• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.575-578
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• 2003

Constructed wetlands have become a popular technology for treating contaminated surface and wastewater. In this study, the field experiment to reduce nonpoint source pollution from watershed runoff during rainy day using wetland and pond. TSS and T-N removal rate of wetland-pond system and pond-wetland system was 91% and 73%, 94% and 70%, respectively and values were same range. $BOD_5$ and T-P removal rate of pond-wetland system (38% and 78%) was higher than wetland-pond system (27% and 62%). overall, pond-wetland system is more useful than wetland-pond system to control NPS.

• Membrane and Water Treatment
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• v.14 no.4
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• pp.147-153
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• 2023

Urbanization has been causing such new pollutants as micro-plastic, thus the environmental impact of new pollutants on ecosystem is rapidly increasing. When it comes to micro-plastic, a representative artificial trace pollutant, its risk has been increased at a much faster rate, however the depth study associated with stormwater sediment and wetland was relatively rare. In this research, soil samples from storm water sediment were analyzed for distribution characteristics of micro-plastics in the J wetland (registered as Ramsar wetland, May 2021 and a representative environmental site in South Korea). Analyzed soil samples found approximately 201 ± 93 particle/kg (based on unit weight, Total micro plastic particles / Total Sample weight) micro-plastics in the samples. When considering the total quantitative numbers in stormwater sediment in the entire area of the J wetland, over 15,000 micro-plastics were estimated to be contaminating such area. In addition, in terms of qualitative numbers, micro-plastics were contaminating the J wetland with 94.7 % ratio of styrofoam type (43.9%) and polyethylene type (50.8%). These research results can be used as base data sets for controlling micro-plastics in the J wetland.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.1
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• pp.61-72
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• 1996

Recently, significant attention is given to the wastewater treatment using Constructed wetland. This is because the wetland system is a kind of natural taeatment system, simple to maintain and it has relatively fewer technical difficulty. Thus, it would be a practical method to employ especially in rural area in Korea. In this paper, the authors dscuss the design criteria of construted wetland developed in USA as an initial feasibility study to adopt it in Korea. We discuss about especially types of vegetation, natural succession and management, planting techniques, seeding teckniques and management after censtruction.

• Environmental Engineering Research
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• v.24 no.2
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• pp.181-190
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• 2019

Constructed wetlands are improvised man-made systems, designed for adopting the principle of natural wetlands for purifying wastewater - the elixir of life. They are used widely as a cost-effective and energy-efficient solution for treating greywater generated from different tertiary treatment sources. It provides an elaborate platform for research activities in an attempt to recycle earth's natural resources. Among the several organic impurities removal mechanisms existing in constructed wetland systems, the earth's active microbial population plays a vital role. This review deals with the recent advancements in constructed wetland systems from a microbiological perspective to (effect/ devise/ formulate) chemical and physical treatment for water impurities. It focuses on microbial diversity studies in constructed wetlands, influence of wetland media on microbial diversity and wetland performance, role of specific microbes in water reuse, removal of trace elements, some heavy metals and antibiotics in constructed wetlands. The impurities removal processes in constructed wetlands is achieved by combined interactive systems such as selected plant species, nature of substrate used for microbial diversity and several biogeochemical effected reaction cycles in wetland systems. Therefore, the correlation studies that have been conducted by earlier researchers in microbial diversity in wetlands are addressed herewith.

• Korean Journal of Ecology and Environment
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• v.56 no.2
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• pp.127-139
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• 2023

Daechung Reservoir has been suffering from severe cyanobacterial blooming periodically due to the water pollutants from the watershed, especially nutrients from nonpoint sources. As a countermeasure, an artificial wetland was constructed to mitigate the pollutant load from the watershed by utilizing the vegetation. We investigated the water quality of the influent and outflow of the wetland during years 2014~2020 to evaluate the performance of pollutant removal through the wetland. Major pollutants (e.g. BOD, COD, SS, T-N, and T-P) were largely reduced during the retention in the wetland while nutrients removal was more efficient than that of organic matters. Pollutant removal efficiency for different inflow concentrations was also investigated to estimate the wetland's capability as a way of managing nonpoint sources. The efficiency of water treatment was significantly higher when inflow concentrations were above 75^th percentile for all pollutant, implying the wetland can be applied to the pre-treatment of high pollution load including initial rainfall runoff. Furthermore, the yearly variation of removal efficiency for seven years was analyzed to better understand long-term trends in water treatment of the wetland. The annual treatment efficiency of T-P was very high in the early stages of vegetation growth with high concentration of inflow water. However, it was confirmed that the concentration of inflow water decreased, vegetation stabilized, and the treatment efficiency gradually decreased as the soil was saturated. The findings of the study suggest that artificial wetlands can be an effective method for controlling harmful algal blooms by alleviating pollutant load from the tributaries of Daechung Reservoir.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.7
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• pp.70-82
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• 2003

