• Environmental Engineering Research
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• 제16권4호
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• pp.237-242
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• 2011

In this study, three pilot-scale plants with the capacity 30 $m^3$/day were designed and set up to treat reservoir water for the production of drinking water. Three treatment processes were compared in the pilot testing: process 1 (coagulation- flocculation- sedimentationsand filtration- ozone- BAC); process 2 (coagulation- flocculation- sedimentation- microfiltration-ozone- BAC); and process 3 (coagulation- flocculation- sedimentation- sand filtration- GAC). The quality of water has been evaluated on the basis of selected parameters such as turbidity, color, consumption of $KMnO_4$, dissolved organic carbon (DOC), trihalomethane formation potential (THMFP), geosmin and 2-MIB. A detailed assessment of performance was carried out during a five months operation. Process 2 was found to have better removal efficiency of DOC, THMFP, geosmin and 2-MIB than process 1 and process 3 under identical conditions, although the removal rate of color was found to be the same in the three cases.

• 상하수도학회지
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• 제19권2호
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• pp.209-213
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• 2005

Slow sand filtration processes amended with 5 and 10cm GAC layers at top was compared to same process at bottom in a pilot study for humic substances removal. In case of 5cm GAC layer, the process amended at bottom was superior to the process at top in DOC and UV254nm removal and same trends were observed in case of 10cm GAC layer. Head loss developments of the process GAC at bottom were higher than the process GAC at top so that maintenance of the process GAC at top is easier than the process GAC at bottom.

• 대한환경공학회지
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• 제22권1호
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• pp.103-111
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• 2000

양어용수 재순환을 위한 생물여과상의 처리효율을 향상시키기 위하여 전처리로서 오존처리와 고급산화($H_2O_2/O_3$) 처리가 다양한 조건하에서 시도되었다. 오존처리시 암모니아는 일차속도반응식으로 제거되었으며, 중탄산염 알칼리도가 증가할수록 제거효율이 향상되어 200 mg/L as $CaCO_3$에서 약 46%가 제거되었다. 고급산화법($H_2O_2/O_3$)을 적용시 알칼리도를 포함한 폐수의 경우 중탄산염의 저해작용으로 암모니아 제거율이 저조하였으나 0.1 N KOH로 초기 pH를 약 8.2로 맞추어 실험한 결과 암모니아 제거율이 오존처리시보다 향상되었다. 특히, $H_2O_2/O_3=0.25$ 조건하에서 가장 높은 암모니아 제거율을 나타내었으며, pH가 9 이상일 때 반응시간 30분동안 약 90%의 암모니아가 제거되었다. 그러나 유기물과 암모니아가 공존시 오존처리와 고급산화처리 모두 유기물과 산화제와의 빠른 반응으로 인하여 암모니아 제거율이 크게 저하되었으며, 최적 $H_2O_2/O_3$ 비도 변하였다. 암모니아 제거와 마찬가지로 고급산화처리의 경우 입자성유기물의 빠른 분해로 인하여 초기 10분간 DOC(dissolved organic carbon)농도가 증가한 후 서서히 감소하였다. 초기 암모니아 농도를 2배 이상 증가시켜도 유기물 산화에 저해를 주지 못하였다.

• 한국해양환경ㆍ에너지학회지
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• 제11권2호
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• pp.105-112
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• 2008

2004년 9월, 11월 그리고 2005년 3월, 5월, 8월, 11월 총 6회에 걸쳐 제주도 차귀도 연안해역 10개 정점에서 표층 수와 저층수를 채수하여 물리, 화학적 수질특성을 조사하였다. 수온은 $12.2{\sim}28.9^{\circ}C$로 변동폭이 $16^{\circ}C$정도였으며 특히 8월에 저층수온이 $13^{\circ}C$로 저온수가 출현하는 양상을 보였다. 염분은 $30.2{\sim}34.9%o$의 범위였으며 8월에 가장 낮은 염분농도를 보인 것은 육상수의 영향으로 보아진다. 식물플랑크톤의 성장인자인 N/P비는 $5{\sim}76$으로 계절별, 정점별로 다양했다. 그러나 평균적으로 22이상을 보이고 있어 인산인 성분이 식물플랑크톤 성장에 제한인자로 나타나고 있었다. 유기탄소 농도는 TOC가 $92.5{\sim}438.3{\mu}M$의 범위였고 평균은 $217{\mu}M$이었으며 DOC는 $82.5{\sim}299.2{\mu}M$의 범위로 평균은 $130{\mu}M$이었다. DOC/POC비는 60%로 용존유기탄소가 많았다.

