• Korean Journal of Ecology and Environment
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• v.49 no.3
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• pp.228-235
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• 2016

Aquatic ecosystems are receiving various harmful effects due to anthropogenic chemical pollutions. To protect wildlife, risk assessments of the chemicals are conducted using reference indexes of toxicity estimated by species-level laboratory tests and/or micro-/mesocosm community-level studies. However, the existing micro-/mesocosm communities are structurally too complicated, and it is also difficult to compare the experimental results directly with those from species-level tests. Here, we developed a procedure of a simple bi-trophic microcosm experiment which contains the common species (a green algae, Pseudokirchneriella subcapitata and a cladoceran, Daphnia magna) for testing chemical toxicities. For the proper operation of bitrophic microcosm experiment, the minimum required concentration of primary producer (P. subcapitata) is $5{\times}10^5cells\;mL^{-1}$. The microcosm system showed higher stability when the initially introduced D. magna population was composed of neonates (<24-h old) than adults and those mixture. This simple microcosm system would be an applicable tool to estimate the disturbing impacts of pollutants on plant-herbivore interactions, and linking the species- and population-/community level risk assessments in the future studies.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.158-158
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• 2002

최근 들어, 일반적으로 알려진 중금속 외에 As 및 Se의 생래독성(예를 들면, 어류 및 양서류의 번식독성)이 많은 연구자나 환경관리자들의 관심대상으로 부각되고있다. 상수원 보호구역내 위치하는 하천이나 호소 인근에 As이나 Se의 오염원이 분포되어 있는 경우, 수서 생태계뿐만 아니라 인체의 건강에 큰 위협이 될 수 있기 때문이다. 그러므로, 본 연구에서는 하천수나 하상 퇴적토의 잠재적 오염 물질인수 종의 중금속에 대한 급성독성과, As 및 Se의 급성, 그리고 번식 독성을 수서곤충을 이용하여 측정하고 이를 상호 비교하였다. 본 실험에 적용된 생물은 생활사가 짧고 배양이 용이하며, 번식력이 높은 물벼룩 (Daphnia magna)과 소형물벼룩 (Ceriodaphia dubia)이었다.

• The Journal of Natural Sciences
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• v.12 no.1
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• pp.61-67
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• 2002

The results of laboratory experiments with microcosms containing Daphnia magna and Chlorella vulgaris demonstrated decrease of the structural exergy of artificial communities after the addition of model toxicants phenol and cobalt chloride. Structural exergy changes were more expressed than changes of components biomasses and total biomass of the community. It once more points to the possibility of the use structural exergy as ecosystem health reflecting parameter.

• Journal of Korean Society on Water Environment
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• v.30 no.1
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• pp.80-86
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• 2014

Unlike to natural organic matters (NOMs), effluent organic matters (EfOMs) are not well understood due to their complexity and heterogeneity. In this study, EfOMs from sewage and industrial wastewater treatment effluents and Suwannee River NOM (SRNOM) were isolated into hydrophobic (HPO), transphilic (TPI) and hydrophilic (HPI) fractions. Specific ultraviolet absorbance (SUVA) and fluorescence excitation emission matrix (FEEM) analyses were used to characterize physicochemical properties. In addition, acute toxicity and oxidative stress to Daphnia magna were evaluated to characterize toxicological properties. EfOMs showed similar properties to microbially derived organic matters having low hydrophobicity, which are totally different from SRNOM having high hydrophobicity. Moreover, acute toxicity and antioxidant enzyme activity in D. magna was largely dependent on fraction types of EfOMs. These findings suggest that EfOMs have different physicochemical and toxicological properties compared with those of NOMs, which needs to be further identified with various sources of EfOMs.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2000.05a
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• pp.241-242
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• 2000

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.81-86
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• 2016

Heavy metal pollution in agricultural fields at the abandoned metal mines has been serious problems in Korea. In order to manage heavy metal pollution in surface water and soil, numerous remediation strategies have been established. Therefore, main purpose of this research was to examine feasibility of ecological toxicity assessment for establishing management strategy in heavy metal polluted agricultural fields. Heavy metal concentration in surface water and soil was monitored along with ecotoxicity experiment with Daphnia magna and Eisenia fetida. Result showed that high toxicity was observed in heavily polluted agricultural field with heavy metals. In case of mortality of Daphnia magna (85%) and Eisenia fetida (6.7%), the highest ratio was observed when heavy metal concentration in surface and soil was high. Calculated ecotoxicity index (EI) ranged 0.06-0.30 and the highest EI was observed in heavily polluted sites among 5 abandoned metal mines. Overall, ecological toxicity assessment is necessary to evaluate heavy metal pollution in agricultural fields near at the abandoned metal mines along with chemical concentration analysis.

