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Sample records for a-01 wetland treatment

  1. Environmental assessment for the A-01 outfall constructed wetlands project at the Savannah River Site

    SciTech Connect

    NONE

    1998-10-01

    The Department of Energy (DOE) prepared this environmental assessment (EA) to analyze the potential environmental impacts associated with the proposed A-01 outfall constructed wetlands project at the Savannah River site (SRS), located near aiken, South Carolina. The proposed action would include the construction and operation of an artificial wetland to treat effluent from the A-01 outfall located in A Area at SRS. The proposed action would reduce the outfall effluent concentrations in order to meet future outfall limits before these go into effect on October 1, 1999. This document was prepared in compliance with the National Environmental Policy Act (NEPA)more » of 1969, as amended; the requirements of the Council on Environmental Quality Regulations for Implementing NEPA (40 CFR Parts 1500--1508); and the DOE Regulations for Implementing NEPA (10 CFR Part 1021).« less

  2. Floating treatment wetlands for domestic wastewater treatment.

    PubMed

    Faulwetter, J L; Burr, M D; Cunningham, A B; Stewart, F M; Camper, A K; Stein, O R

    2011-01-01

    Floating islands are a form of treatment wetland characterized by a mat of synthetic matrix at the water surface into which macrophytes can be planted and through which water passes. We evaluated two matrix materials for treating domestic wastewater, recycled plastic and recycled carpet fibers, for chemical oxygen demand (COD) and nitrogen removal. These materials were compared to pea gravel or open water (control). Experiments were conducted in laboratory scale columns fed with synthetic wastewater containing COD, organic and inorganic nitrogen, and mineral salts. Columns were unplanted, naturally inoculated, and operated in batch mode with continuous recirculation and aeration. COD was efficiently removed in all systems examined (>90% removal). Ammonia was efficiently removed by nitrification. Removal of total dissolved N was ∼50% by day 28, by which time most remaining nitrogen was present as NO(3)-N. Complete removal of NO(3)-N by denitrification was accomplished by dosing columns with molasses. Microbial communities of interest were visualized with denaturing gradient gel electrophoresis (DGGE) by targeting specific functional genes. Shifts in the denitrifying community were observed post-molasses addition, when nitrate levels decreased. The conditioning time for reliable nitrification was determined to be approximately three months. These results suggest that floating treatment wetlands are a viable alternative for domestic wastewater treatment.

  3. ENGINEERING BULLETIN: CONSTRUCTED WETLANDS TREATMENT

    EPA Science Inventory

    Constructed wetlands have been demonstrated effective in removing organic, metal, and nutrient elements including nitrogen and phosphorus from municipal wastewaters, mine drainage, industrial effluents, and agricultural runoff. The technology is waste stream-specific, requiring...

  4. MANUAL - CONSTRUCTED WETLANDS TREATMENT OF MUNICIPAL WASTEWATERS

    EPA Science Inventory

    Constructed wetlands are man-made wastewater treatment systems. They usually have one or more cells less than 1 meter deep and are planted with aquatic greenery. Water outlet structures control the flow of wastewater through the system to keep detention times and water levels at ...

  5. Are constructed treatment wetlands sustainable sanitation solutions?

    PubMed

    Langergraber, Guenter

    2013-01-01

    The main objective of sanitation systems is to protect and promote human health by providing a clean environment and breaking the cycle of disease. In order to be sustainable, a sanitation system has to be not only economically viable, socially acceptable and technically and institutionally appropriate, but it should also protect the environment and the natural resources. 'Resources-oriented sanitation' describes the approach in which human excreta and water from households are recognized as resource made available for reuse. Nowadays, 'resources-oriented sanitation' is understood in the same way as 'ecological sanitation'. For resources-oriented sanitation systems to be truly sustainable they have to comply with the definition of sustainable sanitation as given by the Sustainable Sanitation Alliance (SuSanA, www.susana.org). Constructed treatment wetlands meet the basic criteria of sustainable sanitation systems by preventing diseases, protecting the environment, and being an affordable, acceptable, and simple technology. Additionally, constructed treatment wetlands produce treated wastewater of high quality, which is fostering reuse, which in turn makes them applicable in resources-oriented sanitation systems. The paper discusses the features that make constructed treatment wetlands a suitable solution in sustainable resources-oriented sanitation systems, the importance of system thinking for sustainability, as well as key factors for sustainable implementation of constructed wetland systems.

  6. Nature and transformation of dissolved organic matter in treatment wetlands

    USGS Publications Warehouse

    Barber, L.B.; Leenheer, J.A.; Noyes, T.I.; Stiles, E.A.

    2001-01-01

    This investigation into the occurrence, character, and transformation of dissolved organic matter (DOM) in treatment wetlands in the western United States shows that (i) the nature of DOM in the source water has a major influence on transformations that occur during treatment, (ii) the climate factors have a secondary effect on transformations, (iii) the wetlands receiving treated wastewater can produce a net increase in DOM, and (iv) the hierarchical analytical approach used in this study can measure the subtle DOM transformations that occur. As wastewater treatment plant effluent passes through treatment wetlands, the DOM undergoes transformation to become more aromatic and oxygenated. Autochthonous sources are contributed to the DOM, the nature of which is governed by the developmental stage of the wetland system as well as vegetation patterns. Concentrations of specific wastewaterderived organic contaminants such as linear alkylbenzene sulfonate, caffeine, and ethylenediaminetetraacetic acid were significantly attenuated by wetland treatment and were not contributed by internal loading.

  7. Mine-drainage treatment wetland as habitat for herptofaunal wildlife

    SciTech Connect

    Lacki, M.J.; Hummer, J.W.; Webster, H.J.

    Land reclamation techniques that incorporate habitat features for herptofaunal wildlife have received little attention. We assessed the suitability of a wetland, constructed for the treatment of mine-water drainage, for supporting herptofaunal wildlife from 1988 through 1990 using diurnal and nocturnal surveys. Natural wetlands within the surrounding watershed were also monitored for comparison. The treatment wetland supported the greatest abundance and species richness of herptofauna among the sites surveyed. Abundance was a function of the frog density, particularly green frogs (rana clamitans) and pickerel frogs (R. palustris), while species richness was due to the number of snake species found. The richmore » mix of snake species present at the treatment wetland was believed due to a combination of an abundant frog prey base and an amply supply of den sites in rock debris left behind from earlier surface-mining activities. Nocturnal surveys of breeding male frogs demonstrated highest breeding activity at the treatment wetland, particularly for spring peepers (Hyla crucifer). Whole-body assays of green frog and bullfrog (R. catesbeiana) tissues showed no differences among sites in uptake of iron, aluminum, and zinc; manganese levels in samples from the treatment wetland were significantly lower than those from natural wetlands. These results suggest that wetlands established for water quality improvement can provide habitat for reptiles and amplibians, with the species composition dependent on the construction design, the proximity to source populations, and the degree of acidity and heavy-metal concentrations in drainage waters. 35 refs., 4 tabs.« less

  8. Mine-drainage treatment wetland as habitat for herptofaunal wildlife

    NASA Astrophysics Data System (ADS)

    Lacki, Michael J.; Hummer, Joseph W.; Webster, Harold J.

    1992-07-01

    Land reclamation techniques that incorporate habitat features for herptofaunal wildlife have received little attention. We assessed the suitability of a wetland, constructed for the treatment of mine-water drainage, for supporting herptofaunal wildlife from 1988 through 1990 using diurnal and nocturnal surveys. Natural wetlands within the surrounding watershed were also monitored for comparison. The treatment wetland supported the greatest abundance and species richness of herptofauna among the sites surveyed. Abundance was a function of the frog density, particularly green frogs ( Rana clamitans) and pickerel frogs ( R. palustris), while species richness was due to the number of snake species found. The rich mix of snake species present at the treatment wetland was believed due to a combination of an abundant frog prey base and an amply supply of den sites in rock debris left behind from earlier surface-mining activities. Nocturnal surveys of breeding male frogs demonstrated highest breeding activity at the treatment wetland, particularly for spring peepers ( Hyla crucifer). Whole-body assays of green frog and bullfrog ( R. catesbeiana) tissues showed no differences among sites in uptake of iron, aluminum, and zinc; managanese levels in samples from the treatment wetland were significantly lower than those from natural wetlands. These results suggest that wetlands established for water quality improvement can provide habitat for reptiles and amphibians, with the species composition dependent on the construction design, the proximity to source populations, and the degree of acidity and heavy-metal concentrations in drainage waters.

  9. Constructed wetlands for wastewater treatment in cold climate - A review.

    PubMed

    Wang, Mo; Zhang, Dong Qing; Dong, Jian Wen; Tan, Soon Keat

    2017-07-01

    Constructed wetlands (CWs) have been successfully used for treating various wastewaters for decades and have been identified as a sustainable wastewater management option worldwide. However, the application of CW for wastewater treatment in frigid climate presents special challenges. Wetland treatment of wastewater relies largely on biological processes, and reliable treatment is often a function of climate conditions. To date, the rate of adoption of wetland technology for wastewater treatment in cold regions has been slow and there are relatively few published reports on CW applications in cold climate. This paper therefore highlights the practice and applications of treatment wetlands in cold climate. A comprehensive review of the effectiveness of contaminant removal in different wetland systems including: (1) free water surface (FWS) CWs; (2) subsurface flow (SSF) CWs; and (3) hybrid wetland systems, is presented. The emphasis of this review is also placed on the influence of cold weather conditions on the removal efficacies of different contaminants. The strategies of wetland design and operation for performance intensification, such as the presence of plant, operational mode, effluent recirculation, artificial aeration and in-series design, which are crucial to achieve the sustainable treatment performance in cold climate, are also discussed. This study is conducive to further research for the understanding of CW design and treatment performance in cold climate. Copyright © 2017. Published by Elsevier B.V.

  10. Groundwater Flow Through a Constructed Treatment Wetland

    DTIC Science & Technology

    2002-03-01

    improves water clarity and quality (Wetlands Research Program, 1993). As highly productive ecosystems, wetlands can support life at several...the roots) to the atmosphere through openings in the leaves called stoma . Research indicates that plants may also be able to expel volatile...During transpiration, plants also take in carbon dioxide and oxygen through their stoma in the leaves to support photosynthesis and respiration

  11. Hydrology and hydraulics of treatment wetlands constructed on drained peatlands

    NASA Astrophysics Data System (ADS)

    Postila, Heini; Ronkanen, Anna-Kaisa; Kløve, Bjørn

    2013-04-01

    Treatment wetlands are globally used for wastewater purification purposes. In Finland, these wetlands are commonly peatland-based and are used to treat runoff from peat extraction sites and peatland forestry. Wetlands are also used for polishing municipal wastewaters and mining waters. In peat extraction the structures are usually called overland flow areas (OFAs), which are traditionally established on pristine peatlands. However, nowadays establishing of new peat extraction sites is guided to drained peatland areas due to the Finnish Peat Use Strategy, which leads difficulties to find undisturbed peatland area for OFA. Therefore treatment wetlands have had to construct also on drained peatland areas. In drained areas peat physical properties have changed due to oxidation and subsidence and the water flow pathways differs from OFAs flow patterns, which maybe have effect on purification results. Thus in the present study we aim to clarify the hydrology and hydraulic properties of treatment wetlands constructed on drained peatland areas. For this purposes, 20 treatment wetlands on drained peatland areas across Finland were detailed measured for peat hydraulic conductivity. In selected areas, runoff was continuously monitored, flow distribution at treatment areas was studied and water residence times measured with tracer tests using potassium iodide (KI). Generally, in the study areas, the ditches had been completely blocked, partly blocked e.g with peat dams or not blocked at all. The ditches were located partly parallel to the flow direction and partly perpendicular to it. The distribution of water to the wetlands has been implemented in many different ways e.g. by distribution ditch or by perforated pipes. Based on the results, in majority of the wetlands, the peat drainage has clearly affected the hydraulic properties of wetlands, but not on all sites. In more than half of the wetlands (12), the median hydraulic conductivity of peat drastically decreased at the

  12. Subsurface Treatment of Domestic Wastewater Using Single Domicile Constructed Wetlands

    NASA Astrophysics Data System (ADS)

    Aseltyne, T.; Steer, D.; Fraser, L.

    2001-05-01

    Analysis of one year of input versus output water quality monitoring data from nine household wastewater treatment wetlands in western Ohio indicates that these systems substantially reduce effluent loads delivered to the local watershed. Overall performance as measured by output water quality improvement varies widely between the nine systems despite their close proximity and identical design. These three-cell systems (septic tank with 2 subsurface wetland cells) are found to reduce biological oxygen demand (BOD) 70-98%, fecal coliform 60-99.9%, NH3 29-97%, Phosphorus 21-99.9% and total suspended solids (TSS) up to 97%. NO3/NO2 readings were only taken at the second wetland cell, but show that NO3/NO2 levels are at 0.005-5.01 mg/l and well below the USEPA standards for discharge from a wetland. On average, the pH of the wastewater increases from 6.6 at the septic tank to 8.7 at the wetland output. Nearly all the monitoring data indicate clear decreases in nutrient loads and bacteria though individual systems are found to non-systematically fail to meet EPA discharge guidelines for one or more of the monitored loads. Preliminary analysis of the data indicates a decrease in overall efficiency of the wetlands in April that may be related to seasonal factors. These systems will be monitored for the next three years in order to relate changing performance trends to seasonal variability.

  13. "Living off the land": resource efficiency of wetland wastewater treatment.

    PubMed

    Nelson, M; Odum, H T; Brown, M T; Alling, A

    2001-01-01

    Bioregenerative life support technologies for space application are advantageous if they can be constructed using locally available materials, and rely on renewable energy resources, lessening the need for launch and resupply of materials. These same characteristics are desirable in the global Earth environment because such technologies are more affordable by developing countries, and are more sustainable long-term since they utilize less non-renewable, imported resources. Subsurface flow wetlands (wastewater gardens(TM)) were developed and evaluated for wastewater recycling along the coast of Yucatan. Emergy evaluations, a measure of the environmental and human economic resource utilization, showed that compared to conventional sewage treatment, wetland wastewater treatment systems use far less imported and purchased materials. Wetland systems are also less energy-dependent, lessening dependence on electrical infrastructure, and require simpler maintenance since the system largely relies on the ecological action of microbes and plants for their efficacy. Detailed emergy evaluations showed that wetland systems use only about 15% the purchased emergy of conventional sewage systems, and that renewable resources contribute 60% of total emergy used (excluding the sewage itself) compared to less than 1% use of renewable resources in the high-tech systems. Applied on a larger scale for development in third world countries, wetland systems would require the electrical energy of conventional sewage treatment (package plants), and save of total capital and operating expenses over a 20-year timeframe. In addition, there are numerous secondary benefits from wetland systems including fiber/fodder/food from the wetland plants, creation of ecosystems of high biodiversity with animal habitat value, and aesthestic/landscape enhancement of the community. Wetland wastewater treatment is an exemplar of ecological engineering in that it creates an interface ecosystem to handle

  14. Effect of treatment in a constructed wetland on toxicity of textile wastewater

    USGS Publications Warehouse

    Baughman, G.L.; Perkins, W.S.; Lasier, P.J.; Winger, P.V.

    2003-01-01

    Constructed wetlands for treating wastewater have proliferated in recent years and their characteristics have been studied extensively. In most cases, constructed wetlands have been used primarily for removal of nutrients and heavy metals. Extensive literature is available concerning construction and use of wetlands for treatment of wastewater. Even so, quantitative descriptions of wetland function and processes are highly empirical and difficult to extrapolate. The processes involved in removal of pollutants by wetlands are poorly understood, especially for waste streams as complex as textile effluents. The few studies conducted on treatment of textile wastewater in constructed wetlands were cited in earlier publications. Results of a two-year study of a full-scale wetland treating textile effluent are presented here. The paper describes the effects of the wetland on aquatic toxicity of the wastewater and draws conclusions about the utility and limitations of constructed wetlands for treatment of textile effluents.

  15. Wetlands.

    ERIC Educational Resources Information Center

    Nelson, Patricia L.

    1986-01-01

    Suggests studying New York's wetlands, both in the classroom and in the field, to illustrate ecological concepts of diversity, succession, and adaptation and to learn about their importance in controlling flooding, erosion, and pollution. (NEC)

  16. Constructed Wetlands

    EPA Pesticide Factsheets

    these systems can improve water quality, engineers and scientists construct systems that replicate the functions of natural wetlands. Constructed wetlands are treatment systems that use natural processes

  17. Resilience of carbon and nitrogen removal due to aeration interruption in aerated treatment wetlands.

    PubMed

    Boog, Johannes; Nivala, Jaime; Aubron, Thomas; Mothes, Sibylle; van Afferden, Manfred; Müller, Roland A

    2018-04-15

    Treatment wetlands have long been used for domestic and industrial wastewater treatment. In recent decades, treatment wetland technology has evolved and now includes intensified designs such as aerated treatment wetlands. Aerated treatment wetlands are particularly dependent on aeration, which requires reliable air pumps and, in most cases, electricity. Whether aerated treatment wetlands are resilient to disturbances such as an aeration interruption is currently not well known. In order to investigate this knowledge gap, we carried out a pilot-scale experiment on one aerated horizontal flow wetland and one aerated vertical flow wetland under warm (T water >17°C) and cold (T water <10°C) weather conditions. Both wetlands were monitored before, during and after an aeration interruption of 6d by taking grab samples of the influent and effluent, as well as pore water. The resilience of organic carbon and nitrogen removal processes in the aerated treatment wetlands depended on system design (horizontal or vertical flow) and water temperature. Organic carbon and nitrogen removal for both systems severely deteriorated after 4-5d of aeration interruption, resulting in effluent water quality similar to that expected from a conventional horizontal sub-surface flow treatment wetland. Both experimental aerated treatment wetlands recovered their initial treatment performance within 3-4d at T water >17°C (warm weather) and within 6-8d (horizontal flow system) and 4-5d (vertical flow system) at T water <10°C (cold weather). In the vertical flow system, DOC, DN and NH 4 -N removal were less affected by low water temperatures, however, the decrease of DN removal in the vertical flow aerated wetland at T water >17°C was twice as high as in the horizontal flow aerated wetland. The quick recovery of treatment performance highlights the benefits of aerated treatment wetlands as resilient wastewater treatment technologies. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Quantification of greenhouse gas emissions from sludge treatment wetlands.

    PubMed

    Uggetti, Enrica; García, Joan; Lind, Saara E; Martikainen, Pertti J; Ferrer, Ivet

    2012-04-15

    Constructed wetlands are nowadays successfully employed as an alternative technology for wastewater and sewage sludge treatment. In these systems organic matter and nutrients are transformed and removed by a variety of microbial reaction and gaseous compounds such as methane (CH(4)) and nitrous oxide (N(2)O) may be released to the atmosphere. The aim of this work is to introduce a method to determine greenhouse gas emissions from sludge treatment wetlands (STW) and use the method in a full-scale system. Sampling and analysing techniques used to determine greenhouse gas emissions from croplands and natural wetlands were successfully adapted to the quantification of CH(4) and N(2)O emissions from an STW. Gas emissions were measured using the static chamber technique in 9 points of the STW during 13 days. The spatial variation in the emission along the wetland did not follow some specific pattern found for the temporal variation in the fluxes. Emissions ranged from 10 to 5400 mg CH(4)/m(2)d and from 20 to 950 mgN(2)O/m(2)d, depending on the feeding events. The comparison between the CH(4) and N(2)O emissions of different sludge management options shows that STW have the lowest atmospheric impact in terms of CO(2) equivalent emissions (Global warming potential with time horizon of 100 years): 17 kg CO(2) eq/PE y for STW, 36 kg CO(2) eq/PE y for centrifuge and 162 kg CO(2) eq/PE y for untreated sludge transport, PE means Population Equivalent. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Managing vegetation in surface-flow wastewater-treatment wetlands for optimal treatment performance

    USGS Publications Warehouse

    Thullen, J.S.; Sartoris, J.J.; Nelson, S.M.

    2005-01-01

    Constructed wetlands that mimic natural marshes have been used as low-cost alternatives to conventional secondary or tertiary wastewater treatment in the U.S. for at least 30 years. However, the general level of understanding of internal treatment processes and their relation to vegetation and habitat quality has not grown in proportion to the popularity of these systems. We have studied internal processes in surface-flow constructed wastewater-treatment wetlands throughout the southwestern U.S. since 1990. At any given time, the water quality, hydraulics, water temperature, soil chemistry, available oxygen, microbial communities, macroinvertebrates, and vegetation each greatly affect the treatment capabilities of the wetland. Inside the wetland, each of these components plays a functional role and the treatment outcome depends upon how the various components interact. Vegetation plays a uniquely important role in water treatment due to the large number of functions it supports, particularly with regard to nitrogen transformations. However, it has been our experience that vegetation management is critical for achieving and sustaining optimal treatment function. Effective water treatment function and good wildlife quality within a surface-flow constructed wetland depend upon the health and sustainability of the vegetation. We suggest that an effective tool to manage and sustain healthy vegetation is the use of hummocks, which are shallow emergent plant beds within the wetland, positioned perpendicular to the water flow path and surrounded by water sufficiently deep to limit further emergent vegetation expansion. In this paper, we describe the use of a hummock configuration, in conjunction with seasonal water level fluctuations, to manage the vegetation and maintain the treatment function of wastewater-treatment wetlands on a sustainable basis.

  20. Accumulation of contaminants in fish from wastewater treatment wetlands

    USGS Publications Warehouse

    Barber, L.B.; Keefe, S.H.; Antweiler, Ronald C.; Taylor, Howard E.; Wass, R.D.

    2006-01-01

    Increasing demands on water resources in arid environments make reclamation and reuse of municipal wastewater an important component of the water budget. Treatment wetlands can be an integral part of the water-reuse cycle providing both water-quality enhancement and habitat functions. When used for habitat, the bioaccumulation potential of contaminants in the wastewater is a critical consideration. Water and fish samples collected from the Tres Rios Demonstration Constructed Wetlands near Phoenix, Arizona, which uses secondary-treated wastewater to maintain an aquatic ecosystem in a desert environment, were analyzed for hydrophobic organic compounds (HOC) and trace elements. Semipermeable membrane devices (SPMD) were deployed to investigate uptake of HOC. The wetlands effectively removed HOC, and concentrations of herbicides, pesticides, and organic wastewater contaminants decreased 40-99% between inlet and outlet. Analysis of Tilapia mossambica and Gambusia affinis indicated accumulation of HOC, including p,p???-DDE and trans-nonachlor. The SPMD accumulated the HOC detected in the fish tissue as well as additional compounds. Trace-element concentrations in whole-fish tissue were highly variable, but were similar between the two species. Concentrations of HOC and trace elements varied in different fish tissue compartments, and concentrations in Tilapia liver tissue were greater than those in the whole organism or filet tissue. Bioconcentration factors for the trace elements ranged from 5 to 58 000 and for the HOC ranged from 530 to 150 000. ?? 2006 American Chemical Society.

