• Journal of Korean Society of Environmental Engineers
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• v.36 no.2
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• pp.113-118
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• 2014

So many nationwide drinking water treatment plants are under much difficulties by new reinforced discharged effluent standards. Generally, the sludge at thickener should be retended for a long time during usual days. Sometime, the soluble manganese and chloroform may be formed under the anaerobic condition in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. It was necessary to improve the operation conditions and process itself in order to meet water quality standard recently reinforced. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. Sludge aeration prevent particle oxidated Manganese eluting soluble de-oxidated Manganese, excrete formated Chloroform from effluent to air, and improve sludge settling through homogenized sludge particle. We aerated sludge at the conventional water treatment plant, measured Manganese and Chloroform of clarified water at upper sludge, and solid-fluid interface height of sludge in mass cylinder. As a result, contaminant's concentrations of the final effluent was much decreased : 41% of manganese, approximately 62% of chloroform and 35% of sludge volume, compared with non-aeration sludge.

• Journal of Korean Society of Disaster and Security
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• v.14 no.3
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• pp.51-63
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• 2021

This study is for the quality improvement of water-sealing & reinforcement grouting in tunnel of the construction of the underground transportation network underneath the city. Existing tunnel grouting process did not technically utilize P~q~t charts fully. It is due to the absence of technical methods to decide how P~q~t charts change in the presence of trouble and what the change represents in grouting. There were no standards to decide which chart pattern represents which ground characteristics, how to categorize ground types, and how to take measures according to the standards. This paper studies on the grouting type, ground characteristics, ground type categorizing method, and countermeasures for both general and algorithm-processed grouting in soil and rock layer to address the aforementioned problems. Newly improved P~q~t charts from grouting in soil was categorized into six different types. Different characteristics and categorization method was developed for each type. Countermeasures for each type of grouting process were developed so that on-site application can be readily available. Improved P~q~t charts for rock layer also have six different types of grouting. Each type was given the countermeasures for rock layer grouting process for easier applications. Therefore, it is expected to be used through out the entire process of grouting from preparation to the last report of the water-sealing & reinforcement grouting in tunnel of the construction of the underground transportation network underneath the city.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.995-1004
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• 2017

Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of $2.14{\times}10^7copies/100ml$ in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.144-154
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• 2007

The acute and chronic toxicity of ambient and effluent water discharged to Lake Shihwa were investigated by using Vibrio fischeri, Daphnia magna and Oryzias latipes. Physicochemical characteristics including biochemical oxygen demand (BOD) and nine heavy metals in a total of 15 water samples were evaluated and were satisfied with relevant Korean Water Quality Standards (KWQS) except for Hg in one sample. Acute toxicity was observed in five samples collected from three sampling locations. When impacts on reproduction and growth after chronic exposure were evaluated with D. magna, all the samples showed significant chronic effects. Reproduction appeared relatively more sensitive endpoint. In 21 days chronic tests on O. latipes, survival, mean egg number per female per day, hatching success rate and time to hatch were affected by increasing sample concentration. The organ-level changes such as gonadosomatic index (GSI), and hepatosomatic index (HSI), and molecular biomarker of vitellogenin (Vtg) induction that evaluated with O. latipes increased as exposure concentrations increased. It is noteworthy that the samples that did not exceed the KWQS resulted in acute and chronic toxicities. The results suggested that numeric criteria based on physicochemical parameters may not be protective of aquatic ecosystem. Acute and chronic toxicity tests with organisms representing different trophic groups should be supplemented in order to provide adequate level of environmental protection.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.139-146
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• 1978

The annual variations of some heavy metal concentrations, Al, Mn, Fe, Cu, Pb, Zn, Cd, Hg were determined on tile day of spring tides in every month from May 1977 to April 1978 at eight stations in the Nagdong River downstream. Samples were taken at intervals of one or two hours from 7 a.m. to 7 p.m. at each station. Annual ranges and means of concentrations of the heavy metals are as follows : aluminium 40.7-3700 ppb, 286 ppb; manganese 10.3-261.5 ppb, 80.8 ppb; iron ND-1237 ppb, 147.7 ppb; copper ND-30.9 ppb, 2.49 ppb; lead ND-29.9 ppb, 1.10 ppb; zinc ND-156.8 ppb, 5.61 ppb; cadmium ND-1.22 ppb, 0.09 ppb; mercury ND-0.37 ppb, 0.02 ppb respectively. In general, the contents of heavy metals except managanese and mercury were higher at the stations above station one, Kupo, though the ranges of the contents showed remarkable difference according to the sampling stations. Annual means of the concentrations of iron and manganese were exceeded already the desirable standards for industrial water and closed to the criteria of raw water for public supply. The values that over the criteria of raw water were sometimes found. Mercury concentration showed comparative high level such as ND-0.37 ppb in annual range but it was not over the environment criterion, 0.5 ppb. Aluminium, iron and mercury showed generally high values in summer period and other metals in winter period, through the patterns of seasonal variations were difference depending on the sampling stations and the kind of metals.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.698-703
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• 2012

