• Journal of Korean Society of Water and Wastewater
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• v.29 no.5
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• pp.543-550
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• 2015

In this study, using soil brick with combined effective microorganisms and emergent plants was identified which it can increase the effect of conservation and improvement of water. Lab-test was consist of four kind of reactors and each of reactors were A(rawwater), B(soil brick), C(emergent plant) and D(soil brick+emergent plant). Iris pseudoacorus, Phargmites australis, Typha angustifolia and Zizania latifolia were used for emergent plant. Evaluation of application on various environment were performed on agricultural waterway and pond. The pH measurement test of soil brick was performed due to evaluate whether a strong alkaline water flows out of the soil brick. Result of lab-test, removal efficiency of D was better than removal efficiency of A presenting 20.9%, 27.9% 21.5%, 33.8% and 58.4% for $COD_{Cr}$, $BOD_5$, TN, TP and TSS respectively. Removal efficiency of soil brick on agricultural waterway was revealed to be 49.5%, 45.0%, 43.7%, 37.3% and 28.6% for $COD_{Cr}$, $BOD_5$, TN, TP and TSS respectively. And removal efficiency of soil brick on the pond was revealed to be 12.7%, 10.5%, 9.32%, 10.4% and 36.3% for $COD_{Cr}$, $BOD_5$, TN, TP and TSS respectively. Result of pH measurement test of soil brick was neutral which was about 6 to 8.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.1
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• pp.57-66
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• 2001

The floating islands have been constructed for the water quality improvement and the biodiversity conservation in an disturbed aquatic ecosystem. We made floating islands consisted of a special float and substrates of coconut fibers implanted with four emergent macrophytes such as Phragmites australis, Zizania latifolia, Iris pseudoacorus, Typha angustifolia. Vegetation structure and plant growth were compared between on the floating islands and on ground in order to select suitable plants for the construction of floating islands. Emergent-macrophytic vegetation on the floating islands showed lower coverages and higher plant biodiversity due to natural introduction of various hydrophytes and hygrophytes. Shoot density was increased on floating islands except for Zizania latifolia. From the point of coverage and density of plants, Phragmites australis and Iris pseudoacorus were suitable for floating islands. Total biomass of emergent macrophytes was decreased on the floating islands. The belowground/aboveground biomass ratio of floating islands was higher than that of the ground. Out of planted macrophytes, Iris pseudoacorus with a high belowground/aboveground biomass ratio could be evaluated a suitable plant for the floating islands because a plenty of its root is profitable to adapt with the nutrient-limited environment of floating islands.

• Animal cells and systems
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• v.2 no.3
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• pp.333-339
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• 1998

Litter decomposition is a key process in energy flow and nutrient cycling in the freshwater littoral zone, and is regulated by physicochemical properties of litters. Using a litterbag method, we compared the decomposition rates of 16 different litter types from 10 plant species of the emergent macrophytes for one year in the littoral zone of the Paltangho Reservoir, Korea. The regression analysis fitted to the various decomposition models showed that mass loss of the litters with time best fitted an asymptotic function. The litters of the emergent macrophytes were composed of two compartments, labile and refractory. The macrophytic litters showed a great variety in decomposition dynamics depending on sources of litters. The labile compartment of the initial litter mass was in a wide range between 18% and 99%, and their decomposition rates varied from 0.0037 to 0.0131 day-1. The decomposition processes of the emergent macrophytes were determined by the relative amounts of the labile and refractory compartments and by the decomposition rate of the habile one in the littoral zone.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.565-572
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• 2006