  1. Seafood wastewater treatment in constructed wetland: tropical case.

    PubMed

    Sohsalam, Prapa; Englande, Andrew Joseph; Sirianuntapiboon, Suntud

    2008-03-01

    A series of investigations were conducted to evaluate the feasibility of using constructed wetlands to remove pollutants from seafood processing wastewater. Six emergent plant species; Cyperus involucratus, Canna siamensis, Heliconia spp., Hymenocallis littoralis, Typha augustifolia and Thalia deabata J. Fraser were planted in surface flow wetland. They were fed with seafood wastewater that was 50% diluted with treated seafood wastewater from an aerated lagoon. All macrophytes were found to meet satisfying treatment efficiency (standard criteria for discharged wastewater) at 5 days hydraulic retention time (HRT). While C. involucratus, T. deabata and T. augustifolia met acceptable treatment efficacy at 3 days HRT. Nutrient uptake rate of these species was observed in the range of 1.43-2.30 g Nitrogen/m(2)day and 0.17-0.29 g Phosphorus/m(2)day, respectively at 3 days HRT. The highest treatment performances were found at 5 days HRT. Average removal efficiencies were 91-99% for BOD(5), 52-90% for SS, 72-92% for TN and 72-77% for TP. Plant growth and nitrogen assimilation were experienced to be most satisfactory for C. involucratus, T. deabata and T. augustifolia. Lower HRTs affected contaminant removal efficiency for all species. C. involucratus, T. deabata and T. augustifolia can remove all contaminants efficiently even at the lowest hydraulic retention time (1 day).

  2. WE-G-16A-01: Evolution of Radiation Treatment Planning

    SciTech Connect

    Rothenberg, L; Mohan, R; Van Dyk, J

    2014-06-15

    Welcome and Introduction - Lawrence N. Rothenberg This symposium is one a continuing series of presentations at AAPM Annual Meetings on the historical aspects of medical physics, radiology, and radiation oncology that have been organized by the AAPM History Committee. Information on previous presentations including “Early Developments in Teletherapy” (Indianapolis 2013), “Historical Aspects of Cross-Sectional Imaging” (Charlotte 2012), “Historical Aspects of Brachytherapy” (Vancouver 2011), “50 Years of Women in Medical Physics” (Houston 2008), and “Roentgen's Early Investigations” (Minneapolis 2007) can be found in the Education Section of the AAPM Website. The Austin 2014 History Symposium will be on “Evolution ofmore » Radiation Treatment Planning.” Overview - Radhe Mohan Treatment planning is one of the most critical components in the chain of radiation therapy of cancers. Treatment plans of today contain a wide variety of sophisticated information conveying the potential clinical effectiveness of the designed treatment to practitioners. Examples of such information include dose distributions superimposed on three- or even four-dimensional anatomic images; dose volume histograms, dose, dose-volume and dose-response indices for anatomic structures of interest; etc. These data are used for evaluating treatment plans and for making treatment decisions. The current state-of-the-art has evolved from the 1940s era when the dose to the tumor and normal tissues was estimated approximately by manual means. However, the symposium will cover the history of the field from the late-1950's, when computers were first introduced for treatment planning, to the present state involving the use of high performance computing and advanced multi-dimensional anatomic, functional and biological imaging, focusing only on external beam treatment planning. The symposium will start with a general overview of the treatment planning process including imaging

  3. Wastewater treatment performance efficiency of constructed wetlands in African countries: a review.

    PubMed

    Mekonnen, Andualem; Leta, Seyoum; Njau, Karoli Nicholas

    2015-01-01

    In Africa, different studies have been conducted at different scales to evaluate wastewater treatment efficiency of constructed wetland. This paper aims to review the treatment performance efficiency of constructed wetland used in African countries. In the reviewed papers, the operational parameters, size and type of wetland used and the treatment efficiency are assessed. The results are organized and presented in six tables based on the type of wetland and wastewater used in the study. The results of the review papers indicated that most of the studies were conducted in Tanzania, Egypt and Kenya. In Kenya and Tanzania, different full-scale wetlands are widely used in treating wastewater. Among wetland type, horizontal subsurface flow wetlands were widely studied followed by surface flow and hybrid wetlands. Most of the reported hybrid wetlands were in Kenya. The results of the review papers indicated that wetlands are efficient in removing organic matter (biochemical oxygen demand and chemical oxygen demand) and suspended solids. On the other hand, nutrient removal efficiency appeared to be low.

  4. Carbon sequestration in surface flow constructed wetland after 12 years of swine wastewater treatment

    USDA-ARS?s Scientific Manuscript database

    Constructed wetlands used for the treatment of swine wastewater may potentially sequester significant amounts of carbon. In past studies, we evaluated the treatment efficiency of wastewater in marsh-pond-marsh design wetland system. The functionality of this system was highly dependent on soil carbo...

  5. Surface flow (SF) treatment wetlands as a habitat for wildlife and humans.

    PubMed

    Knight, R L; Clarke, R A; Bastian, R K

    2001-01-01

    Water quality improvement is generally the primary objective of treatment wetlands. Creation of wildlife habitat is an inevitable outcome of these projects. However, an increasing number of treatment wetland projects have been purposely designed and operated to enhance their beneficial utility to wildlife and humans. This trend to multi-purpose treatment wetlands has broadened the basis for assessing the advantages of this natural treatment alternative. There are at least 21 treatment wetlands in the U.S. that were implemented with wildlife habitat creation and/or human use as principal goals. A number of treatment wetlands outside the U.S. also share these priorities. Hundreds of other wetlands have collected and reported quantitative data on wildlife and/or human uses. The North American Treatment Wetland Database (NADB) has been expanded to include critical wildlife habitat and human use data. This paper provides a preliminary inventory of these habitat and human use treatment wetlands, summarizes lessons learned, and identifies additional data needs.

  6. The performance of constructed wetlands for, wastewater treatment: a case study of Splash wetland in Nairobi Kenya

    NASA Astrophysics Data System (ADS)

    Nzengy'a, Daniel Muasya; Wishitemi, B. E. L.

    2001-12-01

    The performance of a constructed wetland for wastewater treatment was examined for four months (December 1995 to March 1996). The study area, hereby referred to as the Splash wetland, is approximately 0·5 ha, and is located in the southern part of Nairobi city. Splash wetland continuously receives domestic sewage from two busy restaurants. Treated wastewater is recycled for re-use for various purposes in the restaurants. Both wet and dry season data were analysed with a view of determining the impact of seasonal variation on the system performance. The physical and chemical properties of water were measured at a common intake and at series of seven other points established along the wetland gradient and at the outlet where the water is collected and pumped for re-use at the restaurants. The physico-chemical characteristics of the wastewater changed significantly as the wastewater flowed through the respective wetland cells. A comparison of wastewater influent versus the effluent from the wetland revealed the system's apparent success in water treatment, especially in pH modification, removal of suspended solids, organic load and nutrients mean influent pH = 5·7 +/- 0·5, mean effluent pH 7·7 +/- 0·3; mean influent BOD5 = 1603·0 +/- 397·6 mg/l, mean effluent BOD5 = 15·1 +/- 2·5 mg/l; mean influent COD = 3749·8 +/- 206·8 mg/l, mean effluent COD = 95·6 +/- 7·2 mg/l; mean influent TSS = 195·4 +/- 58·7 mg/l, mean effluent TSS = 4·7 +/- 1·9 mg/l. As the wastewater flowed through the wetland system dissolved free and saline ammonia, NH4+, decreased from 14·6 +/- 4·1 mg/l to undetectable levels at the outlet. Dissolved oxygen increased progressively through the wetland system. Analysis of the data available did not reveal temporal variation in the system's performance. However, significant spatial variation was evident as the wetland removed most of the common pollutants and considerably improved the quality of the water, making it safe for re-use at the

  7. Insights to bioprocess and treatment competence of urban wetlands.

    PubMed

    Mahapatra, Durga Madhab; Joshi, N V; Ramachandra, T V

    2018-01-15

    Wetlands play a major role in the recharge of groundwater resources, maintenance of water quality (remediation), moderate microclimate while supporting local livelihood through provision of fish, fodder, etc. The present study aims to investigate algal-bacterial consortium as a function of residence time with the water quality dynamics in two major wetlands in Bangalore city, India. Over thirty-two genera of algae were recorded with more than 40 species in the lakes and two dominant bacterial assemblages. The higher Ammonium-N content favoured the growth of these members. Significant correlation was observed between the nutrient concentrations and the community structure at the inflows and the outflows. The algal community showed negative correlation to filterable COD and high nutrients levels while bacterial abundance was observed under high loadings. The green algae Chlorophyceae (Chlorella blooms), which are indicators of nutrient enrichment were observed predominantly, that needs an immediate attention. Higher overall treatment efficiency was observed in terms of CNP removal during the Pre-monsoon season attributed to absence of macrophytes cover and rapid growth of algal assemblage's due to higher temperature regimes with adequate solar insolation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Wineries wastewater treatment by constructed wetlands: a review.

    PubMed

    Masi, F; Rochereau, J; Troesch, S; Ruiz, I; Soto, M

    2015-01-01

    The application of wetland systems for the treatment of wineries wastewater started in the early 1990s in the USA followed a few years later by France, Italy, Germany and Spain. Various studies demonstrated the efficiency of constructed wetlands (CWs) as a low cost, low maintenance and energy-saving technology for the treatment of wineries wastewater. Several of these experiences have also shown lessons to be learnt, such as some limits in the tolerance of the horizontal subsurface flow and vertical subsurface flow classic CWs to the strength of the wineries wastewater, especially in the first stage for the multistage systems. This paper is presenting an overview of all the reported experiences at worldwide level during the last 15 years, giving particular attention and provision of details to those systems that have proven to get reliable and constant performances in the long-term period and that have been designed and realized as optimized solutions for the application of CW technology to this particular kind of wastewater. The organic loading rates (OLRs) applied to the examined 13 CW systems ranged from about 30 up to about 5,000 gCOD/m² d (COD: chemical oxygen demand), with the 80th percentile of the reported values being below 297 gCOD/m² d and the median at 164 gCOD/m² d; the highest OLR values have in all cases been measured during the peak season (vintage) and often have been linked to lower surface removal rates (SRRs) in comparison to the other periods of the year. With such OLRs the SRRs have ranged from a minimum of 15 up to 4,700 gCOD/m² d, with the 80th percentile of the reported values being below 308 gCOD/m² d and the median at 112 gCOD/m² d.

  9. Design and hydrologic performance of a tile drainage treatment wetland in Minnesota, USA

    USDA-ARS?s Scientific Manuscript database

    Treatment wetlands are increasingly needed to remove nitrate from agricultural drainage water to protect downstream waters such as the Gulf of Mexico. A 0.10 ha wetland was designed,installed and monitored to treat subsurface drainage flow from farmland in Minnesota, USA. This project sought to deve...

  10. Technical, economic and environmental assessment of sludge treatment wetlands.

    PubMed

    Uggetti, Enrica; Ferrer, Ivet; Molist, Jordi; García, Joan

    2011-01-01

    Sludge treatment wetlands (STW) emerge as a promising sustainable technology with low energy requirements and operational costs. In this study, technical, economic and environmental aspects of STW are investigated and compared with other alternatives for sludge management in small communities (<2000 population equivalent). The performance of full-scale STW was characterised during 2 years. Sludge dewatering increased total solids (TS) concentration by 25%, while sludge biodegradation lead to volatile solids around 45% TS and DRI(24h) between 1.1 and 1.4 gO(2)/kgTS h, suggesting a partial stabilisation of biosolids. In the economic and environmental assessment, four scenarios were considered for comparison: 1) STW with direct land application of biosolids, 2) STW with compost post-treatment, 3) centrifuge with compost post-treatment and 4) sludge transport to an intensive wastewater treatment plant. According to the results, STW with direct land application is the most cost-effective scenario, which is also characterised by the lowest environmental impact. The life cycle assessment highlights that global warming is a significant impact category in all scenarios, which is attributed to fossil fuel and electricity consumption; while greenhouse gas emissions from STW are insignificant. As a conclusion, STW are the most appropriate alternative for decentralised sludge management in small communities. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. STORMWATER TREATMENT: WET/DRY PONDS VS. CONSTRUCTED WETLANDS

    EPA Science Inventory

    Extant data were used to assess the relative effectiveness of ponds vs. wetland-type BMPs. Compared to wet ponds, wetlands tended toward higher constituent concentrations in effluent, were inefficient at nitrogen removal, and appeared to preferentially retain phosphorous. These d...

  12. Treatments of oil-refinery and steel-mill wastewaters by mesocosm constructed wetland systems.

    PubMed

    Yang, L; Hu, C C

    2005-01-01

    In this study, two types of industrial wastewater, oil-refining and steel-milling, were selected for investigating their feasibility of treatment by mesocosm constructed wetland systems. The secondly treated effluents from the wastewater treatment plants were directly discharged into the systems controlled at different flow rates. Three wetland mesocosms were installed in the two industries: mesocosms A and B were in the oil refinery, and mesocosm C was in the steel mill. The substratum media used in wetland systems were sand (mesocosm A) and gravel (mesocosms B and C), while the vegetation types selected were reeds (mesocosms A and B) and mixed species of reeds and cattails (mesocosm C). The flow regimes were controlled as free water surface (FWS) and subsurface flow (SSF) for the sand- and gravel-beds, respectively. According to the experimental results, we found that the system treating oil-refining wastewater performed better than that treating steel-milling wastewater learned by comparing the removal efficiencies of COD, total N and total P. In addition, it was found that for oil-refining wastewater treatments, the SSF wetland system (mesocosm B) performed better than FWS (mesocosm A) wetland system when comparing both of their removal of pollutants and growth of vegetation. Besides, the effluents from these two industrial wetland treatment systems might be reclaimed and reused for boiler water, cooling, cleaning and miscellaneous purposes in industries. Further treatments are required if the constructed wetland effluents are thought about being reused for processing in industries.

  13. Constructed Wetlands for Wastewater Treatment and Wildlife Habitat: 17 Case Studies

    EPA Pesticide Factsheets

    This document provides brief descriptions of 17 wetland treatment systems from across the country that are providing significant water quality benefits while demonstrating additional benefits such as wildlife habitat.

  14. [Enhancement strategies in vertical flow constructed wetlands for domestic wastewater treatment].

    PubMed

    Wang, Sheng; Xu, Zu-xin; Li, Huai-zheng

    2006-12-01

    Because pollutants load is too high for root oxygenation, plant absorbance of nutrient and media absorption in vertical down flow wetland to remove pollutants from domestic wastewater, some deficiency do exist, which were confronted by pre-treatment enhancement, media optimization and technological revolution in this study. The strategies include chemically enhanced settlement, pre-aeration, addition of N-adsorption media and P"adsorption media, high, middle and low water level and dynamic saturation line within the soil profile. Chemically enhanced settlement can not only remove P but reduce 63% of the surface area of the connected wetland, but can not remove N effectively. Pre-aeration just increase 1% of the removal percentage of NH4+-N. The wetland with addition of N-adsorption media has the initial removal percentage of 84 % , which decreases to 64 % for consumption of adsorption capacity in 5 months. The saturation time of P-adsorption media is longer for the lower load of P on wetland. So, nitrogen removal only can be achieved by microorganism. Under stable saturation line, removal percentage of COD, NH+ -N, TN, TP in wetland with high water level is 50% , 21% , 32% , - 26% , and those in wetland with middle water level is 53% , 48% , 48% , - 14%, and those in wetland with low water level is 74 % , 96% , 35 % , 22 % . Dynamic saturation line was proposed and Cyclic Batch Subsurface Wetland (CBSW) was invented in this paper, which achieves removal percentage of 67% , 62%, 53%, 33% individually for COD, NH4+ -N, TN, TP. The result suggest that CBSW enhances N removal ability in single-stage wetland and perform better in anti-clogging, and so is the best enhancement strategy in subsurface wetland for domestic wastewater treatment.

  15. Specifically Designed Constructed Wetlands: A Novel Treatment Approach for Scrubber Wastewater

    SciTech Connect

    John H. Rodgers Jr; James W. Castle; Chris Arrington: Derek Eggert

    2005-09-01

    A pilot-scale wetland treatment system was specifically designed and constructed at Clemson University to evaluate removal of mercury, selenium, and other constituents from flue gas desulfurization (FGD) wastewater. Specific objectives of this research were: (1) to measure performance of a pilot-scale constructed wetland treatment system in terms of decreases in targeted constituents (Hg, Se and As) in the FGD wastewater from inflow to outflow; (2) to determine how the observed performance is achieved (both reactions and rates); and (3) to measure performance in terms of decreased bioavailability of these elements (i.e. toxicity of sediments in constructed wetlands and toxicity ofmore » outflow waters from the treatment system). Performance of the pilot-scale constructed wetland treatment systems was assessed using two criteria: anticipated NPDES permit levels and toxicity evaluations using two sentinel toxicity-testing organisms (Ceriodaphnia dubia and Pimephales promelas). These systems performed efficiently with varied inflow simulations of FGD wastewaters removing As, Hg, and Se concentrations below NPDES permit levels and reducing the toxicity of simulated FGD wastewater after treatment with the constructed wetland treatment systems. Sequential extraction procedures indicated that these elements (As, Hg, and Se) were bound to residual phases within sediments of these systems, which should limit their bioavailability to aquatic biota. Sediments collected from constructed wetland treatment systems were tested to observe toxicity to Hyalella azteca or Chironomus tetans. Complete survival (100%) was observed for H. azteca in all cells of the constructed wetland treatment system and C. tentans had an average of 91% survival over the three treatment cells containing sediments. Survival and growth of H. azteca and C. tentans did not differ significantly between sediments from the constructed wetland treatment system and controls. Since the sediments of the

  16. Adsorption, sedimentation, and inactivation of E. coli within wastewater treatment wetlands.

    PubMed

    Boutilier, L; Jamieson, R; Gordon, R; Lake, C; Hart, W

    2009-09-01

    Bacteria fate and transport within constructed wetlands must be understood if engineered wetlands are to become a reliable form of wastewater treatment. This study investigated the relative importance of microbial treatment mechanisms in constructed wetlands treating both domestic and agricultural wastewater. Escherichia coli (E. coli) inactivation, adsorption, and settling rates were measured in the lab within two types of wastewater (dairy wastewater lagoon effluent and domestic septic tank effluent). In situ E. coli inactivation was also measured within a domestic wastewater treatment wetland and the adsorption of E. coli was also measured within the wetland effluent. Inactivation of E. coli appears to be the most significant contributor to E. coli removal within the wastewaters and wetland environments examined in this study. E. coli survived longer within the dairy wastewater (DW) compared to the domestic wastewater treatment wetland water (WW). First order rate constants for E. coli inactivation within the WW in the lab ranged from 0.09 day(-1) (d(-1)) at 7.6 degrees C to 0.18d(-1) at 22.8 degrees C. The average in situ rate constant observed within the domestic wetland ranged from 0.02 d(-1) to 0.03 d(-1) at an average water temperature of 17 degrees C. First order rate constants for E. coli inactivation within the DW ranged from 0.01 d(-1) at 7.7 degrees C to 0.04 d(-1) at 24.6 degrees C. Calculated distribution coefficients (K(d)) were 19,000 mL g(-1), 324,000 mL g(-1), and 293 mL g(-1) for E. coli with domestic septic tank effluent (STE), treated wetland effluent (WLE), and DW, respectively. Approximately 50%, 20%, and 90% of E. coli were "free floating" or associated with particles <5 microm in size within the STE, WLE, and DW respectively. Although 10-50% of E. coli were found to associate with particles >5 microm within both the STE and DW, settling did not appear to contribute to E. coli removal within sedimentation experiments, indicating that the

  17. Degradation of benzotriazole and benzothiazole in treatment wetlands and by artificial sunlight.

    PubMed

    Felis, Ewa; Sochacki, Adam; Magiera, Sylwia

    2016-11-01

    Laboratory-scale experiments were performed using unsaturated subsurface-flow treatment wetlands and artificial sunlight (with and without TiO 2 ) to study the efficiency of benzotriazole and benzothiazole removal and possible integration of these treatment methods. Transformation products in the effluent from the treatment wetlands and the artificial sunlight reactor were identified by high performance liquid chromatography coupled with tandem mass spectrometry. The removal of benzothiazole in the vegetated treatment wetlands was 99.7%, whereas the removal of benzotriazole was 82.8%. The vegetation positively affected only the removal of benzothiazole. The major transformation products in the effluents from the treatment wetlands were methylated and hydroxylated derivatives of benzotriazole, and hydroxylated derivatives of benzothiazole. Hydroxylation was found to be the main process governing the transformation pathway for both compounds in the artificial sunlight experiment (with and without TiO 2 ). Benzotriazole was not found to be susceptible to photodegradation in the absence of TiO 2 . The integration of the sunlight-induced processes (with TiO 2 ) with subsurface-flow treatment wetlands caused further elimination of the compounds (42% for benzotriazole and 58% for benzothiazole). This was especially significant for the elimination of benzotriazole, because the removal of this compound was 96% in the coupled processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Performance of a half-saturated vertical flow wetland packed with volcanic gravel in stormwater treatment.

    PubMed

    Chen, Yaoping; Park, Kisoo; Niu, Siping; Kim, Youngchul

    2014-01-01

    A half-saturated pilot-scale wetland planted with Acorus calamus was built to treat urban stormwater. The design comprises a sedimentation tank for pretreatment, and a vertical flow volcanic gravel wetland bed equipped with a recirculation device. Eighteen rainfall events were monitored in 2012. The treatment system achieved total removal efficiencies of 99.4, 81, 50, and 86% for suspended solids, organic matter, nitrogen and phosphorus, respectively, and 29, 68, and 25% for copper, zinc, and lead, respectively, at a 3-day hydraulic residence time. In the wetland bed, the removal of ammonia, total nitrogen, and zinc were improved by recirculation. Plant uptake provided 18% of nitrogen removal and 39% of phosphorus removal. During the experimental stage, only 1.4% of the pore volume in substrate was reduced due to clogging, implying that the wetland can operate without clogging for a relatively long period.

  19. Feasibility study of a constructed wetland for sewage treatment in a Korean rural community.

    PubMed

    Yoon, C G; Kwun, S K; Ham, J H

    2001-01-01

    A pilot study was performed to examine the feasibility of using a constructed wetland system for treatment of sewage in a Korean rural community. The treatment system was a subsurface flow wetland with a loading rate and hydraulic residence time of 6.3 cm/day and 3.5 days, respectively. The wetland system was highly effective in treating the sewage; median removal efficiencies of BOD5 (biological oxygen demand) and TSS (total suspended solids) were about 70.0%, with median effluent concentrations of 24 and 13 mg/L, respectively, for these constituents. However, BOD5 and TSS did often exceed the effluent water quality standards of 20 mg/L. Removal of TN (total nitrogen) and TP (total phosphorus) was relatively less effective and median effluent concentrations were approximately 81 and 8 mg/L, respectively. The treatment system did not experience any clogging or accumulation of organic and inorganic solids during the study, and during winter a substantial amount of removal of BOD5 and TSS continued to occur. Overall, the constructed wetland was judged to be an effective sewage treatment system, but not sufficient by itself to attain regional water quality standards. Therefore, treatment of rural sewage by a wetland system should be followed by another process such as use of the effluent for irrigation of agricultural crops (e.g., rice).

