• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.127-137
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• 2018

Radioactive contamination has become an important environmental concern after the accident occurred in Fukushima Daiichi Nuclear Power Plants. $^{134}Cs$ and $^{137}Cs$ are the major fission products and they are main problems in radioactive contamination. Huge amounts of Cs were released during the Fukushima Daiichi Nuclear Power Plants accident and as a result of this incident, many researchers focused on the development of adsorbents for decontamination of radiotoxic cesium. This review will critically evaluate recent advances in the preparation of Prussian blue and its analogue compounds, which are promising materials for cesium removal. Furthermore, this review will discuss recent studies on the cesium adsorption using different types of clay and clay based adsorbents and summarize various types of newly developed Cs adsorbents reported in recent years.

• Journal of Korean Society of Rural Planning
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• v.21 no.4
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• pp.157-165
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• 2015

The purpose of this study is on identifying charactreistics and management direction of complementary pond of Dalmaji village in Gangjin. Accordingly, this village was indicated as Experience and Resort village by Korean government. This study describes the construction background and characteristics and identifies species diversity and characteristics through field survey. For this, literature and field survey was performed. In field survey, vegetational survey was performed in Aug. of 2015. D(Dominant degree) and S(Sociability degree) was measured by Brown-Blanquet's method. The answer was searched from Myungsanron(明山論), a textbook of Fengsui(風水) in Joseon dynasty. Of these causes, it was considered that the representative one is a protection of fire and infectious disease because the Wolgak mountain is a fire mountain(火山) as a stone mountain in Fengsui. The results demonstrate decline of aquatic ecosystem because of neglect management. The total number of species was 24. Of the species, Zelkova serrata is a natural vegetation of this complementary forest. This is nominated as Lagerstroemia indica and Camellia japonica community. Species composition demonstrate the characteristics of Korean southern region as mixed forest of evergreen trees and deciduous ones which are indigenous plants. It was considered Juniperus chinensis KaizukaVariega in central round island was planted in Japanese colonial period and it have to be removed. It was considered that name of moon pond and moon island etc. projects the mind of village ancestors which are going to reach an ideal condition of moon. And management of quantity and depth of pond water was critical for restoration of disappearing lotus from related literature. Periodic management was needed for ecological structure and function improvement because of ecological disturbance by the invasive plants like Humulus japonicus.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.821-826
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• 2011

Synthetic musk compounds are widely used as fragrances in a variety of personal care products like soaps, sampoos, cosmetics and perfumes. The occurrence of synthetic musk compounds in municipal sewage effluent and other environmental samples could negatively impact the health of the ecosystem and humans, due to persistent and long-term chronic exposure of aquatic organisms. Fifteen synthetic musk compounds (musk ketone, musk xylene, musk ambrette, musk moskene, musk tibetene, HHCB, AHTN, ADBI, AHDI, DPMI, ATII, ethylenebrasssylate, ambretettolide, cyclopentadecanolide, OTNE) were analysed in surface waters and sewage treatment plants (STP) influents/effluents in Korea by GC/MS. Method detection limits were $0.005{\sim}0.398{\mu}g/L$. HHCB and AHTN were most frequently observed in both surface waters and STP influents/effluents.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.62-72
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• 2006

Biological health in aquatic environments has been assessed by several approaches using various bio-taxa. Especially, fish has been identified as one of the best ecological indicators for an integrative health assessments in aquatic environments. In this preliminary study, the necropsy-based approach using the Health Assessment Index (Adams et al., 1993; HAI, Blazer, 2000), was employed for the assessments of aquatic environments influenced by effluent water from wastewater disposal plants (WDP) near a urban stream (i.e., Cap-Stream). For the impact analysis from the effluents, we developed 10 metric necropsy-based model including $M_l\;skin,\;M_2\;fin,\;M_3\;thymus,\;M_4\;spleen,\;M_5\;hindgut,\;M_6\;kidney,\;M_7\;liver.\;M_8\;eyes,\;M_9\;gill,\;and\;M_{10}$ pseudobranch. We set up duplicate controls (natural upstream water plus 5 fishes in each control tank) and duplicate treatments (effluent water from the WDP plus 5 fishes in each treatment tank) in the laboratory. Preliminary results showed that HAI values in the controls were zero, indicating an excellent condition by the criteria of HAI, while the HAI values in the treatments ranged between 40 and 150, indicating a poor condition. Also, various health conditions, based on the index of biological integrity (IBI), species richness, tolerance guilds, and trophic guilds supported the HAI approach. The HAI approach, not applied in Korea, not may be used as an surrogate fer ecological health assessment in lotic ecosystems.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.9
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• pp.918-924
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• 2008

