• Clean Technology
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• v.27 no.2
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• pp.174-181
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• 2021

This study analyzed the groundwater quality characteristics according to the main source of pollution and quarter (season) by using data from the pollution exclusive monitoring network in the Gyeongsangnam-do area for five years (2013-2017). The main source of pollution was the industrial complex areas, waste mines, and sewage treatment facilities. The analysis items were field measurement items (water temperature, pH, electrical conductivity, dissolved oxygen, oxide reduction potential), positive ions, and negative ions. Water temperature and pH did not vary significantly according to the main source of pollution. In industrial complex areas, the value of electrical conductivity was the highest, and dissolved oxygen value was the lowest. The mean concentration of positive and negative ions was the largest in industrial complex areas, followed by sewage treatment facilities and waste mines. It was shown that the concentration of sodium ion was the highest in industrial complex areas and calcium ion in waste mines and sewage treatment facilities. The concentration of bicarbonate ion was the highest in all main sources of pollution. Water temperature, pH, and concentrations of cations and anions did not vary significantly from quarter to quarter. Of the water quality types, the Na-HCO₃ type accounted for the highest proportion, but the Na-Cl type, which has a high possibility of external contamination, accounted for about 20% of the total data in the pollution exclusive monitoring network.

• Analytical Science and Technology
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• v.22 no.6
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• pp.480-487
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• 2009

The herbicide dicamba (2-methoxy-3,6-dichlorobenzoic acid) in soil and plants was determined by gas chromatography-mass spectrometry (GC/MS). The samples were extracted with diethyl ether at pH 2, and washed with 0.1 N HCl, and then dried. The dried residue was derivatized in 1 mL of 10% $H_2SO_4$-MeOH for 2 hr at $80^{\circ}C$. The reaction mixture was neutralized with 4 mL of sodium bicarbonate solution and reextracted with 5 mL of diethyl ether. After the extract was concentrated, dicamba was determined by GC/MS-SIM mode. There was good linearity above 0.999 in the ranges of the $1.0{\sim}100{\mu}g/kg$. Total 42 sample including 32 soil samples and 10 plants samples were analyzed by developed method. Dicamba was detected in the concentration range of $2.9-123.9{\mu}g/kg$ in 15 samples among 32 soil samples and in the concentration range of $43-33,252{\mu}g/kg$ in 5 samples among 10 plants samples. A cause of the wither and die of the pine trees is suspected to spray dicamba around or directly to them.

• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.18-26
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• 2014

We analyzed the demand of competent authorities requiring adequate technical information for initial investigation of chemical accidents. Reflecting technical reports on chemical accident response by environmental agencies in the U.S. and Canada, we presented information on environmental diffusion and toxic effects available for the first chemical accident response. Hydrogen fluoride may have the risk potential to corrode metals and cause serious burns and eye damages. In case of inhalation or intake, it could have severe health effects. The substance itself is inflammable, but once heated, it decomposes producing corrosive and toxic fume. In case of contact with water, it can produce toxic, corrosive, flammable or explosive gases and its solution, a strong acid, may react fiercely with a base. In case of hydrogen fluoride leak, the preventive measures are to decrease steam generation in exposed sites, prevent the transfer of vapor cloud and promptly respond using inflammable substances including calcium carbonate, sodium bicarbonate, ground limestone, dried soil, dry sand, vermiculite, fly ash and powder cement. The method for fire fighting is to suppress fire with manless hose stanchions or monitor nozzles by wearing the whole body protective clothing equipped with over-pressure self-contained breathing apparatus from distance. In case of transport accident accompanied with fire, evacuation distance is 1,600m radius. In cae of fire, fire suppression needs to be performed using dry chemicals, CO₂, water spray, water fog, and alcohol-resistance foam, etc. The major symptoms by exposure route are dyspnoea, bronchitis, chemical pneumonia and pulmonary edema for respiration, skin laceration, dermatitis, burn, frostbite and erythema for eyes, and nausea, diarrhea, stomachache, and tissue destruction for digestive organs. In atmosphere, its persistency is low, and its bioaccumulation in aquatic organism is also low.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.65-80
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• 1980