  20. A cost-effectiveness analysis of seminatural wetlands and activated sludge wastewater-treatment systems.

    PubMed

    Mannino, Ilda; Franco, Daniel; Piccioni, Enrico; Favero, Laura; Mattiuzzo, Erika; Zanetto, Gabriele

    2008-01-01

    A cost-effectiveness analysis was performed to evaluate the competitiveness of seminatural Free Water Surface (FWS) wetlands compared to traditional wastewater-treatment plants. Six scenarios of the service costs of three FWS wetlands and three different wastewater-treatment plants based on active sludge processes were compared. The six scenarios were all equally effective in their wastewater-treatment capacity. The service costs were estimated using real accounting data from an experimental wetland and by means of a market survey. Some assumptions had to be made to perform the analysis. A reference wastewater situation was established to solve the problem of the different levels of dilution that characterize the inflow water of the different systems; the land purchase cost was excluded from the analysis, considering the use of public land as shared social services, and an equal life span for both seminatural and traditional wastewater-treatment plants was set. The results suggest that seminatural systems are competitive with traditional biotechnological systems, with an average service cost improvement of 2.1-fold to 8-fold, according to the specific solution and discount rate. The main improvement factor was the lower maintenance cost of the seminatural systems, due to the self-regulating, low artificial energy inputs and the absence of waste to be disposed. In this work, only the waste-treatment capacity of wetlands was considered as a parameter for the economic competitiveness analysis. Other goods/services and environmental benefits provided by FWS wetlands were not considered.

  1. A Cost-Effectiveness Analysis of Seminatural Wetlands and Activated Sludge Wastewater-Treatment Systems

    NASA Astrophysics Data System (ADS)

    Mannino, Ilda; Franco, Daniel; Piccioni, Enrico; Favero, Laura; Mattiuzzo, Erika; Zanetto, Gabriele

    2008-01-01

    A cost-effectiveness analysis was performed to evaluate the competitiveness of seminatural Free Water Surface (FWS) wetlands compared to traditional wastewater-treatment plants. Six scenarios of the service costs of three FWS wetlands and three different wastewater-treatment plants based on active sludge processes were compared. The six scenarios were all equally effective in their wastewater-treatment capacity. The service costs were estimated using real accounting data from an experimental wetland and by means of a market survey. Some assumptions had to be made to perform the analysis. A reference wastewater situation was established to solve the problem of the different levels of dilution that characterize the inflow water of the different systems; the land purchase cost was excluded from the analysis, considering the use of public land as shared social services, and an equal life span for both seminatural and traditional wastewater-treatment plants was set. The results suggest that seminatural systems are competitive with traditional biotechnological systems, with an average service cost improvement of 2.1-fold to 8-fold, according to the specific solution and discount rate. The main improvement factor was the lower maintenance cost of the seminatural systems, due to the self-regulating, low artificial energy inputs and the absence of waste to be disposed. In this work, only the waste-treatment capacity of wetlands was considered as a parameter for the economic competitiveness analysis. Other goods/services and environmental benefits provided by FWS wetlands were not considered.

  2. Treatment of table olive washing water using trickling filters, constructed wetlands and electrooxidation.

    PubMed

    Tatoulis, Triantafyllos; Stefanakis, Alexandros; Frontistis, Zacharias; Akratos, Christos S; Tekerlekopoulou, Athanasia G; Mantzavinos, Dionissios; Vayenas, Dimitrios V

    2017-01-01

    The production of table olives is a significant economic activity in Mediterranean countries. Table olive processing generates large volumes of rinsing water that are characterized by high organic matter and phenol contents. Due to these characteristics, a combination of more than one technology is imperative to ensure efficient treatment with low operational cost. Previously, biological filters were combined with electrooxidation to treat table olive washing water. Although this combination was successful in reducing pollutant loads, its cost could be further reduced. Constructed wetlands could be an eligible treatment method for integrated table olive washing water treatment as they have proved tolerant to high organic matter and phenol loads. Two pilot-scale horizontal subsurface constructed wetlands, one planted and one unplanted, were combined with a biological filter and electrooxidation over a boron-doped diamond anode to treat table olive washing water. In the biological filter inlet, chemical oxygen demand (COD) concentrations ranged from 5500 to 15,000 mg/L, while mean COD influent concentration in the constructed wetlands was 2800 mg/L. The wetlands proved to be an efficient intermediate treatment stage, since COD removal levels for the planted unit reached 99 % (mean 70 %), while the unplanted unit presented removal rates of around 65 %. Moreover, the concentration of phenols in the effluent was typically below 100 mg/L. The integrated trickling filter-constructed wetland-electrooxidation treatment system examined here could mineralize and decolorize table olive washing water and fully remove its phenolic content.

  3. EPS solubilization treatment by applying the biosurfactant rhamnolipid to reduce clogging in constructed wetlands.

    PubMed

    Du, Mingpu; Xu, Dong; Trinh, Xuantung; Liu, Shuangyuan; Wang, Mei; Zhang, Yi; Wu, Junmei; Zhou, Qiaohong; Wu, Zhenbin

    2016-10-01

    Application of extracellular polymeric substances (EPS) solubilization treatment with biosurfactant rhamnolipid (RL) to reduce clogging in constructed wetlands was first conducted in this study. The results showed significant improvement in the solubilization and dispersion of clogging matter following the treatment. And RL dosage of 0.09-0.15g/L altered microbial group make-up and had an overall positive effect on the growth of microorganisms. Moreover, RL was found to enhance EPS dissolution and dispersion, which was beneficial for the release of enzymes embedded in the EPS, and resulted in enhanced pollutant removal. The treatment had no apparent detrimental effect on wetland plants. Our results indicate that the optimum dosage of RL is 0.12g/L, and that the approach provides a promising and moderate option to reverse wetland clogging through RL-mediated solubilization treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Performance of a Small-scale Treatment Wetland for Treatment of Landscaping Wash Water

    NASA Astrophysics Data System (ADS)

    Thompson, R. J.; Fayed, E.; Fish, W.

    2011-12-01

    A large number of lawn mowers and related equipment must be cleaned each day by commercial landscaping operations and state and local highway maintenance crews. Washing these devices produces wastewater that contains high amounts of organic matter and potentially problematic nutrients, as well as oil and grease and other chemicals and metals that come from the machinery itself. Dirty water washes off the mowers, flows off the pavement and into nearby storm drains without any kind of treatment. A better idea would be to collect such wastewater, retain it in an appropriate catchment such as an engineered wetland where natural processes could break down any pollutants in the wash water, and allow the water to naturally evaporate or percolate into the soil where it could recharge ground water resources safely. This research examines the performance of a small-scale treatment wetland tailored to remove nitrogen from landscaping wash water by incorporating both aerobic and anaerobic phases. Contaminants are analyzed through physical and chemical methods. Both methods involve collection of samples, followed by standardized, validated analytical laboratory tests for measuring total solids, total kjeldahl nitrogen, nitrates, total and dissolved phosphorus, COD, BOD, oil and grease, and metals (Zn and Cu). High levels of total solids, total kjeldahl nitrogen, nitrates, total and dissolved phosphorus, COD, BOD, oil and grease are found. Zinc and copper levels are low. Wetland treatment removes 99% total solids, 77% total kjeldahl nitrogen, 100% nitrates, 94% total phosphorus, 86% dissolved phosphorus, 94% COD, 97% BOD, and 76% oil and grease. The results will be a critical step towards developing a sustainable low-energy system for treating such wastewater that could be used by private landscaping companies and government agencies.

  5. Potential integration of wetland wastewater treatment with space life support systems.

    PubMed

    Nelson, M; Alling, A; Dempster, W F; Van Thillo, M; Allen, J P

    2002-01-01

    Subsurface-flow constructed wetlands for wastewater treatment and nutrient recycling have a number of advantages in planetary exploration scenarios: they are odorless, relatively low labor and low energy, assist in purification of water and recycling of atmospheric CO2, and can directly grow some food crops. This article presents calculations for integration of wetland wastewater treatment with a prototype ground-based experimental facility ("Mars on Earth") supporting four people showing that an area of 4-6 m2 may be sufficient to accomplish wastewater treatment and recycling. Discharge water from the wetland system can be used as irrigation water for the agricultural crop area, thus ensuring complete reclamation and utilization of nutrients within the bioregenerative life support system. Because the primary requirements for wetland treatment systems are warm temperatures and lighting, such bioregenerative systems can be integrated into space life support systems because heat from the lights may be used for temperature maintenance in the human living environment. Subsurface-flow wetlands can be modified for space habitats to lower space and mass requirements. Many of its construction requirements can eventually be met with use of in situ materials, such as gravel from the Mars surface. Because the technology does not depend on machinery and chemicals, and relies more on natural ecological mechanisms (microbial and plant metabolism), maintenance requirements (e.g., pumps, aerators, and chemicals) are minimized, and systems may have long operating lifetimes. Research needs include suitability of Martian soil and gravel for wetland systems, system sealing and liner options in a Mars base, and determination of wetland water quality efficiency under varying temperature and light regimes.

  6. Performance of a vertical subsurface flow (VSF) wetland treatment system using woodchips to treat livestock stormwater.

    PubMed

    Niu, Siping; Guerra, Heidi B; Chen, Yaoping; Park, Kisoo; Kim, Youngchul

    2013-08-01

    This study was conducted to develop a vertical subsurface flow (VSF) wetland remediation system packed with woodchips to control stormwater pollution arising from livestock agriculture. Three lab-scale VSF wetlands were operated with recirculation during the interval (Δ) between storms as 2, 4 and 8 days, respectively. The fed water was 100% recirculated one time per 24 h; the recirculation frequency was 1, 3 and 7 times at Δ of 2, 4 and 8 days, respectively. The constructed wetland systems proved to be effective in reducing total suspended solid (TSS), but also had potential for increasing TSS in the effluent due to the properties of the woodchips. The release of organic matter, especially in the dissolved form, occurred during the initial 60 days. The removal efficiencies of total nitrogen (TN) were 26.2%, 34.1% and 50.0% at Δ of 2, 4 and 8 days, respectively. Nitrification was promoted by the abundant oxygen supplied when the water in wetland was recirculated and fed into the wetland. Denitrification was stable and effective due to the availability of carbon sources. The influent total phosphorus (TP) was reduced from an average of 2.05 mg L(-1) to 1.79 mg L(-1), 1.36 mg L(-1) and 0.86 mg L(-1) at Δ as 2, 4 and 8 days, respectively. The result shows that woodchips can be used as substrate material for VSF wetland treatment systems to control nutrient influx from livestock stormwater.

  7. Fate of Volatile Organic Compounds in Constructed Wastewater Treatment Wetlands

    USGS Publications Warehouse

    Keefe, S.H.; Barber, L.B.; Runkel, R.L.; Ryan, J.N.

    2004-01-01

    The fate of volatile organic compounds was evaluated in a wastewater-dependent constructed wetland near Phoenix, AZ, using field measurements and solute transport modeling. Numerically based volatilization rates were determined using inverse modeling techniques and hydraulic parameters established by sodium bromide tracer experiments. Theoretical volatilization rates were calculated from the two-film method incorporating physicochemical properties and environmental conditions. Additional analyses were conducted using graphically determined volatilization rates based on field measurements. Transport (with first-order removal) simulations were performed using a range of volatilization rates and were evaluated with respect to field concentrations. The inverse and two-film reactive transport simulations demonstrated excellent agreement with measured concentrations for 1,4-dichlorobenzene, tetrachloroethene, dichloromethane, and trichloromethane and fair agreement for dibromochloromethane, bromo-dichloromethane, and toluene. Wetland removal efficiencies from inlet to outlet ranged from 63% to 87% for target compounds.

  8. Wetland treatment of oil and gas well waste waters. Final report

    SciTech Connect

    Kadlec, R.; Srinivasan, K.

    1995-08-01

    Constructed wetlands are small on-site systems that possess three of the most desirable components of an industrial waste water treatment scheme: low cost, low maintenance and upset resistance. The main objective of the present study is to extend the knowledge base of wetland treatment systems to include processes and substances of particular importance to small, on-site systems receiving oil and gas well wastewaters. A list of the most relevant and comprehensive publications on the design of wetlands for water quality improvement was compiled and critically reviewed. Based on our literature search and conversations with researchers in the private sector, toxicmore » organics such as Phenolics and b-naphthoic acid, (NA), and metals such as CU(II) and CR(VI) were selected as target adsorbates. A total of 90 lysimeters equivalent to a laboratory-scale wetland were designed and built to monitor the uptake and transformation of toxic organics and the immobilization of metal ions. Studies on the uptake of toxic organics such as phenol and b-naphthoic acid (NA) and heavy metals such as Cu(II) and Cr(VI), the latter two singly or as non-stoichiometric mixtures by laboratory-type wetlands (LWs) were conducted. These LWs were designed and built during the first year of this study. A road map and guidelines for a field-scale implementation of a wetland system for the treatment of oil and gas wastewaters have been suggested. Two types of wetlands, surface flow (SF) and sub surface flow (SSF), have been considered, and the relative merits of each configuration have been reviewed.« less

  9. Technical and Regulatory Guidance Document for Constructed Treatment Wetlands

    DTIC Science & Technology

    2003-12-01

    Health Protection and Preventive Medicine ; Michael Ogden, Natsys, Inc; Danielle Talkington, U.S. Army Corps of Engineers; John Kornuc, Anteon Corp/NFESC...potential ecological impacts. Some important considerations include • use of nonnative, invasive, or noxious plants ; • clearly identifying the... plant growth. Wetland plants , whose seeds are dispersed ubiquitously in soils, begin to grow in the sediments where water flows are quiescent and

  10. Feasibility of using ornamental plants in subsurface flow wetlands for domestic wastewater treatment

    Treesearch

    Marco A. Belmont

    2000-01-01

    Constructed wetlands are possible low-cost solutions for treating domestic and industrial wastewater in developing countries such as Mexico. However, treatment of wastewater is not a priority in most developing countries unless communities can derive economic benefit from the water resources that are created by the treatment process. As part of our studies directed at...

  11. Investigation of nitrogen transformations in a southern California constructed wastewater treatment wetland

    USGS Publications Warehouse

    Sartoris, J.J.; Thullen, J.S.; Barber, L.B.; Salas, D.E.

    2000-01-01

    A 9.9-ha combined habitat and wastewater treatment demonstration wetland was constructed and planted in the summer of 1994, at Eastern Municipal Water District’s (EMWD) Hemet/San Jacinto Regional Water Reclamation Facility (RWRF) in southern California. From January 1996 through September 1997, the marsh–pond–marsh wetland system was operated to polish an average of 3785 m3 d−1 (1×106 gal day−1) of secondary-treated effluent from the RWRF. Nitrogen removal was a major objective of this wetland treatment. Weekly inflow/outflow water quality monitoring of the wetland was supplemented with biannual, 45-station synoptic surveys within the system to determine internal distribution patterns of the nitrogen species (total ammonia, nitrite, nitrate, and organic nitrogen), total organic carbon (TOC), and ultraviolet absorbance at 254 nm (UV254). Synoptic surveys were carried out during May 22 and September 17, 1996, and May 6 and September 25, 1997 and the results were mapped using the ARC/INFO processing package and inverse distance weighted mathematical techniques. Distribution patterns of the various nitrogen species, TOC, and UV254 within the wetland indicate that the nitrogen dynamics of the system are influenced both by variations in treatment plant loading, and, increasingly, by the degree of coverage and maturity of the emergent vegetation.

  12. Urban stormwater inputs to an adapted coastal wetland: role in water treatment and impacts on wetland biota.

    PubMed

    Howitt, Julia A; Mondon, Julie; Mitchell, Bradley D; Kidd, Toby; Eshelman, Bruce

    2014-07-01

    The Lake Pertobe wetland system is a semi-natural wetland that has been modified primarily for recreational use. However, this lake system receives stormwater from much of the central business district of Warrnambool City (Victoria, Australia) and serves as a buffer zone between the stormwater system and the Merri River and Merri Marine Sanctuary. This work considers the impact of stormwater inputs on Lake Pertobe and the effectiveness of the lake in protecting the associated marine sanctuary. Sediment contaminants (including heavy metals and polycyclic aromatic hydrocarbons (PAHs)) and water quality parameters within the lake, groundwater and stormwater system were measured. Water quality parameters were highly variable between stormwater drains and rain events. Suspended solids rapidly settled along open drains and shortly after entering the lake. Groundwater inputs increased both salinity and dissolved nitrogen in some stormwater drains. Some evidence of bioaccumulation of metals in the food chain was identified and sediment concentrations of several PAHs were very high. The lake acted as a sink for PAHs and some metals and reductions in Escherichia coli, biological oxygen demand and total phosphorus were observed, affording some protection to the associated marine sanctuary. Nutrient retention was inadequate overall and it was identified that managing the lake primarily as a recreational facility impacted on the effectiveness of stormwater treatment in the system. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. ASSESSING THE EFFECT OF ANTIBIOTICS ON THE RESISTANCE OF RESIDENT MICROBES IN WETLANDS CONSTRUCTED FOR WASTEWATER TREATMENT

    EPA Science Inventory

    The use of constructed wetlands as a cost effective and environmentally friendly option for wastewater treatment is becoming more prevalent. These systems are championed as combining many of the benefits of tertiary treatment while also providing high quality wetland habitat as...

  14. The fate of estrogenic hormones in an engineered treatment wetland with dense macrophytes

    USGS Publications Warehouse

    Gray, J.L.; Sedlak, D.L.

    2005-01-01

    Recently, the estrogenic hormones 17??-estradiol (E2) and 17??-ethinyl estradiol (EE2) have been detected in municipal wastewater effluent and surface waters at concentrations sufficient to cause feminization of male fish. To evaluate the fate of steroid hormones in an engineered treatment wetland, lithium chloride, E2, and EE 2 were added to a treatment wetland test cell. Comparison of hormone and tracer data indicated that 36% of the E2 and 41% of the EE 2 were removed during the cell's 84-h hydraulic retention time (HRT). The observed attenuation was most likely the result of sorption to hydrophobic surfaces in the wetland coupled with biotransformation. Sorption was indicated by the retardation of the hormones relative to the conservative tracer. Biotransformation was indicated by elevated concentrations of the E2 metabolite, estrone. It may be possible to improve the removal efficiency by increasing the HRT or the density of plant materials.

  15. Enhancing phosphorus removal in constructed wetlands with ochre from mine drainage treatment.

    PubMed

    Heal, K V; Dobbie, K E; Bozika, E; McHaffie, H; Simpson, A E; Smith, K A

    2005-01-01

    No single end-use has yet been identified that is capable of consuming the projected production of ochre (mainly iron (III) oxides) from mine drainage treatment. However, the high sorption capacity of ochre for phosphorus (up to 26 mg kg(-1)) means that it could be used in constructed wetlands to enhance phosphorus removal. Laboratory batch experiments showed that coarse-grained ochre removes 90% of all phosphorus forms from sewage effluent after 15 minutes of shaking. From a larger-scale experiment, it is estimated that constructed wetlands with an ochre substrate should remove phosphorus from sewage effluent for up to 200-300 years. The suitability of ochre for phosphorus removal is being investigated at the field scale in a wastewater constructed wetland (175 m2 area) in Berwickshire, UK. The hydraulic and treatment performance of the wetland were monitored for 15 months prior to installation at the inlet in November 2003 of a tank containing approximately 1200 kg ochre. Results so far show that improved hydraulic design is required for ochre to increase the mean phosphorus removal efficiency of the system (27 +/- 28%), but potentially toxic metals (Al, Cd, Cr, Cu, Fe, Ni, Pb, Zn) have not been released from the ochre into the wetland outflow.

  16. Influence of hummocks and emergent vegetation on hydraulic performance in a surface flow wastewater treatment wetland

    USGS Publications Warehouse

    Keefe, Steffanie H.; Daniels, Joan S.; Runkel, Robert L.; Wass, Roland D.; Stiles, Eric A.; Barber, Larry B.

    2010-01-01

    A series of tracer experiments were conducted biannually at the start and end of the vegetation growing season in a surface flow wastewater treatment wetland located near Phoenix, AZ. Tracer experiments were conducted prior to and following reconfiguration and replanting of a 1.2 ha treatment wetland from its original design of alternating shallow and deep zones to incorporate hummocks (shallow planting beds situated perpendicular to flow). Tracer test data were analyzed using analysis of moments and the one-dimensional transport with inflow and storage numerical model to evaluate the effects of the seasonal vegetation growth cycle and hummocks on solute transport. Following reconfiguration, vegetation coverage was relatively small, and minor changes in spatial distribution influenced wetland hydraulics. During start-up conditions, the wetland underwent an acclimation period characterized by small vegetation coverage and large transport cross-sectional areas. At the start of the growing season, new growth of emergent vegetation enhanced hydraulic performance. At the end of the growing season, senescing vegetation created short-circuiting. Wetland hydrodynamics were associated with high volumetric efficiencies and velocity heterogeneities. The hummock design resulted in breakthrough curves characterized by multiple secondary tracer peaks indicative of varied flow paths created by bottom topography.

  17. Influence of hummocks and emergent vegetation on hydraulic performance in a surface flow wastewater treatment wetland

    USGS Publications Warehouse

    Keefe, Steffanie H.; Daniels, Joan S.; Runkel, Robert L.; Wass, Roland D.; Stiles, Eric A.; Barber, Larry B.

    2010-01-01

    A series of tracer experiments were conducted biannually at the start and end of the vegetation growing season in a surface flow wastewater treatment wetland located near Phoenix, AZ. Tracer experiments were conducted prior to and following reconfiguration and replanting of a 1.2 ha treatment wetland from its original design of alternating shallow and deep zones to incorporate hummocks (shallow planting beds situated perpendicular to flow). Tracer test data were analyzed using analysis of moments and the one‐dimensional transport with inflow and storage numerical model to evaluate the effects of the seasonal vegetation growth cycle and hummocks on solute transport. Following reconfiguration, vegetation coverage was relatively small, and minor changes in spatial distribution influenced wetland hydraulics. During start‐up conditions, the wetland underwent an acclimation period characterized by small vegetation coverage and large transport cross‐sectional areas. At the start of the growing season, new growth of emergent vegetation enhanced hydraulic performance. At the end of the growing season, senescing vegetation created short‐circuiting. Wetland hydrodynamics were associated with high volumetric efficiencies and velocity heterogeneities. The hummock design resulted in breakthrough curves characterized by multiple secondary tracer peaks indicative of varied flow paths created by bottom topography.