A pilot study was performed from July 1998 to December 2002, including winter performance, to examine seasonal performance of a constructed wetland and subsequent pond system for treatment of sewage in small communities of Korea. Pond was operated as a intermittent-discharge pond during winter period, and continuous flow system during growing season; its effects was evaluated from December 2001 to April 2003. The subsurface flow (SSF) wetland was satisfactory for treating sewage with good removal efficiency even during the winter period. The wetland effluent concentrations of $BOD_5$ and TSS were often higher in winter than in the growing season, but this was explained by the higher loading rates, rather than lower removal efficiency. The relatively poor-quality wetland effluent was further polished during winter in the pond. The upper layer of the pond water column became remarkably clear immediately after ice melt. In the growing season, ponds could be operated as a continuous flow system to remove nutrients and pathogens, and the effluent of pond could be reused as a supplemental irrigation water without risk of infection by sewage-borne pathogens as well as causing adverse effect on growth and yield. Overall, the wetland system was found to be adequate for treating sewage with stable removal efficiency, and the intermittent-discharge pond was found to be effective for further polishing if necessary. Therefore, the combination of a wetland and subsequent pond system and reuse of effluent as crop irrigation water is recommended as a practical alternative to treat sewage in Korean small communities, and partial discharge of pond water in March is suggested.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.709-717
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• 2008

The field scale experiment which is constructed with four sets (0.88 ha for each set) of wetland (0.8 ha) and pond (0.08 ha) systems was performed to examine the effect of plant coverage on the constructed wetland performance and to recommend the optimum development and management of macrophyte communities. After six growing seasons of wetlands, plant coverage was about 100%. And the concentration of DO showed low value (1.0~5.4 mg/L). This is caused by a blighted plant consumed dissolved oxygen with decay in water column. As the result, water column went to be anaerobic conditions and T-N removal rate are 58~67%. Dead vegetation increased nitrogen removal during winter because it is a source of organic carbon which is an essential parameter in denitrification. However, wetland released phosphorus caused by a blighted plant and accumulation, the removal rate of phosphorus might be decreased. To rise of DO concentration, the three open-waters were constructed in cell 3 and 4. Cell 3 has two open-waters (width 10 m, depth 1.8 m) and cell 4 has one open-water (width 20 m, depth 1.8 m). As the result, DO concentration and treatment efficiency of nutrient and BOD were improved. In case that constructed wetland is operated for a long time, physical circulation structure such as open water help continuous circulation of aerobic and anaerobic conditions. Through the constructed open-water, treatment efficiency of phosphorus and nitrogen in wetland could be improved effectively.

• Journal of Korean Society on Water Environment
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• v.29 no.5
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• pp.591-597
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• 2013

The input emergy of an advanced treatment plant for reducing the 1 kg of TN and TP was estimated 4.14E+14 sej/kg, 5.02E+15 sej/kg, respectively. In addition, the input emergy of constructed wetland for reduction of the 1 kg of TN and TP reduction was estimated to be 2.48E+14 sej/kg, 3.38E+15 sej/kg, respectively. The cost reducing 1 kg of TN and TP for an advanced treatment plant was estimated 197,466 won and 2,388,739 won respectively and constructed wetland was estimated 117,976 won and 1,609,213 won respectively. As a result, All of the emergy source of constructed wetland for reducing non-point source is renewable resource. If we use the constructed wetland, it results in enhancing economic value by reducing of non-point pollution, controlling a flood and providing the habitat of animals or plants. Improving water quality program in the Nakdong River Basin should be changed into an ecological treatment facilities from expansion of the sewage treatment facilities and advanced treatment plant using high cost and non-renewable energies.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.5
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• pp.1-9
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• 2006

The purpose of this study is to make a design guideline in designing constructed wetland which can treat water quality both of point and nonpoint source water pollution. It focuses on structural aspects of two case studies of constructed wetland applying SSB(Sustainable Structured wetland Biotope) system in Korea. The constructed wetland of Lake Ju-am which was constructed in 2002 by Environmental Management Corporation, was designed by applying SSB system. It shows higher removal efficiency than expected - 56% of BOD removal efficiency, 60% of T-N removal, and 76% of T-P removal efficiency. In two cases, total wetland areal extents were calculated referred to treatment efficiency. The system is consist of micro-cell structures : inflow channel, forebay, multiple wetland cells and micro-pool. When designing constructed wetland appropriate in local area, the total organic system of vertical and horizontal structure : geology, hydrology, land use, and ecological surroundings of the sites should be considered totally.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.19-27
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• 2010

Submerged plants whose most of vegetative mass are below the water surface can have great effects on wetland biogeochemistry and water purification through their photosynthesis and nutrient uptake processes. In this study, change of dissolved oxygen concentration and pH as well as nutrient removal capacity of the submerged plant dominant wetland were investigated using wetland mesocosm experiments. Obvious periodic DO and pH fluctuation was observed due to photosynthetic activities of the submerged plants. It implies that the submerged plants can provide periodic or sequential changes of oxic and anoxic conditions that affect nitrification and denitrification processes and contribute permanent nitrogen removal in the wetland system. The pH changes in the wetland mesocosm suggested that submerged plant could also play an important role as a temporary $CO_2$ storage. Higher nutrient removal efficiency was observed in the submerged plant dominant wetland mesocosm. The removal efficiencies under experimental conditions were 38.89, 84.70, 91.21, 70.76, 75.30% of TN, DIN, $NH_4-N$, TP, $PO_4-P$ in the wetland mesocosm, while those were 26.11, 57.34, 63.87, 28.19, 55.15% in the control treatment, respectively.