• Korean Journal of Ecology and Environment
• /
• v.38 no.3 s.113
• /
• pp.403-411
• /
• 2005

The Shihwa constructed wetland was established for the treatment of severely polluted water from Banwoul, Donghwa and Samhwa streams, This study was focused on investigating dynamics of phytoplankton community at 5 stations of open waters in the Shihwa constructed wetland from October 2001 to July 2002. The concentration of T-N and T-P of inlet stations from the streams were decreased by flowed through the wetland. However, the TN/TP ratios at all stations were shown as a little over 16 indicating that the T-P plays an important role as a limitation factor. Phytoplankton communities were identified as a total of 413 taxa which were composed of 375 species, 21 varieties, 2 forma and 15 unidentified species. The standing crops of phytoplankton communities and chlorophyll-a concentrations ranged 330 ${\sim}$ 36, 420 cells $mL^{-1}$ and $2.5\;{\sim}\;170.7\;{\mu}g\;L^{-1}$ respectively, and showed a decreasing tendency after flowing through the wetland at almost stations. Dominant species were 14 taxa at all stations which were Euglena oblonga, Synura spinosa, and etc. The species composition, standing crops and chlorophyll concentrations of phytoplankton communities appeared a distinct differences between open waters of inlet from stream and open waters flowed through the wetland. Theses results were affected from decreasing effects of TN, TP and SS by flowed through the wetland from inlet waters of streams.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.4
• /
• pp.642-648
• /
• 2012

To evaluate the water quality in Juksancheon constructed wetlands for treating non-point source pollution, the removal rates of nutrients in water and the total amounts of T-N and T-P uptakes by water plants were investigated. Chemical characteristics of T-N and T-P in sediment were investigated. The concentrations of BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), SS (Suspended Solids), T-N and T-P in inflow were 0.07~1.47, 0.60~2.65, 0.50~4.60, 1.38~6.26 and $0.08{\sim}0.32mg\;L^{-1}$, respectively. The removal rates of BOD, COD, SS, T-N, and T-P were -10, 51, 66, -3 and 5%, respectively. The maximum amount of T-N uptake by water plants in August was $368.7mg\;plant^{-1}$ in the $2^{nd}$ treatment stage by Nymphoides peltata, $1314.6mg\;plant^{-1}$ in the $3^{rd}$ treatment stage by Iris pseudacorus, $1160.4mg\;plant^{-1}$ in the $4^{th}$ treatment stage by Nymphaea tetragona GEORGI, respectively. The maximum amount of T-P uptake by water plants in August was $121.7mg\;plant^{-1}$ by Nymphoides peltata in the $2^{nd}$ treatment stage, $268.7mg\;plant^{-1}$ by Iris pseudacorus in the $3^{rd}$ treatment stage and $212.0mg\;plant^{-1}$ by Nymphaea tetragona GEORGI in the $4^{th}$ treatment stage, respectively. Organic matter contents in sediments were not different. Contents of T-N and T-P in sediments were higher in spring. Microbial biomass C:N:P ratios in sediments in spring, summer, autumn and winter were 117~140:1~4:1, 86~126:5~6:1, 68~101:2~6:1 and 47~138:2~4:1, respectively. We could conclude that Juksancheon constructed wetlands show high removal efficiencies of COD and SS. However, improvements of management in winter season should be considered to improve the removal efficiencies of pollutants.