• 한국물환경학회지
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• 제37권1호
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• pp.1-9
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• 2021

The depletion of dissolved oxygen (DO) in urban streams has a profound effect on the aquatic ecosystem; however, the change in DO by resuspension of sediments and the cause have not been sufficiently investigated. In this study, the physicochemical properties (particle size, and the content of organic and heavy metals) of the sediments of an urban stream (Anyang Stream) and the characteristics of water quality changes (DO, dissolved organic carbon (DOC), dissolved nitrogen (DN), sediment oxygen demand (SOD), and adenosine triphosphate (ATP)) by sediment resuspension were investigated. The sediment content of fine particles (< 0.2 mm) increased from 36.7% to 52.7% from the upstream to the downstream, and the contents of heavy metals and organic matter of the sediment were also higher towards the downstream. The depletion of DO by resuspension was observed in the sediment at the downstream sites (P8, P9), where the fine particle content was high, and biological SOD (BSOD) was more than 88% compared to the total SOD. The increase in BSOD coincided with the increase in ATP. It was also confirmed that the depletion of DO could increase the amount of heavy metals (such as Fe, Mn, and Pb) released from the sediment. Based on the above results, it can be concluded that resuspension of sediments induces rapid water quality changes and may cause accidents, such as fish mortality, during rainfall, and such a water quality effect can be more pronounced in sediments with a high content of fine particles and organic matter and high biological activity.

• Advances in environmental research
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• 제1권3호
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• pp.181-189
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• 2012

Trihalomethanes, produced as a result of chlorination of drinking water, are considered a potential health hazard. The trihalomethane formation potential (THMFP) of a raw water source may indicate the maximum trihalomethanes (THMs) that are likely to be produced when chlorine reacts with natural organic matter (NOM) present in the water. A study was conducted to evaluate the THMFP in seven different drinking water sources in the vicinity of Kalpakkam, a rural township, on the east coast of India. Water from seven stations were analysed for THMFP. THMFP was compared with surrogate parameters such as dissolved organic carbon (DOC), ultraviolet absorbance ($UV_{254}$) and bromide. The data showed that THMFP was high in water from open wells as compared to closed bore wells, possibly due to more photosynthetic activity. Proximity to sea, and consequently the levels of bromide, was an important factor that influenced THM formation. THM surrogate parameters showed good correlation with THMFP.

• KSBB Journal
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• 제18권3호
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• pp.211-216
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• 2003