  18. Effects of habitat management treatments on plant community composition and biomass in a Montane wetland

    USGS Publications Warehouse

    Austin, J.E.; Keough, J.R.; Pyle, W.H.

    2007-01-01

    Grazing and burning are commonly applied practices that can impact the diversity and biomass of wetland plant communities. We evaluated the vegetative response of wetlands and adjacent upland grasslands to four treatment regimes (continuous idle, fall prescribed burning followed by idle, annual fall cattle grazing, and rotation of summer grazing and idle) commonly used by the U.S. Fish and Wildlife Service. Our study area was Grays Lake, a large, montane wetland in southeastern Idaho that is bordered by extensive wet meadows. We identified seven plant cover types, representing the transition from dry meadow to deep wetland habitats: mixed deep marsh, spikerush slough, Baltic rush (Juncus balticus), moist meadow, alkali, mesic meadow, and dry meadow. We compared changes in community composition and total aboveground biomass of each plant cover type between 1998, when all units had been idled for three years, and 1999 (1 yr post-treatment) and 2000 (2 yr post-treatment). Analysis using non-metric multidimensional scaling indicated that compositional changes varied among cover types, treatments, and years following treatment. Treatment-related changes in community composition were greatest in mixed deep marsh, Baltic rush, and mesic meadow. In mixed deep marsh and Baltic rush, grazing and associated trampling contributed to changes in the plant community toward more open water and aquatic species and lower dominance of Baltic rush; grazing and trampling also seemed to contribute to increased cover in mesic meadow. Changing hydrological conditions, from multiple years of high water to increasing drought, was an important factor influencing community composition and may have interacted with management treatments. Biomass differed among treatments and between years within cover types. In the wettest cover types, fall burning and grazing rotation treatments had greater negative impact on biomass than the idle treatment, but in drier cover types, summer grazing stimulated

  19. Treatment of tannery wastewater in a pilot-scale hybrid constructed wetland system in Bangladesh.

    PubMed

    Saeed, Tanveer; Afrin, Rumana; Muyeed, Abdullah Al; Sun, Guangzhi

    2012-08-01

    This paper reports the pollutant removal performances of a hybrid wetland system in Bangladesh for the treatment of a tannery wastewater. The system consisted of three treatment stages: a subsurface vertical flow (VF) wetland, followed by a horizontal flow (HF) and a VF wetland. The wetlands were planted with common reed (Phragmites australis), but employed different media, including organic coco-peat, cupola slag and pea gravel. In the first stage, experimental results demonstrated significant removal of ammonia (52%), nitrate (54%), BOD (78%), and COD (56%) under high organics loading rate (690 g COD m(-2)d(-1)); simultaneous nitrification, denitrification, and organics degradation were attributed to the unique characteristics of the coco-peat media, which allowed greater atmospheric oxygen transfer for nitrification and organic degradation, and supply of organic carbon for denitrification. The second stage HF wetland produced an average PO(4) removal of 61%, primarily due to adsorption by the iron-rich cupola slag media. In the third treatment stage, which was filled with gravel media, further BOD removal (78%) from the tannery wastewater depleted organic carbon, causing the accumulation of NO(3) in the wastewater. Overall, the average percentage removals of NH(3)-N, NO(3)-N, BOD, COD, and PO(4) were 86%, 50%, 98%, 98% and 87%, respectively, across the whole hybrid system. The results provided a strong evidence to support widespread research and application of the constructed wetland as a low-cost, energy-efficient, wastewater treatment technology in Bangladesh. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Treatment wetlands in decentralised approaches for linking sanitation to energy and food security.

    PubMed

    Langergraber, Guenter; Masi, Fabio

    2018-02-01

    Treatment wetlands (TWs) are engineered systems that mimic the processes in natural wetlands with the purpose of treating contaminated water. Being a simple and robust technology, TWs are applied worldwide to treat various types of water. Besides treated water for reuse, TWs can be used in resources-oriented sanitation systems for recovering nutrients and carbon, as well as for growing biomass for energy production. Additionally, TWs provide a large number of ecosystem services. Integrating green infrastructure into urban developments can thus facilitate circular economy approaches and has positive impacts on environment, economy and health.

  1. SEASONAL MONITORING OF ELEMENTS AT THREE CONSTRUCTED TREATMENT WETLANDS: 1999-2001

    EPA Science Inventory

    A suite of major, minor, and trace elements in sediment, pore water, and overlying water were monitored during winter and summer over a three year period at three different types of constructed treatment wetlands to evaluate their efficacy with season. Acid-volatile sulfide (AVS)...

  2. Performance and cost evaluation of constructed wetland for domestic waste water treatment.

    PubMed

    Deeptha, V T; Sudarsan, J S; Baskar, G

    2015-09-01

    Root zone treatment through constructed wetlands is an engineered method of purifying wastewater. The aim of the present research was to study the potential of wetland plants Phragmites and Typha in treatment of wastewater and to compare the cost of constructed wetlands with that of conventional treatment systems. A pilot wetland unit of size 2x1x0.9 m was constructed in the campus. 3x3 rows of plants were transplanted into the pilot unit and subjected to wastewater from the hostels and other campus buildings. The raw wastewater and treated wastewater were collected periodically and tested for Total nitrogen (TN),Total Phosphorous (TP), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD). It was observed that this pilot unit reduced the concentrations of TN, TP, BOD and COD by 76, 73, 83 and 86%, respectively, on an average. Root zone system achieved standards for tertiary treatment with low operating costs, low maintenance costs, enhance the landscape, provide a natural habitat for birds, and did not emit any odour.

  3. Effects of Habitat Management Treatments on Plant Community Composition and Biomass in a Montane Wetland

    EPA Science Inventory

    We evaluated the vegetative response of wetlands and adjacent upland grasslands to four treatment regimes (continuous idle, fall prescribed burning followed by idle, annual fall cattle grazing, and rotation of summer grazing and idle) commonly used by the USGS. . . Our results il...

  4. TREATMENT OF CHLORINATED VOLATILE ORGANIC COMPOUNDS IN UPFLOW WETLAND MESOCOSMS. (R828773C003)

    EPA Science Inventory

    Sorption, biodegradation and hydraulic parameters were determined in the laboratory for two candidate soil substrate mixtures for construction of an upflow treatment wetland for volatile organic compounds (VOCs) at a Superfund site. The major parent contaminants in the groundw...

  5. Field investigation of advanced filtration for phosphorus removal from constructed treatment wetland effluents.

    PubMed

    Calder, N; Anderson, B C; Martin, D G

    2006-10-01

    Three sorptive media, blast furnace slag, cement clinker, and gravel were investigated for their capacity to remove phosphorus in a subsurface flow constructed treatment wetland post-treatment filter. Three filters were designed: two containing a mixture of either slag and gravel or clinker and gravel, and one with gravel only as the control filter. They were installed as a demonstration polishing treatment step to a constructed treatment wetland treating residential wastewater collected from 137 mobile home units at the Sunny Creek Estates Mobile Home Park. The filters were commissioned during the summer of the field season, with the data gathering taking place over a period of one year. The slag filter consistently had the lowest outflow dissolved phosphorus concentrations (0.27 +/- 0.08 mg l(-1), n=21), whereas the clinker filter had the highest outflow dissolved phosphorus concentrations (0.72 +/- 0.20 mg l(-1), n=23). The clinker filter performed well below expectations based on previous laboratory investigations, possibly due to lower pH conditions encountered in the field study. All of the filters maintained relatively constant outflow concentrations of phosphorus below 1 mg l(-1), despite varying input conditions and environmental factors such as temperature and phosphorus loading, and the occurrence of net export of phosphorus from the wetland. Net export of phosphorus from the filters occurred in the winter months, which was attributed to the decrease in input phosphorus concentrations below the maintained outflow concentrations (leading to phosphorus desorption), rather than cold temperatures or failure of the filter. Although the exact mechanisms of phosphorus removal are still under investigation, the results from this field study allowed for recommendations to be made for improving phosphorus removal at the Sunny Creek Estates constructed treatment wetland, in addition to providing valuable information for new and existing constructed treatment

  6. Application of constructed wetlands for wastewater treatment in tropical and subtropical regions (2000-2013).

    PubMed

    Zhang, Dong-Qing; Jinadasa, K B S N; Gersberg, Richard M; Liu, Yu; Tan, Soon Keat; Ng, Wun Jern

    2015-04-01

    Constructed wetlands (CWs) have been successfully used for treating various wastewaters for decades and have been identified as a sustainable wastewater management option for developing countries. With the goal of promoting sustainable engineered systems that support human well-being but are also compatible with sustaining natural (environmental) systems, the application of CWs has become more relevant. Such application is especially significant for developing countries with tropical climates, which are very conducive to higher biological activity and productivity, resulting in higher treatment efficiencies compared to those in temperate climates. This paper therefore highlights the practice, applications, and research of treatment wetlands under tropical and subtropical conditions since 2000. In the present review, removal of biochemical oxygen demand (BOD) and total suspended solid (TSS) was shown to be very efficient and consistent across all types of treatment wetlands. Hybrid systems appeared more efficient in the removal of total suspended solid (TSS) (91.3%), chemical oxygen demand (COD) (84.3%), and nitrogen (i.e., 80.7% for ammonium (NH)4-N, 80.8% for nitrate (NO)3-N, and 75.4% for total nitrogen (TN)) as compared to other wetland systems. Vertical subsurface flow (VSSF) CWs removed TSS (84.9%), BOD (87.6%), and nitrogen (i.e., 66.2% for NH4-N, 73.3% for NO3-N, and 53.3% for TN) more efficiently than horizontal subsurface flow (HSSF) CWs, while HSSF CWs (69.8%) showed better total phosphorus (TP) removal compared to VSSF CWs (60.1%). Floating treatment wetlands (FTWs) showed comparable removal efficiencies for BOD (70.7%), NH4-N (63.6%), and TP (44.8%) to free water surface (FWS) CW systems. Copyright © 2015. Published by Elsevier B.V.

  7. Treatment of waters polluted with crude oil and heavy metals by means of a natural wetland.

    PubMed

    Groudeva, V I; Groudev, S N; Doycheva, A S

    2003-01-01

    In the Dolni Dubnik oil deposit, Northern Bulgaria, waters polluted with crude oil and heavy metals (iron, manganese, zinc, cadmium, lead, copper) were treated by means of a natural wetland located in the deposit. The waters had a pH in the range of about 4.5-6.5 and contained about 1-5 mg/l oil. The concentrations of heavy metals usually were about 2-4 times higher than the relevant permissible levels for waters intended for use in the agriculture and industry. The watercourse through the wetland covered a distance of about 100 m and the water flow rate varied in the range of about 0.2-0.8 l/s. The wetland was characterized by an abundant water and emergent vegetation and a diverse microflora, including different oil-degrading bacteria and fungi. The treatment of the polluted waters by means of the above-mentioned wetland markedly depended on the temperature but was efficient during the different climatic seasons, even during the cold winter months at temperatures close to 0 degrees C. The oil content in the wetland effluents in most cases was decreased to less than 0.2 mg/l, and the concentrations of heavy metals were decreased below the relevant permissible levels. The removal of oil was connected with its microbial degradation. The removal of heavy metals was due to different processes but the microbial dissimilatory sulphate reduction and the sorption of metals on the organic matter and clay minerals present in the wetland played the main role.

  8. Treatment of artificial wastewater containing two azo textile dyes by vertical-flow constructed wetlands.

    PubMed

    Hussein, Amjad; Scholz, Miklas

    2018-03-01

    The release of untreated dye textile wastewater into receiving streams is unacceptable not only for aesthetic reasons and its negative impacts on aquatic life but also because numerous dyes are toxic and carcinogenic to humans. Strategies, as of now, used for treating textile wastewaters have technical and economical restrictions. The greater part of the physico-chemical methods, which are used to treat this kind of wastewater, are costly, produce large amounts of sludge and are wasteful concerning some soluble dyes. In contrast, biological treatments such as constructed wetlands are cheaper than the traditional methods, environmental friendly and do not produce large amounts of sludge. Synthetic wastewater containing Acid Blue 113 (AB113) and Basic Red 46 (BR46) has been added to laboratory-scale vertical-flow construction wetland systems, which have been planted with Phragmites australis (Cav.) Trin. ex Steud. (common reed). The concentrations 7 and 208 mg/l were applied for each dye at the hydraulic contact times of 48 and 96 h. Concerning the low concentrations of BR46 and AB113, the unplanted wetlands are associated with significant (ρ < 0.05) reduction performances, if compared with planted wetlands concerning the removal of dyes. For the high concentrations of AB113, BR46 and a mixture of both of them, wetlands with long contact times were significantly (ρ < 0.05) better than wetlands that had short contact times in terms of dye, colour and chemical oxygen demand reductions. Regarding nitrate nitrogen (NO 3 -N), the reduction percentage rates of AB113, BR46 and a mixture dye of both of them were between 85 and 100%. For low and high inflow dye concentrations, best removals were generally recorded for spring and summer, respectively.

  9. Performance of the Iron-Caron Coupling Constructed Wetland for Rural Sewage Treatment

    NASA Astrophysics Data System (ADS)

    Xia, Ruize; Peng, Yutao; Zhong, Shan; Tu, Lijun; Xie, Yuanshan; Zhang, Lishan

    2017-01-01

    In recent years, rural decentralized sewage treatment have gained widespread attention. Although wastewater treatment facility has been developed for rural areas, most rural population are left without adequate wastewater treatment systems. In the present study, the performance of iron-carbon coupling constructed wetland system (ICCWS) and constructed wetland system (CWS) receiving synthetic domestic wastewater were compared in side-by-side trials. Studies have found that CWS filled with spherical iron-carbon packing showed better treatment efficiency than normal CWS. When the HRT is 3 days, the ICCWS have 95.8% COD and 96.6% PO4 3- removal rate, higher than 67.0% COD and 74.3% PO4 3- removal rate in CWS respectively. The use of ICCWS planted with canna and cattail proved to be efficient technology for the removal of rural wastewater pollutants.

  10. Organic and metallic pollutants in water treatment and natural wetlands: a review.

    PubMed

    Haarstad, K; Bavor, H J; Mæhlum, T

    2012-01-01

    A literature review shows that more than 500 compounds occur in wetlands, and also that wetlands are suitable for removing these compounds. There are, however, obvious pitfalls for treatment wetlands, the most important being the maintenance of the hydraulic capacity and the detention time. Treatment wetlands should have an adapted design to target specific compounds. Aquatic plants and soils are suitable for wastewater treatment with a high capacity of removing nutrients and other substances through uptake, sorption and microbiological degradation. The heavy metals Cd, Cu, Fe, Ni and Pb were found to exceed limit values. The studies revealed high values of phenol and SO(4). No samples showed concentrations in sediments exceeding limit values, but fish samples showed concentrations of Hg exceeding the limit for fish sold in the European Union (EU). The main route of metal uptake in aquatic plants was through the roots in emergent and surface floating plants, whereas in submerged plants roots and leaves take part in removing heavy metals and nutrients. Submerged rooted plants have metal uptake potential from water as well as sediments, whereas rootless plants extracted metals rapidly only from water. Caution is needed about the use of SSF CWs (subsurface flow constructed wetlands) for the treatment of metal-contaminated industrial wastewater as metals are shifted to another environmental compartment, and stable redox conditions are required to ensure long-term efficiency. Mercury is one of the most toxic heavy metals and wetlands have been shown to be a source of methylmercury. Methyl Hg concentrations are typically approximately 15% of Hgt (total mercury). In wetlands polycyclic aromatic hydrocarbons (PAH), bisphenol A, BTEX, hydrocarbons including diesel range organics, glycol, dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCB), cyanide, benzene, chlorophenols and formaldehyde were found to exceed limit values. In sediments only PAH and PCB

  11. Effects of nutrients on mosquitoes and an emergent macrophyte, Schoenoplectus maritimus, for use in treatment wetlands.

    PubMed

    Duguma, Dagne; Walton, William E

    2014-06-01

    Schoenoplectus maritimus (alkali bulrush) has desirable attributes, such as a short growth habit (height of mature stands < 1.5 m) and annual senescence, for a potential alternative to tall (height > 3 m) emergent macrophytes in shallow constructed treatment wetlands treating ammonium-dominated wastewater. The effects of different ammonium nitrogen (NH4-N) levels on alkali bulrush growth and its ability to take up nutrients from the wastewater, as well as on mosquito production, across the range of NH4-N found in constructed wetlands of southern California are unknown. We evaluated the effects of enrichment with NH4-N on mosquito production and on the nutrient uptake and growth of alkali bulrush in two studies. Overall, significantly greater numbers (> 50%) of immature mosquitoes (mainly Culex tarsalis) were found in mesocosms enriched with NH4-N than in mesocosms receiving ambient (<0.3 mg/liter) NH4-N. High NH4-N enrichment (up to 60 mg/liter) did not adversely impact the height and stem density of S. maritimus, although a significant decrease in biomass was observed at the highest enrichment level. Nitrogen uptake by alkali bulrush increased directly with NH4-N enrichment, whereas carbon was conserved in the above-ground biomass across the enrichment gradient. Alkali bulrush is recommended for use as part of integrated mosquito management programs for moderately enriched, multipurpose, constructed treatment wetlands that improve water quality as well as provide wetland habitat for waterfowl. © 2014 The Society for Vector Ecology.

  12. Effects of vegetation management in constructed wetland treatment cells on water quality and mosquito production

    USGS Publications Warehouse

    Thullen, J.S.; Sartoris, J.J.; Nelson, S.M.

    2002-01-01

    The impact of three vegetation management strategies on wetland treatment function and mosquito production was assessed in eight free water surface wetland test cells in southern California during 1998–1999. The effectiveness of the strategies to limit bulrush Schoenoplectus californicus culm density within the cells was also investigated. Removing accumulated emergent biomass and physically limiting the area in which vegetation could reestablish, significantly improved the ammonia–nitrogen removal efficiency of the wetland cells, which received an ammonia-dominated municipal wastewater effluent (average loading rate=9.88 kg/ha per day NH4-N). We determined that interspersing open water with emergent vegetation is critical for maintaining the wetland's treatment capability, particularly for systems high in NH4-N. Burning aboveground plant parts and thinning rhizomes only temporarily curtailed vegetation proliferation in shallow zones, whereas creating hummocks surrounded by deeper water successfully restricted the emergent vegetation to the shallower hummock areas. Since the hummock configuration kept open water areas interspersed throughout the stands of emergent vegetation, the strategy was also effective in reducing mosquito production. Decreasing vegetation biomass reduced mosquito refuge areas while increasing mosquito predator habitat. Therefore, the combined goals of water quality improvement and mosquito management were achieved by managing the spatial pattern of emergent vegetation to mimic an early successional growth stage, i.e. actively growing plants interspersed with open water.

  13. Effects of vegetation management in constructed wetland treatment cells on water quality and mosquito production

    USGS Publications Warehouse

    Thullen, J.S.; Sartoris, J.J.; Walton, W.E.

    2002-01-01

    The impact of three vegetation management strategies on wetland treatment function and mosquito production was assessed in eight free water surface wetland test cells in southern California during 1998-1999. The effectiveness of the strategies to limit bulrush Schoenoplectus californicus culm density within the cells was also investigated. Removing accumulated emergent biomass and physically limiting the area in which vegetation could reestablish, significantly improved the ammonia - nitrogen removal efficiency of the wetland cells, which received an ammonia-dominated municipal wastewater effluent (average loading rate = 9.88 kg/ha per day NH4-N). We determined that interspersing open water with emergent vegetation is critical for maintaining the wetland's treatment capability, particularly for systems high in NH4-N. Burning aboveground plant parts and thinning rhizomes only temporarily curtailed vegetation proliferation in shallow zones, whereas creating hummocks surrounded by deeper water successfully restricted the emergent vegetation to the shallower hummock areas. Since the hummock configuration kept open water areas interspersed throughout the stands of emergent vegetation, the strategy was also effective in reducing mosquito production. Decreasing vegetation biomass reduced mosquito refuge areas while increasing mosquito predator habitat. Therefore, the combined goals of water quality improvement and mosquito management were achieved by managing the spatial pattern of emergent vegetation to mimic an early successional growth stage, i.e. actively growing plants interspersed with open water. ?? 2002 Elsevier Science B.V. All rights reserved.

  14. MO-H-19A-01: FEATURED PRESENTATION - Treatment Planning Tool for Radiotherapy with Very High-Energy Electron Beams

    SciTech Connect

    Bazalova, M; Qu, B; Palma, B

    2014-06-15

    Purpose: To develop a tool for treatment planning optimization for fast radiotherapy delivered with very high-energy electron beams (VHEE) and to compare VHEE plans to state-of-the-art plans for challenging pelvis and H'N cases. Methods: Treatment planning for radiotherapy delivered with VHEE scanning pencil beams was performed by integrating EGSnrc Monte Carlo (MC) dose calculations with spot scanning optimization run in a research version of RayStation. A Matlab GUI for MC beamlet generation was developed, in which treatment parameters such as the pencil beam size and spacing, energy and number of beams can be selected. Treatment planning study for H'N andmore » pelvis cases was performed and the effect of treatment parameters on the delivered dose distributions was evaluated and compared to the clinical treatment plans. The pelvis case with a 691cm3 PTV was treated with 2-arc 15MV VMAT and the H'N case with four PTVs with total volume of 531cm3 was treated with 4-arc 6MV VMAT. Results: Most studied VHEE plans outperformed VMAT plans. The best pelvis 80MeV VHEE plan with 25 beams resulted in 12% body dose sparing and 8% sparing to the bowel and right femur compared to the VMAT plan. The 100MeV plan was superior to the 150MeV plan. Mixing 100 and 150MeV improved dose sparing to the bladder by 7% compared to either plan. Plans with 16 and 36 beams did not significantly affect the dose distributions compared to 25 beam plans. The best H'N 100MeV VHEE plan decreased mean doses to the brainstem, chiasm, and both globes by 10-42% compared to the VMAT plan. Conclusion: The pelvis and H'N cases suggested that sixteen 100MeV beams might be sufficient specifications of a novel VHEE treatment machine. However, optimum machine parameters will be determined with the presented VHEE treatment-planning tool for a large number of clinical cases. BW Loo and P Maxim received research support from RaySearch Laboratories. E Hynning and B Hardemark are employees of Ray

  15. Soil and phosphorus accretion rates in sub-tropical wetlands: Everglades Stormwater Treatment Areas as a case example.