This research investigates the influences of the presence of aquatic macrophytes on the changes of biogeochemistry in the sediments through the comparative analysis of porewater and sediments. From the in situ measurements, elevated SO$_4{^{2-}}$ concentrations were observed in the rhizosphere during the growing season, which was resulted from the oxidation of reduced sulfide in the sediments by the oxygen release from the plant roots. There was sufficient AVS in the sediments to induce observed SO$_4{^{2-}}$ concentrations. The amount of oxygen in the oxidation of AVS to produce observed SO$_4{^{2-}}$ concentrations is 0.85 g/m$^2$ day which is relevant to the results of other researches. The AVS concentrations in the vegetated sediments increased with the depth whereas there is higher mass of AVS in the surface of the non-vegetated sediments. This shows that evapotranspiration induces the transportation of SO$_4{^{2-}}$ in the surface water into the anaerobic sediments. In addition, the elevated organic content caused by the presence of plants increased $\beta$-glucosidase activities which play an important role in the carbon cycle of the sediments.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.694-706
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• 2012

The purpose of this study was to offer the raw data for conservation and restoration of aquatic ecosystem by surveying and analysing a water quality, sediment, benthic macroinvertebrate, fish and hydrophyte in Junam reservoir. In the result of analysing the water quality, pH was 8.2~8.4, 6.0~7.5mg/${\ell}$ in COD, 10.0~10.3mg/${\ell}$ in SS, 8.3~11.5mg/${\ell}$ in DO, 0.1mg/${\ell}$ in T-P and 1.2~1.3mg/${\ell}$ in T-N. In case of the sediments, Cd was 0.47~0.52mg/kg, 7.08~7.43mg/kg in Cu, 0.22~0.32mg/kg in As, 0.02~0.03mg/kg in Hg, 6.20~7.45mg/kg in Pb, 32.80~39.70mg/kg in Ni, 513.0~543.0mg/kg in F and 137.0~140.0mg/kg in Zn. $Cr^{6+}$ was not detected. The benthic macroinvertebrates were 432 individuals including 3 phyla, 5 classes, 9 orders, 26 families, 33 genera and 39 species, and the ecological score of benthic macroinvertebrate community(ESB) was 25. The fishes were 8 families and 14 species, and the invasive alien species were 2 taxa including Micropterus salmoids and Lepomis macrochirus. The hydrophytes were 63 taxa including 28 families, 42 genera, 56 species, 1 subspecies and 6 varieties. The emergent plants were 38 taxa(60.3%), 5 taxa(7.9%) in floating-leaved plants and each 10 taxa(15.9%) in free-floating plants and submerged plants.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.50-56
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• 2002

This experiment was carried out to obtain some information about overwintering, physiological and ecological characteristics of apple snails. Another purpose of this experiment was to characterize an appetite for rice plants by apple snails and to elucidate their choice of fresh green ones (vegetables, some other crops, weeds in rice fields). The freshwater snails were found with higher population at sites abundant organic compounds such as plant debris and at regions with high temperature. They also prefer calcium-rich water. This is a naturally occurring process. Apple snails were exceptionally veil-adapted to the south regions of Korea, especially Janghang, Jangseong and Haenam, even if the temperature of winter season is cold below 0$^{\circ}C$. Apple snails were not very selective in their food choice and eat almost everything available in their environment. A snail have something called a radula in its mouth for grinding up its food. A apple snail also chews on fruits and young succulent plant barks. In case of reproduction. apple snails deposit about 157$\sim$784 (average of 321 eggs) milky white to pale orange colored eggs above the waterline. In approximately every 22.4 seconds a new egg appears. The total time needed to deposit a egg mass varies from 58 minutes$\sim$4 hours 13 minutes. Apple snails reproduct actively from May to June and from September to October. An appetite of apple snails for rice plants was the different depending on their size and glowing stage for rice plants. Apple snails had a great appetite of rice plants as well as dropwort, tomato, cabbage, radish, aquatic plants etc. They preferred to eat young rice plants and drastically quit eating rice plants of over 40 cm in height. Thus considering the food preference of apple snail for various plants including rice, they were thought to be a potentially strong predator in fields, especially, at regions with warmer winter.

