• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.923-931
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• 2005

A study was carried out to identify the major causes of sediments pollution in the Paldang Lake in the vicinity of Gyeongan river. Samples from 40 sites were collected and analyzed to characterize the regional distributions of grain size, organic matter contents, and concentrations of T-N, T-P and heavy metals. contaminations. The mean grain size(Mz) ranged from sand type(Mz, $1{\sim}3\;{\phi}$) where Bukhan River and Namhan River converges at a high flow rate to silt type(Mz, $5{\sim}10\;{\phi}$) at the downstream of Gyeongancheon and Paldang lake, reflecting the water circulation in the area. Except sampling point St. 36 near the wetland, the determination coefficient($r^2$) of Mz and organic matter(LOI) was 0.88, showing that more organic matters are concentrated inside finer sediments. The concentrations of T-N and T-P in sediments were higher in the area at which Mz and organic matters are also higher. High concentrations of T-P analyzed in the sediments, ranging from $216{\sim}1,623\;{\mu}g/g$ (Avg. $769\;{\mu}g/g$) could be considered as a critical level. Adsorbed-P and NAI-P, which are easily released to the surrounding environments when physico-chemical characteristics of sediments are changed, was found to be around 20%, which was showed by the result of fractionated-P. Moreover, Principle Component Analysis(PCA), showed that high concentrations of T-N, T-P, organophilic metals (Cd, Cu, Pb, Zn) are distributed in the areas where high organic matter contents and fine grain-sized sediments are found. However, results of $I'_{geo}$ (Geoaccumulation Index) that considers the grain size of sediments showed that heavy metal concentrations in the lake was low enough to be considered as Class 1 indicating the relative degree of pollution was less than zero.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.123-136
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• 2010

In order to remediate heavy metal contaminated Nong island, Maehyang-ri shooting range soils through the batch reactor scale washing were evaluated. The experiment texture soil of N3 in the Nong island at north side incline was (g)mS containing 12.9% gravel, 47.0% sand, 35.1% silt and 5.0% clay. And the N3 soil area was contaminated with Cd($22.5\pm1.9$ ppm), Cu($35.5\pm4.0$ ppm), Pb($1,279.0\pm5.1$ ppm) and Zn($403.4\pm9.8$ ppm). The EDTA(ethylene diamine tetra acetic acid, $C_{10}H_{16}N_2O_8$) in the N3 soil was observed as most effective extractants among the 5 extractants(citric acid, EDTA, phosphoric acid, potassium phosphate and oxalic acid) tested. And chemical partitioning of heavy metals after washing N3 soil with EDTA was evaluated. Removal efficiency of residual fractions was higher than that of non-residual fractions. To choose EDTA extractant which is the most effective in soil washing technology using batch reactor process cleaning Pb and Zn contaminated sits; Pb and Zn removal rates were investigated 92.4%, 94.0% removal(1,000 mM, soil:solution=5, $20^{\circ}C$, 24 hour shaking, pH=2, 200 RPM), respectively. The results of the batch test showed that the removal efficiency curve was logarithmic in soil was removal. Thus, EDTA washing process can be applied to remediate the Pb and Zn contaminated soil used in this study.

• Food Science and Preservation
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• v.4 no.3
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• pp.287-293
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• 1997

This study was investigated to viscosity, color, chemical properties, and lipid and fatty acid composition for examination of physical and chemical characteristics of sesame oils. Yield of sesame oil was higher in Ansan sesame than that of Chinese and Dambaek sesame. Viscosity of sesame oils was higher than that of shame oils from Dambaek and Chinese sesame, but turbidity and sedimentation rate were higher in Dambaek's sesame oil than those of Ansan's and Chinese sesame oils. In the acid value, saponification value and iodine value of sesame oils, and chemical characteristics of Dambaek's sesame oil were better than those of the others. The neutral, glycolipid and phosholipid contents of sesame oils were 91.1∼92.1, 2.5∼3.5 and 5.5∼6.4%, respectively. The major fatty acids of sesame oils were oleic, linoleic palmitic and stearic acid. The content of oleic acid was higher in Dambaek's and Ansan's sesame oil than that of Chinese sesame oil, and the content of linoleic acid was higher in Chinese sesame oil than the others. The fatty acid composition of neutral lipid, glycolipid and phospholipid were similar to those of total lipid. The ratio of unsaturated fatty acid and saturated fatty acid was higher in Korean sesame oils than those in Chinese sesame oil. The mineral(Mg, Cu, Fe, In, Al, Mn) content of Korean sesame oils was higher than that of Chinese sesame oil. and heavy metals(Cu, Ag, Pb, Cd, As) were not detected.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.4
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• pp.303-310
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• 2000

