• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.213-213
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• 2000

점토살포에 의한 적조생물 구제효과가 알려지면서, 점토광물로 구성되어있는 산야토양 성분인 황토의 적조구제에 대한 관심도가 매우 높아지고 있으며, 최근 한국에서는 대규모로 발생되고 있는 Cochlodinium polykrikoides 적의 구제물질로서 황토를 대량 사용하고 있다. 그러나 황토의 적조구제 효율은 약 20∼80% 범위로서, 황토의 종류, 입자크기 및 살포방법 등에 따라 큰 차이를 보이고 있다. 이에 황토의 적조구제효과를 증진시키려는 일련의 노력들이 활발히 이루어지고 있다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.143-144
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• 2000

자연황토를 해수와 혼합 분쇄, 적조발생 해역에 정확히 살포하여 보다 경제적으로 황토를 살포하는 황토살포기 및 황토가 pH값의 변화에 따라 활성도가 달라지는 연구결과에 착안하여 해수를 전기분해하여 생성되는 전해수(산성수 및 알칼리수)에 황토를 혼합하여 황토를 활성화시켜 적조구제효율을 높이는 방법에 대하여 연구를 실시, 보다 효율적이며 친환경적인 적조구제 기술을 개발하였다. (중략)

• Economic and Environmental Geology
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• v.36 no.6
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• pp.557-561
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• 2003

It is important to find out a new material having high removal efficiency for the harmful algal blooms because the dispersion of Hwangto in a large amount to the sea water may bring some ecologically unfavorable problems. For this purpose, the efficiency of several natural and synthetic mineral species for the mitigation of algal blooms was measured. The mixing ratio of monominerals and the sea water with 3,000∼5,000 cells/$m\ell$ of Cochlodinium polykrikoides was 10 g/${\ell}$ and the removal ratio was measured by counting the living cells after the dispersion time of 10, 30 and 60 min., respectively. According to the experimental results, the removal ratio by illite, kaolinite, montmonmorillonite, red mud, Na-A type of zeolite ranged 84-92% after 1hr of contact time, which is comparable to that of Hwangto. The size of above monominerals ranged 3∼50${\mu}m$. Meanwhile, the amorphose material and hematite with the size of 50∼100 nm showed excellent removal ratio of more than 99% after 30min. of dispersion. The results of the study showed that the removal ratio was not related to the chemical composition and pH of the minerals applied but to the grain size. The experimental results strongly suggest that the main mitigation mechanism would be the contact and coagulation.

• Journal of the Mineralogical Society of Korea
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• v.18 no.4 s.46
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• pp.267-276
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• 2005

The study is to determine the feasibility of activated red mud as an anti-red tide material. The red mud, a byproduct of Bayer process for the production of alumina from bauxite, contained hematite, boehmite, calcite, sodalite, quartz, zircon, anatase and an unknown phase. In the adsorption study of the red mud, its adsorption efficiencies for heavy elements were close to $100\%$ except $92\%$ In As. These results seem to be attributed by the high adsorption ability of iron oxides for heavy elements. As a result of leaching tests with the red mud at various pHs (pH $1\∼13$), the high leaching efficiencies for As, Cu and Zn at low pHs (at acidic condition) were obtained. It indicated that removal efficiency of heavy elements could be excellent in acidic treatment of red mud. The activated red mud, red mud reacted with acid, contained hematite, boehmite and so on, and desorption of heavy metals from the activated red mud increased with increasing temperature. The grain of the activated red mud was tens nm in size. The removal efficiency for 5 types of plankton was generally in inverse proportion to pH, especially to final pH. Of five plankton types, Prorocentrum minimum and Alexandrium tamarense promptly were removed more than $90\%$ as soon as the activated red mud was sprayed and $100\%$ after 30 minutes. These results indicated that the activated red mud seems to be a promising anti-red tide material.

• Proceedings of the Petrological Society of Korea Conference
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• 2004.05a
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• pp.128-132
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• 2004

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.277-289
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• 2006

This study was carried out to find a new material having high removal efficiency for the harmful red tide. C. polykrikoides grow very fast and accumulate into dense and visible patches near the surface of the seawater ('Water bloom'). Some mineral medicines and Hwangto (reddish soil consist of clay minerals and Fe-oxides) were used in this study to remove C. polykrikoides. The pre-determined sprinkling ratio of mineral vs. seawater which contains approximately 5,000 cells/mL of C. polykrikoides was 10 g/L. In order to quantify the removal efficiency, the density of living cells was measured by counting with the Intervals of 0, 10, 30, and 60 minutes after sprinkling. Five Hwangtos feom different localities were examined in this study. It is found that a material with a high concentration of Fe and Al was the most effective to remove C. polykrikoides. After the sprinkling of the Hwangto showing the best removal efficiency in the test, 99% of total algaes were found to be eliminated within 60 minutes. Jeokeokji showed the highest removal efficiency among clay mineral medicines(92% removal efficiency after 60 minutes), and the rests in decreasing order are as follows: Gamto (91%) > Baekseokji (89%) > Hydromica (81%). In addition, Fe-oxide mineral medicine similarly looking as fine-grained earthy Daejaseok showed 100% removal efficiencyafter 30 minutes, and Wooyoeryang, 95% after 60 minutes. It is noted that even little addition (1 g/L) of Daejaseok, 10% of Hwangto concentration into seawater showed the removal efficiency of 100% after 60 minutes. From the results, it could be concluded that the fine-grained earthy Daejaseok was the most effective natural mineral medicine to remove the C. polykrikoides from seawater. Under the microscope the removal mechanism was found to be activated in the following order: adsorption, swelling of chain colony, chain colony crisis and algaecide.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2004.05a
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• pp.128-132
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• 2004

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.191-192
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• 2004

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.1 s.28
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• pp.21-28
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• 2007

The purpose of this study was to observe the effect on the water quality and sediment environment by the use of Nano-S for anti-Red tide material. The experiment was performed at subtidal and intertidal zone during six months(from Aug 2005 to Feb. 2006). The experiment sites were divided with concentration of materials. One is lower concentration(0.1%) and the other is higher concentration(1%). The results of experiments didn't show the remarkable influence of the materials effect before and after applying the Nano-S and the red mud. pH, salinity and DO were slowly increased during experiment period but nutrients were conversely decreased in the seawater. In the subtidal zone, qualities of sediments, IL, AVS and COD, were gradually lowered and the similar results were appeared in the intertidal zone. These results showed similar trends over all the experiment sites including control site. The results of heavy metals also did not show the interest different effect before and after applying the Nano-S and red mud compared with control site.

• Korean Journal of Microbiology
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• v.42 no.1
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• pp.7-11
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• 2006

To see effect of marine rock powder and fungal culture supernatant, we analyzed the biodegradation rates of harmful marine dinoflagellate, Heterosigma akashiwo and Prorocentrum minimum for developing the effective control methodology of algal bloom. Relatively low removal rates were observed in the treatment of marine rock powder or buffer solution alone. However, the lysis of H. akashiwo and P. minimum was enhanced in the combined treatments of marine rock powder with fungal supernatant. The effective concentration and exposure time of fungal supernatant for the lysis of H. akashiwo and P. minimum were 5 ml/l and 30 minutes, respectively. These results suggest that the fungal supernatant may be a biocontrol agent for the control of algal blooms in seawater.