• 한국농공학회지
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• 제44권4호
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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.

• Journal of Ecology and Environment
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• 제34권4호
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• pp.333-345
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• 2011

Aquatic macrophytes, often also called hydrophytes, are key components of aquatic and wetland ecosystems. This review is to briefly summarizes various macrophyte classifications, and covers numerous aspects of macrophytes' role in wetland ecosystems, namely in nutrient cycling. The most widely accepted macrophyte classification differentiates between freely floating macrophytes and those attached to the substrate, with the attached, or rooted macrophytes further divided into three categories: floating-leaved, submerged and emergent. Biogeochemical processes in the water column and sediments are to a large extent influenced by the type of macrophytes. Macrophytes vary in their biomass production, capability to recycle nutrients, and impacts on the rhizosphere by release of oxygen and organic carbon, as well as their capability to serve as a conduit for methane. With increasing eutrophication, the species diversity of wetland macrophytes generally declines, and the speciose communities are being replaced by monoculture-forming strong competitors. A similar situation often happens with invasive species. The roles of macrophytes and sediment microorganisms in wetland ecosystems are closely connected and should be studied simultaneously rather than in isolation.

• 한국물환경학회지
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• 제24권6호
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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.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.72-76
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• 2004

Wetland is an important eco-system on the earth and can effectively control agricultural non-point source pollution. Reed is a typical wetland plant for land/inland water ecotone in north China. The studies indicated that reed had a underground rooted-stem, which formed a 'high speeded-connecting vessels' i.e. reed root channel (RRC) in Baiyangdian lake of Hebei province. It spread predominantly along horizontal direction underground and are mainly distributed at 18-75 cm. The results of field work from healthy reed-wetland (HRW) and regarded reed-wetland (RRW) showed that the reed, averagely, in HRW is 4.2 m height, 1 cm diameter, 65/m2 density; in RRW is 2.4 m height, 3 mm diameter, 86/m2 density. These results indicated the regradation of the function of RRC in RRW. The results of laboratory work of sewage purification from reed soil column (RSC) $(0\~100cm)$ and wheat soil column (WSC) showed that the efficiency of purification to sewage, in RSC, is high than in WSC, especially for phosphorus. The efficiency of purification, in RSC, is $92.6\%$ for total phosphorus, $43.5\%$ for total nitrogen, $54.1\%$ fur COD, respectively; in WSC, is $86.0\%$ for total phosphorus, $241.3\%$ for total nitrogen, $29.8\%$ for COD, respectively.

• 한국농공학회지
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• 제45권7호
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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.

• 생태와환경
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• 제42권1호
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• pp.1-8
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• 2009

본 연구에서는 mesocosm을 이용하여, 습지내 인의 거동을 살펴보기 위한 현장실험 자료를 고찰하였으며, 결과를 요약하면 다음과 같다. Mesocosm내 수체의 TP농도는 대조구인 M1에서는 $0.48\;mg\;L^{-1}$에서 $0.6\;mg\;L^{-1}$으로 증가한 반면, 처리구인 M2, M3, M4에서는 12.4, 20.4, $23.6\;mg\;L^{-1}$에서 1.92, 6.97, $6.94\;mg\;L^{-1}$로 감소되었고 TP 감소율은 M2, M3, M4에서 각각 84.5, 65.8, 70.6%로 평균 73.7%의 감소율을 보였다. 처리구 중 부착조류가 사멸하지 않은 M2와 대조구인 M1의 전체적인 물질 수지를 비교해 보면, M1의 경우는 부착조류에서의 인의 양이 소량 증가하였고, 갈대와 퇴적물에서의 인의 양은 소량 감소하였다. M1에서 부착조류의 인의 양이 늘어난 것은 대형수생식물이 고사기에 접어들어 습지내의 광조건이 충분해지면서 조류의 증가가 일어난 것이라 판단된다. M2의 경우엔 퇴적물내의 인의 총양은 5, 443 mg에서 8, 086 mg으로 증가하였고, 부착조류와 갈대 역시 각각 1, 147 mg, 1, 740 mg에서 2, 452 mg, 2.160 mg으로 증가하였다. 이로써 습지내 인의 거동에 있어 부착조류와 거대조류에 의한 인의 흡수와 침전 및 식물체에 의한 흡수가 주된 역할을 한다고 판단되며, 부착조류의 흡수가 활발했던 M2의 경우 TP 감소율이 85%에 이르고 부착조류의 흡수가 없었던 M3, M4에서 70% 이하의 TP 감소율을 나타낸 것을 볼 때, 침전과 식물체에 의한 흡수가 병행되는 것이 고농도의 TP처리에 상당히 효과적이라 생각된다. Mesocosm을 이용한 인의 이동경로 추정은 영향인자가 많은 습지내 오염물질 거동을 규명하는 매우 유용한 방법이라 판단되며, 그 결과는 인공습지를 조성하여 활용하는 데 필요한 기초자료로서 활용될 수 있을 것으로 판단된다.

