• Monthly Duck's Village
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• s.6
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• pp.3-6
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• 1998

• Monthly Duck's Village
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• s.4
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• pp.11-14
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• 1998

• Korean Journal of Organic Agriculture
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• v.22 no.1
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• pp.197-208
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• 2014

The present study was conducted to provide basic data for efficient vermicomposting of swine manure by investigating the effect of sawdust mix on growth and reproduction of earthworms, amount of earthworm cast produced, and its chemical composition when mixing swine manure in different levels (0(SSD0), 10(SSD10), 20(SSD20), 30(SSD30), and 40%(SSD40)) with sawdust commonly used as moist control in manure composting. The C/N ratio of the feed and the survival rate of earthworms for the SSD0 treatment (10.19, 35.2%), The C/N ratio of the feed was 11.09-16.44 and increased with higher level of sawdust mixed, and the survival rate of earthworms during the experiment period was 35.2-100%. The number of earthworms was 16.6 in the SSD40 treatment, and young worms were not found in the SSD0 treatment or the treatment with less than 30% sawdust in the mix. The number and the weight of cocoons in SSD30 and SSD40 treatments were found to be in the ranges of 23.8-59.8 and 256-660 mg respectively. The production of earthworm cast and digested amount were higher with the higher level of mixed sawdust (p<0.05), and the C/N ratio of cast increased with the mixed sawdust ratio, being significantly higher ratio in SSD30 and SSD40 than other treatments (p<0.05). Heavy metals content tended to decrease with the mixed sawdust level. To summarize, the higher level of mixed sawdust was associated with improvement in growth and reproduction of earthworms, and 30-40% sawdust mix in particular could result in efficient vermicomposting.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.4
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• pp.193-200
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• 2016

Water flea is a widely used test species in the aquatic ecotoxicity test. In Korea, D. magna is currently used as a standard test species, however that do not inhabit in the Korean aquatic ecosystem. In this study, Daphnia galeata, which is a dominant species in the Korean aquatic ecosystem, was collected from domestic lake and investigated to suggest the D. galeata for ecotoxicity assessment in Korea. We investigated the characteristics, life span, and toxicity sensitivity compared with D. magna. The life span test of D. galeata was performed in this study, and then the results were compared to the sensitivity with D. magna to confirm the applicability for ecotoxicity assessment. The 48h-L(E)C50 values for seven heavy metals (As, Cd, Cr, Cu, Hg, Ni, and Zn) of D. galeata and D. magna were collected and analyzed. As a results, shorter lifetime, less reproduction, smaller body size of D. galeata were observed compared with D. magna. D. galeata was similar or more sensitive than D. magna for seven heavy metals. Therefore, we propose that D. galeata is a suitable test species for ecotoxicity testing in Korea.