• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.3
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• pp.154-159
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• 2006

It is essential to understand the decomposition characteristics for developing the optimum anaerobic digestion system of organic wastes. In this study, BMP (Biochemical Methane Potential) test using serum bottle was conducted to evaluate the anaerobic degradability of fish offal. 3 different groups of fish offal including waste from mackerel and hairtail handling except viscera and fish viscera were chosen for the substrates. Grinded fish offal was transferred anaerobically to serum bottle in amounts of 50 ml, 100 ml and 150 ml, respectively. BMP test was carried out in triplicate. Cumulative methane production and methane production rate depending on incubation time were evaluated. These results varied depending on substrate characteristics. The average values of ultimate methane yield ranged between $420ml{\cdot}CH_4/g{\cdot}VS$ and $490ml{\cdot}CH_4/g{\cdot}VS$, and the methane production and degradation rate of viscera were higher than those of other parts of fish offal. According to the analysis of elemental composition, average C/N ratio of fish offal used in this study was 5.2. Theoretical ultimate methane yield calculated from elemental composition was $522ml{\cdot}CH_4/g{\cdot}VS$. Biodegradability was calculated as 0.847.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.28-33
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• 2005

A resource recovery technique using sub- and supercritical water hydrolysis was applied to recover amino aicds from waste fish entrails. The effect of reaction parameters such as temperature and time necessary for the control of reaction towards optimum yield of amino acids was investigated using semi-batch and batch reactors. Results showed a maximum yield of total amino acids (137 mg/g-dry entrails) from waste fish entrails at T=$250^{\circ}C$ (P=4 MPa) and reaction time of 60 min in a batch reactor. Under supercritical conditions (e.g., T=$400^{\circ}C$, P=45 MPa), the yield decreased due to rapid decomposition compared to production rate of amino acids. As a result, the low temperature and the short reaction time were needed to produce a maximum yield of amino acids.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.268-273
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• 2014

Experiments on carbonization were conducted using fish offal generated from fish market for the purpose of resource recycling. Elemental composition of fish offal and effect of carbonation temperature on the overall yield were investigated. Carbon and hydrogen contents of fish offal were 51.1% and 7.6%, respectively in view of elemental composition. Particularly, nitrogen and sulfur contents were as high as 9.8% and 1.0%, respectively. These values suggests that odor problem of fish offal can be serious. Comparing elemental composition of fish offal with other waste materials, it is thought that carbon and hydrogen contents are considerably high. These implies that thermal disposal will be the best option for final disposal method of fish offal. As a results of carbonization experiments on Mackerel, Hairtail, Croaker and mixed sample of Mackerel, Hairtail and Croaker, carbonization patterns were quite similar irrespective of fish species. Carbonization yield was varied significantly depending on carbonization temperature at the carbonization time of 5 minutes and 10 minutes. When the carbonization time was maintained longer than 30 minutes, yield variation depending on time variation at each temperature was insignificant. Thus, it can be concluded that effect of carbonization time on overall yield was minor when the carbonization time was maintained longer than 30 minutes. Primary vaporization in carbonization conducted at the temperature of $400^{\circ}C$ was minor. Thus, difference of yield between temperature of $500^{\circ}C$ and $400^{\circ}C$ was appeared greatly. It can be concluded that yield difference depending on carbonization temperature can be neglected if the carbonizing temperature exceed $600^{\circ}C$ and carbonizing time exceed 10 minutes at the same time.

• KSBB Journal
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• v.18 no.6
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• pp.495-499
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• 2003

The effect of operating parameters (reaction temperature and time) and reaction modes (batch and semi-batch) on the behavior of amino acid production from hydrothermal decomposition of fish-derived wastes was investigated. The amino acids obtained in batch experiments at temperature of 250$^{\circ}C$ were mainly alanine (Ala) and glycine (Gly) at maximum yield of 65 and 28mg/g-dry fish, respectively. At relatively lower temperature of 200$^{\circ}C$, the yield of high-molecular-weight amino acids such as aspartic acid (Asp) and serine (Ser) is high, but decreases as temperature increases. It is likely that high-molecular-weight amino acids decompose faster than low-molecular ones. Semi-batch mode of reaction suppressed decomposition of amino acids into organic acids (or volatile materials) by continuously removing the products from the reaction zone as soon as they are formed. Thus, large amount of high-molecular-weight amino acids such as Asp and Ser at this reaction mode was observed.

• Journal of Energy Engineering
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• v.13 no.3
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• pp.228-233
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• 2004

This paper reports production of low-molecular weight carboxylic acids from the hydrothermal treatment of representative organic wastes and compounds with or without oxidant (H$_2$O$_2$). Organic acids such as acetic, formic, succinic and lactic acids were obtained. This result increased to 42mg/g dry waste fish entrails in the presence of H$_2$O$_2$. Experiments on glucose representing cellulosic wastes were also carried out, getting acetic acid of about 29mg/g glucose. Studies on temperature dependance of formation of organic acids showed thermal stability of acetic acid, whereas, formic acid decomposed readily under hydrothermal conditions. In general. results demonstrated that the presence of oxidants favored formation of organic acids with acetic acid being the major product.

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.1
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• pp.71-85
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• 1997

There are approximately 500 abandoned mining sites in Korea. Abandoned mines cause various environmental and safety problems such as landscape damage, soil, groundwater and stream pollution by heavy metal, acid mine drainage and soil erosion. According to the survey, there are significant numbers of mines causing environmental problems in Korea. For a environmentally sound management of abandoned mines, the Soil Pollution Control Act should include the regulation concerning soil pollution and recovery standards of the abandoned mines. Also, comprehensive survey about abandoned mines, setting-up of tile recovery priority, finance for clean-up are necessary.

• Journal of Life Science
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• v.8 no.5
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• pp.589-597
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• 1998

In order to effectively utilize marine processing by-product such as fish scale, chemical compositions for the scale were analyzed. The selected fishes were gray mullet, Mugil cephalus, living in the sea and carp, Cyprinus carpio in the fresh water, having a lot of scales among the fishes living in seawater and fresh water. And we also investigated the difference in the chemical compositions between gray mullet and carp, depending on both living circumstances. The major components of the scales were found to be crude ash and crude protein which were each about 49% for gray mullet and which were about 20% and 79% for carp, respectively, on the basis of dried scales. The proteins extracted from both scales proved to be collagen through amino acid compositions and SDS polyacrylamide gel electrophoretic patterm. Also this scale collagen was assumed to by Type I collagen because the migration rate of $\alpha$1 and $\alpha$2 subunit of the collagen were almost the same those as calf skin Type I collagen. Most of proteins from gray mullet was collagen, however, the collagen content in proteins from carp was estimated to be only about 53%, on the basis of the ratio of hydroxyproline to protein. The crude ashes of both scales identified to be hydroxyapatite through element compositions and X-ray diffraction analysis. In conclusion, both fishes in different living circumstances were almost similar to in the chemical compositions but chemical contents for crude ash and crude protein.