본 연구에서는 오존과 생물활성탄 연계공정의 효율성을 비교하고자 원수, 원수오존처리, 원수오존응집 침전 공정 처리수를 생물확성탄에 유입시켜 용존 유기물질의 제거효과를 비교ㆍ연구하였다. 또한 생물활성탄의 생물학적 처리능을 조사하기 위하여 총질소, 총인, 암모니아성 질소의 제거경향을 파악하였으며 그 결과 다음과 같은 결론을 얻었다. 오존 생물활성탄 처리시의 평균 제거율은 30.7%로 다른 처리 공정에 비하여 상대적으로 높은 용존 유기물질 제거율을 나타냈는데, 이것은 생물황성탄 컬럼 상에서 용존산소의 농도를 증가시킴과 오존의 산화로 인하여 유기물의 생분해도를 증가시킴으로서 활성탄 컬럼 내의 용존 유기물질 제거를 증가시킨 것으로 사료되며, 생물활성탄 컬럼의 DOC 저감율이 가장 높은 EBCT 10분을 최적의 EBCT로 판단하였다. 또한 각 공정별 유기물의 성상변화를 살펴보기 위하여 specific ultra violet adsorbance 성상 변화를 조사하였으며 오존처리에 의해 다량의 hydrophobic 성분이 hydrophilic 성분으로 전환되었으며 생물활성탄 처리에 의해 28%의 SUVA 값의 제거가 발생하였다. 이것은 오존 처리에 의해 다량의 hydrophobic 성분이 hydrophilic 성분으로 전환되었으며, 이러한 hydrophilic 성분이 생물활성탄 처리에 의해 제거된 것으로 사료된다. 원수를 유입시킨 생물 활성탄 처리수는 45.3%, 오존 처리수를 유입시킨 컬럼에서는 44.6%, 오존응집ㆍ침전처리수를 유입시킨 컬럼에서 58.4%의 UV$_{254}$ 제거율을 나타내었으며, 암모니아성 질소의 경우 66%, 81%, 29%의 제거율을 나타내어 생물학적 제거가 활발함을 관찰할 수 있었다. 따라서 본 연구를 통하여 오존산화처리와 황성탄의 연계처리는 용존 유기물질의 저감 뿐만 아니라 생물활성탄의 생물학적 처리능을 향상시키는 효율적인 공정임을 확인할 수 있었다.id의 효과와 거의 대등한 것을 나타났다. 이것으로 쇠비름 조추출물이 항산화효과 (in vitro)가 있음이 증명되었으며, 이 항산화활성은 극성이 비교적 큰 화합물들에 의한 것임을 추정할 수 있다. 현재 쇠비름 추출물로부터 항산화활성성분을 분리하기 위한 연구가 진행 중이다.는 exp-onential phase 동안 급격한 균체성장으로 용존산소가 부족하여 NADH balance에 의해 astaxanthin 생합성 경로 중 탈수소화 단계가 저해되기 때문으로 사료되었다. 최종 세포농도는 43.3 g/L, 단위부피당 carotenoids 함량은 149.4 mg/L, astaxanthin 함량은 110.6 mg/L로서 산업적인 생산성이 있는 것으로 나타났다. 이번 연구를 통하여 개발된 변이주 B76 및 이의 대량 발효를 위한 최종조건의 정립은 향후 astaxanthin의 산업적 생산공정에 필요한 기초자료로 이용될 것으로 기대된다.색총말내에 소형의 도형, 소형의 장형 연접소포 및 DENSE CORE VESICLE의 3가지 연접소포를 가지고 있었고 출현빈도수는 촉각엽에서 가장 큰 33%이었다. 제5형 신경연접은 축색종말내에 중등도크기의 원형, 대형의 원형연접소포 및 DENSE CORE VESICLE을 포함하였고 13%의 출현빈도수로 관찰되었다. 배추횐나비의 촉각에 있는 지각신경세포가 뇌의 촉각엽으로 뻗어 들어가 위의 5가지 신경연접중 어느 형을 형성하는지를 관찰하기 위하여 좌측 촉각의 기부를 제거하여 지각신경세포를 절단하였는데 그 결과, 좌측 촉각엽에서 제4형의 신경연접이 퇴행성 변화를 나타내었다. 그러므로 촉각의 지각신경세포는 뇌의 같은 족 촉각엽에 뻗어와 제4형 신경연접을 형성한다고 결론되었다.$/ 값이 210 $\mu\textrm{g}$/$m\ell$로서 효과적인 저해 활성을 나타내었다 따라서, 본 연구에서 빈랑으로부터 분리한 phenol 성 물질은 피부

• Ecology and Resilient Infrastructure
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• 제4권2호
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• pp.93-96
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• 2017