Processing conditions of the krill products such as paste food, krill protein concentrate, seasoned dried krill, powdered seasoning, meat ball, and snack have been examined and the quality was evaluated chemically and organoleptically. In the processing of paste food, krill juice was yielded $71\%$ and krill scrap $29\%$. The yields of paste and broth from the krill juice showed $53\%$ and $43\%$, respectively. In amino acid composition of the krill paste, proline, glutamic acid, aspartic acid, lysine, and leucine were abundant, while histidine, methionine, tyrosine, serine and threonine were poor. The optimum condition for solvent extraction in the processing of krill protein concentrate was the 5 times repetitive extraction using isopropyl alcohol at $80^{\circ}C$ for 5 mins. The yield of krill protein concentrate when used fresh frozen materials was $10.2\%$ in isopropyl alcohol solvent and $8.8\% in ethyl alcohol, and when used preboiled frozen materials, the yield was $13.0\%$ in isopropyl alcohol and $11.8\%$ in ethyl alcohol. Amino acid composition of krill protein concentrate showed a resemblance to that of fresh frozen krill meat. In quality comparison of the seasoned dried krill, hot air dried krill was excellent as raw materials and sun dried krill was slightly inferior to hot air dried krill, but preboiled frozen krill showed the poorest quality. The result of quality evaluation for seasoning made by combination of dried powdered krill, parched powdered sesame, salt, powdered beef extract, monosodium glutamate, powdered red pepper and ground pepper showed that the hot air dried krill was good in color and sundried krill was favorable in flavor. When krill meat ball was prepared using wheat flour, monosodium glutamate and salt as side materials, the quality of the products added up to $52\%$ of krill meat was good and the difference in quality upon the results of the organoleptic test for raw materials was not recognizable between fresh frozen and preboiled frozen krill. In the experiment for determining the proper amount of materials such as dried Powdered krill, $\alpha-starch$, sweet potato starch, sugar, salt, monosodium glutamate, glycine, potassium tartarate, ammonium bicarbonate, and sodium bicarbonate in processing krill snack, sample B(containing $7.7\%$ of dried powdered krill) and sampleC (containing $10.8\%$ of dried powdered krill) showed the most palatable taste from the view point of organoleptic test. Sweet potato starch in testing side materials was good in the comparison of suitability for processing krill snack. Corn starch and kudzu starch were slightly inferior to sweet potato starch, while wheat flour was not proper for processing the snack. In the experiment on frying method, oil frying showed better effect than salt frying and the suitable range of frying temperature was $210-215^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.47-56
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• 1999

$^{15}N$-Isotope concentrations of groundwater from l4 wells with different land-use types in Kyonggi Province were measured to investigate the nitrate contamination sources. Water samples were collected monthly from January to December 1997 and analyzed for pH. PC, anions (fluoride, chloride, nitrate, sulfate, inorganic phosphate, and bicarbonate), and canons (calcium, magnesium, potassium, and sodium). For the analysis of the $^{15}N/^{14}N$ ratio as ${\delta}^{15}N$, $N_2$ samples were prepared through Kjeldahl-Rittenberg method and were analyzed using an isotope ratio mass spectrometer (VG Optima IRMS). Reproducibility of the method and precision of the IRMS were below 1.0‰ and 0.1‰, respectively. The ionic composition of each groundwater sample was only slightly different according to the land-use type. The nitrate concentrations of groundwater in cropland or livestock farming areas were higher than those in the residential area. The percentages of nitrate to total anions of groundwater samples from the livestock farming area were higher than those of other areas. The ${\delta}^{15}N$ values of ammonium sulfate, urea, groundwater sample in the non-contaminated area, and water from the animal manure septic tank were -2.7, 1.4, 5.5, and 27.2‰, respectively. Based on the ${\delta}^{15}N$ values, the sources of nitrate could be classified as originated from chemical fertilizers with ${\delta}^{15}N$ values below 5% and as from animal manure or municipal waste with ${\delta}^{15}N$ values over 10‰. In most cases, contamination sources investigated from ${\delta}^{15}N$ values of groundwater samples were correlated with the specific sources according to the land-use types. However, some ${\delta}^{15}N$ values did not matched the apparent land-use types, and there were seasonal variations of ${\delta}^{15}N$ values within the same well. These results suggest that the groundwater quality was affected by two or more contamination sources and the contribution of each source to the groundwater quality varied depending on the sampling season.

