토와 거의 동등한 흡착능력을 가지고 있다는 것을 알게 되었다.

• 한국환경농학회지
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• 제25권2호
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• pp.129-137
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• 2006

농촌 마을단위 하수처리장에서 오염물질의 존재형태별 처리 경향을 파악하여 하수처리장의 설계 및 시공시 부지면적 감소와 오염물질의 처리효율 극대화를 위한 기초자료로 활용하기 위하여 농촌 마을 단위 하수처리장을 호기성조와 혐기성조로 구분하여 시공한 다음 하수처리 경과시기별, 오염물질 부하량별 및 계절별로 각 오염물질의 존재형태별 수처리 효율을 조사하였다. 하수처리 경과시기에 따른 오염물질 처리효율을 조사한 결과 호기성조 처리수에서 하수처리 시간이 경과함에 따라 BOD, COD, TOC 및 SS처리량은 큰 폭으로 증가하였다. 처리된 오염물질의 존재형태를 조사한 결과 호기성조 및 혐기성조에서 BOD는 대부분 IBOD로, COD는 대부분 ICOD로, TOC는 대부분 STOC로, SS는 대부분 VSS로, T-N은 대부분 DTN 및 T-P는 대부분 DTP로 처리되었다. 부하량별 오염물질 처리효율을 조사한 결과 BOD 처리량은 호기성조와 방류수 모두에서 처리된 대부분의 BOD는 IBOD이었다. COD 처리량도 BOD와 유사하게 호기성조에서는 대부분 ICOD형태로 처리되었으나, 혐기성조에서는 ICOD와 SCOD가 비슷한 처리량을 보였다. 그러나 하수처리장에서 처리되는 TOC의 존재형태별 처리량은 BOD 및 COD와는 달리 호기성조 처리수와 방류수 모두에서 STOC의 처리량이 약간 많았다. 부하량별 SS 처리효율은 호기성조 처리수에서 95%정도 처리되어 대부분의 SS는 호기성조에서 처리되었으며, 처리되는 SS의 용존형태는 호기성조 처리수에서는 대부분 VSS로 처리되었고, 방류수에서는 VSS와 FSS가 비슷한 양으로 처리되었다. 부하량별 T-N 처리효율은 호기성조 처리수에서 32%정도이었고, 방류수에서 24%정도이었다. 또한 처리되는 T-N의 용존형태는 호기성조 처리수와 방류수 모두에서 DTN이 STN에 비해 월등히 많은 양이 처리되었다. 부하량별 T-P 처리효율은 호기성조에서 62%정도이었고, 혐기성조에서 14%정도로 대부분 호기성조에서 처리되었으며, 처리되는 T-P의 용존형태는 호기성조와 방류수 모두에서 대부분 DTP형태이었다. 계절별 오염물질 처리량을 조사한 결과 BOD, COD, TOC, SS, T-N 및 T-P 처리량은 여름과 가을이 봄과 겨울에 비해 처리량이 약간 증가되었으며, BOD, COD, TOC, SS, T-N 및 T-P는 4계절 모두 방류수의 처리효율이 각각 92, 89, 73, 95, 46 및 84%이상의 높은 처리효율을 나타내었다.

• Membrane and Water Treatment
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• 제9권1호
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• pp.17-21
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• 2018

A series of laboratory scale experiments were performed to investigate the feasibility of membrane separation technology for natural rubber (NR) wastewater treatment and reuse. Three types of spiral wound membranes were employed in the cross-flow experiments. The NR wastewater pretreated by sand filtration and cartridge filtration was forced to pass through the ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes successively. The UF retentate, which containing abundant proteins, can be used to produce fertilizer, while the NF retentate is rich in quebrachitol and can be used to extract quebrachitol. The permeate produced by the RO module was reused in the NR processing. Furthermore, about 0.1wt% quebrachitol was extracted from the NR wastewater. Besides, the effluent quality treated by the membrane processes was much better than that of the biological treatment. Especially for total dissolved solids (TDS) and total phosphorus (T-P), the removal efficiency improved 53.11% and 49.83% respectively. In addition, the removal efficiencies of biological oxygen demand (BOD) and chemical oxygen demand (COD) exceeded 99%. The total nitrogen (T-N) and ammonia nitrogen (NH4-N) had approximately similar removal efficiency (93%). It was also found that there was a significant decrease in the T-P concentration in the effluent, the T-P was reduced from 200 mg/L to 0.34 mg/L. Generally, it was considered to be a challenging problem to solve for the biological processes. In brief, highly resource utilization and zero discharge was obtained by membrane separation system in the NR wastewater treatment.