Journal of the Korean Society of Environmental Restoration Technology
/
v.6
no.6
/
pp.49-55
/
2003
Total phosphorous removal rate was examined of a subsurface-flow treatment wetland system which was constructed on floodplain in the down reach of the Kwangju Stream in Korea from May to June 2001. Its dimensions were 29 meter in length, 9 meter in width and 0.65 meter in depth. A bottom layer of 45 cm in depth was filled with crushed granite with about 15~30 mm in diameter and a middle layer of 10 cm in depth had pea pebbles with about 10 mm in diameter. An upper layer of 5 cm in depth contained course sand. Reeds(Phragmites australis) were transplanted on the surface of the system. They were dug out of natural wetlands and stems were cut at about 40 cm height from their bottom ends. Water of the Kwangju Stream flowed from a submerged dam into it via a pipe by gravity flow and treated effluent was funneled back into the Stream. The number of reed stems increased from 80 stems/$m^2$ in July 2001 to 136 stems/$m^2$ in September 2001. The hight of stems was 44.2 cm in July 2001 and 75.3 cm in September 2001. The establishment of reeds at early operating stage of the system was good. Volume and water quality of inflow and outflow were investigated from July 2001 through December 2001. The average inflow was 40 $m^3$/day and hydraulic detention time was about 1.5 days. The concentration of total phosphorous n influent and effluent was 0.83 and 0.33 mg/L, respectively. The removal rate of total phosphorous averaged about 60%. The removal efficiency was slightly higher, compared with that of subsurface-flow wetlands operating in North America, whose retention rate of total phosphorous was reported to be about 56%. The good abatement rate could be attributed to sedimentation of particle phosphorous in pores of the media and adsorption of phosphorous to the biofilm developed on the surface of them. Increase of standing density of reeds within a few years will develop root zones which may lead to increment in the phosphorous retention rate.
The purpose of this study is to improve the polluted stream water quality by pilot-scale five different constructed wetlands (CWs). Cell 1 to 3 are newly designed 2SFCW (Surface-subsurface flow CW) with 1 to 3 flow shifters (FS) in the middle of the wetland system. Cell 4 and 5 are control CW (CCW), but Cell 5 is the same type as Cell 3. The FS, which converts the route of surface and subsurface flow between two wetlands connected in series, was able to enhance the treatability of TN via nitrification and denitrification and of SS due to filtration and sedimentation. The void fraction and dispersion number of Cell 1, 2 and 3 obtained from the RTD analysis were found to be 0.73 and 0.17, respectively. COD and TP removal efficiencies of Cell 1 to 3 were similar to that of Cell 4 and 5. SS removal efficiencies of Cell 1 to 3 and 5 with FS were 5-10% higher than that of Cell 4 without FS. TN removal efficiencies of Cell 1 to 3 were 3-14% higher than that of Cell 4 and 5. The average $R^2$ values of COD, SS, TN and TP obtained from nonlinear regression analysis were similar to the results of other researchers.
Journal of the Korean Society of Environmental Restoration Technology
/
v.4
no.4
/
pp.56-63
/
2001
This paper presents treatment efficiency and plant growth of a subsurface-flow constructed wetland system (23 m in length, 6.5 m in width, 0.65 m in depth) over one year after its establishment on floodplain of a stream in June 2000. An upper layer of 10 cm in depth was filled with course sand and the main biological layer of 50 cm depth with crushed stone with 8 - 15 mm in diameter. The system was planted with common reeds (Phragmites australis) grown on pots. Effluent discharged from a secondary-level treatment plant was funneled into it. Reed stems emerging in April 2001 grew up to 145.9cm until July 2001. The number of reed stems in July 2001 increased by about 11 times compared with that just after planting. The system was inundated seven times by storms over the monitoring period. Reeds were slightly bent after flooding, however they returned to almost upright standing in a couple of weeks. Small portion of inside slope of berm was eroded and the system surface had a sedimentation of 2 - 3 mm in depth. The average removal rates for SS, $BOD_5$, T-N and T-P was 73%, 70%, 53%, and 72%, respectively. The purification efficiencies for SS and $BOD_5$ were fairly good. The reduction rates for T-N was relatively low for the period of late fall through winter until early spring due to lower water temperature which retarded microbial nitrification and denitrification mechanisms. Reduction in the concentration of T-P during fall and winter was relatively higher than that during spring. Leach of phosphorous from plant litters lying on system surface and slight resuspension of precipitated phosphorous in substrates resulted in lower reduction for T-P in spring.