• Journal of the Mineralogical Society of Korea
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• v.7 no.1
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• pp.49-61
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• 1994

As the groundwater flows along the fractures of crystalline rocks, it will be in contact with the fracture walls mostly coated by secondary minerals which are quite different form those of host rocks. The presence of fracture-filling minerals in crystalline rocks is important on the view point of radioactive waste disposal because of their great surface reactivity. The Surichi drill hole of 200 m in depth in the Yugu area composed mainly of Precambrian gneiss was selected to study the formation process of clay minerals on the fracture wall of gneiss, and their relation with present groundwater. The water-rock interaction in fractures resulted in the formation of gibbsite and clay minerals. They are formed by two different processes : (1) Incongruent dissolution of feldspar by groundwater diffused from a fracture path into rock matrix produced smectite and illite in situ, (2) on the wall of fracture, gibbsite, kaolinite, smectite and illite are formed by precipitation of dissolved species in groundwater. They show the paragenetic sequence such as gibbsite${\leftrightarrow}$kaolinite${\leftrightarrow}$smectite or illite. The paragenetic sequence of fracture-filling minerals was controlled by increase of pH of groundwater, decrease of fracture permeability by precipitation of fillings, and immobility of alkali or alkaline earths in groundwater. The groundwater from the Surichi borehole is a $Na-HCO_{3}$ type with pH range of 8.6-9.2. The sodium and bicarbonate in groundwater would be supplied by the dissolution of albite and calcite, respectively. The saturation index of groundwater and surface water calculated by WATEQ4F indicates that gibbsite and kaolinite are under precipitation to equilibrium state, and that smectite and illite are under equilibrium to redissolution environment. The stability relation of clay minerals in the $Na_{2}O-Al_{2}O_{3}-SiO_{2}-H_{2}O$ system shows that kaolinite is stable for all waters.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.283-290
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• 1982

Sardine and mackerel so called dark muscled fish have been underutilized due to the disadvantages in bloody meat color, high content of fat, and postmortem instability of protein. Recent efforts were made to overcome these defects and develope new types of product such as texturized protein concentrates and dark muscle eliminated minced fish. Approach of this study is based on the rapid dehydration of foamed fish-starch paste by dielectric heating. In process comminuted sardine meat was washed more than three times by soaking and decanting in chilled water and finally centrifuged. The meat was ground in a stone mortar added Ivith adequate amounts of salt, foaming agent, and other ingredients for aid to elasticity and foam stability. The ground meat paste was extruded in finger shape and heated in a microwave oven to give foamed, expanded, and porous solid structure by dehydration. Dielectric onstant $(\varepsilon')$ and dielect.ic loss $(\varepsilon")$ values of sardine meat paste were influenced by wavelength and moisture level. Those values at 100 KHz and 15 MHz were ranged 2.25-9.86; 2.22-4,18 for E' and 0.24-19.24; 0.16-1.20 for E", respectively, at the moisture levels of $4.2-13.8\%$. For a formula for fish-starch paste preparation, addition of $20-30\%$ starch (potato starch) to the weight of fish meat, $2-4\%$ salt, and $5-10\%$ soybean protein was adequate to yield 4-5 folds of expansion in volume when heated. Addition of e99 yolk was of benefit to micronize foam size and better crispness. In order to provide better foaming and dehydration, addition of $0.2-0.5\%$sodium bicarbonate, foaming agent, was proper to result in foam size of 0.5-0.7 mm and foam density of $200-400\;/cm^2$ which gave a good crispness. Heating time was depended upon the moisture level of fish-starch paste. For a finger shaped paste (1.0cm. $D\times10cm.L$) heating for 150-200 sec. in a microwave oven (700W. 2.45GHz) was sufficient to generate foams, expand, and solidify the porous structure of fish-starch paste. When the moisture content was above $55\%$ browning and scorching was deepened due to over-expansion and over-heating whereas the crispness was hardened by insufficient expansion at lower moisture content. In quality evaluation of the product, chemical composition of $30\%$ starch and $3\%$ salt added product was moisture $8.8\%$, lipid $2.4\%$, carbohydrate $46.7\%$, protein $36.1\%$, and ash $6.0\%$. Eleven membered panel test evaluated that fish-starch paste was acceptable in color, crisp-ness, taste, except a trace of fishy odour which could be masked by the addition of spice extracts.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.352-362
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• 1985