This study is conducted in order to find more improved solidifying effects than the former converter slag solidification technology. The converter slag is used as a solidifying agent, and the quick lime and the gypsum are used as solidifying aids. Several tests are performed for the purpose of investigating the solidifying effects and the applicability of the solidified sludge as a daily or intermediate landfill cover. The unconfined uniaxial compressive strength, pH and leaching of heavy metal are investigated. In the case of using both quick lime and gypsum as solidifying aids, the compressive strength of specimen has significantly increased that of specimen which used quick lime only. The compressive strength of each specimen cured for 7 days which is mixed with quick lime and gypsum as mixing ratios 7:1, 5:1 and 3:1 are $0.59kg/cm^2$, $1.18kg/cm^2$, and $1.25kg/cm^2$, respectively. The results of all the leaching tests of specimen cured for 7 days show that the concentrations of leachate heavy metals(Cu, Pb, Cd and $Cr^{6+}$) are lower than the Korea toxic waste criteria. The microstructure analysis by SEM shows that needlelike crystals appear as the solidification proceed. The analysis of these crystals by EDS confirms that these main components are Ca. Si etc. Also, XRD analysis shows that the main solidification products are CSH and Ettringite; in addition, $Ca(OH)_2$ CAH are observed. When the added gypsum is used as a solidifying aid, more improved solidifying effects are obtained and the solidified sludge may be appropriately used as a daily or intermediate landfill cover.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.265-271
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• 2021

Intertidal mud crab (Macrophthalmus japonicus) is an organism with a hard chitinous exoskeleton and has function for an osmotic control in response to the salinity gradient of seawater. Crustacean exoskeletons change in their natural state in response to environmental factors, such as changes in the pH and water temperature, and the presence of pollutant substances and pathogen infection. In this study, the ecotoxicological effects of irgarol exposure and heavy metal distribution were presented by analyzing the surface roughness of the crab exoskeleton. The exoskeleton surface roughness and variation reduced in M. japonicus exposed to irgarol. In addition, it was confirmed that the surface roughness and variation were changed in the field M. japonicus crab according to the distribution of toxic heavy metals(Cd, Pb, Hg) in marine sediments. This change in the surface roughness of the exoskeleton represents a new end-point of the biological response of the crab according to external environmental stressors. This suggests that it may affect the functional aspects of exoskeleton protection, support, and transport. This approach can be utilized as a useful method for monitoring the aquatic environment as an integrated technology of mechanical engineering and biology.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.149-158
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• 2006

Objectives : This study was carried out to characterize the 'Kaolinitum' used as mineral medicine before and after physical and chemical manipulation. Methods : The mineralogy of the original raw kaolinitumes with different localities was identified by X-ray diffraction analysis. The concentrations of major, minor and trace elements of samples, furthermore, measured by the X-ray fluorescence spectrometer (XRF) and inductively coupled plasma-mass spectrometer (ICP-MS). In order to understand the variety of kaolinitum after thermal treatment, the differential thermal analysis (DTA) and the thermo-gravimetric analysis (TGA) were carried out. Results : According to the result of X-ray diffraction analysis, the kaolinitumes are composed ofcalcite, alunite and quartz. Si and Al are the major ions and heavy metals such as Cd, Cr, Pb, Zn, As, Ni and Cu are included in the kaolinitumes as trace ions. The concentration of these metals in the samples decreased after physical and chemical manipulation. The weight of kaolinitum was also decreased at $500^{\circ}C$ and about $700^{\circ}C$during experiment of TGA. Conclusion : The results of this study can be used to provide the scientific basis of the medical usage of kaolinitum.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.41-53
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• 1997

Geochemical data of soil and water samples were presented in order to assess the environmental impart for drinking water sites. Microscopic observation of rock samples and physical and chemical analysis of soil and water samples were undertaken. The geology of study areas are classified into three groups such as granitic rocks, meta-sedimentary rocks and sedimentary rocks. Enrichment of heavy metals derived from those rocks is not found in this study areas. Soils were analyzed for Cu, Pb, Zn, Cd and Cr using AAS extracted by HNO$_3$+HClO$_4$ and 0.1 N HCl. Heavy metal concentrations in soils are within the range of those in uncontaminated soils. In comparison of metal contents extracted by 0.1 N HCl and HNO$_3$+HC1O$_4$, less than 10% of the heavy metals are present in the exchangeable fraction. In particular, an pollution index has been proposed to assess the degree of soil contamination. Pollution index in soils are between 0.03 and 0.47 therefore, soils are not polluted with heavy metals. Deep groundwaters within granitic rocks have been evolved into Na$\^$＋/-HCO$_3$$\^$-/ type, whereas other deep groundwaters evolved into Ca$\^$2＋/-HCO$_3$$\^$-/ type. The predominance of Na$\^$＋/ over Ca$\^$2＋/ in deep groundwaters within granitic rocks is a result of dissolution of plagioclase, but for sedimentary and meta-sedimentary rocks, dissolution of calcite is a dominant factor for their hydrogeochemistry. The pH, conductivity and contents of the most dissolved ions in the water increase with depth. Shallow groundwaters, however, are highly susceptible to pollution owing to agricultural activities, considering the fact that high contents of nitrate, chloride and potassium, and high K/Na ratio are observed in some shallow groundwaters. In a thermodynamic approach, most natural water samples are plotted within the stability fields of kaolinite and smectite. Therefore, microcline and other feldspars will alter to form clay minerals, such as kaolinite and smectite. From the modelling for water-rock interactions based on mass balance equation, models accord well with behavior of the ions and results of thermodynamic studies are derived.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.232-237
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• 2010