• Journal of Wetlands Research
• /
• v.25 no.2
• /
• pp.145-158
• /
• 2023

Constructed wetlands (CWs) are effective technologies for urban wastewater management, utilizing natural physico-chemical and biological processes to remove pollutants. This study employed a bibliometric analysis approach to investigate the progress and future research trends in the field of CWs. A comprehensive review of 100 most-recently published and open-access articles was performed to analyze the performance of CWs in treating wastewater. Spain, China, Italy, and the United States were among the most productive countries in terms of the number of published papers. The most frequently used keywords in publications include water quality (n=19), phytoremediation (n=13), stormwater (n=11), and phosphorus (n=11), suggesting that the efficiency of CWs in improving water quality and removal of nutrients were widely investigated. Among the different types of CWs reviewed, hybrid CWs exhibited the highest removal efficiencies for BOD (88.67%) and TSS (95.67%), whereas VSSF, and HSSF systems also showed high TSS removal efficiencies (83.25%, and 78.83% respectively). VSSF wetland displayed the highest COD removal efficiency (71.82%). Generally, physical processes (e.g., sedimentation, filtration, adsorption) and biological mechanisms (i.e., biodegradation) contributed to the high removal efficiency of TSS, BOD, and COD in CW systems. The hybrid CW system demonstrated highest TN removal efficiency (60.78%) by integrating multiple treatment processes, including aerobic and anaerobic conditions, various vegetation types, and different media configurations, which enhanced microbial activity and allowed for comprehensive nitrogen compound removal. The FWS system showed the highest TP removal efficiency (54.50%) due to combined process of settling sediment-bound phosphorus and plant uptake. Phragmites, Cyperus, Iris, and Typha were commonly used in CWs due to their superior phytoremediation capabilities. The study emphasized the potential of CWs as sustainable alternatives for wastewater management, particularly in urban areas.

• Korean Journal of Ecology and Environment
• /
• v.35 no.4 s.100
• /
• pp.285-294
• /
• 2002

The purpose of this study was to evaluate the relationships between purification characteristics and hydraulic conditions, and to clarify the basic and essential factors required to be considered in the construction and management of artificial wetland system for the improvement of reservoir water quality. The artificial wetland system was composed of a pumping station and six sequential plants beds with five species of macrophytes: Oenanthe javanica, Acorus calamus, Zizania latifolia, Typha angustifolia, and Phragmites australis. The system was operated on free surface-flow system, and operation conditions were $3,444-4,156\; m^3/d$ of inflow rate, 0.5-2.0 hr of HRT, 0.1-0.2 m of water depth, 6.0-9.4 m/d of hydraulic loading, and relatively low nutrients concentration (0.224-2.462 mgN/L, 0.145-0.164 mgP/L) of inflow water. The mean purification efficiencies of TN ranged from 12.1% to 14.3% by showing the highest efficiency at the Phragmites australis bed, and these of TP were 6.3-9.5% by showing the similar ranges of efficiencies among all species. The mean purification efficiencies of SS and Chl-A ranged from 17.4% to 38.5% and from 12.0% to 20.2%, respectively, and the Oenanthe javanica bed showed the highest efficiency with higher concentration of influent than others. The mean purification amount per day of each pollutant were $9.8-4.1\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in BOD, $1.299-2.343\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in TN, $0.085-1.821\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in TP, $17.9-111.6\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in SS and $0.011-0.094\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in Chl-a. The purification amount per day of TN revealed the hi링hest level at the Zizania latifolia bed, and TP showed at the Acrous calamus bed. SS and Chl-a, as particulate materials, revealed the highest purification amount per day at the Oenanthe javanica bed that was high on the whole parameters. It was estimated that the purification amount per day was increased with the high concentration of influent and shoot density of macrophytes, as was shown in the purification efficiency. Correlation coefficients between purification efficiencies and hydraulic conditions (HRT and inflow rate) were 0.016-0.731 of $R^2$ in terms of HRT, and 0.015-0.868 of $R^2$ daily inflow rate. Correlation coefficients of purification amounts per day with hydraulic conditions were 0.173-0.763 of Ra in terms of HRT, and 0.209-0.770 daily inflow rate. Among the correlation coefficients between purification efficiency and hydraulic condition, the percentages of over 0.5 range of $R^2$ were 20% in HRT and in daily inflow rate. However, the percentages of over 0.5 range of correlation coefficients ($R^2$) between purification amount per day and hydraulic conditions were 53% in HRT and 73% in daily inflow rate. The relationships between purificationamount per day and hydraulic condition were more significant than those of purifi-cation efficiency. In this study, high hydraulic conditions (HRT and inflow rate) are not likely to affect significantly the purification efficiency of nutrient. Therefore, the emphasis should be on the purification amounts per day with high hydraulicloadings (HRT and inflow rate) for the improvement of eutrophic reservoir withrelatively low nutrients concentration and large quantity to be treated.