Spatial variations of physicochemical and microbiological variables were examined to understand spatial heterogeneity of those variables in intertidal flat. Variograms were constructed for understanding spatial autocorrelations of variables by a geostatistical analysis and spatial correlations between two variables were evaluated by applications of a Cross-Mantel test with a Monte Carlo procedure (with 999 permutations). Water content, organic matter content, pH, nitrate, sulfate, chloride, dissolved organic carbon (DOC), four extracellular enzyme activities (${\beta}-glucosidase$, N-acetyl-glucosaminidase, phosphatase, arylsulfatase), and bacterial diversity in soil were measured along a transect perpendicular to shore line. Most variables showed strong spatial autocorrelation or no spatial structure except for DOC. It was suggested that complex interactions between physicochemical and microbiological properties in sediment might controls DOC. Intertidal flat sediment appeared to be spatially heterogeneous. Bacterial diversity was found to be spatially correlated with enzyme activities. Chloride and sulfate were spatially correlated with microbial properties indicating that salinity in coastal environment would influence spatial distributions of decomposition capacities mediated by microorganisms. Overall, it was suggested that considerations on the spatial distributions of physicochemical and microbiological properties in intertidal flat sediment should be included when sampling scheme is designed for decomposition processes in intertidal flat sediment.

• 한국물환경학회지
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• 제40권2호
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• pp.67-78
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• 2024

The introduction of a significant amount of phosphorous into aquatic environments can lead to eutrophication, which can in turn result in algal blooms. For the effective management of watersheds and the prevention of water quality problems related to nonpoint organic matter (OM) sources, it is essential to pinpoint the predominant OM sources. Several potential OM sources were sampled from upper agricultural watersheds, such as fallen leaves, riparian reeds, riparian plants, paddy soil, field soil, riparian soil, cow manure, and swine manure. Stream samples were collected during two storm events, and the concentrations of dissolved organic carbon (DOC) and phosphorous (DOP) from these OM sources and stream samples were assessed. DOM indicators using fluorescence spectroscopy, including HIX, FI, BIX, and EEM-PARAFAC, were evaluated in terms of their relevance in discerning DOM sources during storm events. Representative DOM descriptors were chosen based on specific criteria, such as value ranges and pronounced differences between low and high-flow periods. Consequently, the spectral slope ratio (S_R) paired with fluorescence index (FI) using end-member mixing analysis (EMMA) proved to be suitable for estimating the contribution of organic carbon (OC). The contribution of each organic phosphorous (OP) in stream samples was determined using the phosphorous-to-carbon (P/C) ratio in conjunction with the OC contribution. Notably, OP derived from swine manure in stream samples was found to make the most dominant contribution, ranging from 61.3% to 94.2% (average 78.1% ± 12.7%). The results of this research offer valuable insights into the selection of suitable indicators to recognize various OM sources and highlight the main sources of OP in forested-agricultural watersheds.

• 한국물환경학회지
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• 제34권4호
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• pp.399-408
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• 2018

This research investigated the effects of weir (Ipobo) construction on the dynamics and the related spatial distributions of pollutants inflowing from tributaries (Yanghwacheon and Bokhacheon). Conductivity measurements and water sampling were conducted longitudinally, horizontally, and vertically in the waterbody upstream of the area located in Ipobo. Additionally, collected water samples were used for the dissolved organic carbon (DOC) analysis and fluorescence analysis which results in the SUVA, HIX, BIX, and FI calculation and parallel factor analysis (PARAFAC). Consequently, the results of the Conductivity, DOC, SUVA, and HIX showed that high concentration of pollutants that were flowing from the area of Bokhacheon which was mixed along the flow of the main river. The results of the BIX and FI did not show significant difference along the river flow which represented that allochthonous and terrestrial DOM, and for this reason was dominated in the whole waterbody rather than just the autochthonous DOM. The PARAFAC results showed that the two fluorescence components, humic-like and protein-like, constituted the fluorescence matrices of the water samples. The prevailing discipline notes that the two components were inflowing from the tributaries, however, a refractory component, humic-like substances, was relatively accumulated near the weir. From the results, the dynamics and spatial distributions of the DOM are dependent on the DOM characteristics, which induces the application of a specialized DOM analysis method to investigate the effects of a subsequent weir construction on the dynamics and spatial distributions of pollutants inflowing from the tributaries.