• 청정기술
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• 제24권4호
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• pp.357-364
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• 2018

미세조류 및 거대조류 등 3세대 바이오매스로부터 바이오가스를 생산하는 연구는 다양한 규모의 실험을 통해 수행된 바 있다. 이 논문에서는 3세대 바이오매스 중 거대조류, 즉 해조류 바이오매스로부터 유래된 바이오가스를 이용하는 복합 열병합 발전의 상용화 가능성을 살펴보았다. 이를 위해 고체산화물 연료전지와 가스터빈, 그리고 유기랭킨사이클로 이루어진 산업 스케일의 통합 열병합발전을 상용 공정모사기를 이용하여 설계, 모사하였고, 계산된 열 및 물질수지를 통해 장치의 가격을 추정하고 경제성을 분석하였다. 모사 결과 설계된 열병합발전 공정은 시간당 62.5톤의 건조 갈조류 원료로부터 생산된 36톤의 바이오가스를 이용하여 68.4 MW의 전력을 생산한다. 이 결과를 토대로 다양한 시나리오에 대해 경제적으로 평가하고 균둥화 발전비용(levelized electricity cost, LEC)을 계산하였는데, SOFC의 수명이 5년, 스택 가격이 $$225kW^{-1}$일 때 LEC는 12.26 ¢ $kWh^{-1}$로 기존의 고정 발전과 동등한 수준으로 나타났다.

• 한국해양생명과학회지
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• 제8권1호
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• pp.56-67
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• 2023

Marine macroalgae are important in coastal ecosystems and interact with marine microorganisms. In this study, we isolated fungi from seven types of marine macroalgae including Cladophora sp., Gloiopeltis furcate, Gracilariopsis chorda, Hydroclathrus clathratus, Prionitis crispata, Sargassum micracanthum, and Ulva lactuca collected in Korea. Morphological and phylogenetic analyses identified the isolates as four Aspergillus spp. (A. fumigatus, A. sydowii, A. tamarii, and A. terreus), three Penicillium spp. (P. crustosum, P. jejuense, and P. rubens), and Cladosporium tenuissimum. Among them, A. fumigatus TOP-U2, A. tamarii SH-Sw5, and A. terreus GJ-Gf2 strains showed the activities of all enzymes examined (amylase, chitinase, lipase, and protease). Based on the enzymatic index (EI) values in solid media, A. terreus GJ-Gf2 and C. tenuissimum UL-Pr1 exhibited the highest amylase and lipase activities, respectively. Chitinolytic activity was only observed in A. terreus GJ-Gf2, A. tamarii SH-Sw5, and A. fumigatus TOP-U2. Penicillium crustosum UL-Cl2 and C. tenuissimum UL-Pr1 showed the highest protease activities. To the best of our knowledge, this is the first report of lipolytic and proteolytic activities in a marine-derived C. tenuissimum strain. Overall, the fungal strains isolated from the marine macroalgae in this study actively produced industrially important enzymes.

• ALGAE
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• 제33권1호
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• pp.109-125
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• 2018

Turkish towel (Chondracanthus exasperatus), Pacific dulse (Palmaria mollis, also known as Red ribbon seaweed), and sea lettuce (Ulva spp.) were cultivated in a land-based intensive culture system at the Manchester Research Station, USA from August 2013 to September 2014. Macroalgae were grown in tumble-aerated tanks, harvested bimonthly for seasonal growth calculations, and analyzed for protein, lipid, ash, and amino acid content. Growth rate of all three species exhibited a similar pattern, with the highest specific growth rates occurring during the summer months (Turkish towel: 7.8%, Pacific dulse: 8.2%, and sea lettuce: 6.2%). Growth of all three species was lowest around winter solstice; with negative growth only observed in sea lettuce. On a dry weight basis significant differences in protein content existed between the three species with highest values for sea lettuce ($29.5{\pm}1.4%$). Lipid content varied between species (0.95-2.78%) with significantly higher lipid observed in sea lettuce (0.58-4.82%). No significant differences were detected on a seasonal basis among each species. Essential amino acids accounted for $43{\pm}0.9$ to $47{\pm}1.2%$ of total amino acids with Turkish towel having the highest value. Turkish towel had a significantly higher taurine level ($0.82{\pm}0.27$) than the other macroalgae. The levels of persistent organic pollutants and heavy metals were low. The estimated annual product of the three species ranged from 50- to $70-mt\;dry\;weight\;ha^{-1}\;y^{-1}$, significantly higher than conventional crops. Land-based culture of these species can produce year-round harvest, consistent product quality, and low contaminant levels.

