• Journal of Korean Society of Water and Wastewater
• /
• v.27 no.6
• /
• pp.703-709
• /
• 2013

Among many microalgae cultivation types, heterotrophic culture with low cost carbon sources and energy saving culture method is crucial. A result of estimating the effects of pH on wastewater treatment using heterotrophic growing microalgae Chlorella sorokiniana shows that there was no difference in microalgae growth amount and nitrogen, phosphorus removal rate by wide range of pH(5 ~ 9). From pH 5 to 9, total nitrogen, phosphorous and glucose removal rates were 10.5 mg-N/L/d, 2 mg-P/L/d, 800 ~ 1000 mg/L respectively. This study reveals that C. sorokiniana cannot metabolite glycerol heterotrophically, however, glucose and acetate were proper carbon sources for growth and T-N, T-P and TOC removal. This research highlights the potential of heterotrophic microalgal growth with wastewater treatment plant with wide range of pH and carbon sources.

• Journal of Korean Society of Water and Wastewater
• /
• v.27 no.1
• /
• pp.77-82
• /
• 2013

The growth and removal capacity of nitrogen and phosphorus of Chlorella vulgaris were evaluated in artificial wastewater with different nitrogen and phosphorus concentrations as element growing components for microalgae growth. The nitrogen concentration was varied in 9, 15, 30 and 60 mg-N/L with fixed phosphorus concentration of 3 mg-P/L. The growth and phosphorus removal capacity of C. vulgaris were high at initial nitrogen concentration of 15 and 30 mg-N/L, and the corresponding N/P ratios calculated were 5 and 10. In the case of varying in 1.5, 3, 6 and 10 mg-P/L of phosphorus concentration with fixed nitrogen concentration of 30 mg-N/L, the growth and removal capacity of nitrogen and phosphorus were excellent with phosphorus concentration of 3 and 6 mg-P/L. The corresponding N/P ratios were shown as 10 and 5. Therefore, the appropriate N/P ratio was concluded between 5 and 10 for wastewater treatment using C. vulgaris.

• Journal of Korean Society of Water and Wastewater
• /
• v.31 no.5
• /
• pp.441-445
• /
• 2017

This study aimed to investigate growth rate and nutrient consumption of Chlorella vulgaris according to different light irradiation interval. Applied light irradiation intervals were 12 hr, 4 hr, 1 hr, and 1 min. The light source was flexible LED(Blue:Red=1:1), light intensity was 200 PPFD and Light/Dark cycle was 1:1. As a result, growth rate and nutrient removal efficiencies showed no significant differences depending on the light irradiation interval. Considering the reproduction characteristics of applied microalgae cultures of this study, this is thought to be one of the possible reasons of above results. Because Chlorella vulgaris performs an asexual reproduction and it is known that there is no significant relationship between light irradiation interval and growth rate, including nutrient consumption in case of asexual reproduction.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.46 no.3
• /
• pp.252-258
• /
• 2013

The quality and quantity of food organisms in fish seed production are important. The marine microalgae Nannochloropsis oculata are used as initial food organisms in the field. We investigated the effects of salinity (0, 10, 20, 30, 40 and 50 psu) on the lipid and fatty acid composition of N. oculata. Cultivation of N. oculata at varying salinities showed the highest growth rate at 20 psu. Total lipid content ranged from 17.26 to 18.63% at salinities from 0 to 50 psu). The nonpolar lipid content increased markedly at 30 psu and was highest at 15.55%. The polar lipid content was lowest at 30 psu, by 84.45%. It was also found that the omega-3 and EPA contents were inversely proportional to salt concentration. For the polar and nonpolar lipid compositions, there was no significant effect of salinity. Omega-3 polyunsaturated fatty acid content especially the content of EPA in the seawater larvae is the essential fatty acid in this food organism. It is thus advantageous to culture N. oculata at 20 psu.

• Journal of Aquaculture
• /
• v.21 no.3
• /
• pp.167-171
• /
• 2008

Common co-existing organism Euplotes (Ciliate, Protozoa) well often observed in the rotifer mass culture tank of marine fish larval rearing stations. Ciliate protozoa (Euplotes) competed to condensed food (micoralgae, Nannochloropsis oculata) with rotifer (Brachionus rotundiformis). As results, rotifer density was rapidly decrease, and what is more, the rotifer was wiped out by dominant bacteria species at that time.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.7
• /
• pp.814-820
• /
• 2016

In order to utilize coal ash for eelgrass beds, a pilot plant experiment was carried out. Eelgrass was transplanted to on artificial bed made of granulated coal ash. Successful settlement of eelgrass was achieved and the density of the eelgrass increased at an exponential rate through vagetative propagation after 24 months. An increase in biodiversity in and around the artificial eelgrass bed was observed after the transplant took place. From the results of this experiment, it can be concluded that granulated coal ash is a suitable material for creating eelgrass beds.

