• 한국환경농학회지
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• 제25권1호
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• pp.25-33
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• 2006

농어촌 등 소규모로 발생되는 생활하수를 자연친화적으로 처리하기 위한 대책의 일환으로 인공습지에 적용되는 최적의 수생식물을 선발하기 위하여 다년생 수생식물 10종을 하수처리장에 식재한 후 하수 처리효율, 처리시기별 수생식물의 생육상 및 무기성분 흡수량 등을 조사하였다. 인공습지 하수처리장에서 하수중 BOD, COD, T-N 및 T-P의 수처리효율은 호기성조를 통과한 호기성조 처리수에서 각각 92%, 74%, 25% 및 57%이었고, 혐기성조를 통과한 방류수에서 각각 96%, 84%, 44% 및 71%이었다. 수생식물 생육 150일 후의 질소 및 인 흡수량은 호기성조에서는 물억새가 각각 17.7 및 2.41 g/plant로 가장 높았으며, 혐기성조에서는 큰고랭이가 각각 8.7및 1.1 g/plant로 가장 높았다. 인공습지 하수처리장의 호기성조에서 최적 수생식물은 물억새>달뿌리풀>갈대의 순이었고, 이들 수생식물은 대부분 뿌리의 발육이 좋은 심근성 수생식물이었고, 여재층 내로 산소를 공급하기 쉬운 통기조직이 발달된 수생식물들이었다. 인공습지 하수처리장의 혐기성조에서 최적 수생식물은 줄>큰고랭이>부들>노랑꽃창포>삿갓사초의 순이었고, 이들 수생식물은 대부분 뿌리의 발육보다 줄기와 잎의 발육이 좋은 천근성 수생식물로서 호기 성조의 최적 수생식물의 역할과는 달리 영양물질의 흡수량이 우수한 수생식물이 선정되었다.

• 대한환경공학회지
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• 제38권7호
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• pp.364-370
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• 2016

본 연구에서는 초순수 생산을 위한 개별공정들의 특성을 고려하여 공정조합 최적화 방안을 결정하는 기법을 연구하였다. 산업 활동에 사용하는 공업용수 중 고도의 기술집합 산업에서 요구되는 고순도 용수인 초순수를 생산하는 공정은 여과, 이온교환, 역삼투, 탈기, 자외선 산화 등 이 있다. 초순수 공정은 다양한 15~20개 정도의 수처리 단위 공정이 조합을 이루고 있다. 본 연구에서는 초순수 생산 모형플랜트를 운영하여 다양한 처리 공정의 조합을 통해 수질 및 경제성을 고려하여 평가하였다. 평가된 19종류의 공정조합 중 11개 공정조합이 목표로 하는 최종 수질을 만족했다. 이러한 11종의 공정조합에 대해 안정성과 경제성을 평가하였다.

• 한국환경과학회지
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• 제29권12호
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• pp.1199-1204
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• 2020

Lentinula edodes mushrooms cultivated under different relative humidities were wrapped at 4℃ and the results of storage characteristics were investigated. Changes in water content of fruiting bodies during the storage period showed the highest water content in fruit bodies harvested from the treatment with the highest relative humidity. The luminosity of the fresh fruiting bodies showed no significant change during the storage period, and the redness was higher in the relative humidity 95% treatment than in the other treatments. According to this study, the relative humidity of the pileus was 65%, and the content of Ergosterol was 0.67 ± 15 g / L at relative humidity of 65%, 80% and 95%. In addition, amino acid analysis and Principal Component Analysis (PCA) confirmed that methionine was the main cause of changes in storage time and relative humidity.

• International Journal of Advanced Culture Technology
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• 제5권1호
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• pp.64-69
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• 2017

The rapid growth of algae occurs can induce the algae bloom when nutrients are supplied from anthropogenic sources such as fertilizer, animal waste or sewage in runoff the water currents or upwelling naturally. The algae blooms creates the human health problem in the environment as well as in the water resource managers including hypoxic dead zones and harmful toxins and pose challenges to water treatment systems. The algal blooms in the source water in water treatment systems affects the drinking water taste & odor while clogging or damaging filtration systems and putting a strain on the systems designed to remove algal toxins from the source water. This paper propose the emerging In-Situ self-diagnosable smart algae sensing device with wireless connectivity for smart remote monitoring and control. In this research, we developed the In-Site Algae diagnosable sensing device with wireless sensor network (WSN) connectivity with Optical Biological Sensor and environmental sensor to monitor the water treatment systems. The proposed system emulated in real-time on the water treatment plant and functional evaluation parameters are presented as part of the conceptual proof to the proposed research.

• 한국물환경학회지
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• 제21권2호
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• pp.158-168
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• 2005

In this study, the discharging effluents from have been 9 municipal wastewater treatment plants surveyed for 1 year-period. Statistics including probability distribution, cumulative occurrence concentration and other statistical parameters were presented. In addition, treatment performance and its stability were also discussed. Most of the plants, have an operational problem of high soluble organic content in the secondary effluent which may be associated with the integrated treatment of human and livestock manures. Nitrogen concentration in the effluents were usually higher during the period of summer and winter. It was found that this is mainly due to lack of the proper C/N ratio during the summer, or/and the effects of low temperature and less dilution by dry weather during the winter. Phosphorus concentration is sharply increased in June. Discussion with plant operators told that it is due to the dissolution of phosphate from the sludge accumulated in the primary settling tanks from the early spring to june. During this period, usually, sludge treatment line is highly overloaded with flush-outs of the sediments also stored in the bottom of combined sewer due to the low flow during winter season. Most of the plants can meet new effluent discharge limits of the nitrogen and phosphorus, and total coliform without further treatment.