This study examined the decomposition of blades and culms of aquatic emergent plant species, Zizania latifolia, Phragmites communis and Typha angustata, which were the most frequent in Lake Paldang. The experiment was carried out from July to December, 2005 in fresh water of lake Paldang using litter bag method. The litter bags had 1.2 mm mesh size and were suspended at 1 m depth of water surface. Remaining mass of blades and culms of each species after 97 days was 21.2% and 22.6% of initial mass in Z. latifolia, 32.5% and 56.4% in P. communis and 44.7% and 38.1 % in T. angustata, respectively. The plant tissue having high N concentration and low C/N exhibited the faster decay rate than the others. However, the tissue of high content of lignin, cellulose, lignin:N, and cullulose:N showed a slow decomposition rate. Water temperature was the most effective environmental factor on the emergent macrophyte litter decomposition in aquatic ecosystems. According to the water temperature, DO, $NO_3^-$-N, and total phosphate concentration were changed in the linear way. The mass loss of plant tissue of emergent macrophytes showed positive relationship with P concentration in water. The experiments on the decomposition of the litter using different mesh sized litter bag did not show significant differences between them. The results suggest that the decomposition of emergent macrophytes in fresh water of lake Paldang, which showed features of lentic and lower part of a stream, was affected by microbial activities better than the micro-invertebrates such as shredders.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.129-144
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• 2010

We have studied the changes of the environmental and vegetational factors according to the hydro-seral stages in the shoreline of the lagoons, Korea. We have divided seral stages into 7 stages from open water stage to the stratified forest stage considering as the characteristics of water body, dominance of submerged and emergent plant, and development of the shrub, subtree and tree layer. According to the successional stage, water depth gradually decreased and water quality changed from seawater to brackish water and from brackish water to fresh water, organic matter in a soil layer gradually increased, and the litter layer grew up. As the development of the vegetation structure, the life-form of the vascular plants changed as follows; open water ${\rightarrow}$ submerged plant and floating-leaved plant ${\rightarrow}$ emergent plant and submerged plant ${\rightarrow}$ emergent plant ${\rightarrow}$ emergent plant, mesophyte and scrub ${\rightarrow}$ mesophyte. In the late seral stage, the 3 different forest types were established by the water retention or drainage and nutrient accumulation of the soil layer. Salix dominant forest developed in the wetted sites, the forest type dominated by Pinus thunbergii, Carex pumila and mesophytes developed in the well drained sites causing by sand substrate, and the forest type dominated by the planted or ruderals such as Pinus densiflora, Robinia psedo-acacia, Festuca ovina, Setaria viridis ect. developed in the sites composed of forest soil introduced by artificial reclamation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.1
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• pp.82-92
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• 2010

Removal rates of NO3-N and TN in a free water surface wetland system during emergent plant growing season and non-growing were investigated. The system was established on floodplain in the down reach of the Gwangju Stream in 2008. Its dimensions were 46 meters in length and 5 meters in width. Typha angustifloria L. growing in pots about two years were planted on the half area of the system and Zizania latifolia Turcz on the other half. Water of the stream was funneled into it by gravity flow and its effluent was discharged back into it. Volumes and water quality of inflow and outflow were analyzed from October 2008 to September 2009. Inflow into the system averaged approximately 715 $m^3$/day and hydraulic residence time was about 1.5 hr. Average influent and effluent $NO_3$-N concentration was 3.37 and 2.74 mg/L, respectively and $NO_3$-N retention amounted to 18.7%. Influent and effluent TN concentration averaged 4.67 and 3.69 mg/L, respectively and TN abatement reached to 20.9%. $NO_3$-N removal rate (%) during plant growing season ($22.67{\pm}3.70$, mean ${\pm}$ standard error) was significantly high (p<0.001) when compared with that during plant non-growing one ($15.02{\pm}3.23$). TN abatement rate (%) during plant growing season ($27.42{\pm}5.98$) was also significantly high (p<0.001) when compared with that during plant non-growing one ($13.66{\pm}3.08$).