    PubMed

    Bhomia, R K; Inglett, P W; Reddy, K R

    2015-11-15

    Wetlands are known to serve as sinks for particulate matter and associated nutrients and contaminants. Consequently rate of soil accretion is critical for continued performance of wetlands to provide ecosystem services including water quality improvement and reduce excess contaminant loads into downstream waters. Here we demonstrate a new technique to determine rate of soil accretion in selected subtropical treatment wetlands located in southern USA. We also report changes in soil accretion rates and subsequent phosphorus (P) removal efficiency with increasing operational history of these treatment wetlands. Utilizing discernible signatures preserved within the soil depth profiles, 'change points' (CP) that corresponded to specific events in the life history of a wetland were determined. The CP was observed as an abrupt transition in the physico-chemical properties of soil as a manifestation of prevailing historical conditions (e.g. startup of treatment wetlands in this case). Vertical depth of CP from the soil surface was equivalent to the depth of recently accreted soil (RAS) and used for soil accretion rate calculations. Annual soil and P accretion rates determined using CP technique (CPT) in studied wetlands ranged from 1.0±0.3 to 1.7±0.8 cm yr(-1) and 1.3±0.6 to 3.3±2 g m(-2) yr(-1), respectively. There was no difference in RAS depth between emergent and submerged aquatic vegetation communities found at the study location. Our results showed that soil and P accretion rates leveled off after 10 yr of treatment wetlands' operation. On comparison, soil accretion rates and RAS depth determined by CPT were commensurate with that measured by other techniques. CPT can be easily used where a reliable record of wetland establishment date or some significant alteration/perturbation is available. This technique offers a relatively simple alternative to determine vertical accretion rates in free-water surface wetlands. Copyright © 2015 Elsevier B.V. All rights

  16. Use of macrophyte plants, sand & gravel materials in constructed wetlands for greywater treatment

    NASA Astrophysics Data System (ADS)

    Qomariyah, S.; Ramelan, AH; Sobriyah; Setyono, P.

    2017-02-01

    Greywater discharged without any treatments into drainage channels or natural water bodies will lead to environmental degradation and health risk. Local macrophyte plants combined with natural materials of sand and gravel have been used in a system of constructed wetland for the treatment of the greywater. This paper presents the results of some studies of the system carried out in Indonesia, Thailand, and Costa Rica. The studies demonstrate the success of the constructed wetland systems in removing some pollutants of BOD, COD, TSS, pathogen, and detergent. The studies resulted in the treated water in a level of treatment that fulfils the requirement of the local standards for wastewater reuse as irrigation water, fishery, or other outdoor needs.

  17. Integrated constructed wetland systems: design, operation, and performance of low-cost decentralized wastewater treatment systems.

    PubMed

    Behrends, L L; Bailey, E; Jansen, P; Houke, L; Smith, S

    2007-01-01

    Several different types of constructed wetland systems are being used as decentralized treatment systems including surface-flow, subsurface-flow, vertical-flow, and hybrid systems. Archetypical wetland systems have design strengths and weaknesses, and therefore it should be possible to design combined (integrated) systems to optimize a number of important treatment processes. This study provides comparative efficacy data for two integrated wetland treatment systems (IWTS) designed to enhance treatment of medium strength wastewater generated from a pilot-scale intensive fish farm. Results from the twenty eight months study included consistently high removal of COD (84% +) and ammonia nitrogen (93%) in both systems. Initially, phosphorus removal was also high (>90%) in both systems, but removal efficacy declined significantly over time. Nitrate removal was significantly better in the system that provided sequential aerobic and anoxic environments. Short hydraulic retention times coupled with sustained removal of COD and ammonia indicate that the ReCip components could be a least-cost wastewater treatment technology in the decentralized market sector.

  18. Biodegradation of anthracene and fluoranthene by fungi isolated from an experimental constructed wetland for wastewater treatment.

    PubMed

    Giraud, F; Guiraud, P; Kadri, M; Blake, G; Steiman, R

    2001-12-01

    Pilot-scale constructed wetlands were used to treat water contaminated by polycyclic aromatic hydrocarbons (PAHs), particularly fluoranthene, and the possible role of fungi present in these ecosystems was investigated. A total of 40 fungal species (24 genera) were isolated and identified from samples (gravel and sediments) from a contaminated wetland and a control wetland. All of them were assayed for their ability to remove anthracene (AC) and fluoranthene (FA) from liquid medium. FA was degraded efficiently by 33 species while only 2 species were able to remove AC over 70%. A selection of 10 strains of micromycetes belonging to various taxonomic groups was further investigated for FA and AC degradation, toxicity assays and phenoloxidases (POx) detection. Interesting and not previously reported species were revealed (Absidia cylindrospora, Cladosporium sphaerospermum, and Ulocladium chartarum). They were all able to highly degrade the PAH-model compounds chosen. An interesting inducibility was noted for Ulocladium chartarum. Degradative ability of fungi was not related to their extracellular POx activity. This study may contribute to the improvement of constructed wetlands for water treatment, which may be enriched in efficient fungi.

  19. Hydraulic characterization and optimization of total nitrogen removal in an aerated vertical subsurface flow treatment wetland.

    PubMed

    Boog, Johannes; Nivala, Jaime; Aubron, Thomas; Wallace, Scott; van Afferden, Manfred; Müller, Roland Arno

    2014-06-01

    In this study, a side-by-side comparison of two pilot-scale vertical subsurface flow constructed wetlands (6.2 m(2)×0.85 m, q(i)=95 L/m(2) d, τ(n)=3.5 d) handling primary treated domestic sewage was conducted. One system (VA-i) was set to intermittent aeration while the other was aerated continuously (VAp-c). Intermittent aeration was provided to VA-i in an 8 h on/4 h off pattern. The intermittently aerated wetland, VA-i, was observed to have 70% less nitrate nitrogen mass outflow than the continuously aerated wetland, VAp-c. Intermittent aeration was shown to increase treatment performance for TN while saving 33% of running energy cost for aeration. Parallel tracer experiments in the two wetlands showed hydraulic characteristics similar to one Continuously Stirred Tank Reactor (CSTR). Intermittent aeration did not significantly affect the hydraulic functioning of the system. Hydraulic efficiencies were 78% for VAp-c and 76% for VA-i. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. An evaluation of free water surface wetlands as tertiary sewage water treatment of micro-pollutants.

    PubMed

    Breitholtz, Magnus; Näslund, Maria; Stråe, Daniel; Borg, Hans; Grabic, Roman; Fick, Jerker

    2012-04-01

    Increased attention is currently directed towards potential negative effects of pharmaceuticals and other micro-pollutants discharged into the aquatic environment via municipal sewage water. A number of additional treatment technologies, such as ozonation, have therefore been suggested as promising tools for improving the removal efficiency of pharmaceuticals in existing Sewage Treatment Plants (STPs). Constructed wetlands are also capable of removing a variety of micro-pollutants, including some pharmaceuticals, and could hence be a resource efficient complement to more advanced treatment technologies. The purpose of the present study was therefore to increase the knowledge base concerning the potential use of constructed wetlands as a treatment step to reduce emissions of organic micro-pollutants from municipal sewage effluents. Under cold winter conditions, incoming and outgoing waters from four Swedish free water surface wetlands, operated as final treatment steps of sewage effluent from municipal STPs, were sampled and analyzed for levels of a set of 92 pharmaceuticals and 22 inorganic components as well as assessed using subchronic ecotoxicity tests with a macro-alga and a crustacean. Sixty-five pharmaceuticals were detected in the range from 1 ng L(-1) to 7.6 μg L(-1) in incoming and outgoing waters from the four investigated wetlands. Although the sampling design used in the present study lacks the robustness of volume proportional to 24h composite samples, the average estimated removal rates ranged from 42% to 52%, which correlates to previous published values. The effects observed in the ecotoxicity tests with the macro-alga (EC(50)s in the range of 7.5-46%) and the crustacean (LOECs in the range of 11.25-90%) could not be assigned to either pharmaceutical residues or metals, but in general showed that these treatment facilities release water with a relatively low toxic potential, comparable to water that has been treated with advanced tertiary

  1. [Treatment of oilfield produced water by biological methods-constructed wetland process and degradation characteristics of organic substances].

    PubMed

    Huang, Xiang-feng; Shen, Jie; Wen, Yue; Liu, Jia; Lu, Li-jun; Zhou, Qi

    2010-02-01

    Hydrolysis acidification-aerobic-constructed wetland process and hydrolysis acidification-constructed wetland were used to treat oilfield produced water after the pretreatment of oil separation-coagulation. Gas chromatography-mass spectrometry was used to study the degradation characteristics of organic substances during the treatment process. The results showed that COD and ammonia nitrogen of both the two process effluents were below 80 mg/L and 15 mg/L, respectively, when HRT was 20 h for hydrolysis acidification, 10 h for aeration and 2 d for constructed wetlands or when HRT was 20 h for hydrolysis acidification and 4 d for constructed wetland. The results of GC-MS analysis showed that biodegradability of the oil produced water was significantly improved in hydrolysis acidification. Substantial removal of benzene compounds was achieved in aerobic and constructed wetland.

  2. Application of subsurface vertical flow constructed wetlands to reject water treatment in dairy wastewater treatment plant.

    PubMed

    Dąbrowski, Wojciech; Karolinczak, Beata; Gajewska, Magdalena; Wojciechowska, Ewa

    2017-01-01

    The paper presents the effects of applying subsurface vertical flow constructed wetlands (SS VF) for the treatment of reject water generated in the process of aerobic sewage sludge stabilization in the biggest dairy wastewater treatment plant (WWTP) in Poland. Two SS VF beds were built: bed (A) with 0.65 m depth and bed (B) with 1.0 m depth, planted with reeds. Beds were fed with reject water with hydraulic load of 0.1 m d -1 in order to establish the differences in treatment efficiency. During an eight-months research period, a high removal efficiency of predominant pollutants was shown: BOD 5 88.1% (A) and 90.5% (B); COD 84.5% (A) and 87.5% (B); TSS 87.6% (A) and 91.9% (B); TKN 82.4% (A) and 76.5% (B); N-NH 4 + 89.2% (A) and 85.7% (B); TP 30.2% (A) and 40.6% (B). There were not statistically significant differences in the removal efficiencies between bed (B) with 1.0 m depth and bed (A) with 0.65 m depth. The research indicated that SS VF beds could be successfully applied to reject water treatment in dairy WWTPs. The study proved that the use of SS VF beds in full scale in dairy WWTPs would result in a significant decrease in pollutants' load in reject water. In the analyzed case, decreasing the load of ammonia nitrogen was of greatest importance, as it constituted 58% of the total load treated in dairy WWTP and posed a hazard to the stability of the treatment process.

  3. Competitive sorption and desorption behavior for three fluoroquinolone antibiotics in a wastewater treatment wetland soil.

    PubMed

    Conkle, Jeremy L; Lattao, Charisma; White, John R; Cook, Robert L

    2010-09-01

    Significant amounts of pharmaceuticals are discharged into the environment through wastewater effluent. Sorption has been shown to be a significant aqueous removal pathway for many of these compounds. Competition between ciprofloxacin (CIP), ofloxacin (OFL) and norfloxacin (NOR) and their sorption to, and desorption from, a surrogate Louisiana wastewater treatment wetland soil were investigated to gain insight into the fate and transport of the pollutants within wastewater treatment wetlands. This study was undertaken in the context of a treatment wetland that continuously receives pharmaceuticals. Therefore it is important to understand the total capacity of this soil to sorb these compounds. Sorption to this treatment wetland soil was found to provide a major and potentially long-term removal pathway for these antibiotics from wastewater. LogK(F) values for all three compounds were between 4.09 and 3.90 for sorption and 4.24 and 4.05 microg(1-1/)(n)(cm(3))(1/)(n)g(-1) for desorption. The compounds were sorbed in amounts ranging from 60% to 90% for high and low loading, respectively. The majority of the compounds were sorbed to the soil within the first 20h, indicating that treatment wetland may not need long retention times (weeks to months) in order to remove these compounds. Sorption K(D) values for competition (20 ppm of each compound for 60 ppm of total fluoroquinolones) ranged from 2300 to 3800 cm(3)g(-1) which is between both the 20 (4300-5800 cm(3)g(-1)) and 60 (1300-3000 cm(3)g(-1)) ppm single compound K(D) values, indicating that there is competition between these three compound for sorption sites. Sorption and desorption data (single component and mixture) collectively provide the following evidence: (1) NOR and, to a lesser extent, CIP outcompete OFL for sorption sites, (2) OFL sorbes to its share of "quality" sorption sites, and (3) competition only occurs for lesser "quality" binding sites. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. Carbon sequestration in a surface flow constructed wetland after 12 years of swine wastewater treatment.

    PubMed

    Reddy, Gudigopuram B; Raczkowski, Charles W; Cyrus, Johnsely S; Szogi, Ariel

    2016-01-01

    Constructed wetlands used for the treatment of swine wastewater may potentially sequester significant amounts of carbon. In past studies, we evaluated the treatment efficiency of wastewater in a marsh-pond-marsh design wetland system. The functionality of this system was highly dependent on soil carbon content and organic matter turnover rate. To better understand system performance and carbon dynamics, we measured plant dry matter, decomposition rates and soil carbon fractions. Plant litter decomposition rate was 0.0052 g day(-1) (±0.00119 g day(-1)) with an estimated half-life of 133 days. The detritus layer accumulated over the soil surface had much more humin than other C fractions. In marsh areas, soil C extracted with NaOH had four to six times higher amounts of humic acid, fulvic acid and humin than soil C extracted by cold and hot water, HCl/HF, and Na pyruvate. In the pond area, humic acid, fulvic acid and humin content were two to four times lower than in the marsh area. More soil C and N was found in the marsh area than in the pond area. These wetlands proved to be large sinks for stable C forms.

  5. Hydraulic and hydrological aspects of an evapotranspiration-constructed wetland combined system for household greywater treatment.

    PubMed

    Filho, Fernando Jorge C Magalhães; Sobrinho, Teodorico Alves; Steffen, Jorge L; Arias, Carlos A; Paulo, Paula L

    2018-05-12

    Constructed wetlands systems demand preliminary and primary treatment to remove solids present in greywater (GW) to avoid or reduce clogging processes. The current paper aims to assess hydraulic and hydrological behavior in an improved constructed wetland system, which has a built-in anaerobic digestion chamber (AnC), GW is distributed to the evapotranspiration and treatment tank (CEvaT), combined with a subsurface horizontal flow constructed wetland (SSHF-CW). The results show that both the plants present in the units and the AnC improve hydraulic and volumetric efficiency, decrease short-circuiting and improve mixing conditions in the system. Moreover, the hydraulic conductivity measured on-site indicates that the presence of plants in the system and the flow distribution pattern provided by the AnC might reduce clogging in the SSHF-CW. It is observed that rainfall enables salt elimination, thus increasing evapotranspiration (ET), which promotes effluent reduction and enables the system to have zero discharge when reuse is unfeasible.

  6. Improving the treatment efficiency of constructed wetlands with zeolite-containing filter sands.

    PubMed

    Bruch, Ingo; Fritsche, Johannes; Bänninger, Dominik; Alewell, Ulrike; Sendelov, Michael; Hürlimann, Heinz; Hasselbach, Ralf; Alewell, Christine

    2011-01-01

    In this study the physical and chemical properties of three different lava sands used in constructed wetlands for municipal wastewater treatment were investigated. The aim was to identify those properties and mechanisms that render lava sands as highly efficient filter media which could substitute conventional, fluviatile sands. It was shown that although lava sands per se may be suitable filter materials, the presence of zeolite minerals within the lava sands enhances the purification efficiency tremendously. Zeolites not only increase the sorption capacity, but even more important, they are able to absorb water in large amounts, which in turn leads to stronger swelling. The latter reduces hydrological conductivity considerably, resulting in a longer contact time to eliminate pollutants. A simple mineralogical survey of filter materials for the presence of zeolites may render many installations of constructed wetlands successful. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Pumice soil: a potential wetland substrate for treatment of domestic wastewater.

    PubMed

    Njau, K N; Minja, R J A; Katima, J H Y

    2003-01-01

    Laboratory and fieldwork studies were carried out to evaluate the potential of pumice soil for use as a wetland substrate in wastewater treatment. The composition of pumice soil was analysed by x-ray fluorescence (XRF) and x-ray diffraction (XRD) techniques. Adsorption kinetic studies were carried out in a semi-batch recycle system. Fieldwork tests were carried out on Subsurface Flow Constructed Wetland (SSFCW) cells planted with Phragmites mauritianus and Vetiveria zizanioides. The results have shown that pumice soil composition contains among other elements Al, Ca, Fe and Mg, which are positive indicators for phosphorus adsorption. The main minerals observed by XRD were augite, hematite, and sodium titanium silicate. Phosphorus adsorption kinetics have shown that phosphorus is adsorbed on pumice soil following first order kinetics and the adsorption was highly influenced by mass transfer. Approximately 3% of the phosphorus was removed by plant uptake.

  8. Application of a constructed wetland for industrial wastewater treatment: a pilot-scale study.

    PubMed

    Chen, T Y; Kao, C M; Yeh, T Y; Chien, H Y; Chao, A C

    2006-06-01

    The main objective of this study was to examine the efficacy and capacity of using constructed wetlands on industrial pollutant removal. Four parallel pilot-scale modified free water surface (FWS) constructed wetland systems [dimension for each system: 4-m (L)x1-m (W)x1-m (D)] were installed inside an industrial park for conducting the proposed treatability study. The averaged influent contains approximately 170 mg l(-1) chemical oxygen demand (COD), 80 mg l(-1) biochemical oxygen demand (BOD), 90 mg l(-1) suspend solid (SS), and 32 mg l(-1) NH(3)-N. In the plant-selection study, four different wetland plant species including floating plants [Pistia stratiotes L. (P. stratiotes) and Ipomoea aquatica (I. aquatica)] and emergent plants [Phragmites communis L. (P. communis) and Typha orientalis Presl. (T. orientalis)] were evaluated. Results show that only the emergent plant (P. communis) could survive and reproduce with a continuous feed of 0.4m(3)d(-1) of the raw wastewater. Thus, P. communis was used in the subsequent treatment study. Two different control parameters including hydraulic retention time (HRT) (3, 5, and 7d) and media [vesicles ceramic bioballs and small gravels, 1cm in diameter] were examined in the treatment study. Results indicate that the system with a 5-d HRT (feed rate of 0.4m(3)d(-1)) and vesicles ceramic bioballs as the media had the acceptable and optimal pollutant removal efficiency. If operated under conditions of the above parameters, the pilot-plant wetland system can achieve removal of 61% COD, 89% BOD, 81% SS, 35% TP, and 56% NH(3)-N. The treated wastewater meets the current industrial wastewater discharge standards in Taiwan.

  9. Removal of enteric bacteria in constructed treatment wetlands with emergent macrophytes: a review.

    PubMed

    Vymazal, Jan

    2005-01-01

    Domestic and municipal sewage contains various pathogenic or potentially pathogenic microorganisms which, depending on species concentration, pose a potential risk to human health and whose presence must therefore be reduced in the course of wastewater treatment. The removal of microbiological pollution is seldom a primary target for constructed treatment wetlands (CWs). However, wetlands are known to act as excellent biofilters through a complex of physical, chemical and biological factors which all participate in the reduction of the number of bacteria. Measurement of human pathogenic organisms in untreated and treated wastewater is expensive and technically challenging. Consequently, environmental engineers have sought indicator organisms that are (1) easy to monitor and (2) correlate with population of pathogenic organisms. The most frequently used indicators are total coliforms, fecal coliforms, fecal streptococci and Escherichia coli. The literature survey of 60 constructed wetlands with emergent vegetation around the world revealed that removal of total and fecal coliforms in constructed wetlands with emergent macrophytes is high, usually 95 to > 99% while removal of fecal streptococci is lower, usually 80-95%. Because bacterial removal efficiency is a function of inflow bacteria number, the high removal effects are achieved for untreated or mechanically pretreated wastewater. Therefore, the outflow numbers of bacteria are more important. For TC and FC the outflow concentrations are usually in the range of 10(2) to 10(5) CFU/ 100 ml while for FS the range is between 10(2) and 10(4) CFU/ 100 ml. Results from operating systems suggest that enteric microbe removal efficiency in CWs with emergent macrophytes is primarily influenced by hydraulic loading rate (HLR) and the resultant hydraulic residence time (HRT) and the presence of vegetation. Removal of enteric bacteria follows approximately a first-order relationship.

  10. Phytoremediation of explosives in groundwater using innovative wetlands-based treatment technologies

    SciTech Connect

    Sikora, F.J.; Behrends, L.L.; Coonrod, H.S.

    1997-12-31

    Many army ammunition plants across the country have problems with groundwater contaminated with explosives. A field demonstration was initiated at the Milan Army Ammunition Plant near Milan, Tennessee early in 1996 to demonstrate the feasibility of treating contaminated groundwater with constructed wetlands. Two different systems were designed and installed. A lagoon system consisted of two cells in series with each cell having dimensions of 24 x 9.4 x 0.6 m (L x W x H). A gravel-bed system consisted of three gravel-beds operated in series with a primary anaerobic cell having dimensions of 32 x 11 x 1.4 m (Lmore » x W x H), followed by a pair of secondary cells each with dimensions of 5.5 x 11 x 1.4 m (L x W x H). The primary cell is maintained anaerobic by adding powdered milk to the water every two weeks. The secondary cells are maintained aerobic via reciprocation, whereby water is pumped back and forth from one cell to another to cause a recurrent fill and drain action. The lagoons were planted with sago pond weed, water stargrass, elodea, and parrot feather. The gravel-bed wetlands were planted with canary grass, wool grass, sweet flag, and parrot feather. Water began flowing to each of the wetland treatment systems at 19 L min{sup {minus}1} starting in June 1996. The design hydraulic retention time through each treatment system was approximately 10 days. Influent and effluent water samples were collected every 2 weeks. Intensive sampling of water interior to the wetlands occurred every 2 months.« less

  11. Constructed wetlands for saline wastewater treatment: A review

    USDA-ARS?s Scientific Manuscript database

    Saline wastewater originating from sources such as agriculture, aquaculture, and many industrial sectors usually contains high levels of salts and other contaminants, which can adversely affect both aquatic and terrestrial ecosystems. Therefore, the treatment of saline wastewater (removal of both sa...

  12. Design and performance of a pilot-scale constructed wetland treatment system for natural gas storage produced water.

    PubMed

    Kanagy, Laura E; Johnson, Brenda M; Castle, James W; Rodgers, John H

    2008-04-01

    To test the hypothesis that water produced from natural gas storage wells could be treated effectively by constructed wetland treatment systems, a modular pilot-scale system was designed, built, and used for treating gas storage produced waters. Four simulated waters representing the range of contaminant concentrations typical of actual produced waters were treated, and the system's performance was monitored. Freshwater wetland cells planted with Schoenoplectus californicus and Typha latifolia were used to treat fresh and brackish waters. Saline and hypersaline waters were treated by saltwater wetland cells planted with Spartina alterniflora and by reverse osmosis. Effective removal of cadmium, copper, lead, and zinc was achieved by the pilot-scale system. Results suggest that use of specifically designed constructed wetland treatment systems provides a flexible and effective approach for treating gas storage produced waters over a wide range of compositions.

