• Mycobiology
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• v.50 no.5
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• pp.345-356
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• 2022

The fungal distribution, diversity, and load were analyzed in the geographically segregated island groundwater systems in Korea. A total of 79 fungal isolates were secured from seven islands and identified based on the internal transcribed spacer (ITS) sequences. They belonged to three phyla (Ascomycota, Basidiomycota, and Chlorophyta), five classes, sixteen orders, twenty-two families, and thirty-one genera. The dominant phylum was Ascomycota (91.1%), with most fungi belonging to the Cladosporium (21.5%), Aspergillus (15.2%), and Stachybotrys (8.9%) genera. Cladosporium showed higher dominance and diversity, being widely distributed throughout the geographically segregated groundwater systems. Based on the diversity indices, the genera richness (4.821) and diversity (2.550) were the highest in the groundwater system of the largest scale. As turbidity (0.064-0.462) increased, the overall fungal count increased and the residual chlorine (0.089-0.308) had low relevance compared with the total count and fungal diversity. Cladosporium showed normal mycelial growth in de-chlorinated sterilized samples. Overall, if turbidity increases under higher fungal diversity, bio-deterioration in groundwater-supplying facilities and public health problems could be intensified, regardless of chlorine treatment. In addition to fungal indicators and analyzing methods, physical hydrostatic treatment is necessary for monitoring and controlling fungal contamination.

• Korean Journal of Ecology and Environment
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• v.34 no.2 s.94
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• pp.126-132
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• 2001

Urbanization and population increase result in the construction of STPs (Sewage Treatment Plants). Discharge from STPs greatly influences on the water quality in the stream which receives discharges. The decision of STP location should be considered with the discharge capacity of STP and self-purification of river in the water quality perspectively. In this study, a change of dissolved oxygen (DO) in a river being affected by STP discharge was simulated by the STELLA model. Minimum DO was 4.98 ppm in 42.6 km downstream of STP. Approximately, it takes 8days to recover the DO by the self-purification and this location is 340 km down-stream from the STP. If the model run for the consideration of the self-purification without phytoplankton algorithms, minimum DO was 4.92 ppm. It took 0.25 day longer to be the minimum DO than that with the phytoplankton functions. Without the phytoplankton algorithm, it took 11days to recover the DO. This proves the importance of phytoplankton in the self-purification processes. Additionally, the effect of adjacent STP discharge should be considered in the construction of new STP.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.4
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• pp.46-55
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• 2001

Analysis of fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research stream water qualities around Mt. Baegun area were monitored seasonally for three years. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. As a result of regression analyses, the linear equation of pH of influent and effluent water of fish farm was, pH of effluent water of fish farm = $0.6234{\times}pH$ of influent water of fish farm + 2.6263. Also, the linear equation of electrical conductivity of influent and effluent water of fish farm was electrical conductivity of effluent water of fish farm = $1.7275{\times}$electrical conductivity of influent water of fish farm - 14.007. Negative effects on stream water quality were observed by indications of increase in electrical conductivity and water temperature of effluent water from the fish farm. Decreases in physicochemical indices such as the amount of dissolved oxygen, total amount of cation and total amount of anion in effluent water from the fish farm were also negative aspects in downstream ecology. It is recommended that water purification system as well as environmentally-friendly fish farm design should be incorporated to large scale fish farm development plan in forested watershed area.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.3
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• pp.35-45
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• 2006

Fallow paddy areas have been increased due to the import of cheap agricultural product, and the unbalance between farming cost and rice price since 1990. In domestic, rice production control that decrease paddy field area has been introduced for the control of rice demand and supply and stabilization of rice price since 2003. Because of the desire of paddy field's owner to create benefit by using paddy for other object, fallow paddy would be continuously increased. In the other aspect, many people in the world is suffering from hunger because of the shortage of food. In case of Korea, continuous drought and flood damages will be potential concern of stable food supply. From this viewpoint, the increasing fallow paddy area needs to be protected from the devastation by weed breeding for the re-cultivation. In this study, fallow paddy managed with the shallow pools and shallows was selected fur monitoring and analyzing of water quality and plant body change. As the results, the managed fallow paddy found to be effective in the purification of water quality and the control of plant growth.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.55-64
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• 2019

This study identified key patents on U.S. underground water technology through patent network analysis. As a result, there were many technologies that used the technology to remove heavy metals to prevent contamination of groundwater. While patents between groundwater technology patents were in charge of intermediaries, the connectivity between groundwater technologies is not high. The patented technologies related to groundwater were largely distinguishable by pumping, monitoring, and decontamination. Monitoring includes techniques that enable identification of physical and biological properties, such as the type of contaminants, as well as geographic characteristics for analysis of groundwater flow, flow or water quality. Pollution purification technology refers to the process of physiochemical and biological purification for soil and groundwater. U.S. technology cases showed that the U.S. had high technology in water treatment area. And patent protection were also needed to cope with water shortages caused by climate change.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.240-246
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• 2021