The function of vertical subsurface flow wetlands can potentially be reduced with time due to clogging and are often assumed to be occurring when ponding and overflow is observed during rainfall. To investigate their clogging potential, three pilot-scale vertical subsurface flow (VSF) wetland systems were constructed employing woodchip, pumice, and volcanic gravel as main media. The systems received stormwater runoff from a highway bridge for seven months, after which the media were taken out and divided into layers to determine the amount and characteristics of the accumulated clogging matters. Findings revealed that the main clogging mechanism was the deposition of suspended solids. This is followed by the growth of biofilm in the media which is more evident in the wetland employing woodchip. Up to more than 30% of the clogging matter were found in the upper 20 cm of the media suggesting that this layer will need replacement once clogging occurs. Moreover, no signs of clogging were observed in all the wetlands during the operation period even though an estimation of at least 2 months without clogging was calculated. This was attributed to the intermittent loading mode of operation that gave way for the decomposition of organic matters during the resting period and potentially restored the pore volume.
Journal of the Korean Society of Environmental Restoration Technology
/
v.12
no.1
/
pp.111-122
/
2009
Abatements of TN and ${NO_3}^-$-N in a horizontal subsurface-flow wetland with litter layer on its surface were compared with those without one. The wetland was constructed in 2001 on floodplain of the Gwangju Stream which flows through Gwangju City in Korea. Its dimensions were 29m in length, 9m in width and 0.65m in depth. A bottom layer of 45cm was filled with crushed granites (15~40mm in diameter) and a middle layer of 10cm had pea pebbles. An upper layer of 5cm contained coarse sands. Reeds (Phragmites australis) growing in natural wetlands were transplanted on its surface. Water of the stream was channelled into the wetland by gravity flow and its effluent was discharged back into the stream. Average Litter layer of 12.2cm was formed on its surface in 2007. The layer and above-ground parts of reeds were eliminated in April 2008. Volumes and water quality of influent and effluent of the wetland were analyzed from May to November in 2007 and 2008, respectively. Inflow into the wetland both in 2007 and 2008 averaged approximately 40$m^3$/day and hydraulic residence time both in 2007 and 2008 was about 1.5days. Influent TN concentration in 2007 and 2008 averaged 3.96 and 3.89mg/L, respectively and average influent ${NO_3}^-$-N concentration in 2007 and 2008 was 2.11 and 2.05mg/L, respectively. With a 0.05 significance level, influent concentrations of TN and ${NO_3}^-$-N, temperatures and pH of effluent, and heights and stem numbers of reeds showed no difference between the wetland with litter layer and without one. TN retention in the wetland with litter layer and without one averaged 64,76 and 54.69%, respectively and ${NO_3}^-$-N removal averaged 60.83 and 50.61%, respectively. Both TN and ${NO_3}^-$-N abatement rates in the wetland with litter layer were significantly high (TN abatement: p<0,001, ${NO_3}^-$-N abatement: p=0.001) when compared with those without one. The subsurface-flow wetland having litter layer on its surface was more efficient for TN and ${NO_3}^-$-N removal.
Surface water pollution is a serious environmental problem in developing countries, like India, due to the unregulated discharge of untreated wastewater. To overcome this, the constructed wetlands (CWs) have been proven to be an efficient technology for wastewater treatment. In this study, different existing and experimental facilities were reviewed to be able to determine the current status of constructed wetlands in India. Based on the collected data from published literature, industrial wastewater contained the highest average chemical oxygen demand (COD), biochemical oxygen demand (BOD). In terms of total nitrogen (TN), Total phosphorous (TP), the lowest concentration was found on domestic wastewater. Vertical flow constructed wetlands (VFCW) and Horizontal flow constructed wetland (HFCW) were more effective in removing TSS, BOD, TP in domestic and industrial wastewater, whereas hybrid constructed wetlands (HCW) showed the highest removal for COD. The use of constructed wetlands as advanced wastewater treatment facilities in India yielded better water quality. The treatment of wastewater using constructed wetlands also enabled further reuse of wastewater for irrigation and other agricultural purposes. Overall, this study can be beneficial in evaluating and promoting the use of constructed wetlands in India.