  13. Alum application to improve water quality in a municipal wastewater treatment wetland.

    PubMed

    Malecki-Brown, Lynette M; White, John R; Sees, M

    2009-01-01

    Nutrient removal in treatment wetlands declines during winter months due to temperature. A 3-mo (wintertime) mesocosm study was conducted to determine the effectiveness of alum in immobilizing P as well as other nutrients during this period of reduced treatment efficiency. Eighteen mesocosms, triplicate alum, and three controls or no alum were established with either Typha spp., Schoenoplectus californicus, or SAV (Najas guadalupensis-dominated). Alum was delivered by timer at a rate of 0.81 g Al m(-2) d(-1) and parameters measured included: pH, soluble reactive phosphorus (SRP), total phosphorus (TP), dissolved organic carbon (DOC), dissolved inorganic nitrogen (DIN), total kjeldahl nitrogen (TKN), and soluble aluminum (Al). Alum-treated mesocosms had significantly lower pH values (8.1) than controls (8.8), but well within the elevated pH range for aluminum toxicity. Alum significantly reduced all measured water column nutrients with the exception of ammonium N, which remained unaffected, and particulate P, which increased. This study demonstrated that seasonal low-dosage alum application to different vegetation communities in a treatment wetland can significantly improve treatment efficiencies for SRP (87 vs. 58%) and TP (62 vs. 44%) but also increase DOC (19 vs. 0%) and TKN (12 vs. -3%) removal capacity to a lesser degree. Alum applications within close proximity of the treatment wetland effluent points should be implemented with caution due to the production of alum floc-bound P which could potentially affect discharge permit compliance for total suspended solids or total P.

  14. Hydraulic reliability of a horizontal wetland for wastewater treatment in Sicily.

    PubMed

    Marzo, A; Ventura, D; Cirelli, G L; Aiello, R; Vanella, D; Rapisarda, R; Barbagallo, S; Consoli, S

    2018-04-25

    The purpose of this study was to evaluate how the hydraulic behavior of a horizontal subsurface wetland (HF), that is part of the hybrid wetland (hybrid-TW) of the IKEA® store in Eastern Sicily (Italy), influences the overall wastewater treatment performance. The HF unit experiences frequent overloading peaks due to the extreme variability in the number of visitors at the store, and after 2 years of operation it showed signals of partial clogging at the inlet area. The hydraulics of the HF unit has been monitored through measurements of hydraulic conductivity at saturation (Ks), tracer tests, and geophysical (i.e. electrical resistivity tomography-ERT) measurements carried out during the years 2016 and 2017. Results indicated a general good agreement between the performed measurement techniques, thus their combination, if adequately performed and calibrated, might be a reliable tool for detecting those wetland areas mainly affected by clogging conditions. The results also indicated that partial clogging had no significant effect on the quality of the discharged water. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Performance evaluation of duplex constructed wetlands for the treatment of diesel contaminated wastewater.

    PubMed

    Mustapha, Hassana Ibrahim; Gupta, Pankaj Kumar; Yadav, Brijesh Kumar; van Bruggen, J J A; Lens, P N L

    2018-04-09

    A duplex constructed wetland (duplex-CW) is a hybrid system that combines a vertical flow (VF) CW as a first stage with a horizontal flow filter (HFF) as a second stage for a more efficient wastewater treatment as compared to traditional constructed wetlands. This study evaluated the potential of the hybrid CW system to treat influent wastewater containing diesel range organic compounds varying from C 7 - C 40 using a series of 12-week practical and numerical experiments under controlled conditions in a greenhouse (pH was kept at 7.0 ± 0.2, temperature between 20 and 23° C and light intensity between 85 and 100-μmol photons m -2 sec -1 for 16 h d -1 ). The VF CWs were planted with Phragmites australis and were spiked with different concentrations of NH 4 + -N (10, 30 and 60 mg/L) and PO 4 3- -P (3, 6 and 12 mg/L) to analyse their effects on the degradation of the supplied petroleum hydrocarbons. The removal rate of the diesel range organics considering the different NH 4 + -N and PO 4 3- -P concentrations were simulated using Monod degradation kinetics. The simulated results compared well with the observed database. The results showed that the model can effectively be used to predict biochemical transformation and degradation of diesel range organic compounds along with nutrient amendment in duplex constructed wetlands. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Oxygen flux implications of observed nitrogen removal rates in subsurface-flow treatment wetlands.

    PubMed

    Tanner, C C; Kadlec, R H

    2003-01-01

    Nitrification, an oxygen-requiring microbial process, is generally considered the rate-limiting step for N removal in subsurface-flow constructed wetlands treating organic wastewaters. We used a simplified model of sequential N transformations and sinks to infer required rates of oxygen supply at 5 stages along experimental wetland mesocosms supplied with four different organic wastewaters with contrasting ratios of COD: N and forms of N. Mass balances of water-borne organic, ammoniacal and nitrate N, and plant and sediment N uptake showed average net rates of N mineralisation ranging from 0.22-0.53 g m(-2) d(-1), nitrification 0.56-2.15 g m(-2) d(-1), denitrification 0.47-1.99 g m(-2) d(-1) (60-84% of measured N removal) and plant assimilation 0.28-0.47 g m(-2) d(-1). The nitrogenous oxygen demand (NOD) required to support the observed nitrification rates alone was high compared to expected fluxes from surficial and plant-mediated oxygen transfer. In the presence of high levels of degradable organic matter (COD removal rates up to 66 g m(-2) d(-1)), heterotrophs with significantly higher oxygen affinities and energy yields are expected to outcompete nitrifiers for available oxygen. Problems with commonly held assumptions on the nature of coupled nitrification-denitrification in treatment wetlands are discussed.

  17. Residential subsurface flow treatment wetlands in northern Minnesota.

    PubMed

    Axler, R; Henneck, J; McCarthy, B

    2001-01-01

    Approximately 30% of Minnesotans use on-site systems (approximately 500,000 residences) and >50% are failing or non-compliant with regulations due to restrictive soils and site conditions. Many sites occur near lakes and streams creating health hazards and deteriorating water quality. SSF CWs have been evaluated year-round at two northern sites since 1995. The NERCC CWs simulate single homes and the Grand Lake demonstration CW treats STE from a cluster of 9 lakeshore homes. Systems were generally able to achieve design criteria of 25 mg TSS/L and 30 mg BOD5/L and the NERCC CWs required only 0.3 m of unsaturated soil to achieve consistent disinfection to <200 fecals/100 mL year round. Seeding experiments with Salmonella indicated removal efficiencies of 99.8% in summer and 95% in winter. High strength (approximately 300 mg BOD/L, 95 mg TN/L) influent at NERCC probably limited system performance, particularly N-removal (mass) which was approximately 42% in summer and 20% in winter. The data indicate CW's are a viable, year-round treatment option for homeowners in terms of performance, ease of operation, and cost but require additional maintenance related to inconsistent vegetation growth, winter insulation, and meeting concentration-based regulatory standards since they were seasonally and annually variable due to rain events, partial freezing, spring snowmelt, and summer evapotranspiration.

  18. Life cycle assessment of vertical and horizontal flow constructed wetlands for wastewater treatment considering nitrogen and carbon greenhouse gas emissions.

    PubMed

    Fuchs, Valerie J; Mihelcic, James R; Gierke, John S

    2011-02-01

    Life cycle assessment (LCA) is used to compare the environmental impacts of vertical flow constructed wetlands (VFCW) and horizontal flow constructed wetlands (HFCW). The LCAs include greenhouse gas (N(2)O, CO(2) and CH(4)) emissions. Baseline constructed wetland designs are compared to different treatment performance scenarios and to conventional wastewater treatment at the materials acquisition, assembly and operation life stages. The LCAs suggest that constructed wetlands have less environmental impact, in terms of resource consumption and greenhouse gas emissions. The VFCW is a less impactful configuration for removing total nitrogen from domestic wastewater. Both wetland designs have negligible impacts on respiratory organics, radiation and ozone. Gaseous emissions, often not included in wastewater LCAs because of lack of data or lack of agreement on impacts, have the largest impact on climate change. Nitrous oxide accounts for the increase in impact on respiratory inorganic, and the combined acidification/eutrophication category. The LCAs were used to assess the importance of nitrogen removal and recycling, and the potential for optimizing nitrogen removal in constructed wetlands. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Impact of influent wastewater quality on nitrogen removal rates in multistage treatment wetlands.

    PubMed

    Gajewska, Magdalena; Jóźwiakowski, Krzysztof; Ghrabi, Ahmed; Masi, Fabio

    2015-09-01

    Nitrogen removal in treatment wetlands is influenced by many factors, and the presence of electron donors (biodegradable organic matter) and electron acceptors (nitrate ions) is the main limiting one; for obtaining these conditions, multistage treatment wetlands (MTWs) are required, where an extensive nitrification can be obtained in the first stages under aerobic conditions leaving then to the following anoxic/anaerobic stages the duty of the denitrification. Most of the biodegradable organic matter is however oxidised in the first stages, and therefore, the inlet to the denitrification beds is usually poor of easily degradable carbon sources. This study is comparing the long-term performances obtained at several MTWs operating in Europe (North and South) and North Africa in order to understand if there is a significant avail in making use of the influent chemical oxygen demand (COD)/N ratio during the design phase for ensuring proper performances in terms of N overall removal. The statistic analysis performed in this study have shown that MTWs are capable to ensure sufficient removal of both organic and nutrients even in unfavourable proportions of macronutrients (C and N). The usual assumptions for conventional biological treatment systems concerning adequate C/N ratios seem to be dubious in case of wastewater treatment in MTWs.

  20. Comparison of grey water treatment performance by a cascading sand filter and a constructed wetland.

    PubMed

    Kadewa, W W; Le Corre, K; Pidou, M; Jeffrey, P J; Jefferson, B

    2010-01-01

    A novel unplanted vertical flow subsurface constructed wetland technology comprising three shallow beds (0.6 m length, 0.45 m width and 0.2 m depth) arranged in a cascading series and a standard single-pass Vertical Flow Planted Constructed Wetland (VFPCW, 6 m² and 0.7 m depth) were tested for grey water treatment. Particular focus was on meeting consent for published wastewater reuse parameters and removal of anionic surfactants. Treatment performance at two hydraulic loading rates (HLR) of 0.08, and 0.17 m³ m⁻² d⁻¹ were compared. Both technologies effectively removed more than 90% turbidity and more than 96% for organics with the prototype meeting the most stringent reuse standard of < 2 NTU and <10 mg/L. However, surfactant removal in the VFPCW was higher (76-85%) than in the prototype which only achieved more than 50% removal at higher loading rate. Generally, the prototype performed consistently better than the VFPCW except for surfactant removal. However, at higher loading rates, both systems did not meet the reuse standard of <1 mg L⁻¹ for anionic surfactants. This observation confirms that shallow beds provide a more oxidised environment leading to higher BOD₅ and COD removals. Presence of plants in the VFPCW led to higher anionic surfactant removal, through increased microbial and sorption processes.

  1. Purification ability and carbon dioxide flux from surface flow constructed wetlands treating sewage treatment plant effluent.

    PubMed

    Wu, Haiming; Lin, Li; Zhang, Jian; Guo, Wenshan; Liang, Shuang; Liu, Hai

    2016-11-01

    In this study, a two-year experiment was carried out to investigate variation of carbon dioxide (CO2) flux from free water surface constructed wetlands (FWS CW) systems treating sewage treatment plant effluent, and treatment performance was also evaluated. The better 74.6-76.6% COD, 92.7-94.4% NH4(+)-N, 60.1-84.7% TN and 49.3-70.7% TP removal efficiencies were achieved in planted CW systems compared with unplanted systems. The planted CW was a net CO2 sink, while the unplanted CW was a net CO2 source in the entire study period. An obvious annual and seasonal variability of CO2 fluxes from different wetland systems was also presented with the average CO2 flux ranging from -592.83mgm(-2)h(-1) to 553.91mgm(-2)h(-1) during 2012-2013. In addition, the net exchange of CO2 between CW systems and the atmosphere was significantly affected by air temperature, and the presence of plants also had the significant effect on total CO2 emissions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Treatment of Oil Wastewater and Electricity Generation by Integrating Constructed Wetland with Microbial Fuel Cell

    PubMed Central

    Yang, Qiao; Wu, Zhenxing; Liu, Lifen; Zhang, Fengxiang; Liang, Shengna

    2016-01-01

    Conventional oil sewage treatment methods can achieve satisfactory removal efficiency, but energy consumption problems during the process of oil sewage treatment are worth attention. The integration of a constructed wetland reactor and a microbial fuel cell reactor (CW-MFC) to treat oil-contaminated wastewater, compared with a microbial fuel cell reactor (MFC) alone and a constructed wetland reactor (CW) alone, was explored in this research. Performances of the three reactors including chemical oxygen demand (COD), oil removal, and output voltage generation were continuously monitored. The COD removals of three reactors were between 73% and 75%, and oil removals were over 95.7%. Compared with MFC, the CW-MFC with a MnO2 modified cathode produced higher power density and output voltage. Maximum power densities of CW-MFC and MFC were 3868 mW/m3 (102 mW/m2) and 3044 mW/m3 (80 mW/m2), respectively. The plants in CW-MFC play a positive role for reactor cathode potential. Both plants and cathode modification can improve reactor performance of electricity generation. PMID:28774005

  3. Assessment of activated sludge, membrane bioreactors and vertical flow wetlands for upgrading sewage treatment works.

    PubMed

    Besançon, A; Le Corre, K S; Dotro, G; Jefferson, B

    2017-01-01

    This paper demonstrates that utilising a vertical flow (VF) wetland after a conventional activated sludge (CAS) delivers equivalent or better effluent quality to a membrane bioreactor (MBR) based on a side-by-side pilot trial. The CAS was operated under the solids retention times (SRT) of 6, 12, and 20 days, with the effluent from each pilot plant fed onto a soil aquifer treatment column to better understand their water reuse application potential. Results showed an upgraded CAS + VF system could deliver effluents with median values of 34 mgO 2 .L -1 , 7 mg.L -1 and 1.9 mg.L -1 for organics, solids and ammonia nitrogen, respectively, which were statistically similar to those from the MBR. Water reuse standards were achieved by the upgraded system for most parameters, with the exception of total coliform removal. The upgraded system delivered superior metal removal when compared to the CAS. An economic analysis showed upgrading a CAS with a VF wetland was more favourable than investing in an MBR system for example works of 5000 and 50,000 population equivalents if the VF system was operated at hydraulic loading rates of 0.03 m.d -1 and 0.08 m.d -1 , respectively. This was delivered for a tenth of the carbon footprint of the MBR treatment.

  4. Effects of effluent recirculation in vertical-flow constructed wetland on treatment efficiency of livestock wastewater.

    PubMed

    Lian-sheng, He; Hong-liang, Liu; Bei-dou, Xi; Ying-bo, Zhu

    2006-01-01

    Enhancing the treatment efficiency of livestock wastewater by effluent recirculation is investigated in a pilot-scale vertical-flow constructed wetland. The wetland system is composed of downflow and upflow stages, on which narrow-leaf Phragmites communis and common reed Phragmites typhia are planted, respectively; each stage has a dimension of 4 m(2) (2 m x 2 m). Wastewater from the facultative pond is fed into the system intermittently at a flow rate of 0.4 m(3)/d. Recirculation rates of 0, 25%, 50%0, 100% and 150% are adopted to evaluate the effect of the recirculation rate on pollutants removal. This shows that with effluent recirculation the average removal efficiencies of NH4-N, BOD5 and SS obviously increase to 61.7%, 81.3%, and 77.1%, respectively, in comparison with the values of 35.6%o, 50.2%, and 49.3% without effluent recirculation. But the improvement of TP removal is slight, only from 42.3% to 48.9%. The variations of NH4-N, DO and oxidation-reduction potential (ORP) of inflow and outflow reveal that the adoption of effluent recirculation is beneficial to the formation of oxide environment in wetland. The exponential relationships with excellent correlation coefficients (R(2) > 0.93) are found between the removal rates of NH4-N and BOD5 and the recirculation rates. With recirculation the pH value of the outflow decreases as the alkalinity is consumed by the gradually enhanced nitrification process. When recirculation rate is kept constant at 100%, the ambient temperature appears to affect NH4-N removal, but does not have significant influence on BOD5 removal.

  5. Ibuprofen removal in horizontal subsurface flow constructed wetlands: treatment performance and fungal community dynamics.

    PubMed

    Zhang, Dongqing; Luo, Jinxue; Lee, Zarraz May Ping; Gersberg, Richard M; Liu, Yu; Tan, Soon Keat; Ng, Wun Jern

    2016-01-01

    The treatment performance of ibuprofen (IBP)-enriched wastewater by horizontal subsurface flow constructed wetlands planted with cattail (Typha angustifolia) and unplanted control mesocosms was investigated. Removal efficiencies of IBP were significantly (p < .05) enhanced in the planted mesocosms (78.5%) compared to those in the unplanted beds (57.9%). An 18S rRNA gene high-throughput pyrosequencing approach was used to investigate the effects of IBP on the structure of the fungal community in these wetland systems. The overall diversity of the fungal community was reduced under the IBP exposure. Taxonomic analysis revealed that 62.2% of the fungal sequences were affiliated with Basidiomycota, followed by Ascomycota (37.4%) at the phylum level. Uncultured fungus (48.2%), Chaetomium sp. (14.2%), Aspergillus sp. (12.4%), Trichoderma sp. (5.7%), Cladosporium sp. (5.4%), and Emericellopsis sp. (5.2%) were identified as dominant genera. At the genus level, a distinct profile of the fungal community in the IBP-enriched mesocosms was observed as compared to the control beds, and as well specific fungal genera were enhanced in the planted beds, regardless of IBP enrichment. However, despite these differences, the composition of the fungal community (as measured by Bray-Curtis similarity) was mostly unaffected by the significant IBP enrichment. On the other hand, a consistent similarity pattern of fungal community structure in the planted mesocosms suggests that the presence of higher macrophytes in the wetland systems may well help shape the fungal community structure.

  6. Emerging organic contaminant removal depending on primary treatment and operational strategy in horizontal subsurface flow constructed wetlands: influence of redox.

    PubMed

    Avila, Cristina; Reyes, Carolina; Bayona, Josep María; García, Joan

    2013-01-01

    This study aimed at assessing the influence of primary treatment (hydrolytic upflow sludge blanket (HUSB) reactor vs. conventional settling) and operational strategy (alternation of saturated/unsaturated phases vs. permanently saturated) on the removal of various emerging organic contaminants (i.e. ibuprofen, diclofenac, acetaminophen, tonalide, oxybenzone, bisphenol A) in horizontal subsurface flow constructed wetlands. For that purpose, a continuous injection experiment was carried out in an experimental treatment plant for 26 days. The plant had 3 treatment lines: a control line (settler-wetland permanently saturated), a batch line (settler-wetland operated with saturate/unsaturated phases) and an anaerobic line (HUSB reactor-wetland permanently saturated). In each line, wetlands had a surface area of 2.95 m(2), a water depth of 25 cm and a granular medium D(60) = 7.3 mm, and were planted with common reed. During the study period the wetlands were operated at a hydraulic and organic load of 25 mm/d and about 4.7 g BOD/m(2)d, respectively. The injection experiment delivered very robust results that show how the occurrence of higher redox potentials within the wetland bed promotes the elimination of conventional quality parameters as well as emerging microcontaminants. Overall, removal efficiencies were always greater for the batch line than for the control and anaerobic lines, and to this respect statistically significantly differences were found for ibuprofen, diclofenac, oxybenzone and bisphenol A. As an example, ibuprofen, whose major removal mechanism has been reported to be biodegradation under aerobic conditions, showed a higher removal in the batch line (85%) than in the control (63%) and anaerobic (52%) lines. Bisphenol A showed also a great dependence on the redox status of the wetlands, finding an 89% removal rate for the batch line, as opposed to the control and anaerobic lines (79 and 65%, respectively). Furthermore, diclofenac showed a greater

  7. Evaluation of an alternative method for wastewater treatment containing pesticides using solar photocatalytic oxidation and constructed wetlands.

    PubMed

    Berberidou, Chrysanthi; Kitsiou, Vasiliki; Lambropoulou, Dimitra A; Antoniadis, Αpostolos; Ntonou, Eleftheria; Zalidis, George C; Poulios, Ioannis

    2017-06-15

    The present study proposes an integrated system based on the synergetic action of solar photocatalytic oxidation with surface flow constructed wetlands for the purification of wastewater contaminated with pesticides. Experiments were conducted at pilot scale using simulated wastewater containing the herbicide clopyralid. Three photocatalytic methods under solar light were investigated: the photo-Fenton and the ferrioxalate reagent as well as the combination of photo-Fenton with TiO 2 P25, which all led to similar mineralization rates. The subsequent treatment in constructed wetlands resulted in further decrease of DOC and inorganic ions concentrations, especially of NO 3 - . Clopyralid was absent in the outlet of the wetlands, while the concentration of the detected intermediates was remarkably low. These findings are in good agreement with the results of phytotoxicity of the wastewater, after treatment with the ferrioxalate/wetlands process, which was significantly reduced. Thus, this integrated system based on solar photocatalysis and constructed wetlands has the potential to effectively detoxify wastewater containing pesticides, producing a purified effluent which could be exploited for reuse applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Constructed wetlands for wastewater and activated sludge treatment in north Greece: a review.

    PubMed

    Tsihrintzis, V A; Gikas, G D

    2010-01-01

    Constructed wetlands used for the treatment of urban, industrial and agricultural wastewater have become very popular treatment systems all over the world. In Greece, these systems are not very common, although the climate is favourable for their use. During recent years, there have been several attempts for the implementation of these systems in Greece, which include, among others, pilot-scale systems used for research, and full-scale systems designed and/or constructed to serve settlements or families. The purpose of this paper is the presentation of systems operating in Northern Greece, which have been studied by the Laboratory of Ecological Engineering and Technology of Democritus University of Thrace and others. A comparison is made of different system types, and the effect of various design and operational parameters is presented. Current research shows the good and continuous performance of these systems.

  9. Resilience of Floating Treatment Wetlands to Repeated Freeze-Thaw Cycles

    NASA Astrophysics Data System (ADS)

    Ortega, K.; Marchetto, P.; Magner, J.

    2017-12-01

    Floating treatment wetlands (FTWs), made of a matrix of recycled polyethylene terephthalate (PET) fibers, are currently being used as a method to reduce nutrient loading in lakes. The matrix encourages growth of biofilms, which uptake nutrients from the water. However, the usefulness of FTWs has only been assessed in areas where the lakes do not freeze over in the winter. Repeated freeze-thaw cycles were run on sections of the FTWs in a laboratory setting in order to test the resilience of the PET fibers over the FTWs' advertised fifteen-year lifespan. Preliminary findings suggest that the stresses caused by freezing and thawing of the surrounding water contribute to deterioration of the PET fibers, leading to production of microplastics. Estimations indicate that approximately 0.063% of a FTW's mass could be lost as microplastics over the course of its lifespan. Production of microplastics contributes to plastic pollution in the treatment water, possibly offsetting any nutrient remediation the FTWs perform.