• Korean Journal of Ecology and Environment
• /
• v.39 no.3 s.117
• /
• pp.402-412
• /
• 2006

The Shihwa constructed wetland was established to treat the severely polluted water from Banwoul, Donghwa and Samhwa streams. This study was focused on investigating the dynamics of epiphytic algal communities on reed (Phragmites communis) planting area at 5 stations from October 2001 to June 2002. The concentration of total nitrogen and phosphorus of inlet stations from the streams were decreased after flowing through the wetland. However, the TN : TP ratios at all stations were slightly over 16 indicating that the total phosphorus may play some role as a limitation factor. Epiphytic algae on the reed were total 329 taxa which were composed of 295 species, 13 varieties, 3 forma and 18 unidentified species. The species numbers were recorded in the order of Chlorophyceae-Bacillariophyceae-Cyanophyceae-Euglenophyceae-Chrysophyceae. The relative percentage showed a seasonal variation from Cyanophyceae to Bacillariophyceae and to Chlorophyceae. The biomass of epiphytic algae measured by chlorophyll-a concentration ranged from 0.6 to $36.4\;{\mu}g\;cm^{-2}$. Dominant species were 16 taxa which were Lyngbya angusta of Cyanophyceae in the early investigation, and were changed to Stigeoclonium lubricum of Chlorophyceae, and Nitzschia palea of Bacillariophyceae etc. in the late. Species number, standing crops and chlorophyll-a concentrations of epiphytic algae showed higher values at the inlet stations than the stations after flowing through the wetland.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.3
• /
• pp.400-407
• /
• 2011

To evaluate the aquatic ecological characteristics in Sinpyongcheon constructed wetlands for treating nonpoint source pollution, the removal rates of nutrients in water, the total amounts of T-N and T-P uptakes by water plants, and chemical characteristics of T-N and T-P in sediment were investigated. The concentrations of BOD, COD, SS, T-N and T-P in inflow were 0.07~1.47, 0.60~2.65, 0.50~4.60, 1.38~6.26 and $0.08{\sim}0.32mg\;L^{-1}$, respectively. The removal rates of BOD, COD, SS, T-N, and T-P were 14%, 6%, 18%, 24%, and 10%, respectively. The maximum amount of T-N uptake by water plants in August was $813mg\;plant^{-1}$ for Phragmites communis TRIV in $2^{nd}$ bed, $1,172mg\;plant^{-1}$ for Typha orientalis PRESL in $3^{rd}$ bed, respectively. The maximum amount of T-P uptake by water plants in August was $247mg\;plant^{-1}$ for Phragmites communis TRIV in $2^{nd}$ bed, $359mg\;plant^{-1}$ for Typha orientalis PRESL in $3^{rd}$ bed, respectively. Organic matter, T-N, and T-P contents in sediments were high in the order of $1^{st}$ bed > $2^{nd}$ bed > $3^{rd}$ bed. Microbial biomass C/N/P ratios in sediments in $1^{st}$, $2^{nd}$, and $3^{rd}$ were 78~110/3~6/1, 73~204/1~6/1, and 106~169/1~6/1, respectively.

• Journal of Korean Society on Water Environment
• /
• v.26 no.5
• /
• pp.781-788
• /
• 2010

A pilot study was performed to examine the feasibility of multiple stage of constructed wetland (CW) for nutrient removal. The system is composed of six wetland cells connected with water-ways. The hydraulic of wetland cells is designed as free water surface flow. The treatment capacity was $25m^3d^{-1}$ at HRT of about one day for each cell. The magnitude of nutrient removal was related with the length of wetlands and plant density. Total N and P removal rates were 1353 and $246mg\;m^{-2}d^{-1}$ respectively. The pilot-scale reactor was model as continuous flow system containing contribution of CSTR and PFR typed-reactors. The $k-C^*$ model equation was applied to predict N and P reduction. The result indicated the equation was well guided to estimate reduction of $NO_3-N$ and $PO_4-P$.