The Chironomidae is a benthic macroinvertebrate commonly found in freshwater ecosystems, along with Ephemeroptera and Trichoptera, which can be used for environmental health assessments. There are approximately 15,000 species of Chironomidae worldwide, but there are limited studies on species identification of domestic Chironomidae larvae. In the present study, we carried out species classification of the Chironomidae larvae that found in Jeju's tap water purification plants using morphological characteristics and genetic identification based on cytochrome c oxidase subunit I (COI) gene of the mitochondrial DNA. Body shape, mentum, antenna, mandible in the head capsule, and claws were observed in the larvae for morphological classification. Analysis of 17 larvae collected from faucets and fire hydrants of domestic tap water purification plants revealed the presence of two species, including 14 Orthocladius tamarutilus and 3 Paratrichocladius tammaater. These results will aid the use of the criteria information about species classification of the Chironomidae for water quality management in water purification plants and diversity monitoring of freshwater environments.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.727-733
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• 2009

This study was performed to investigate the physical characteristics like compressive strength, permeability, porosity and the water quality removal characteristics of permeable concrete pavement filled with microbial-soil sheet to remove SS, organic matter and nutrients in artificial rainfall. As a result, it can show the removal efficiency is SS 90~95%, COD 85~93%, BOD 80~83%, T-N 61~75%, T-P 71~78% on WAPS I(W1) and WAPS II(W2). Therefore, permeable concrete pavement filled with microbial-soil sheet shows higher removal efficiency(SS 10%, organic matter and nutrients 30%) than a conventional porous concrete(W3). By filling microbial-soil sheet to permeable concrete pavement, we confirm that the function and efficiency are improved significantly and that a naturally-friendly facility can be developed and applied to treat non-point sources.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.75-81
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• 2011

This study performed field examinations of a zero discharge and reuse system developed by Hong and Choi(2009). The system installed one of villages located in Hyoryeong-myeon, Gunwee-gun for the experiments. The zero discharge and reuse system consists of anoxic, FES (Ferrous Electricity System), Oxic, Cralifier processes for water treatments. The main feature of the system is to remove phosphorous by using Fe-ionizing module within the FES process. The water purification performances of the system were evaluated, while any defects for using the system were investigated through the field monitoring. It was found that the removal capacities of T-P, T-N, and BOD of the system meet the required water quality with outstanding performance from T-P by obtaining the results of over 90 % removal rates. The efficiency of T-P removal rate of the system found to be greatly influenced by whether using an automatic washing system to the Fe-ionizing module and conducting replacement of iron plate within a proper period.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.545-551
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• 2011

Recently, demands for generating high quality tap waters are increasing with high concern of water pollution and corrosion of water pipelines. For the reasons, developing water quality stabilization technique in water purification system is sought rather than replacing to a new pipelines. In this study, high-purity liquid lime($Ca(OH)_2$) was introduced for a water quality stabilization technique in water purification process and simulated water distribution system of pilot-scale size was applied to evaluate anti-corrosion control effect. The effect of anti-corrosion control was calculated in terms of LSI(Langelier Saturation Index) In conclusion, the result of pilot plant showed improvement of corrosiveness by liquid lime($Ca(OH)_2$) with reduction of released iron(Fe). Application of anti-corrosion control technique to the mild steel coupon and the copper coupon were effective by indicating 35.4, 44.5% of improvements. Besides, sample pipes which were treated with liquid lime had formated more thicker layer of corrosion product inside of pipes. As a result, the process of injecting water stabilizer can greatly contribute to the high quality of tap water.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.4
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• pp.139-148
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• 2002

Pilot study was performed to examine the feasibility of the pond system for further polishing of treatment wetland effluent from December 2000 to June 2001. The wetland system used for the experiment was highly effective to treat the sewage during the growing season, but it was less effective and its effluent was still high to discharge to the receiving water body. Therefore, the wetland effluent may need further treatment to prevent water quality degradation. Pond system could be used to hold and further polish the wetland effluent during the winter season and ots feasibility was evaluated in this study. Additional water quality improvement was apparent in the pond system during winter season, and the pond effluent could be good enough to meet the effluent water quality standards if it is properly managed. Timing of the pond effluent discharge appears to be critical for pond system management because it is a closed system and whole water quality constituents are affected by physical, chemical, and biological pond environments. Once algae started to grow in mid-April, constituents in the pond water column interact each other actively and its control becomes more complicated. Therefore, upper layer of the pond water column which is clearer than the lower layer my need be discharged in March right after ice cover melted. In the experiment, water quality of the upper water column was markedly clear in March than ant other times probably because of freezing-thawing effect. The remaining lower water column could be further treated by natural purification as temperature goes up or diluted with better quality of wetland effluent for appropriate water uses. This study demonstrated the feasibility of pond system for subsequent management of wetland effluent during the winter season, however, more study is needed for field application.