  10. Treatment of industrial effluents in constructed wetlands: challenges, operational strategies and overall performance.

    PubMed

    Wu, Shubiao; Wallace, Scott; Brix, Hans; Kuschk, Peter; Kirui, Wesley Kipkemoi; Masi, Fabio; Dong, Renjie

    2015-06-01

    The application of constructed wetlands (CWs) has significantly expanded to treatment of various industrial effluents, but knowledge in this field is still insufficiently summarized. This review is accordingly necessary to better understand this state-of-the-art technology for further design development and new ideas. Full-scale cases of CWs for treating various industrial effluents are summarized, and challenges including high organic loading, salinity, extreme pH, and low biodegradability and color are evaluated. Even horizontal flow CWs are widely used because of their passive operation, tolerance to high organic loading, and decolorization capacity, free water surface flow CWs are effective for treating oil field/refinery and milking parlor/cheese making wastewater for settlement of total suspended solids, oil, and grease. Proper pretreatment, inflow dilutions through re-circulated effluent, pH adjustment, plant selection and intensifications in the wetland bed, such as aeration and bioaugmentation, are recommended according to the specific characteristics of industrial effluents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Management and treatment of landfill leachate by a system of constructed wetlands and ponds in Singapore.

    PubMed

    Sim, C H; Quek, B S; Shutes, R B E; Goh, K H

    2013-01-01

    Lorong Halus, Singapore's first landfill leachate treatment system, consists of a pre-treatment system (8,000 m(2)), five constructed reed beds (38,000 m(2)), five polishing ponds (13,000 m(2)), an education centre and a learning trail for visitors. Eight species of wetland plants (total 160,000 plants) were selected for their ability to uptake nutrients, tolerance to low phosphorus concentrations and resistance to pest infestations. The wetland was launched in March 2011 and water quality monitoring started in April 2011. The removal efficiencies of the pre-treatment system from April 2011 to August 2012 are biochemical oxygen demand (BOD5) 57.4%; chemical oxygen demand (COD) 23.6%; total suspended solids (TSS) 55.1%; ammoniacal nitrogen (NH4-N) 76.8%; total phosphorus (TP) 33.3% and total nitrogen (TN) 60.2%. Removal efficiencies of the reed beds are BOD5 47.0%; COD 42.2%; TSS 57.0%; NH4-N 82.5%; TP 29.3% and TN 83.9%. Plant growth is generally satisfactory, but the lower than designed volume of leachate has adversely affected some sections of plants and resulted in uneven flow distribution in reed beds. The plant management programme includes improving plant regrowth by harvesting of alternate strips of plants and replanting. The treated effluent meets water quality limits for discharge to the public sewer and is subsequently treated by the NEWater treatment system, which recycles water for industrial and indirect potable use.

  12. Advantages of using subsurface flow constructed wetlands for wastewater treatment in space applications: ground-based Mars Base prototype.

    PubMed

    Nelson, M; Alling, A; Dempster, W F; van Thillo, M; Allen, John

    2003-01-01

    Research and design of subsurface flow wetland wastewater treatment systems for a ground-based experimental prototype Mars Base facility has been carried out, using a subsurface flow approach. These systems have distinct advantages in planetary exploration scenarios: they are odorless, relatively low-labor and low-energy, assist in purification of water and recycling of atmospheric CO2, and will support some food crops. An area of 6-8 m2 may be sufficient for integration of wetland wastewater treatment with a prototype Mars Base supporting 4-5 people. Discharge water from the wetland system will be used as irrigation water for the agricultural crop area, thus ensuring complete recycling and utilization of nutrients. Since the primary requirements for wetland treatment systems are warm temperatures and lighting, such bioregenerative systems may be integrated into early Mars base habitats, since waste heat from the lights may be used for temperature maintenance in the human living environment. "Wastewater gardens (TM)" can be modified for space habitats to lower space and mass requirements. Many of its construction requirements can eventually be met with use of in-situ materials, such as gravel from the Mars surface. Because the technology requires little machinery and no chemicals, and relies more on natural ecological mechanisms (microbial and plant metabolism), maintenance requirements are minimized, and systems can be expected to have long operating lifetimes. Research needs include suitability of Martian soil and gravel for wetland systems, system sealing and liner options in a Mars Base, and wetland water quality efficiency under varying temperature and light regimes. c2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  13. Incorporation of oxygen contribution by plant roots into classical dissolved oxygen deficit model for a subsurface flow treatment wetland.

    PubMed

    Bezbaruah, Achintya N; Zhang, Tian C

    2009-01-01

    It has been long established that plants play major roles in a treatment wetland. However, the role of plants has not been incorporated into wetland models. This study tries to incorporate wetland plants into a biochemical oxygen demand (BOD) model so that the relative contributions of the aerobic and anaerobic processes to meeting BOD can be quantitatively determined. The classical dissolved oxygen (DO) deficit model has been modified to simulate the DO curve for a field subsurface flow constructed wetland (SFCW) treating municipal wastewater. Sensitivities of model parameters have been analyzed. Based on the model it is predicted that in the SFCW under study about 64% BOD are degraded through aerobic routes and 36% is degraded anaerobically. While not exhaustive, this preliminary work should serve as a pointer for further research in wetland model development and to determine the values of some of the parameters used in the modified DO deficit and associated BOD model. It should be noted that nitrogen cycle and effects of temperature have not been addressed in these models for simplicity of model formulation. This paper should be read with this caveat in mind.

  14. Eutrophication and Bacterial Pathogens as Risk Factors for Avian Botulism Outbreaks in Wetlands Receiving Effluents from Urban Wastewater Treatment Plants

    PubMed Central

    Vidal, Dolors; Laguna, Celia; Díaz-Sánchez, Sandra; Sánchez, Sergio; Chicote, Álvaro; Florín, Máximo; Mateo, Rafael

    2014-01-01

    Due to the scarcity of water resources in the “Mancha Húmeda” Biosphere Reserve, the use of treated wastewater has been proposed as a solution for the conservation of natural threatened floodplain wetlands. In addition, wastewater treatment plants of many villages pour their effluent into nearby natural lakes. We hypothesized that certain avian pathogens present in wastewater may cause avian mortalities which would trigger avian botulism outbreaks. With the aim of testing our hypothesis, 24 locations distributed in three wetlands, two that receive wastewater effluents and one serving as a control, were monitored during a year. Sediment, water, water bird feces, and invertebrates were collected for the detection of putative avian pathogenic Escherichia coli (APEC), Salmonella spp., Clostridium perfringens type A, and Clostridium botulinum type C/D. Also, water and sediment physicochemical properties were determined. Overall, APEC, C. perfringens, and C. botulinum were significantly more prevalent in samples belonging to the wetlands which receive wastewater. The occurrence of a botulism outbreak in one of the studied wetlands coincided with high water temperatures and sediment 5-day biochemical oxygen demand (BOD5), a decrease in water redox potential, chlorophyll a, and sulfate levels, and an increase in water inorganic carbon levels. The presence of C. botulinum in bird feces before the onset of the outbreak indicates that carrier birds exist and highlights the risk of botulinum toxin production in their carcasses if they die by other causes such as bacterial diseases, which are more probable in wastewater wetlands. PMID:24795377

  15. Effect of plant harvest on methane emission from two constructed wetlands designed for the treatment of wastewater.

    PubMed

    Zhu, Nanwen; An, Ping; Krishnakumar, B; Zhao, Ling; Sun, Liwei; Mizuochi, Motoyuki; Inamori, Yuhei

    2007-12-01

    The emission of methane from two constructed wetlands [a free water surface flow system (FWS) and a subsurface flow system (SF)], constructed for the treatment of waste water, was evaluated at different sites inhabited by reeds (Phragmites communis), to test the effects of plant harvest. High methane emission was recorded immediately after harvesting in both wetlands. Several days after harvesting, the emission decreased in the FWS but remained high in the SF. The variation was significantly influenced by temperature, with lower emission and higher dissolved CH(4) in water occurring at lower temperatures. Both the emission and concentration of dissolved CH(4) were also influenced significantly by water quality, wetland design, level of stalk butt left above the water level, etc. The methane flux was explained on the basis of rizhospheric methanogenic and methanotrophic microbial populations. FISH analysis indicated the presence of Type A and Type B methanotrophs in both wetlands, and the methane flux was directly influenced by the quantitative variation in methanogenic and methanotrophic bacteria in both wetlands.

  16. Wetland-based passive treatment systems for gold ore processing effluents containing residual cyanide, metals and nitrogen species.

    PubMed

    Alvarez, R; Ordóñez, A; Loredo, J; Younger, P L

    2013-10-01

    Gold extraction operations generate a variety of wastes requiring responsible disposal in compliance with current environmental regulations. During recent decades, increased emphasis has been placed on effluent control and treatment, in order to avoid the threat to the environment posed by toxic constituents. In many modern gold mining and ore processing operations, cyanide species are of most immediate concern. Given that natural degradation processes are known to reduce the toxicity of cyanide over time, trials have been made at laboratory and field scales into the feasibility of using wetland-based passive systems as low-cost and environmentally friendly methods for long-term treatment of leachates from closed gold mine tailing disposal facilities. Laboratory experiments on discrete aerobic and anaerobic treatment units supported the development of design parameters for the construction of a field-scale passive system at a gold mine site in northern Spain. An in situ pilot-scale wetland treatment system was designed, constructed and monitored over a nine-month period. Overall, the results suggest that compost-based constructed wetlands are capable of detoxifying cyanidation effluents, removing about 21.6% of dissolved cyanide and 98% of Cu, as well as nitrite and nitrate. Wetland-based passive systems can therefore be considered as a viable technology for removal of residual concentrations of cyanide from leachates emanating from closed gold mine tailing disposal facilities.

  17. Effect of design and operational conditions on the performance of subsurface flow treatment wetlands: Emerging organic contaminants as indicators.

    PubMed

    Kahl, Stefanie; Nivala, Jaime; van Afferden, Manfred; Müller, Roland A; Reemtsma, Thorsten

    2017-11-15

    Six pilot-scale subsurface flow treatment wetlands loaded with primary treated municipal wastewater were monitored over one year for classical wastewater parameters and a set of emerging organic compounds (EOCs) serving as process indicators for biodegradation: caffeine, ibuprofen, naproxen, benzotriazole, diclofenac, acesulfame, and carbamazepine. The wetland technologies investigated included conventional horizontal flow, unsaturated vertical flow (single and two-stage), horizontal flow with aeration, vertical flow with aeration, and reciprocating. Treatment efficiency for classical wastewater parameters and EOCs generally increased with increasing design complexity and dissolved oxygen concentrations. The two aerated wetlands and the two-stage vertical flow system showed the highest EOC removal, and the best performance in warm season and most robust performance in the cold season. These three systems performed better than the adjacent conventional WWTP with respect to EOC removal. Acesulfame was observed to be removed (>90%) by intensified wetland systems and with use of a tertiary treatment sand filter during the warm season. Elevated temperature and high oxygen content (aerobic conditions) proved beneficial for EOC removal. For EOCs of moderate to low biodegradability, the co-occurrence of aerobic conditions and low content of readily available carbon appears essential for efficient removal. Such conditions occurred in the aerated systems and with use of a tertiary treatment sand filter. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Methodologies for Pre-Validation of Biofilters and Wetlands for Stormwater Treatment

    PubMed Central

    Zhang, Kefeng; Randelovic, Anja; Aguiar, Larissa M.; Page, Declan; McCarthy, David T.; Deletic, Ana

    2015-01-01

    Background Water Sensitive Urban Design (WSUD) systems are frequently used as part of a stormwater harvesting treatment trains (e.g. biofilters (bio-retentions and rain-gardens) and wetlands). However, validation frameworks for such systems do not exist, limiting their adoption for end-uses such as drinking water. The first stage in the validation framework is pre-validation, which prepares information for further validation monitoring. Objectives A pre-validation roadmap, consisting of five steps, is suggested in this paper. Detailed methods for investigating target micropollutants in stormwater, and determining challenge conditions for biofilters and wetlands, are provided. Methods A literature review was undertaken to identify and quantify micropollutants in stormwater. MUSIC V5.1 was utilized to simulate the behaviour of the systems based on 30-year rainfall data in three distinct climate zones; outputs were evaluated to identify the threshold of operational variables, including length of dry periods (LDPs) and volume of water treated per event. Results The paper highlights that a number of micropollutants were found in stormwater at levels above various worldwide drinking water guidelines (eight pesticides, benzene, benzo(a)pyrene, pentachlorophenol, di-(2-ethylhexyl)-phthalate and a total of polychlorinated biphenyls). The 95th percentile LDPs was exponentially related to system design area while the 5th percentile length of dry periods remained within short durations (i.e. 2–8 hours). 95th percentile volume of water treated per event was exponentially related to system design area as a percentage of an impervious catchment area. Conclusions The out-comings of this study show that pre-validation could be completed through a roadmap consisting of a series of steps; this will help in the validation of stormwater treatment systems. PMID:25955688

  19. Reed beds: constructed wetlands for municipal wastewater treatment plant sludge dewatering.

    PubMed

    Begg, J S; Lavigne, R L; Veneman, P L

    2001-01-01

    Reed beds are an alternative technology wastewater treatment system that mimic the biogeochemical processes inherent in natural wetlands. The purpose of this project was to determine the effectiveness of a reed bed sludge treatment system (RBSTS) in southern New England after a six-year period of operation by examining the concentrations of selected metals in the reed bed sludge biomass and by determining the fate of solids and selected nutrients. Parameters assessed in both the reed bed influent and effluent: total suspended solids, biochemical oxygen demand, nitrate-nitrogen and total phosphorus. In addition, the following metals were studied in the reed bed influent, effluent and Phragmites plant tissue and the sludge core biomass: boron, cadmium, chromium, copper, iron, lead, manganese, molybdenum, nickel, and zinc. The removal efficiencies for sludge dewatering, total suspended solids and biochemical oxygen demand were all over 90%. Nitrate and total phosphorus removal rates were 90% and 80% respectively. Overall metals removal efficient was 87%. Copper was the only metal in the sludge biomass that exceeded the standards set by the Massachusetts Department of Environmental Protection for land disposal of sludge. The highest metal concentrations, for the most part, tended to be in the lower tier of the sludge profile. The exception was boron, which was more concentrated in the middle tier of the sludge profile. The data and results presented in this paper support the notion that reed bed sludge treatment systems and the use of reed beds provide an efficient and cost effective alternative for municipal sludge treatment.

  20. Constructed wetland as an ecotechnological tool for pollution treatment for conservation of Ganga river.

    PubMed

    Rai, U N; Tripathi, R D; Singh, N K; Upadhyay, A K; Dwivedi, S; Shukla, M K; Mallick, S; Singh, S N; Nautiyal, C S

    2013-11-01

    With aim to develop an efficient and ecofriendly approach for on-site treatment of sewage, a sub-surface flow constructed wetland (CW) has been developed by raising potential aquatic macrophytes; Typha latifolia, Phragmites australis, Colocasia esculenta, Polygonum hydropiper, Alternanthera sessilis and Pistia stratoites in gravel as medium. Sewage treatment potential of CW was evaluated by varying retention time at three different stages of plant growth and stabilization. After 6 months, monitoring of fully established CW indicated reduction of 90%, 65%, 78%, 84%, 76% and 86% of BOD, TSS, TDS, NO3-N, PO4-P and NH4-N, respectively in comparison to inlet after 36 h of retention time. Sewage treatment through CW also resulted in reduction of heavy metal contents. Thus, CW proved an effective method for treatment of wastewater and may be developed along river Ganga stretch as an alternative technology. Treated water may be drained into river to check further deterioration of Ganga water quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. The removal efficiency of constructed wetlands filled with the zeolite-slag hybrid substrate for the rural landfill leachate treatment.

    PubMed

    He, Hailing; Duan, Zhiwei; Wang, Zhenqing; Yue, Bo

    2017-07-01

    The removal efficiencies of two horizontal subsurface flow constructed wetlands (HSSF CWs, down-flow (F1) and up-flow (F2)) filled with the zeolite-slag hybrid substrate for the rural landfill leachate treatment were investigated. The adsorption experiment was conducted to evaluate the potential of zeolite and slag as the wetland substrate. The effects of distance variations along the longitudinal profile of wetland bed on pollutant removal were assessed by sampling at four locations (inlet, outlet, 0.55 m, and 1.10 m from the inlet). During the operation time, the influent and effluent concentrations of chemical oxygen demand (COD), ammonia nitrogen (NH 3 -N), total nitrogen (TN), heavy metals, and polycyclic aromatic hydrocarbon (PAH) were measured. The results showed that the constructed wetlands were capable of removing COD, 20.5-48.2% (F1) and 18.6-61.2% (F2); NH 3 -N, 84.0-99.9% (F1) and 93.5-99.2% (F2); TN, 80.3-92.1% (F1) and 80.3-91.2% (F2); and heavy metals, about 90% (F1 and F2). The zeolite-slag hybrid substrate performed excellent removal efficiency for the nitrogen and heavy metals. The inlet area was the most active region of leachate removal. The up-flow constructed wetland (F2) has a higher removal efficiency for the PAH compounds. The significant removal efficiency illustrated that the rural landfill leachate can be treated using the horizontal subsurface flow constructed wetland filled with the zeolite-slag hybrid substrate.

  2. Using sorbent waste materials to enhance treatment of micro-point source effluents by constructed wetlands

    NASA Astrophysics Data System (ADS)

    Green, Verity; Surridge, Ben; Quinton, John; Matthews, Mike

    2014-05-01

    Sorbent materials are widely used in environmental settings as a means of enhancing pollution remediation. A key area of environmental concern is that of water pollution, including the need to treat micro-point sources of wastewater pollution, such as from caravan sites or visitor centres. Constructed wetlands (CWs) represent one means for effective treatment of wastewater from small wastewater producers, in part because they are believed to be economically viable and environmentally sustainable. Constructed wetlands have the potential to remove a range of pollutants found in wastewater, including nitrogen (N), phosphorus (P), biochemical oxygen demand (BOD) and carbon (C), whilst also reducing the total suspended solids (TSS) concentration in effluents. However, there remain particular challenges for P and N removal from wastewater in CWs, as well as the sometimes limited BOD removal within these treatment systems, particularly for micro-point sources of wastewater. It has been hypothesised that the amendment of CWs with sorbent materials can enhance their potential to treat wastewater, particularly through enhancing the removal of N and P. This paper focuses on data from batch and mesocosm studies that were conducted to identify and assess sorbent materials suitable for use within CWs. The aim in using sorbent material was to enhance the combined removal of phosphate (PO4-P) and ammonium (NH4-N). The key selection criteria for the sorbent materials were that they possess effective PO4-P, NH4-N or combined pollutant removal, come from low cost and sustainable sources, have potential for reuse, for example as a fertiliser or soil conditioner, and show limited potential for re-release of adsorbed nutrients. The sorbent materials selected for testing were alum sludge from water treatment works, ochre derived from minewater treatment, biochar derived from various feedstocks, plasterboard and zeolite. The performance of the individual sorbents was assessed through

  3. Temperature and wetland plant species effects on wastewater treatment and root zone oxidation.

    PubMed

    Allen, Winthrop C; Hook, Paul B; Biederman, Joel A; Stein, Otto R

    2002-01-01

    Constructed wetlands are widely used for wastewater treatment, but there is little information on processes affecting their performance in cold climates, effects of plants on seasonal performance, or plant selection for cold regions. We evaluated the effects of three plant species on seasonal removal of dissolved organic matter (OM) (measured by chemical oxygen demand and dissolved organic carbon) and root zone oxidation status (measured by redox potential [Eh] and sulfate [SO4(2-)]) in subsurface-flow wetland (SSW) microcosms. A series of 20-d incubations of simulated wastewater was conducted during a 28-mo greenhouse study at temperatures from 4 to 24 degrees C. Presence and species of plants strongly affected seasonal differences in OM removal and root zone oxidation. All plants enhanced OM removal compared with unplanted controls, but plant effects and differences among species were much greater at 4 degrees C, during dormancy, than at 24 degrees C, during the growing season. Low temperatures were associated with decreased OM removal in unplanted controls and broadleaf cattail (Typha latifolia L.) microcosms and with increased removal in beaked sedge (Carex rostrata Stokes) and hardstem bulrush [Schoenoplectus acutus (Muhl. ex Bigelow) A. & D. Löve var. acutus] microcosms. Differences in OM removal corresponded to species' apparent abilities to increase root zone oxygen supply. Sedge and bulrush significantly raised Eh values and SO4(2-) concentrations, particularly at 4 degrees C. These results add to evidence that SSWs can be effective in cold climates and suggest that plant species selection may be especially important to optimizing SSW performance in cold climates.

  4. Long-term investigation of constructed wetland wastewater treatment and reuse: Selection of adapted plant species for metaremediation.

    PubMed

    Saggaï, Mohamed Mounir; Ainouche, Abdelkader; Nelson, Mark; Cattin, Florence; El Amrani, Abdelhak

    2017-10-01

    A highly diverse plant community in a constructed wetland was used to investigate an ecological treatment system for human wastewater in an arid climate. The eight-year operation of the system has allowed the identification of a highly adapted and effective plant consortium that is convenient for plant-assisted metaremediation of wastewater. This constructed wetland pilot station demonstrated effective performance over this extended period. Originally, there were twenty-five plant species. However, because of environmental constraints and pressure from interspecific competition, only seven species persisted. Interestingly, the molecular phylogenetic analyses and an investigation of the photosynthetic physiology showed that the naturally selected plants are predominately monocot species with C4 or C4-like photosynthetic pathways. Despite the loss of 72% of initially used species in the constructed wetland, the removal efficiencies of BOD, COD, TSS, total phosphorus, ammonia and nitrate were maintained at high levels, approximately 90%, 80%, 94%, 60% and 50%, respectively. Concomitantly, the microbiological water tests showed an extremely high reduction of total coliform bacteria and streptococci, about 99%, even without a specific disinfection step. Hence, the constructed wetland system produced water of high quality that can be used for agricultural purposes. In the present investigation, we provide a comprehensive set of plant species that might be used for long-term and large-scale wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Composting plant leachate treatment by a pilot-scale, three-stage, horizontal flow constructed wetland in central Iran.

