• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.37-40
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• 2001

We showed the result that an appreciable difference of secondary structures in the intracrystlline protein was observed between Normal and Deform shells. In order to understand the exact secondary structure of proteins, we investigated the changes in protein conformation from the specific layers via Fourier Self-Deconvolution(FSD) techniques, using ATR(Attenuated Total Reflection) information.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.906-913
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• 2019

To evaluate the removal performance of PO₄-P and NH₃-N, laboratory experiments were conducted by filling a container with oyster shells, pyrolyzed at 100℃ (POS100), 600℃ (POS600) and 800℃ (POS800), and passing artificial wastewaters through the container. The pH in the ef luent was found to increase due to CaO eluted from oyster shell. Removal amounts of PO₄-P of ~23.1 mg/kg, 16.1 mg/kg, and 15.9 mg/kg were obtained when POS100, POS600, and POS800, respectively, were used; therefore, the highest PO₄-P removal amount was obtained when POS100 was used. It is considered that Ca and dolomite in the oyster shells adsorbed and precipitated PO₄-P. Removal amounts of NH₃-N were of ~3.56 mg/kg, 5.72 mg/kg, and 3.97 mg/kg were obtained when POS100, POS600, and POS800, respectively, were used The low removal rate for NH₃-N is probably due to unstable nitrification, use of sealed containers, and the effect of NH₃-N being converted to NH₄⁺ upon increasing pH. Based on these results, pyrolyzed oyster shell is expected to promote changes in PO₄-P and NH₃-N concentrations through chemical reactions. These results can also be used for basic research in the development of wastewater treatment.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.411-418
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• 2017

This study classified oyster shells that produced as a industrial waste into 3 distribution by washing, drying and processing them. Mortar specimens with a constant ratio by using this to substitute fine aggregates were made, and the specimens were heated under the heating conditions of $300^{\circ}C$, $600^{\circ}C$ and $900^{\circ}C$ based on the 28-day age. On the age of 28 days, the plain flexural strength was found to be 9.2MPa, and in O 0.15, it was shown to be 4.4~7.9MPa depending on the substitution rate. It was found to be 4.4~7.7MPa in O 1.2~2.5 depending on the substitution rate, and last but not least, it was shown to be 6.1~8.8MPa in case of O 2.5~5.0 depending on the substitution rate. In case of the compressive strength of the 28-day age, it showed the difference of 23.6~43.2MPa in O 0.15 depending on the substitution rate, and 20.4~45.1MPa in O 1.2~2.5 depending on the substitution rate, and last but not least, 17.1~40.4MPa in case of O 2.5~5.0. As a result of measuring the residual strength through heating, in case of substituting fine aggregates less than O 0.15 by 100%, it showed the lowest strength reduction ratio, and it is expected that the heat-resisting property could be achieved through processing and proper mixing of oyster shells through these results.

• Environmental Engineering Research
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• v.10 no.5
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• pp.205-212
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• 2005

The study was conducted to investigate the removal of heavy metals by using Hydroxyapatite(HAp) made from waste oyster shells and wastewater with high concentration of phosphorus. The maximum calcium concentration for the production of HAp in this study was released up to 361 mg/L at pH of 3 by elution experiments. When the pH was at adjusted 6, the maximum calcium released concentration was 41 mg/L. During the elution experiment, most of the calcium was released within 60 minutes. This reaction occurred at both pH levels of 3 and 6. The result of the XRD analysis for the HAp product used in this study shows the main constituent was HAp, as well as OCP. The pH was 8.6. As the temperature increased, the main constituent did not vary, however its structure was crystallized. When the pH was maintained at 3, the removal efficiency decreased as the heavy metal concentration increased. The order of removal efficiency was as follows: $Fe^{2+}$(92%), $Pb^{2+}$(92%) > $Cu^{2+}$(20%) > $Cd^{2+}$(0%). Most of these products were dissolved and did not produce sludge in the course of heavy metals removal. As the heavy metal concentration increased at pH of 6, the removal efficiency increased. The removal efficiencies in all heavy metals were over 80%. From the analysis of the sludge after reaction with heavy metals, the HAp was detected and the OCP peak was not observed. Moreover, lead ion was observed at the peaks of lead-Apatite and lead oxidant. In the case of cadmium, copper and iron ions, hydroxide forms of each ion were also detected.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.7-14
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• 2003

In this study, undrained shear test was performed$K_o$ consolidation in order to study the shear strength characteristics of oysters-marine clay mixtures for three mixed ratios(0%, 25% and 50%). And, in order to study shear strength characteristics of oysters-marine clay mixtures, three different effective vertical stresses(200, 300 and 400kPa) were applied for the $K_o$ consolidation tests. In addition three different axial strain rates(0.005%/min, 0.05%/min, 0.5%/min) were applied for the case of effective vertical stress, 300kPa. According to experimental results, the more mixed ratios were increased, the more deviator stress was increased by crushing effect of oysters particles. especially, when effective vertical stress is 300kPa and mixed ratio increase from 25% to 50%, Test shows the increase of shear strength. But axial strain rate was not effect on the undrained shear strength. In the comparison and analysis that are based on the values of tests on the oysters-marine clay mixtures and the Mayne & Bishop's empiric formula, the undrained shear strength ratio shows a similar pattern of the tests. But for the prediction of the coefficient of the pore water pressure, the value of empiric formula shows more overestimated than the values of the tests at 0%, mixture ratio.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.59-68
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• 2012

