• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.11a
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• pp.90-90
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• 2001

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.37-44
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• 2006

Ecotoxicity assessments of 90 selected effluents of 22 industry types from 2002 to 2004 in Korea were evaluated by a toxic battery of bioassay test using fish Oryzias latipes, invertebrate Daphnia magna, algae Selenastrum capricornutum and bacteria Vibrio fischeri with the physicochemical measurement items and permit concentrations on the present Water Quality Conservation Act in Korea. Total toxic unit (${\Sigma}TU$) of 8 industry types of 22 industry types by the toxic battery appeared in order of the value site as follows; Pigment Dye Manufacturing (${\Sigma}TU$ 217.1) > Textile and Dye (${\Sigma}TU$ 39.3) > Semiconductor Electronic Manufacturing (Small) (${\Sigma}TU$ 25.6) > Wastewater and Sewage Treatment Plants (${\Sigma}TU$ 25.4) > Coating (${\Sigma}TU$ 23.8) > Leather Skin Manufacturing (${\Sigma}TU$ 18.0) > Synthetic Resin Manufacturing (${\Sigma}TU$ 15.6) > Assemble Metal Manufacturing (${\Sigma}TU$ 10.7). Our results demonstrate that ecotoxicity assessment, by bioassay test, is effective and practical for industrial wastewater management for 90 selected effluents with the limitation of the physicochemical permit. Among 90 effluents, 9 samples failed physicochemical permit limitation and 81 passed it. In result of ecotoxicity assessment of 90 effluents by the toxic battery, 76 effluents exhibited ecotoxicity and the others did not. The physicochemical measurement items and permit concentrations on the present Water Quality Conservation Act in Korea were low related to the ecotoxicity value by the toxic battery and appeared limited for water quality management to water-ecosystem and environment-friendly management of water.

• Journal of Environmental Science International
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• v.23 no.7
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• pp.1269-1275
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• 2014

Ecotoxicity assessments with the physiochemical water quality items and the bioassay test using Daphnia magna were conducted for 18 selected effluents of 6 industrial types (metal processing, petroleum refining, synthetic textile manufacturing, plating, alcohol beverage manufacturing, inorganic compound manufacturing) being detected toxicity from industrial effluent in Ulsan city, and the interrelationship between total toxic unit (${\Sigma}TU$) and concentrations of Water Quality Conservation Act in Korea were investigated. The average toxic unit(TU) of effluents for 6 industrial types displayed the following ascending order: petroleum refining (0.2) < synthetic textile manufacturing (0.6) < alcohol beverage manufacturing (0.9) < metal processing (1.3) ${\leq}$ inorganic compound manufacturing (1.3) < plating (3.0). These values were less than effluent permission standard. Based on the result of substances causing ecotoxicity, the correlation analysis was not easy because most of heavy metals were not detected or were less than effluent permission standard. Toxicological assessment of industrial effluent was suitable for the evaluation of the mixture toxicity for pollutant. The whole effluent toxicity test using a variety of species was needed for the evaluation of industrial wastewater.

• Journal of Korean Society on Water Environment
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• v.30 no.6
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• pp.585-595
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• 2014

The temporal trends of the prioritized toxic water pollutants generated and discharged from the industrial facilities in the Geum-River basin, Korea were analyzed with the results of the nationwide Water Pollution Source Survey conducted in 2001 - 2012. The statistical results indicated rapid increase in the volume of raw toxic wastewaters whereas the amount of each toxic pollutant kept fluctuating for 12 years. Serious discrepancies in the survey data of the same type of industries demonstrated a low reliability of the survey result, which stemmed from several error factors. A unit-load for each type of industrial facility was devised to estimate the amount of prioritized toxic water pollutant based on the total volume of industrial wastewater generated from the same type of industrial facilities. The supplementary measures with an effective permit issuance policy and adding survey parameters of terminal wastewater treatment plants to use them as references to the Water Pollution Source Survey were suggested as means to minimize the errors associated with the false reports from the industries.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.185.1-185
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• 1998

No Abstract, See Full Text

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.3
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• pp.89-96
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• 2005