• 대한원격탐사학회지
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• 제36권2_2호
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• pp.293-307
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• 2020

매년 황해와 동중국해에서는 대형 부유조류인 녹조와 갈조가 대량으로 발생하고 있다. 이러한 대형 부유조류는 연안의 양식 시설물이나 해변으로 유입되며, 제거하는데 막대한 경제적 손실을 발생시킨다. 현재는 연안으로 유입되는 대형 부유조류를 탐지하기 위해 원격탐사 방법이 활발하게 사용되고 있다. 그러나 대형 부유조류는 해양의 다양한 대상들과 중첩되는 파장이 존재하기에 이를 정확하게 탐지하는데 한계가 있다. 더욱이 녹조와 갈조는 유사한 스펙트럼 특성을 보이기 때문에 원격탐사 자료를 이용한 구분을 더욱 어렵게 만든다. 따라서 본 연구에서는 위성 영상에 딥러닝 기법을 적용하여 녹조와 갈조를 효과적으로 구분하고자 하였다. 이를 위한 네트워크를 결정하기 위해 최적의 학습 조건을 찾아 AlexNet 신경망을 전이 학습하였으며, 학습과 검증을 위해 Gaofen-1 WFV 영상을 이용하여 데이터셋을 구성하였다. 최적의 학습 조건으로 학습된 네트워크를 이용하여 실험 데이터에 대한 결과를 확인하였다. 그 결과 실험 데이터에 대한 정확도는 88.89%를 보였으며, 녹조와 갈조에 대해 각각 66.67%와 100%의 정밀도로 구분이 가능하였다. 이는 전이 학습된 AlexNet 신경망이 녹조와 갈조의 미세한 차이를 구분할 수 있는 것으로 해석된다. 본 연구를 통해 해양의 다양한 대상으로부터 녹조와 갈조를 효과적으로 분류하고 각각 구분할 수 있을 것으로 기대된다.

• 공업화학
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• 제23권6호
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• pp.594-598
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• 2012

본 연구에서는 해조류 다시마를 바이오매스로 이용하는 혐기성 소화로부터 바이오가스를 생산하였다. 최적의 혐기성 배양조건을 확립하기 위해 슬러지는 $-70^{\circ}C$에서 20 min 동안 냉동 전처리를 하였다. 대조군과 비교했을 때 수소와 메탄가스는 각각 2.7배와 3.4배 증가한 667.28 mL/L와 3420.24 mL/L를 생산하였다. 냉동 전처리한 슬러지의 초기 pH 최적 조건은 7.0이었고, 다시마 바이오매스의 초기 pH 최적 조건은 8.0이었으며 알칼리 조건에서 보다 산성 조건에서 바이오가스 생산량이 크게 감소하는 것을 확인할 수 있었다. 슬러지의 냉동 전처리와 바이오매스 및 슬러지의 최적 pH 조건에서 최대 643.73 mL/L의 수소와 4291.6 mL/L의 메탄가스를 생산하였다. 이는 대조군과 비교했을 때 각각 2.6배와 4.3배 증가한 생산량이었다. 또한 최적 조건의 5-L 회분식 혐기성 배양에서 바이오가스의 생산량을 측정한 결과 기질에 포함된 다시마에 의해 생산될 수 있는 최대 생산량은 수소 1605.03 mL/L와 메탄가스 4593.71 mL/L로 확인되었다.

• ALGAE
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• 제18권2호
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• pp.129-134
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• 2003

In order to examine the effects of deep seawater (mesopelagic water in the broad sense) on the growth of macroalgae, the growth and nutrient uptake (nitrate and phosphate) of Ulva sp. (Ulvophyceae, Chlorophyta) were investigated by cultivation in deep seawater (taken from 687 m depth at Yaizu, central Japan, in August 2001), surface seawater (taken from 24 m depth), and a combination of the two. Culture experiments were carried out in a continuous water supply system and an intermittent water supply system, in which aerated 500-mL flasks with 4 discs of Ulva sp. (cut sections of ca. 2 $cm_2$) were cultured at 20$^{\circ}C$ water temperature, 100 $\mu$mol photons $m^{-2}{\cdot}s^{-1}$ light intensity, and a 14:10 light:dark cycle. Nutrient uptake by Ulva sp. was high in all seawater media in both culture systems. The frond area, dry weight, chlorophyll a content, dry weight per unit area, and chlorophyll a content per unit area of Ulva sp. at the end of the experimental period were the highest in deep seawater and the lowest in surface seawater in both culture systems. These values, except for dry weight per unit area and chlorophyll a content per unit area, for each seawater media in the intermittent water supply system were higher than those in the continuous water supply system. We conclude that not only deep seawater as the culture medium but also the seawater supply system is important for effective cultivation of macroalgae.