This study was carried out to evaluate the safety of circulated oriental medicines and their related preparations in Gyeonggi-do. Total 366 samples (165 species) were analyzed about heavy metals, residual contents of sulfur dioxide ($SO_2$), and 68 samples were analyzed about preservatives. 17 samples (13 species, 4.6%) were exceeded the legal limit of heavy metal. The concentrations over the legal limit for Pb, Cd, As and Hg were 6.1~19.2 mg/kg, 0.4~0.7 mg/kg, 6.9 mg/kg and 0.7 mg/kg, respectively. In particular, the exceeding ratio (5.9%) of the legal limit of heavy metals in foreign products was 3.3 times more than domestic products (1.8%). 13 samples (10 species, 3.6%) exceeded the limit of residual sulfur dioxide and the concentration ranges were 105 to 428 mg/kg in domestic products, on the other hand foreign products were from 114 to 2,468 mg/kg. The mean concentration over the limit of residual sulfur dioxide of foreign products (804 mg/kg) was 2.4 times more than domestic products (338 mg/kg). In studying of the preservatives in oriental preparation, the contents of dehydroacetic acid (48.9~64.1%) in 3 samples of labeled solutions were under the labeled preservative contents and the contents of benzoic acid (139.9%) in 1 sample of labeled pill product was exceeded the labeled preservative contents. The numbers of the detected preservatives in unlabeled solutions, pills and granules were 4, 11 and 7, respectively.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.525-528
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• 2001

This study was conducted to estimate the contents of heavy metals in some health foods available on Korean markets. The samples were digested with microwave system, then analyzed using GF-AAS for the contents of lead (Pb), cadmium (Cd) and arsenic (As). The contents of mercury (Hg) were determined using a mercury analyzer. The average values of Hg, Pb, Cd and As in calcium (Ca) health foods were 0.007, 1.08, 0.02 and 0.48 mg/kg respectively. Those values in chitosan health foods were 0.001, 0.36, 0.01 and 0.03 mg/kg respectively. Those values in propolis health foods were 0.013, 4.96, 0.01 and 0.13 mg/kg, respectively. The health foods that contained cow bone powders had the highest lead contents. Based on the variation in lead contents of those products, it could be possible that they might be contaminated through raw materials and/or manufacuring process. Some propolis products were also very high in lead contents. There could be risks for some population, especially the aged who overtake those health foods, to have heavy intake of lead. Therefore, we established the lead standards of 3.0, 2.0 and 5.0mg/kg less than for Ca, chitosan and propolis health foods respectively, based on the Codex method.

• Analytical Science and Technology
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• v.29 no.3
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• pp.114-125
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• 2016

In this study, 165 wastewater discharge facilities in 10 business types were investigated with regard to 24 specific hazardous substances that included heavy metals, VOCs, CN, and phenol in the Gwangju city. Cu in the range from from 0.008 to 35.420 mg/L was detected in all business types and the detection rate was 46.8 %. Other heavy metals, such as Cd, As, Hg, Pb, and Cr⁺⁶ were detected as well. However, their detection rates ranged between 0.6 and 1.8 %. CN and phenol were detected in one and five facilities, respectively. 12 species of VOCs were detected: chloroform 80.6 % (0.42 to 81.60 μg/L), benzene 16.4 % (1.49 to 3.31 μg/L), trichloroethylene 11.5 % (1.78 to 6.02 μg/L), 1,1-dichloroethylene 10.3 % (1.23 to 5.89 μg/L), and dichloromethane 8.5 % (0.28 to 968.86 μg/L) in the detection rate order. The concentration of VOCs was detected in trace amounts, except for dichloromethane that exceeded the effluent quality standard in three business types, namely, metal manufacturing, food industry, and car washing facility. Chloroform was detected in all business types, where 24.88 μg/L were detected in the laundry business and 53.41 μg/L in the water supply business; the mean concentration of chloroform in these two business types was higher than elsewhere. Therefore, for the disposal of non-degradable specific hazardous substances in industrial wastewater, it is necessary to introduce physical and chemical processes, such as activated carbon adsorption, fenton oxidation, ozone treatment, as well as photocatalyst and the UV radiation.