This survey was conducted to obtain basic data of the quality of groundwater for agriculture in Gyeongnam province. Groundwater samples from paddy 15, upland 15, and plastic film house 30 sites were collected on April, July, and October in every two years from 2002 to 2008. According to the result of water quality analysis, groundwater quality was suitable for irrigation purpose averagely. The $NO_3$-N contents by land use were in the order of plastic film house > upland > paddy field and its contents were 6.53, 4.80, and $3.68mg\;L^{-1}$, respectively. In annual changes of water quality, pH was no significant change in paddy, upland, and plastic film house by 6.6~6.9. EC was increased in upland and plastic film house in 2008 and majors factors were $NO_3$-N and $Cl^-$. In upland and plastic film house, $NO_3$-N contents were 4.72 and $6.52mg\;L^{-1}$ in 2002, respectively, whereas they were 5.63 and $8.70mg\;L^{-1}$ in 2008, respectively. Of the investigated sites, $NO_3$-N was exceeded water quality standards for agriculture by 3.3~15.0% in plastic film house and $Cl^-$ was exceeded water quality standards for agriculture by 2.2% in upland of 2004. The $NO_3$-N contents were decreased with well depth and their contents were $5.38mg\;L^{-1}$ from 3~10 m, $4.87mg\;L^{-1}$ from 10~20 m, and $2.58mg\;L^{-1}$ from above 30 m. The $NO_3$-N contents by soil texture were highest in sandy loam by $5.73mg\;L^{-1}$ and lowest in clay loam by $4.13mg\;L^{-1}$. The $NO_3$-N contents by crops category were in order of fruit vegetables > leaf vegetables > rice > fruits > beans, contents of fruit vegetables and leaf vegetables were 5.81 and $5.30mg\;L^{-1}$, respectively.

• Analytical Science and Technology
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• v.31 no.5
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• pp.179-184
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• 2018

Diphencyprone (DPCP) is frequently used as a compounded preparation in dermatology for the treatment of alopecia and recalcitrant warts based on the immune reaction of skin allergy. However, DPCP is a non-recognized agent in Pharmacopoeia, because there are no criteria or analytical method for quality control of its powder and formulation. DPCP is unstable under light irradiation because as it easily decomposes to diphenylacetylene (DPA). This study aims to develop a simultaneous HPLC analytical method for analyzing DPCP and DPA in the raw materials and compounded preparation. The method required a C18 column ($250{\times}4.6mm$, $5{\mu}m$) at $40^{\circ}C$ with a mobile phase of (A) 0.01 M phosphoric acid in water and (B) acetonitrile at UV 220 nm. DPA conversion to DPCP in the powder and compounded preparations was accelerated after light exposure for 60 min. In addition, this resulted in different patterns depending on the wavelength of light and the formulation. That is, DPCP in compounded preparation was more unstable than that in the powder. However, the DPCP formulation in amber bottles was observed to remain stable, although the measured concentrations of DPCP were somewhat different from the nominal concentration of the compounded preparations. The control of the exact concentration is required for effective disease treatment, depending on the state of the patient. In conclusion, these results will be useful for the recognition of DPCP in Pharmacopoeia and new DPCP formulation development to prevent photodecomposition.

• Journal of environmental and Sanitary engineering
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• v.1 no.1 s.1
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• pp.1-29
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• 1986

The guidelines and regulations that have revised by World Health Organization, the United States of America, Canada and Japan were reviewed for standards relevant to health of the people. The substances and parameters were discussed. Various standards were presented and recent changes in policies were relighted with their scientific information.

• Journal of Haehwa Medicine
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• v.13 no.2
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• pp.197-204
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• 2004

Now many sustitution and false articles is used in korea instead of chenpi. To use chenpi correctly, we will make a quilitative certificational plan of chenpi to investigate all of lieraturea, records and documents. And we could reach conclusions as folloews. 1) Source In china source of Chen-pi is pericarp of citrus reticula Blanco(Family;rutaceae)and in korea source of Chen-pi is pericarp of citrus unshiu Markovich(Family;rutaceae). Though source of both countries are not same, it has no problems because of containing family plants and culture variants. 2) Harvesting and processing After the peel attained full growth, wash cleanly in water. And dry in shade or in low temporature at state of eliminating pericarp. 3) Quality (1) Functional standards Exocarp is soft and clear yellow with numerous oil sports. The less white mesocarp is the better. (2) Physicochemical standards We need to suggest new standards about hesperidin to various conditions by processing methods and storing time. The loss on drying is less than 13.5%. Ash content is less than 4.0%. A standard capacity of hesperidin is more than 4.0%. The content of heavy metal is less than 30 ppm. We can not detect reminding agricultural medicines.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.6
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• pp.43-48
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• 2002

This study was carried out to clarify the change characteristics of stream water quality by land-use of forest from July to September, 2000 in three stands(Pinus densiflora, Castanea crenata (I), Castanea crenata (II) stand) of Jeongpyeong-ri, Jinju-si, Gyeongnam. The mean pH of rainfall results in acid rain of 5.3. The pH of stream water in three stands was high in order of Pinus densiflora (pH 6.59), Castanea crenata (II)(pH 6.53) and Castanea crenata (I) stand(pH 6.47). The electrical conductivity of stream water was high in order of Castanea crenata (I), Pinus densiflora and Castanea crenata (II) stand. Cations contents of three stands in stream water were high in order of $Ca^{2+}$, $Na^{2+}$, $Mg^{2+}$, $K^+$ and ${NH_4}^+$. But anions of stream water in Pinus densiflora stand and Castanea crenata (II) stand were high in order of ${SO_4}^{2-}$, $Cl^-$ and ${NO_3}^-$. In Castanea crenata (I) stand cations of stream water were high in order of ${NO_3}^-$, ${SO_4}^{2-}$ and $Cl^-$. The level of pH, ${NH_4}^+$, ${NO_3}^-$, $Cl^-$ and ${SO_4}^{2-}$ of stream water in Pinus densiflora stand and Castanea crenata (II) stand reached within the level of domestic use standard for drinking water But the level of ${NO_3}^-$ of stream water in Castanea crenata (I) stand was higher than that of domestic use standard. Therefore, non-point sources like forest watersheds which are fertilizer application lands should be taken to the appropriate mitigation measures.