In the present work, production of organophosphorus hydrolase (OPH) that is secreted in periplasmic space of recombinant Escherichia coli was performed for degradation of environmental toxic organophosphate compounds, paraoxon. The optimal conditions for enhancement of OPH production were 1.0 mM isopropyl-${\beta}$-D-thiogalactopytanoside (IPTG), 0.25 mM $Co^{2+}$, and 0.1 mM ethylenediamine tetraacetate (EDTA). Under these culture conditions, the maximum OPH production was $174Unit/L{\cdot}OD$. In addition, 1 mM of paraoxon was completely degraded by OPH. These results can be used as a bioremediation tool for removal of environmental toxic organophosphate compounds remaining in soil and aquatic environment.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.1-12
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• 2019

In this study, TI(Toxic Index) of Daphnia toximeter corresponded to ecological toxicity standard 1 TU(Toxic Unit) was set up using Daphnia toximeter and when operating NOEC(water quality standards for drinking water) and $EC_{50}$ Daphnia toximeter alarm was issued appropriately, which enables real time ecological toxicity evaluation. I studied to get a good shot and the research was conducted by investigating domestic and international related data and conducting a preliminary study. 6 of 59 hazardous substances (As, Hg, Cr, Diazinon, Dioxane, and Phenol) recommended by the water quality monitoring items for artificial river water were selected and static, dynamic and quality management test, TI was shown to be good in other materials except Diazinon, and as a result of $EC_{50}$ spiking test, TI was matched to TU by distinguishing between 1 TU and 1 TU. in suggesting the complementary point of ecological toxicity management system and the future of research on water Daphnia toximeter.

• Microbiology and Biotechnology Letters
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• v.27 no.4
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• pp.278-285
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• 1999

In order to use heat shock promoter for the detection of toxic substances, dnaK promoter was amplified from E. coli genomic DNA by using a polymerase chain reaction(PCR) followed by sequencing and sub-cloning into the multi-cloning site of the plasmid, pUCD615. The pUCD615 is a broad-host-range vector containing promoterless lux operon originated from V.fischeri. The recombinant plasmid was transfered to E. coli DH5$\alpha$ through electroporation. The recombinant E. coli showed several patterns of bioluminescent responses to ethanol stress. The bioluminescent E. coli also showed responses to other toxic substances including FeK3(CN)6, CdCl2, p-nitrophenol and HgCl2. The increases of RLU(Relative Light Unit) were observed at 100ppm of FeK3(CN)6, 10ppm and 100ppm and 100ppm of CdCl2, 1ppm of 10ppm of p-nitrophenol and at 1ppm of HgCl2.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.913-918
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• 2006

Both raw wastewater and effluent from a rubber products manufacturing factory were found to be toxic to Daphnia magna though the effluent satisfied current water quality standards. Thus, in order to reduce toxicity, advanced oxidation processes (AOPs) such as gamma-ray (${\gamma}-ray$) treatment and ozonation ($O_3$) were applied. A combined ${\gamma}-rays/O_3$ treatment at 20 kGy after coagulation significantly reduced toxicity of raw wastewater, changing 48-h toxic unit (TU) value from 201.21 to 23.92. However, toxicity of treated water was higher than that of effluent (TU = 12.15). This shows limitation of gamma-ray treatment to remove toxicity of raw wastewater. In case of effluent, the combined ${\gamma}-rays/O_3$ treatment at 20 kGy efficiently decomposed toxic compounds down to non toxic level. This work strongly supports the necessity of toxicity reduction evaluation as well as toxicity-based effluent management.

• Journal of Korean society of Dental Hygiene
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• v.17 no.1
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• pp.13-25
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• 2017

Objectives: The purpose of this study was to compare colony forming unit (CFU) method and multiplex real-time polymerase chain reaction (MRT-PCR) method for accurate quantitative analysis of bacteria. Methods: We compared the CFU method and the MRT-PCR method, which are still used in Korea, for Prevotella intermedius (P. intermedius), a periodontal disease pathogen selected by MRT-PCR, and Streptococcus mutans (S. mutans), a dental caries causative organism. The subjects of this study were 30 patients who visited the C dental hospital. Results: Total microorganisms in MRT-PCR method were significantly higher in both types of bacteria (p<0.05), since DNA of dead bacteria was also analyzed. This was because the periodontal dise(-) anaerobes, and even dead bacteria contain large amounts of toxic substances called LPS in the extracellular membrane, and fimbriae and pili, which are motility structures, still remain as a strong toxic substance in periodontal tissue. Conclusions: Therefore, in terms of the total amount of bacteria found, the MRT-PCR method will be a useful technique for searching all the bacteria in the oral cavity including live bacteria, as well as sterilization.