• Proceedings of the Korea Technology Innovation Society Conference
• /
• 2017.11a
• /
• pp.755-755
• /
• 2017

공공분야에서의 지식생산이라는 국가 R&D사업의 본연의 임무에 사회문제해결이라는 보다 구체적인 요구가 커지고 있다. 취약계층, 노인, 장애인과 같은 사회적 약자들의 삶의 질 개선에 더불어 조류 인플루엔자, 미세먼지오염 등 국민생활에 영향을 주는 사회문제의 해결에 과학기술지식이 기여하라는 사회적 요청이 커지고 있다. 그동안 산업 지원과 학문 발전을 중심으로 발전해오던 국가R&D시스템이 이제는 공공분야에서의 지식생산시스템 격상이라는 과제를 안게 되었다. 정부는 2012년 '신과학기술 프로그램 추진전략(안)'을 통해서 이러한 요구를 수용하기 시작했으며 2014년에 다(多)부처 기획을 통해 11개 사업 분야를 선정하고 사회문제해결을 위한 R&D를 다(多)부처 사업으로서 2015년부터 시작하였다. 또한 과학기술정보통신부(구 미래부)는 단일 부처사업으로서 '사회문제해결형 사업' 을 2104년부터 추진하였다. 논문이나 특허보다는 현장문제의 해결책, 솔루션 생산을 목표로 제시하였으며 현장의 사용자나 시민이 연구개발의 전 과정에 참여하는 리빙랩이라는 새로운 방법론의 적용을 사회문제해결형 R&D사업의 성격으로 제안하였다. 본 연구는 사회문제해결형 R&D라는 이 새로운 시도가 국가R&D 시스템 안에서 어떻게 시행되었는지 NTIS data를 통해서 분석해보고자 한다. 먼저 다부처 기획으로 선정되어 추진된 과제들의 특성, 즉 연구적용분야, 연구 단계 등을 분석하고 단일부처 사업으로 수행된 '사회문제해결형 사업' 및 유사 단일부처 사업 과제들의 특성을 알아본다. 연구수행주체, 연구방법론 등 사회문제해결형 R&D 기획에서 제시한 새로운 방법들의 수행 여부를 알아보고 이를 통해 공공분야 국가R&D 시스템의 발전 및 사회문제해결형 R&D 사업의 향후 발전 방안을 제안한다.

• Journal of the Korean Solar Energy Society
• /
• v.31 no.6
• /
• pp.66-71
• /
• 2011

Various single solvents were tested to find the effective solvent for the extraction of algae oil from wet-form Chlorella minutissima. In the case of single solvents, their extractabilities for algae oil were increased with their polarity because the water in wet algae cell is to form a solvent shell around the lipids. Based on these results, the wet-form algae samples were treated with a polar alcohol solvent and then a nonpolar solvent was added in algae residue. In the algae oil extraction by ethanol/n-hexane, total lipid contents were 40-50% and composition of triglyceride in extracted oil was 46.50%. Considering solvent toxicity of conventional solvent mixture such as chloroform and methanol for algae oil extraction, the ethanol/n-hexane system was identified as the effective one for the oil extraction from wet-form Chlorella minutissima.

• Spatial Information Research
• /
• v.17 no.3
• /
• pp.351-359
• /
• 2009

Nowadays, a precision multiple-beam epoch sounder is a depth-sounding apparatus, which is widely used especially for the mapping of bottom of the sea in the coastal area and the bed of river. However, there has been no attempt to verify the accuracy of the depth-sounding apparatus with the data obtained through the actual measurement. As a consequence, the efficient and systematic evaluation of the survey results cannot be performed. In this paper, the accuracy of the multiple beam echo sounder is analyzed by comparing the in-situ measurements and reference data. The test results show that the highest level of accuracy, indicated by IHO, can be achieved even though the magnitude of error increases with the depth of water.

• Journal of Fisheries and Marine Sciences Education
• /
• v.29 no.2
• /
• pp.552-559
• /
• 2017

To assess the effect of LED lights on marine microalgae growth in the laboatory, Tetraselmis suecica, Chaetoceros simplex and Isochrysis galbana were cultured under $20{\pm}1^{\circ}C$, Walne's medium and aeration using 3.6 L glass vessels. The LED light sources were Blue, Red, Blue+Red, CoolWhite and WarmWhite. The experiments were conducted three times. The density of microalgae was shown as the counted number of cells per day, and the specific growth rate was calculated by using the density. The statistical analysis was performed by analysis of variance using the SPSS 20.0 program. T. suecica culture was the highest density under the Blue LED light source, so the light source was the most effective for the growth of this alga. C. simplex and I. galbana culture had the highest density under the Blue+Red LED light source, therefore this light source was the most effective for the growth of these algae. The result of analysis of variance showed significant between groups.