• Membrane and Water Treatment
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• v.10 no.1
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• pp.57-65
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• 2019

This study assessed the contribution of emergent vegetation (Phragmites australis, Typha latifolia, and Nelumbo nucifera) to the submerged surface area, the amount of biofilms attached to the submerged portions of the plants, and the treatment performance of a free water surface (FWS) constructed wetland. Results showed that a 1% increase ($31m^2$) in the vegetative area resulted in an increase of $220m^2$ of submerged surface area, and 0.48 kg Volatile Suspended Solids (VSS) of attached biofilm. As the vegetation coverage increased, effluent organic matter and total Kjeldahl nitrogen decreased. Conversely, a higher nitrate concentration was found in the effluent as a result of increased nitrification and incomplete denitrification, which was limited by the availability of a carbon source. In addition, a larger vegetation coverage resulted in a higher phosphorus in the effluent, most likely released from senescent biofilms and sediments, which resulted from the partial suppression of algal growth. Based on the results, it was recommended that constructed wetlands should be operated with a vegetation coverage of just under 50% to maximize pollutant removal.

• Journal of Wetlands Research
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• v.8 no.2
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• pp.65-74
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• 2006

A study of the vascular hydrophyte communities and biomass was undertaken in the Bigumdo wetlands, Shinangun, from March to November, 2005. As a result, the vegetation was divided into 14 communities. Among them, emergent hydrophytes consisted of 6 communities, including Miscanthus sacchariflorus community, Phragmites communis community, Typha angustata community, Leersia japonica community, Paspalum disticum var. indutum community, and Persicaria thunbergii community, floating hydrophytes 5 communities including Hydrocharis dubia community, Nelumbo nucifera community, Euryale ferox community, Trapa japonica community and Nymphaea tetragona var. angusta community, free-floating hydrophytes 2 commuinties including Lemna paucicostata community and Spirodela polyrhiza community, and submergent hydrophyte 1 community, including Myriophyllum verticillatum community. Biomass was the highest at emergent hydrophytes and decreased along the life form, in the order like floating hydrophytes, submergent hydrophyte and free-floating hydrophytes. In addition, hydrophytes in the Bigumdo wetland showed the typical vertical zonation pattern like a natural swamp. These results were considered that the wetland of Bigumdo was characterized by the typical structure of aquatic plant ecosystem.

• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.21-25
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• 2006

Phragmites australis (reed) has received much attention as being one of the principle emergent aquatic plants for treating industrial and civil wastewater. Plant regeneration via plant tissue culture in p. australis was investigated. Three types of callus were identified from seeds on N6 medium plus 4.5 UM 2,4-dichlorophenoxyacetic acid (2,4-D). Yellow compact type showed the best redifferentiation, whereas white compact type and yellow friable were not competent to differentiate into plane. Solid medium culture was better than liquid suspension culture for enhancing callus growth when N6 medium supplemented with 4.5 ${\mu}M$ 2,4-D was used. Phytagel, as a gelling agent, was superior to agar in plant regeneration on N6 medium, supplemented with 9.4 ${\mu}M$ kinetin and 0.54 ${\mu}M$ $\alpha$-naphthaleneacetic acid (NAA). Transfer of the plantlets regenerated from kinetin and NAA-supplemented N6 medium to growth regulator-free MS medium enhanced the further development of the plantlets. Plantlets on subsequently grown to maturity when tansferred to potting soil. The regenerated plants exhibited morphologically normal. The system for plant regeneration of P. australis enables to propagate elite lines on a large scale for water purification in the ecosystem

• Journal of applied mathematics & informatics
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• v.8 no.2
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• pp.505-518
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• 2001

The huge and complicated plants such as nuclear power stations are likely to cause the operators to make mistakes due to a variety of inexplicable reasons and symptoms in case of emergency. That’s why the prevention system assisting the operators is being developed for. First of all. I suggest an improved fuzzy diagnosis. Secondly, I want to demonstrate that a classification system of nuclear plant’s accident investigating the causes of accidents foresees possible problems, and maintains the reliability of the diagnostic reports in spite of improper working in part. In the event of emergency in a nuclear plant, a lot of operational steps enable the operators to find out what caused the problems based on an emergent operating plan. Our system is able to classify their types within twenty to thirty seconds. As so, we expect the system to put down the accidents right after the rapid detection of the damage control-method concerned.