• 한국물환경학회지
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• 제26권5호
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• pp.871-879
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• 2010

To figure out the removal efficiency of indicator and pathogenic bacteria by unit processes of a sewage treatment plant using activated sludge process, analyses were done for incoming sewage, influent and effluent of primary clarifier, aeration tank, secondary clarifier and final discharge conduit of the plant. A matrix of bacterial items (average of bacterial reduction [log/ml], p value of paired t-test, number of decreased cases of twenty analyses, removal percentage only for decreased cases) between incoming sewage and final effluent of the plant were heterotrophic plate counts (1.54, 0.000, 20, 95.01), total coliforms (1.38, 0.000, 19, 83.94), fecal coliforms (0.90, 0.000, 20, 94.84), fecal streptococci (0.90, 0.000, 20, 98.08), presumptive Salmonella (0.23, 0.561, 7, 99.09), and presumptive Shigella (1.02, 0.002, 15, 92.98). Total coliforms, fecal coliforms, heterotrophic plate counts, and fecal streptococci showed highest decrease through secondary clarifier about 1-log (p<0.001) between 88% and 96%, and primary clarifier represented the significant (p<0.05) decrease. However, final effluent through discharge conduit showed higher total coliforms and fecal streptococci than effluent of secondary clarifier (p<0.05). In addition, final effluent once violated the water quality standard while effluent of secondary clarifier satisfied the standard. Hence some control measures including elimination of deposits in discharge conduit or disinfection of final effluent are necessary.

• 전기학회논문지
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• 제57권8호
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• pp.1392-1397
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• 2008

The mechanical integrity of generator stator windings is one of the critical point because the electric power is generated and conducted to power system through these windings. De-mineralized water is used to cool stator bars during the normal operation of generator in large power plants because the water cooled method has highest cooling efficient. Water absorption of bar insulation is progressed by several causes such as generation of water leak path by corrosion, delamination of insulation by vibration, and inadequate water treatment, etc.. Reliable water absorption diagnostics of generator stator bar is important to ensure the availability of power plant and to reduce maintenance cost by generator accident. It is described that the water absorption characteristics for generator stator bar insulation used in 500MW capacity standard fossil power plant by cooling water temperature. It is verified that the management of stator cooling water temperature is one of the important factors to decrease water absorption rate of generator stator bars.

• 한국환경과학회지
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• 제14권7호
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• pp.683-689
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• 2005

The consecutive combination process of a biological process as the pre-treatment and a chemical process as the post-treatment is applied for the dyeing wastewater. The poor efficiency of biological treatment using pure oxygen makes the chemical treatment cost high. It is necessary to improve the efficiency of biological treatment in order to reduce the cost of chemical treatment. The purpose of this paper is to find the minimum dose of chemical reagent to fit the Discharged Water Quality Standards for the different biological treatment effluents. Results revealed that the minimum dosage of Fenton's reagent lead to save the cost of chemical treatment based on the guideline dose in the treatment plant. The possible maximum saving reagents was up to $70\%$ for the effluent of the pilot plant packed with the carrier imbedded microorganisms which were selected from the present treatment plant.

• 상하수도학회지
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• 제31권5호
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• pp.409-414
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• 2017

In this study, we divided the process operation scenarios into three categories based on raw water temperature and turbidity. We will select and operate the process operation scenario according to the characteristics of the raw water. The number of algae in the DAF treated water has been analyzed to be less than 100 cells/mL. These results indicated that the DAF process is effective in removing the algae. In addition, the scenario of the integrated management decision algorithm of the DAF process was developed. DAF pilot plants ($500m^3/day$) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21~1.56 NTU).

• 한국환경과학회지
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• 제25권7호
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• pp.999-1005
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• 2016

The H water treatment plant has been operating since 1982 and has had no renovation. It is assumed that the filters have been operated for more than 30 years and therefore are deteriorated. Many of the filters show an unequal state of air scouring during backwashing. For this study one filter, which was presumed most deteriorated among eighteen filters, was selected as a model filter for renovation. Some of the effects seen after renovation of the underdrain system were a lower average filtrated turbidity by approximately 0.02 NTU and an equal backwash state throughout the filter bed. Sand wash efficiencies by backwash before renovation of the underdrain system were 28%, 8%, and 5% at the surface, 50 cm depth, and 100 cm depth, respectively, and after renovation of the underdrain system were 94%, 26%, and 15%, respectively. The standard deviation of the effective sand size was 0.025-0.033 mm before renovation of the underdrain system and 0.002-0.011 mm after renovation of the underdrain system, meanings there was equal backwash pressure throughout the filter. Filtration time after renovation was approximately 2 times longer than before renovation.