• Water for future
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• v.27 no.1
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• pp.69-77
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• 1994

As the standard of living improves, the amount of synthetic detergent consumption greatly increases. Detergents which are not treated in the sewer treatment processes, flow into rivers or waterstreams and accelerate the pollution of the surface water resources. Detergents contain lots of toxicants. And it is difficult to evaluate gross toxicity of each toxicant in thereceiving water. In the study, the acute toxicity of the synthetic detergents for home laundering and kitchen use were monitored with daphnia magna and photobacterium phosphoreum. Seven kinds of detergents were tested to evaluate the acute toxicity. The mean 24hr, 48hr-LC50 of the synthetic detergent for home laundering were 4.25%, 2.50% and these for kitchen use were 2.01%, 1.36% respectively. And the mean 5min, 15min-EC50 of the synthetic detergent for home laundering were 1.83%, 1.02%.

• Journal of Soil and Groundwater Environment
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• v.29 no.1
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• pp.72-83
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• 2024

Most of the slags generated from steel-making industry in Korea are recycled into media-contact aggregates such as fill and cover materials. For their use as media-contact aggregates, the slags must meet not only the waste quality criteria, but also the Daphnia magna acute toxicity test criteria. In this study, Korean Leaching Test ES 06150.e (Korea), Japanese Leaching Test JIS K 0058-1(Japan), Detuch Leaching Test DIN 19529 (Germany), Toxicity Characteristic Leaching Procedure (USA) were conducted for batch leaching test of slags from 6 Korean steel-making companies. In addition, Korean Standard up-flow percolation test (ES 06151.1) mimicking field conditions was conducted to assess the impact of the slag leachate on the surrounding environment indirectly. Heavy metals such as Cr⁶⁺ and Zn²⁺ were detected from both extractant and leachate samples, but all of them did not exceed waste quality criteria of each country. However, Daphnia magna acute toxicity tests using the leachate samples from up-flow percolation test with slag alone and slag/natural soil conditions exceeded ecotoxicity standard (TU=2) due to their high pH (11.3-12.5). After neutralizing the pH of the slag leachate to 6.5~8.5, the Daphnia magna mortality and immobilization were reduced to satisfy ecotoxicity standard. As the reducing pH of slag leachate would be extremely difficult, appropriate recycling management considering the physicochemical characteristics of he slags should be stuided further.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.05a
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• pp.122-122
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• 2001

The reaction kinetics of hexavalent chromium with ferrous ions were studied to determine the influence of reduction on the toxicity of chromium to aquatic organisms. The changes in chemical forms of the chromate in the presence of ferrous ions were examined in a bioassay system using Dphnia magna as a test organism. (omitted)

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.138-144
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• 2023

In this study, the effect of electrochemical treatment in mitigating alkali leaching into an aquatic environment was investigated. To modify the surface of cement paste, 1000 mA/m² of the direct current was passed through anodic graphite to the external mesh for 4 weeks. Then, the cement paste specimen was exposed to still water in air-tight condition to prevent natural healing of alkali leaching in the water. For 100 days of monitoring in water, the pH value was marginally increased at the electrochemical treatment, while control specimen ranked to the even higher pH accounting for 13.2 in the pH. Moreover, after the pH monitoring, the pH profile for the paste specimen indicated that the electrochemical treatment was effective in securing the higher alkalinity of cement matrix. The water obtained from alkali leaching process, was used to ecological test for Daphnia magna. It was evident that the electrochemical treatment had minimal adverse effect on ecological impact, while control specimen mostly immobilized the standard Daphnia magna.