In succession to the previous paper, the present study was directed to investigate the optimal processing conditions of meat paste products with mackerel. To improve the gel forming ability of meat paste, washing conditions with water and alkaline solution, setting time and temperature, and heating temperature were controlled, and the influences of the freshness of raw mackerel and mixing ratios of ordinary and dark muscle on the qualities of meat paste products were discussed. The most effective condition for the keeping freshness of raw mackerel meat among different storage conditions was the forozen storage at $-20^{\circ}C$, followed by the storage at $-3^{\circ}C$ and ice storages, and this relation was coincided with the effect for maintaining of gel forming ability among above conditions, but there was no effect on keeping freshness of raw mackerel in the storage at $25^{\circ}C$. Gel strength of meat washed with tap water decreased with washing time, particularly, the meat washed three times showed higher gel strength than the meat washed more than 5 times. And the removal ratios of water soluble protein were $60\%$ in the meat washed three times and $90\%$ in the meat washed nine times. Washing effect of raw mackerel meat with alkaline solution was great at pH $6.5{\sim}7.0$ of meat paste yielding the highest gel strength in the meat washed with $0.5\%$ sodium bicarbonate solution. Gel strength of meat paste product decreased with the increase of mixing ratios of ordinary and dark muscle in the raw meat. In the setting conditions of meat paste examined, 15 hours at $5^{\circ}C$ and 2 hours at $30^{\circ}C$. The most suitable temperature for gel forming in heating conditions was $90^{\circ}C$, fellowed by $100^{\circ}C\;and\;80^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.401-408
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• 1985

In order to develop new types of product which can offer a sanitary and preservative duality, and convenience to consumers in marketing and cooking particularly in urban area, two processing methods of ready-to-cook food materials with dark fleshed fishes like sardine and mackerel were investigated. A method applied, in this work, is processing of ready-to-cook sardine meat "surimi" in which sardine meat is treated with alkaline solution to stabilize myofibrillar proteins, washed thoroughly with water to remove soluble components, and added with a proper amount of polyphosphate and sorbitol to enforce the functional property of meat such as water holding capasity, elasticity, and gel strength. The textural properties of fish meat paste made from the "surimi" meat were greatly dependent upon the stability of myofibrillar proteins and the elimination of water soluble components. The salt soluble proteins of sardine meat were so unstable in post-mortem stage that the gel forming ability was lost within 3 days at $5^{\circ}C$ storage and 2 to 3 weeks even at $-20^{\circ}C$ although the freshness was well kept for a week at $5^{\circ}C$ and several months of storage at $-20^{\circ}C$. A proper way of treatment to keep the proteins stable was that fish meat must be washed with $0.4\%$ sodium bicarbonate solution followed by 3 to 4 times washing with water. This resulted in removal of $80\%$ water soluble proteins and 50 to $60\%$ lipids. The addition of polyphosphate and sorbitol affected the stability of proteins during the storage of "surimi" meat. When phosphate and sorbitol were added in the ratio of $0.3\%:\;0.3\%,\;0.6\%:\;3\%,\;0.6\%:\;6\%,\;0:\,0.3\%\;and\;0.3\%:\;0$, the gel forming ability terminated in 35 days, 21 days, 14 days, 14 days, and 14 days of storage at $-30^{\circ}C$, respectively, while that of the control was 7 days. And it was also noteworthy that at least 8.0 mg/g of salt soluble protein nitrogen content was required for gel formation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.339-351
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• 1985

This study was carried out to investigate the optimal conditions for meat paste production with sardine. To improve the gel forming ability of meat paste, washing time and condition with alkaline solution, setting time and temperature, and heating temperature before pasteurization were controlled, and the influences of the freshness of raw sardine and the mixing ratios of ordinary and dark muscles on the duality of the meat paste product were discussed. The frozen storage showed a predominant effect on keeping freshness of raw sardine at different storage conditions and gel forming ability was maintained for 1 day at ice storage, for 3 days at $-3^{\circ}C$ and for 4 days at frozen condition, but there was no effect on keeping freshness of raw sardine in the storage at $25^{\circ}C$. Gel strength of meat paste product tended to decrease with washing time of raw meat, and in case of washing 3 times the meat appeared excellent in gel strength, but in case of seven and nine times the meat showed lower water holding capacity and decreased organoleptic test score in the quality of meat paste prtoduct. Raw meat washed with alkaline solution showed a desirable effect on gel forming ability compared with that washed with tap water, and in the case of washed with $0.5\%$ sodium bicarbonate solution exhibited the most favorable effect on gel forming. The gel strength of the meat paste product decreased with the increase of mixing ratios of dark muscle in the raw meat. Setting time and temperature for the gel forming ability of meat paste were good at $5^{\circ}C$ for 20 hours and at $20^{\circ}C$ for 2 hours. In the heating temperature of meat paste, heating treatment at $90^{\circ}C$ was desirable for gel forming.