This study was conducted to investigate the economic analysis of fermented diet made of agricultural and marine by-products such as, dropped apples, persimmon shells, mushroom (Flammulina velutipes) by-products, king oyster mushroom by-products and brewer's grain in Berkshire or crossed pigs. The daily diet cost were decreased by 2.16~3.44%, 3.83~13.35% and 7.47~41.61% when fermented dropped apples diet, fermented persimmon shells diet and fermented mushroom (F. velutipes) by-products diet were fed to Berkshire pigs. The daily feed cost was also decreased by 1.59~4.05% and 59.09~66.90% when fermented king oyster mushroom by-products diet and fermented brewer's grain diet were fed to crossed pigs. Carcass prices were increased by 3.09%, 1.20~3.40% and 1.13% when 2% fermented dropped apples diet, fermented persimmon shells diet and 0.5~1.0% fermented mushroom (F. velutipes) by-products diet were fed to Berkshire pigs. Carcass prices were increased by 2.87~4.19% and 41.31~49.14% when fermented king oyster mushroom by-products diet and fermented brewer's grain were fed to crossed pigs. Therefore, fermented agro by-products diet of dropped apples, persimmon shells, king oyster mushroom, mushroom (F. velutipes) and brewer's grain was expected to improve swine farms income due to decreased diet cost and increased carcass prices in Berkshire pigs or crossed pigs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.23-28
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• 1972

The following results were obtained from the experiment on the oyster spatfall, Crassostrea gigas by means of the rack method in YonghoBay, on the southern coast of Korea, from June to August in 1962 and 1963. 1. The Outside of shells as a collector showed better result than inside in numbers of attached oyster spats. 2. The horizontal type of the rack was more efficient for spatfall than the typical type of the rack. 3. The mode variance, in shell height, were shown as 21-25mm and 26-30mm, and the variance of range was 13.0-53.0mm for 77 days. 4. The optimum spat-fall season was from August 17 to 19 and 24 to 27, and spat of the oyster were attached in number of 7 per collector each day. 5. The optimum exposure time in spatfall was 4 hours. 6, The average water temperature and specific gravity, during the spawning season, was $25.98^{\circ}C$ and 0.1871, respectively.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.2
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• pp.75-82
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• 2011

This study was performed to evaluate the water purification properties of bio-composites planting blocks using oyster shell and effective microorganism that have high absorption ability of heavy metals and organics to develop environmentally friendly river embankment technique contained various factors such as oyster shells, effective microorganism, porous concrete and planting embankment block. To maximize greening effect, the seeds were arbitrarily sown. In addition, in order to analyze the effect of water quality purification after the planting, the samples were collected from each designated zone 1, 7 and 30 days after steeping in water. Then, the samples were analyzed in terms of seven test items such as SS, BOD, COD, T-N, T-P, pH, etc. on the basis of the test method for water pollution. The following conclusions were reached from the test result. As a result of analysis for water quality purification for the concrete block containing the effective microorganism, it was found that the values for SS, BOD, T-N and T-P for the sample taken after 30 days were lower than the initial values, which indicated that the water purification effect had been created. The result of the water quality purification analysis for the concrete block containing oyster shell showed that the values for SS, BOD, COD and T-P for the sample taken after 30 days were lower than the initial values which also indicated that it had been effective in water quality purification.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.2
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• pp.66-70
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• 2001

In this study farm soil was tested under artificial acid rain(pH = 5.34), which is average pH of Pusan metropolitan area. and to find out the soil's acid neuralization capacity, soil acidity, CEC(cation exchange capacity)and akaline meatals, such as K, Ca and Na were tested. Because oyster shells(OS) had portion of alkaline metals, OS could play a role in acid soil amendment. And soil addition of sewage treatment sludge(STS) could be a alternative for disposal method. The purpose of this study is to evlauate acid soil amendment using STS and OS. In case of soil and STS, mixing ratio was10:0, 9:1, 8:2, 7:3. And STS mixed OS was also added in acid soil as same ratio as STS. Throught the experiment, soil acidity was stationary state with slight decrease, and CEC was also stationary state but with slight increase. Allkaline metals showed differences in concentration, but all of them were tend to decrease. In conclusion, STS mixed OS could play a part in amendment of acid soil.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.2
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• pp.71-76
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• 2011

In this study, a heavy metal stabilization treatment using waste resource stabilizing agents was utilized on army firing range soil contaminated with Pb and Cu. Both calcined oyster shells (COS; 5% w/w) and waste cow bone (WCB; 3% w/w) were applied for a wet-curing duration of 28 days. Following the stabilization treatment, the process efficiency was evaluated by various extraction methods for Pb and Cu. Neutral and weak acid extraction methods, such as water soluble extraction and SPLP, did not show positive results for heavy metal stabilization with very low leachability. On the other hand, TCLP and 0.1 N HCl extraction showed that the stabilizing agents significantly reduced the amount of the heavy metals leached from the soil, which strongly supports that the treatment efficiency is positively evaluated in acidic leaching conditions. Specifically, in the 0.1 N HCl extraction, the reduction efficiencies of Pb and Cu leaching were 99.9% and 83.9%, respectively. From the sequential extraction results, a difference between Pb and Cu stabilization was observed, which supports that Pb stabilization is more effective due to the formation of insoluble Pb complexes. This study demonstrates that the application of waste resources for the stabilization of heavy metals is feasible.