• 한국습지학회지
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• 제3권1호
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• pp.75-89
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• 2001

Constructed wetlands were typically cost less to build and operate, and require less energy than standard mechanical treatment technology but they have similar performance to centralized wastewater treatment plants. Therefore, they were constructed especially many in rural areas, where are small villages but not industries. Accordingly, plantless column tests were performed to investigate the possibility on using zeolite as a filter medium of constructed wetland for the wastewater treatment. $COD_{cr}$ removal efficiency was 94.63% at hydraulic load $314L/m^2{\cdot}d$ and filtering hight 100cm filled with a zeolite mixture. This zeolite mixture consisted of 1 : 1 by volume of a zeolite in the diameter range of 0.5 to 1mm to a zeolite in the diameter range of 1 to 3mm. According, hydraulic load $314L/m^2{\cdot}d$ was considered as optimal. Three zeolite mixture were used to determine the optimal mixing ratio by volume of a zeolite(A) in the diameter range of 0.5 to 1mm to a zeolite(B) in the diameter range of 1 to 3mm diameter. 1 : 3, 1 : 1 and only B in A to B by volume were tested at hydraulic load $314L/m^2{\cdot}d$ and filtering hight 100cm. $COD_{cr}$ removal efficiency was more than 89% at mixing ratios of 1 : 3 and 1 : 1 in A to B. Removal efficiency was lower at the column filled with only B. Removal efficiency was better at filter medium filled with mixing ratio 1 : 1 in A to B than with the other mixing ratios. Thus, it was found that the mixture of mixing ratio 1 : 1 in A to B was appropriate for filter medium of constructed wetland. Removal efficiency was higher in down-flow than in up-flow, and $COD_{cr}$ and BOD were removed best in 20cm filter height near feeding area.

• 한국환경복원기술학회지
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• 제6권3호
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• pp.69-78
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• 2003

The main purpose of this study was to verify the shore margin protection effect of the root system of Salix gracilistyla Miq. developed from direct sticking cuttings on wetland, focusing on the effect of the root system reducing soil particle dissociation rate in water. The soil dissociation rate was examined through slaking tests with cylindric pure soil column at maximum particle density and the same size column of root reinforced soil. The dry weight of remained soil was measured after 5, 10, 15, 30minutes and 1, 6, 12, 24, 48hours inundation. As results, the soil particles began to dissociate severely at 10 minutes and only 10% of soil particles were left after 25minutes inundation. The stable slope angle of pure soil was $36^{\circ}$after 24 hours. On the other hand, the columns of root reinforced soil were stable even after 24hours, being dissociated only 7.2% of soil particles. So, it was revealed that the root system was very effective materials protecting more than 80% of soil particle from dissociation in inundation.

• 한국물환경학회지
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• 제24권5호
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• pp.603-610
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• 2008

A mathematical model was developed to understand how the presence of plants affects vertical profiles of electron acceptors, their reduced species, and trace metals in the wetland sediments. The model accounted for biodegradation of organic matter utilizing sequential electron acceptors and subsequent chemical reactions using stoichiometric relationship. These biogeochemical reactions were affected by the combined effects of oxygen release and evapotranspiration driven by wetland plants. The measured data showed that $SO_4{^{2-}}$ concentrations increased at the beginning of the growing season and then gradually decreased. Based on the measured data, it was hypothesized that the limitation of the solid phase sulfide in direct contact with the roots may result in the gradual decrease of $SO_4{^{2-}}$ concentrations. With the dynamic formulation for the limitation of the solid phase sulfide, model simulated time variable sulfate profiles using published model parameters. Oxygen release from roots produced divalent metal species (i.e. $Cd^{2+}$) as well as oxidized sulfur species (i.e. $SO_4{^{2-}}$) in the sediment pore water. Evapotranspiration-induced advection increased flux of divalent metal species from the overlying water column into the rhizosphere. The increased divalent metal species were converted to the metal sulfide with sufficient FeS around the rhizosphere, which contributed to the decrease of bioavailability and toxicity of divalent metal activity in the pore water. Since the divalent metal activity is a good predictor of the metal bioavailability, this model with a proper simulation of solid phase sulfide plays an essential role to predict the dynamics of trace metals in the wetland sediments.

• 한국습지학회지
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• 제18권1호
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• pp.68-75
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• 2016

본 연구에서는 습지에 널리 적용되는 혼합토양이나 자갈여재 대신 공극율이 90% 이상으로 매우 커서 공극폐색의 염려가 적은 합성섬유를 대체여재로 적용한 수직 흐름형 컬럼습지를 제작하여 서로 다른 수리학적 체류시간, 내부순환빈도 및 오염 부하량 조건에서 축산지역 인공 강우유출수 처리시험을 수행하였다. 모든 습지에서 TSS 제거효율은 94~96%, COD 68~73%, TN 35~58% 이었다. 체류시간 등의 운전인자가 TSS와 COD 제거에 미치는 영향은 미미하였다. 그러나 질소의 경우 부하량과 체류시간, 내부순환빈도가 증가할수록 효율이 증가하였다. 특히 운전기간 동안 합성섬유의 생물학적 분해작용으로 인하여 유기물질이 다량 용출되었으며 탈질을 위한 내부공급 탄소원으로 기여하는 것으로 밝혀졌다. 그러나 용출기간은 40일 정도 지속되었으므로 그 효과는 매우 제한적이었다. 습지 내부충진 여재로서 합성섬유가 갖는 장점은 가벼우므로 구조체의 시공에 소요되는 비용을 저감할 수 있고, 비표면적이 크고 습지수명을 연장할 수 있다는 점이다.