Joo, Kwang Jin;Lee, Dong Min;Kim, Ki Jung;Cho, Yong Chul;Jang, Gwang Hyeon;Choi, I Song;Oh, Jong Min
Ecology and Resilient Infrastructure
/
v.4
no.3
/
pp.142-148
/
2017
Nitrogen and phosphorus are key factors in causing eutrophication of water body. In this study, ceramics media was selected to increase the removal efficiency of nitrogen and phosphorus. We designed vertical, horizontal flow constructed wetlands to create aerobic and anaerobic flow conditions by using the media, then proceeded to performance evaluations after acrylic reactors were produced. In the case of vertical and horizontal flow constructed wetlands, we measured oxygen concentrations to evaluate aerobic and anaerobic conditions. we got the result of 2.7 mg/L in the aerobic condition, N.D in the anaerobic condition respectively, which suited our purpose. The result of the combined vertical and horizontal flow condition showed that the removal efficiency of SS was 94%, 91%, 61% at 140 min, 80 min, 60 min of running times, respectively, and the removal efficiency of T-P was 84%, 71%, 63% during each running time. In case of T-N, the removal efficiency was 63%, 49%, 42% during each running time. We found that the reactor exerted better removal efficiency when in the short time compared to 12 - 24 hr residence time of existing wetlands. In this study, we conducted experiments to explore functional effects after applying combined vertical and horizontal flow methods in the field. Further study will be carried out to identify its mechanism and administrative perspective.
Nam, Gui Sook;Pae, Yo Sop;Kim, Hyung Joong;Lee, Sang Joon;Lee, Gwang Sik
Journal of Wetlands Research
/
v.6
no.4
/
pp.59-69
/
2004
Constructed wetlands are regarded as an important water treatment system for agricultural water quality improvement and management. The purpose of this study is to evaluate the application of subsurface flow wetland(SFW), using the Pharagmites australis as macrophytes, and to clarify the basic and essential factors to be considered in the construction and management of constructed wetlands. This study was carried out relatively short hydraulic residence time(HRT), 6hr ~ 72hr (3days), using eutrophic reservoir water with relatively low concentrations of influent and large quantity to be treated. The effluent satisfied the criteria of agricultural water quality. Removal efficiencies of Biochemical oxygen demand(BOD), Chemical oxygen demand(COD), Suspended solids(SS) and Chlorophyll a(Chl-a) were high in HRT 24hr, not any more significant increasement of removal efficiencies in HRT 48hr and 72hr. However, removal efficiencies of nitrogen and phosphorus increased as HRT increased, showing the highest efficiency at the 72hr of HRT in nitrogen, and 48hr in phosphorous. The SFW was very effective system for reservoir water quality improvement, and had the advantages of the reduction of purchasing cost to land required, lack of odors, and harmful insects, especially mosquito, the improvement of the scenic beauty and minimal risk of public exposure. Therefore, it was evaluated that the SFW was very available water treatment system for the water quality improvement of agricultural reservoir. However, it was need to consider with application of the SFW in high cost of construction and troublesome of management.
Journal of Korean Society of Environmental Engineers
/
v.32
no.4
/
pp.379-392
/
2010
In these days, constructed wetlands are applied in Korea for various purposes ; post-treatment of effluent in wastewater treatment, management of stormwater and restoration of aquatic ecosystems. However, the removal mechanisms for water pollutant in constructed wetlands are not clearly understood because they are affected by climate, influent characteristics and local constraints. Therefore, this paper is focused on the process that the pollutant, especially nitrogen and phosphorus, of the wetland is removed by. In this study, the main nitrogen removal is performed by nitrification/denitrification mechanism in the rhizosphere of constructed wetlands. And the majority of the phosphorus is removed by adsorption on the substrate of wetland. However the fate of phosphorus in wetlands can be diverse depending on the Oxidation Reduction Potential(ORP), adsorption/desorption, precipitation/dissolution, microbial effect, etc.
The application of constructed subsurface-flow wetlands for treatment of wastewater from abandoned mines is being increased. Crushed limestone, oak chips, and mushroom composites are often employed in a bulk form, as the substrates in the bed media. Efficiency of the subsurface-flow treatment system drops with time as the hydraulic conductivity of the wetland soil decreases significantly, presumably due to chemical reactions with the wastewater. The purpose of this study is to investigate the applicability of immobilized beads carrying sulfate reducing bacteria for acid mine drainage treatment system. The ingredients of immobilized beads are organic materials such as mushroom composite and oak chips, limestone powder for a pH buffer, mixed with a modified Coleville Synthetic Brine. It was found that immobilized beads are more efficient than the bulk form for pH recovery, sulfate and heavy metal removal.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.