• ALGAE
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• 제27권4호
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• pp.269-281
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• 2012

Marado is a small rocky island located off the south coast of Jeju Island and acts as the first gateway of the Kuroshio Current to Korean coastal ecosystems. This island is one of the most unpolluted and well preserved sea areas around the Jeju coast. We extensively observed macroalgal assemblages of species and functional forms in the intertidal and subtidal zones through four seasons on Marado, Jeju Island, Korea to demonstrate the seasonality of vertical distribution patterns and biomass. A total of 144 species (14 Chlorophyta, 40 Phaeophyta, and 90 Rhodophyta) were identified in quadrats and were analyzed seasonally and vertically to define the variation patterns. The annual mean biomass of macroalgae was $2,932.3g\;wet\;wt\;m^{-2}$ and the highest value was recorded in spring and the lowest was in winter. The annual dominant species by biomass was Ecklonia cava followed by Sargassum fusiforme, S. macrocarpum, Amphiroa galapagensis, Chondria crassicaulis, and S. thunbergii. Obvious biomass zonation patterns of macroalgal species were detected in relation to tidal height and depth. Macroalgal biomass, diversity index (H'), and community dynamics were the highest in the shallow subtidal zone. Species number was higher in the subtidal than in the intertidal zone and similar throughout the entire subtidal zone. Our results provide revealing insights into the distribution patterns of macroalgal assemblages in an unpolluted sea area around Jeju Island.

• 한국환경과학회지
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• 제13권9호
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• pp.819-826
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• 2004

In order to elucidate the polycyclic aromatic hydrocarbon concentration and its origin in arctic area, four arctic brown algae (Laminaria saccharina, L. digita, Alaria esculenta, Desmarestia aculeata), one marine invertebrate (Echinoidea) and sediments were collected from Kongsfjorden in Spitsbergen from the late July to early August, 2003. In case of macroalgae, the young blade part above growth point and the old stipes and blades beneath growth point were separated and analyzed for polycyclic aromatic hydrocarbons (PAHs) in an attempt to check the mechanism of uptake in macroalgae to accumulate PAH. There was no difference in PAH concentrations between sampling sites (Stations B and C), species, and blades beneath and above growth point. PAH concentrations in all samples collected in this study were relatively higher than those reported in other areas of arctic. Especially, station C, which is known as an unpolluted area, showed 10 times higher PAH concentration (8,765 ng/g) in sediment than station A (694 ng/g) around harbor. In addition high PAH concentration, station C had very higher proportion of methylated PAH to parent PAH in sediment than station A. Source analysis using PAH isomer pair ratios as indicators showed that Kongsfjorden area seemed to be relatively contaminated with PAH derived from direct petroleum input.

• 한국환경과학회지
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• 제19권9호
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• pp.1083-1092
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• 2010

The spatial variability in the food chain structure of an estuary environment (Nanakita estuary, Japan) was investigated using fatty acid. Potential organic matter sources (terrestiral plants, macroalgae, benthic microalgae, dinflagellates and bacteria), sedimentary organic matters and benthic invertebrates (Nuttallia olivacea and Nereidae) were sampled in four locations with different tidal flat type. The main objective of the present study was to determine the origin of sediment and the food sources of N. olivacea and Nereidae along with small-scale spatial variability. The origin of sedimentary organic matters were mainly the fatty acid of bacteria and benthic microalgae. Especially, The organic matter of terrestrial plant origin was found the highest in station C. The diets of N. olivacea and Nereidae were found to be dominated by diatoms and terrestrial plants. Whereas, macroalgae and dinoflagellates showed little influence to benthic invertebrates. Moreover, according to principal component analysis, it is showed that benthic invertebrates in the same region are using the same food without relation with species. On the other hand, the N. olivacea and Nereidae of station D clearly contrasts with station B in terms of main food sources. From these results, it is suggested that food competition of benthic invertebrates revealed high a connection between small-scale spatial variability and food source in estuary.

• ALGAE
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• 제26권4호
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• pp.333-342
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• 2011

Macroalgae are important primary producers in marine ecosystem. They don't only play an important role as bioindicators but also provide economic resources for humans. Seasonal and vertical variations in seaweed species composition and biomass were examined to determine the ecological status of seaweed beds around Udo, near Jeju Island. We obtained samples at two sites in the high-intertidal to subtidal zones using the quadrat method between June 2010 and May 2011. A total of 262 species were collected, including 31 green, 61 brown, and 170 red algae. The composition of algal species revealed a decrease in species growing in cold water in comparison with the list 20 years ago. The macroalgal mean biomass (g wet wt $m^{-2}$) was 3,476 g and 2,393 g from the two sites, respectively. Ecklonia cava had the greatest biomass at both sites. The seasonal dominant species by biomass at site 1 from the low-intertidal to 1-3 m depth of the subtidal zone was mostly comprised of thick-leathery form, such as Sargassum hemiphyllum, S. coreanum, and Ecklonia cava, whereas site 2 was comprised of the turf form, such as Chondrophycus intermedius, Chondracanthus intermedius, Dictyopteris prolifera, and Gelidium elegans. The current ecological status of the seaweed community in Udo is stable based on diversity and dominance indices.