• Korean Journal of Ecology and Environment
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• v.35 no.4 s.100
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• pp.273-284
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• 2002

During January 1998-October 1999, the impact of free-floating plants (FFP) on limnology of the wetland ecosystem was evaluated through the investigation of physicochemical characteristics of the Woopo Wetland along with in situ manipulation experiments of aquatic plants. Flooding events occurred in the wetland during the summer period (Jun.-Aug.) and water levels rose to 2-3 m due to precipitation from the catchment and inflow from the main channel of the Nakdong River. Physicochemical parameters and plankton dynamics in the wetland during the summer were greatly influenced by floods and growth of free-floating plants. Dissolved oxygen (Jun.-Sept., 4.5${\pm}$2.5 mg/1; Oct.-May, 8,1 ${\pm}$4.0 mg/1) and pH (Jun.-Sept., 6.9${\pm}$0.4; Oct.-May,7.4${\pm}$0.8) levels were significantly lower during the summer than any other seasons. Three types of enclosure experiments (100 L, treatments with floating plants, screened and opened) were conducted under the presence and absence of sediment for 15 days in the 1999 summer. The treatments with sediment had higher levels of nutrient concentrations than those of the others. Among the treatments with sediment, nutrient concentrations in the treatments with free-floating plants were higher than the others. Zooplankton communities in each treatment showed a similar variation, although the scale of zooplankton densities differed. Rotifer community dominated the zooplankton at the initial phase of the experiment, but decreased drastically along with an increase of cladoceran and copepod communities. In conclusion, low levels of dissolved oxygen and pH in the Woopo Wetland during the summer seemed to be caused by a proliferation of free-floating plants and active decomposition process at the bottom of the sediment.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1192-1198
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• 2010

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the aquatic environment. Many pharmaceuticals are not completely removed during wastewater treatment, leading to their presence in wastewater treatment effluents, rivers, lakes, and ground water. Here, we developed analytical methods for monitoring ten pharmaceuticals from surface water by LC/ESI-MS/MS. For sample clean-up and extraction, MCX (mixed cation exchange) and HLB (hydrophilic-lipophilic balance) solid-phase extraction (SPE) cartridges were used. The limits of detection (LOD) in distilled water and the blank surface water were in the range of 0.006 - 0.65 and 1.66 - 45.05 pg/mL, respectively. The limits of quantitation (LOQ) for the distilled water and the blank surface water were in the range of 0.02 - 2.17 and 5.52 - 150.15 pg/mL, respectively. The absolute recoveries for fortified water samples were between 62.1% and 125.4%. Intra-day precision and accuracy for the blank surface water were 2.9% - 24.1% (R.S.D.) and -16.3% - 16.3% (bias), respectively. In surface wastewater near rivers, chlortetracycline and acetylsalicylic acid were detected frequently in the range of 0.017 - 5.404 and 0.029 - 0.269 ng/mL, respectively. Surface water near rivers had higher levels than surface water of domestic treatment plants.

• Korean Journal of Environmental Biology
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• v.24 no.3
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• pp.294-299
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• 2006

Mt. Seokseong is located $37^{\circ}15'15'{\sim}37^{\circ}17'00'N$ in latitude at $127^{\circ}09'30'{\sim}127^{\circ}11'00'E$ in longitude in Yongin-si. As the result of cluster analysis, B site has 170 taxa of vascular plants, so it is the most abundant site in this area. And C site has 140 taxa of that, it is secondly abundant. But it has the highest similarity index (53.7%) between A site and B site. To construct natural resort for residents, it needed make thorned park just as hiking course, woods bathing site, aquatic place, pebble path, and natural garden path. And to protect ecological isolation of this area ecobridges must be constructed at Myeokjogogae and at Yongin Medical Hospital.