• Korean Journal of Environmental Agriculture
• /
• v.23 no.1
• /
• pp.59-67
• /
• 2004

The Shihwa constructed wetland was established for the treatment of severely polluted water from Banwoul, Donghwa and Samhwa streams. This study was focused on investigating dynamics of phytoplankton communities in open waters and periphytic algae on reed (Phragmites communis) planting area at 5 stations from October 2001 to July 2002. The concentration of T-N and T-P of inlet stations from the streams were decreased by flowed through the wetland. However, the TN/TP ratios at all stations were shown as a little over 16 indicating that the T-P will play some role as a limitation factor. Phytoplankton communities were identified as a total 413 taxa which were composed of 375 species, 21 varieties, 2 forma and 15 unidentified species. Standing crops of phytoplankton communities and chlorophyll-a concentrations ranged from $330{\sim}36,420\;cells/mL$ and $2.5{\sim}170.7\;{\mu}g/L$ respectively, and showed the decreasing tendency after flowing through the wetland at almost all stations. Dominant species were 14 taxa at all stations which were Euglena oblonga and Synura spinosa etc. Periphytic algae on the reed were a total 329 taxa which were composed of 295 species, 13 varieties, 3 forma and 17 unidentified species. The species numbers were recorded in order of Chlorophyceae-Bascillariophyceae-Cyanophyceae-Euglenophyceae-Chrysophyceae. The relative abundance (%) was showed a seasonal variation from Cyanophyceae to Bascillariophyceae and to Chlorophyceae. Chlorophyll-a concentrations, ie. the biomass of periphytic algae were ranged from $5.5{\sim}363.8\;mg/m^2$. Dominant species were 16 taxa which were Lyngbya angusta of Cyanophyceae in the early investigation, and were changed to Stigeoclonium lubricum of Chlorophyceae, and Nitzschia plea of Bacillariophyceae etc. in the late. Species number, standing crops and chlorophyll-a concentrations of phytoplankton and perphytic algae were shown higher values at the inlet stations than the stations after flowing through the wetland.

• Journal of Wetlands Research
• /
• v.17 no.2
• /
• pp.184-192
• /
• 2015

This study is a basic research for low maintenance constructed wetlands which can prevent water quality deterioration due to wetland soils. The purpose of this study is to analyze water quality control mechanisms of constructed wetland on the artificial ground which installed the modular revetment structure(MRS), a device that separates water and soil. This study was then conducted with two different wetland mesocosms (a treatment plot and a control). These mesocosms were monitored to analyze effects of water quality control of the MRS. A treatment plot was built, and separated into soil and water, by filling the MRS with the decomposed granite soil in the mesocosm made of rubber material. A control plot was built where the decomposed granite soils were exposed to water by leaving the soil on the bottom of the mesocosm made of rubber material. Water quality was then analyzed by using Kolmogorov-Smirnov Z examination which then showed that pH, BOD, SS, Chl-a, T-P, T-N had statistically valid difference between a container with the MRS and one without it. According to the analysis of the water quality, the temperature and the EC level came out similarly and both mesocosm showed same level on pH and DO. A treatment plot had higher levels of BOD, SS Chl-a, and T-P. A control plot's T-N value was little lower than that of the treatment plot. This study suggests method of constructed wetlands using the MRS prevents problems occurring in wetland soils: aridity of wetlands by soil erosion, eutrophication, and algal blooms due to nutrients released from wetland soil. These functions of constructed wetland with the MRS increase aesthetic, ecologic, social, and economic value of the wetland. Outcomes of this research will later enable more proficient way of stabilizing water quality and provide data for planning low maintenance constructed wetlands.

• Journal of Wetlands Research
• /
• v.10 no.3
• /
• pp.79-86
• /
• 2008

To improve water quality for agricultural use, it is needed to introduce the natural and low-cost self-purification system. It is also necessary to develop the water purification facilities for more efficient and convenient design, construction, operation and management. This study aims to develop the practical facilities to improve water quality for agricultural use. The practical detention pond system, which uses artificial floating island and shield skirts with bio-media, enhanced removal efficiencies of SS, TN and TP more particularly than the detention pond using an auxiliary dam. The removal efficiencies SS, TN and TP for the practical detention pond were 55.7%, 61.0% and 55.9%, respectively. The facilities of the practical detention pond has a lot of disadvantages such as the low-cost and high efficiency as well as uncountable impacts regarding ecology and landscape. However, an auxiliary dam is recommended to be installed in shallow depth due to low efficiency.