    PubMed

    Bakhshoodeh, Reza; Alavi, Nadali; Paydary, Pooya

    2017-10-01

    Handling and treatment of composting leachate is difficult and poses major burdens on composting facilities. The main goal of this study was to evaluate usage of a three-stage, constructed wetland to treat leachate produced in Isfahan composting facility. A pilot-scale, three-stage, subsurface, horizontal flow constructed wetland, planted with vetiver with a flow rate of 24 L/day and a 15-day hydraulic retention time, was used. Removal of organic matter, ammonia, nitrate, total nitrogen, suspended solids, and several heavy metals from Isfahan composting facility leachate was monitored over a 3-month period. Constructed wetland system was capable of efficiently removing BOD 5 (87.3%), COD (74.5%), ammonia (91.5%), nitrate (87.9%), total nitrogen (87.8%), total suspended solids (85.5%), and heavy metals (ranging from 70 to 90%) from the composting leachate. High contaminant removal efficiencies were achieved, but effluent still failed to meet Iranian standards for treated wastewater. This study shows that although a three-stage horizontal flow constructed wetland planted with vetiver cannot be used alone to treat Isfahan composting facility leachate, but it has the potential to be used as a leachate pre-treatment step, along with another complementary method.

  6. Assessment of the ecological potential of mine-water treatment wetlands using a baseline survey of macroinvertebrate communities.

    PubMed

    Batty, L C; Atkin, L; Manning, D A C

    2005-12-01

    A baseline survey of macroinvertebrate populations in two mine-water treatment wetlands, one treating a net acidic spoil heap discharge and one a net alkaline ferruginous pumped mine water, was undertaken to assess the potential of these systems to provide habitats for faunal communities. Both wetlands were found to be impoverished in comparison to natural wetlands but did sustain a macroinvertebrate community that could support higher organisms. Wetland size and water quality in terms of pH, conductivity and metal concentrations were found to be important factors in determining the quality of the populations supported. Direct toxicity to organisms was unlikely to be the main cause of lower diversity, but the smothering of organisms via the precipitation of iron hydroxides particularly in the early parts of the treatment systems affected macroinvertebrate communities. The presence of areas of open water within the planted systems was found to be important for providing habitats for macroinvertebrates and this should be both a future design and maintenance consideration for environmental managers.

  7. Constructed wetlands for tannery wastewater treatment in Portugal: ten years of experience.

    PubMed

    Calheiros, Cristina S C; Rangel, António O S S; Castro, Paula M L

    2014-01-01

    Wastewaters from tannery industry are complex in composition and providing adequate treatment can be difficult. Constructed wetlands (CW) are regarded as an alternative treatment to the conventional biological systems, as a developing cost-effective and environmentally friendly phytoremediation technology. The present review compiles and integrates information on CWs technology for the needs of the tannery sector. The following issues arise as crucial for the implementation of such systems, namely i) an accurate wastewater characterization and an effective pretreatment before reaching the CW, ii) choosing the plants species better adapted to the imposed conditions, iii) substrate selection and iv) range of organic loadings applied. The examples practiced in Portugal give indication that horizontal subsurface flow systems, with expanded clay media, are a suitable option to be considered when dealing with high organic loading tannery wastewater (up to c.a. 3800 kgCODha(-1)d(-1)), being resilient to a wide range of hydraulic variations. Plants such as Phragmites and Typha have shown to be adequate for tannery wastewater depuration, with Arundo donax proving resilient to high salinity wastewaters. The flexibility of implementation allows the CW to be adapted to different sites with different configurations, being suitable as main secondary or tertiary treatment stage.

  8. A review on the sustainability of constructed wetlands for wastewater treatment: Design and operation.

    PubMed

    Wu, Haiming; Zhang, Jian; Ngo, Huu Hao; Guo, Wenshan; Hu, Zhen; Liang, Shuang; Fan, Jinlin; Liu, Hai

    2015-01-01

    Constructed wetlands (CWs) have been used as a green technology to treat various wastewaters for several decades. CWs offer a land-intensive, low-energy, and less-operational-requirements alternative to conventional treatment systems, especially for small communities and remote locations. However, the sustainable operation and successful application of these systems remains a challenge. Hence, this paper aims to provide and inspire sustainable solutions for the performance and application of CWs by giving a comprehensive review of CWs' application and the recent development on their sustainable design and operation for wastewater treatment. Firstly, a brief summary on the definition, classification and application of current CWs was presented. The design parameters and operational conditions of CWs including plant species, substrate types, water depth, hydraulic load, hydraulic retention time and feeding mode related to the sustainable operation for wastewater treatments were then discussed. Lastly, future research on improving the stability and sustainability of CWs were highlighted. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Biogeochemical and ecological considerations in designing wetland treatment systems in post-mining landscapes.

    PubMed

    Kalin, M

    2001-01-01

    Although wetlands have gained acceptance as important components of ecosystems in post-mining landscapes in the past decade, their roles in contaminant retention/removal have not been well integrated into the designing of restoration programs. This paper describes the integration of sediment microbial activities and natural precipitation processes, along with approaches to defining the contaminant load from the mine wastes. The contaminant removal rates, which can be expected by a wetland sediment, are summarized and how they need to be reflected in the wetland size required, and the carbon supply which is needed. Contaminant loading from mining wastes can be balanced by wetland ecological processes, including wetland primary production and microbial mineralization in the sediment. This ecological engineering approach is demonstrated using case studies on hard-rock mining waste in Canada.

  10. Application of constructed wetlands for wastewater treatment in developing countries--a review of recent developments (2000-2013).

    PubMed

    Zhang, Dong Qing; Jinadasa, K B S N; Gersberg, Richard M; Liu, Yu; Ng, Wun Jern; Tan, Soon Keat

    2014-08-01

    Inadequate access to clean water and sanitation has become one of the most pervasive problems afflicting people throughout the developing world. Replication of centralized water-, energy- and cost-intensive technologies has proved ineffective in resolving the complex water-related problems resulting from rapid urbanization in the developing countries. Instead constructed wetlands (CWs) have emerged and become a viable option for wastewater treatment, and are currently being recognized as attractive alternatives to conventional wastewater treatment methods. The primary objective of this review is to present a comprehensive overview of the diverse range of practice, applications and researches of CW systems for removing various contaminants from wastewater in developing countries, placing them in the overall context of the need for low-cost and sustainable wastewater treatment systems. Emphasis of this review is placed on the treatment performance of various types of CWs including: (i) free water surface flow CW; (ii) subsurface flow CW; (iii) hybrid systems; and, (iv) floating treatment wetland. The impacts of different wetland design and pertinent operational variables (e.g., hydraulic loading rate, vegetation species, physical configurations, and seasonal variation) on contaminant removal in CW systems are also summarized and highlighted. Finally, the cost and land requirements for CW systems are critically evaluated. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Combined Industrial Wastewater Treatment in Anaerobic Bioreactor Posttreated in Constructed Wetland

    PubMed Central

    Zeb, Bibi Saima; Mahmood, Qaisar; Jadoon, Saima; Pervez, Arshid; Irshad, Muhammad; Bilal, Muhammad; Bhatti, Zulfiqar Ahmad

    2013-01-01

    Constructed wetland (CW) with monoculture of Arundo donax L. was investigated for the posttreatment of anaerobic bioreactor (ABR) treating combined industrial wastewater. Different dilutions of combined industrial wastewater (20, 40, 60, and 80) and original wastewater were fed into the ABR and then posttreated by the laboratory scale CW. The respective removal efficiencies of COD, BOD, TSS, nitrates, and ammonia were 80%, 78–82%, 91.7%, 88–92%, and 100% for original industrial wastewater treated in ABR. ABR was efficient in the removal of Ni, Pb, and Cd with removal efficiencies in the order of Cd (2.7%) > Ni (79%) > Pb (85%). Posttreatment of the ABR treated effluent was carried out in lab scale CW containing A. donax L. CW was effective in the removal of COD and various heavy metals present in ABR effluents. The posttreatment in CW resulted in reducing the metal concentrations to 1.95 mg/L, 0 mg/L, and 0.004 mg/L for Ni, Pb, and Cd which were within the permissible water quality standards for industrial effluents. The treatment strategy was effective and sustainable for the treatment of combined industrial wastewater. PMID:24396832

  12. Decentralized domestic wastewater treatment using intermittently aerated vertical flow constructed wetlands: impact of influent strengths.

    PubMed

    Wu, Haiming; Fan, Jinlin; Zhang, Jian; Ngo, Huu Hao; Guo, Wenshan; Hu, Zhen; Liang, Shuang

    2015-01-01

    In this study, the removal performances of organic pollutants and nitrogen in vertical flow constructed wetlands (VFCWs) with and without intermittent aeration fed with different strengths of influent were evaluated as a possible treatment for decentralized domestic wastewater in northern China. The intermittent aeration strategy not only significantly increased removal efficiencies of organic pollutants and ammonium nitrogen (NH4(+)-N), but also successfully created alternate aerobic and anaerobic conditions resulting in high total nitrogen (TN) removal. Moreover, increasing influent strength did not affect the removal efficiencies of organic matters and nitrogen in aerated VFCWs. Compared with non-aerated VFCWs, much higher removal of organic pollutants (96%), NH4(+)-N (98%), and TN (85%) was obtained simultaneously in intermittent aeration VFCWs, especially at high influent strengths. The results suggest that the intermittent aeration could be an appropriate strategy for achieving the high removal performance in VFCWs, especially for in-situ treatment of high strength decentralized domestic wastewaters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Assessment of pre-digested piggery wastewater treatment operations with surface flow integrated constructed wetland systems.

    PubMed

    Harrington, Caolan; Scholz, Miklas

    2010-10-01

    Non-point source pollution such as land-spreading of nitrogen-rich piggery wastewater poses a significant threat to surface waters. The aim was to examine the treatment of anaerobically digested piggery wastewater using four different meso-scale integrated constructed wetland (ICW) systems planted with Glyceria maxima. Four replicates were used for each system to assess differences due to nutrient loading, hydraulic loading and effluent recycling. All systems were effective in removing total organic nitrogen, ammonia-nitrogen, nitrate-nitrogen and molybdate reactive phosphorus. However, ammonia-nitrogen removal was the greatest challenge for high flow rates (>100 m³/ha/d). Nitrification was higher in summer than winter. Findings show for the first time that effluent recycling within ICW was beneficial to lower ammonia-nitrogen but was associated with higher operational costs. The cost-benefit ratio based on ammonia-nitrogen removal for standard, recycling, high nutrients and high flow rate treatments was 1.08:1.04:1.06:1.00. It follows that a high flow rate was only marginally more cost-effective.

  14. Assessment of pre-digested piggery wastewater treatment operations with surface flow integrated constructed wetland systems.

    PubMed

    Harrington, Caolan; Scholz, Miklas

    2010-09-01

    Non-point source pollution such as land-spreading of nitrogen-rich piggery wastewater poses a significant threat to surface waters. The aim was to examine the treatment of anaerobically digested piggery wastewater using four different meso-scale integrated constructed wetland (ICW) systems planted with Glyceria maxima. Four replicates were used for each system to assess differences due to nutrient loading, hydraulic loading and effluent recycling. All systems were effective in removing total organic nitrogen, ammonia-nitrogen, nitrate-nitrogen and molybdate reactive phosphorus. However, ammonia-nitrogen removal was the greatest challenge for high flow rates (>100 m(3)/ha/d). Nitrification was higher in summer than winter. Findings show for the first time that effluent recycling within ICW was beneficial to lower ammonia-nitrogen but was associated with higher operational costs. The cost-benefit ratio based on ammonia-nitrogen removal for standard, recycling, high nutrients and high flow rate treatments was 1.08:1.04:1.06:1.00. It follows that a high flow rate was only marginally more cost-effective. Copyright 2010 Elsevier Ltd. All rights reserved.

  15. Modelling of organic matter degradation in constructed wetlands for treatment of combined sewer overflow.

    PubMed

    Henrichs, Malte; Langergraber, Günter; Uhl, Mathias

    2007-07-15

    Subsurface vertical flow constructed wetlands (CWs) have been found to be a useful system to treat combined sewer overflow (CSO). The study presented uses numerical simulation to increase the understanding of the fundamental processes of COD degradation in CWs for CSO treatment. The multi-component reactive transport module CW2D was used for the simulation study. The simulation results showed that the measured behaviour of the system can only be modelled when COD adsorption is considered as additional process. A new parameter set for CW2D for modelling CSO treatment is presented. A range of values for COD adsorption parameters, COD fractionation and bacteria concentrations were estimated by an identifiability analysis. For the simulation a step wise approach was developed. On the one hand a lysimeter study was used for calibration and validation, and on the other hand field and lab-scale experiments were used for validation. Single-event simulations as well as long-term simulations were carried out. For the single-event simulations (lysimeter and field studies) a good match between measured and simulated data could be achieved. However, the long-term simulations showed that there is a need for further investigations mainly due to the uncertainties during long dry periods between the loadings.

  16. Treatment and utilization of septic tank effluent using vertical-flow constructed wetlands and vegetable hydroponics.

    PubMed

    Cui, Li-Hua; Luo, Shi-Ming; Zhu, Xi-Zhen; Liu, Ying-Hu

    2003-01-01

    Vertical flow constructed wetlands is a typical ecological sanitation system for sewage treatment. The removal rates for COD, BOD5, SS, TN, and TP were 60%, 80%, 74%, 49% and 79%, respectively, when septic tank effluent was treated by vertical flow filter. So the concentration of COD and BOD5 in the treated effluent could meet the quality standard for irrigation water. After that the treated effluent was used for hydroponic cultivation of water spinach and romaine lettuce, the removal efficiencies of the whole system for COD, BOD5, SS, TN and TP were 71.4%, 97.5%, 96.9%, 86.3%, and 87.4%, respectively. And it could meet the integrated wastewater discharge standard for secondary biological treatment plant. It was found that using treated effluent for hydroponic cultivation of vegetables could reduce the nitrate content in vegetables. The removal rates for total bacteria and coliform index by using vertical flow bed system with cinder substrate were 80%-90% and 85%-96%, respectively.

  17. Designing and construction of simulated constructed wetland for treatment of sewage containing metals.

    PubMed

    Upadhyay, A K; Singh, N K; Bankoti, N S; Rai, U N

    2017-11-01

    A simulated horizontal flow constructed wetland (CW) has been designed with gravel medium and aquatic plants Typha latifolia and Polygonum hydropiper to assess its performance efficiency for sewage treatment. Monitoring of fully developed CW revealed a high removal of nutrients and metals from sewage after treatment at varying retention times. The percent (%) removal of biological oxygen demand, total dissolved solids, total suspended solids, PO 4 -P and total nitrogen in CW planted with T. latifolia were 88.20, 61.9, 72.12, 74.23 and 66.78%; however, with P. hydropiper, reductions were 79.47, 53.47, 55.46, 60.40 and 52.87%, respectively, at 8 d retention time. In addition, T. latifolia and P. hydropiper accumulated substantial amount of metals in their tissues particularly in roots. T. latifolia root accumulated maximum amount of Zn (40.44 µg/g dw) followed by Cu (39.24 µg/g dw), Pb (37.78 µg/g dw) and Cr (19.95 µg/g dw) as compared to P. hydropiper, which was 17.85, 33.43, 36.19 and 9.67 µg/g dw, respectively. Further, plant-specific high translocation factor (>1) of metals were observed at different retention times. Results suggest that simulated CW may be applied as an ecofriendly and low-cost tool to treat sewage before discharge into a fresh water body.

  18. Combined industrial wastewater treatment in anaerobic bioreactor posttreated in constructed wetland.

    PubMed

    Zeb, Bibi Saima; Mahmood, Qaisar; Jadoon, Saima; Pervez, Arshid; Irshad, Muhammad; Bilal, Muhammad; Bhatti, Zulfiqar Ahmad

    2013-01-01

    Constructed wetland (CW) with monoculture of Arundo donax L. was investigated for the posttreatment of anaerobic bioreactor (ABR) treating combined industrial wastewater. Different dilutions of combined industrial wastewater (20, 40, 60, and 80) and original wastewater were fed into the ABR and then posttreated by the laboratory scale CW. The respective removal efficiencies of COD, BOD, TSS, nitrates, and ammonia were 80%, 78-82%, 91.7%, 88-92%, and 100% for original industrial wastewater treated in ABR. ABR was efficient in the removal of Ni, Pb, and Cd with removal efficiencies in the order of Cd (2.7%) > Ni (79%) > Pb (85%). Posttreatment of the ABR treated effluent was carried out in lab scale CW containing A. donax L. CW was effective in the removal of COD and various heavy metals present in ABR effluents. The posttreatment in CW resulted in reducing the metal concentrations to 1.95 mg/L, 0 mg/L, and 0.004 mg/L for Ni, Pb, and Cd which were within the permissible water quality standards for industrial effluents. The treatment strategy was effective and sustainable for the treatment of combined industrial wastewater.

  19. Factors affecting the performance of horizontal flow constructed treatment wetland vegetated with Cyperus papyrus for municipal wastewater treatment.

    PubMed

    Abou-Elela, Sohair I; Elekhnawy, Mohamed A; Khalil, Magdy T; Hellal, Mohamed S

    2017-11-02

    The effect of hydraulic loading rate (HLR) and hydraulic retention time (HRT) on the bioremediation of municipal wastewater using a pilot scale subsurface horizontal flow constructed treatment wetland (HFCTW) vegetated with Cyprus papyrus was investigated. Different HLRs were applied to the treatment system namely 0.18, 0.10, and 0.07 m 3 /m 2 . d with corresponding HRTs of 1.8, 3.2, and 4.7 days, respectively. The flow rate was 8 m 3 /d, and the average organic loading rate (OLR) was 0.037 kg BOD/m 3 /d. Results showed that the performance of the HFCTW was linearly affected by decreasing the HLR and increasing the HRT. The highest treatment efficiency was achieved at HRT (4.7 days) and HLR (0.07 m 3 /m 2 . d). The percentage reductions of chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total suspended solids (TSS) were 86%, 87%, and 80%, respectively. Satisfactory nutrient removal was obtained. Also, removal of 2-3 logs of bacterial indicators of pollution was achieved. The dry biomass of Cyperus was 7.7 kg/m 2 and proved to be very efficient in nitrification processes due to high diversity of the roots that increase the treatment surface area.

  20. Alum application to improve water quality in a municipal wastewater treatment wetland: effects on macrophyte growth and nutrient uptake.

    PubMed

    Malecki-Brown, Lynette M; White, John R; Brix, Hans

    2010-03-01

    Application of low doses of alum to treatment wetlands to reduce elevated outflow winter phosphorus concentrations were tested in mesocosms vegetated with either Typhadomingensis, Schoenoplectus californicus, or submerged aquatic vegetation (SAV) (Najas guadalupensis-dominated). Alum was pumped to experimental units at a rate of 0.91 g Al m(-2) d(-1) and water quality monitored for 3 months. The alum application significantly improved the outflow water quality and overall the growth of the plants was unaffected by the alum application. Biomass and growth varied between species and through time, but no significant effects of alum application were detected. The concentrations of nutrients and mineral elements in the aboveground tissues differed between species and over time, but only the concentration of Al in plant tissue was increased by alum additions. The concentration of Al was 50-fold higher in alum-treated SAV as compared to the control, and in Typha and Schoenoplectus the concentrations were 4- and 2-fold, higher, respectively. The N/P ratios in the plant tissues were low (<10) suggesting that their growth and biomass was limited by nitrogen. The research suggests that a continuous or seasonal low-dosage alum application to treatment wetlands provides an effective tool to maintain discharge concentrations within permitted values during the inefficient winter treatment times. We suggest that the use of alum should be restricted to treatment wetland areas dominated by emergent vegetation as the effects of the elevated Al concentrations in SAV needs further study. 2010 Elsevier Ltd. All rights reserved.

  1. Synergistic wetland treatment of sewage and mine water: pollutant removal performance of the first full-scale system.

    PubMed

    Younger, Paul L; Henderson, Robin

    2014-05-15

    Wetland systems are now well-established unit processes in the treatment of diverse wastewater streams. However, the development of wetland technology for sewage treatment followed an entirely separate trajectory from that for polluted mine waters. In recent years, increased networking has led to recognition of possible synergies which might be obtained by hybridising approaches to achieve co-treatment of otherwise distinct sewage and mine-derived wastewaters. As polluted discharges from abandoned mines often occur in or near the large conurbations to which the former mining activities gave rise, there is ample scope for such co-treatment in many places worldwide. The first full-scale co-treatment wetland anywhere in the world receiving large inflows of both partially-treated sewage (∼100 L s(-)(1)) and mine water (∼300 L s(-1)) was commissioned in Gateshead, England in 2005, and a performance evaluation has now been made. The evaluation is based entirely on routinely-collected water quality data, which the operators gather in fulfillment of their regulatory obligations. The principal parameters of concern in the sewage effluent are suspended solids, BOD5, ammoniacal nitrogen (NH4-N) and phosphate (P); in the mine water the only parameter of particular concern is total iron (Fe). Aerobic treatment processes are appropriate for removal of BOD5, NH4-N and Fe; for the removal of P, reaction with iron to form ferric phosphate solids is a likely pathway. With these considerations in mind, the treatment wetland was designed as a surface-flow aerobic system. Sample concentration level and daily flow rate date from April 2007 until March 2011 have been analyzed using nonparametric statistical methods. This has revealed sustained, high rates of absolute removal of all pollutants from the combined wastewater flow, quantified in terms of differences between influent and effluent loadings (i.e. mass per unit time). In terms of annual mass retention rates, for instance

  2. Eutrophication and bacterial pathogens as risk factors for avian botulism outbreaks in wetlands receiving effluents from urban wastewater treatment plants.

    PubMed

    Anza, Ibone; Vidal, Dolors; Laguna, Celia; Díaz-Sánchez, Sandra; Sánchez, Sergio; Chicote, Alvaro; Florín, Máximo; Mateo, Rafael

    2014-07-01

    Due to the scarcity of water resources in the "Mancha Húmeda" Biosphere Reserve, the use of treated wastewater has been proposed as a solution for the conservation of natural threatened floodplain wetlands. In addition, wastewater treatment plants of many villages pour their effluent into nearby natural lakes. We hypothesized that certain avian pathogens present in wastewater may cause avian mortalities which would trigger avian botulism outbreaks. With the aim of testing our hypothesis, 24 locations distributed in three wetlands, two that receive wastewater effluents and one serving as a control, were monitored during a year. Sediment, water, water bird feces, and invertebrates were collected for the detection of putative avian pathogenic Escherichia coli (APEC), Salmonella spp., Clostridium perfringens type A, and Clostridium botulinum type C/D. Also, water and sediment physicochemical properties were determined. Overall, APEC, C. perfringens, and C. botulinum were significantly more prevalent in samples belonging to the wetlands which receive wastewater. The occurrence of a botulism outbreak in one of the studied wetlands coincided with high water temperatures and sediment 5-day biochemical oxygen demand (BOD5), a decrease in water redox potential, chlorophyll a, and sulfate levels, and an increase in water inorganic carbon levels. The presence of C. botulinum in bird feces before the onset of the outbreak indicates that carrier birds exist and highlights the risk of botulinum toxin production in their carcasses if they die by other causes such as bacterial diseases, which are more probable in wastewater wetlands. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  3. Assessment of the nutrient removal effectiveness of floating treatment wetlands applied to urban retention ponds.

    PubMed

    Wang, Chih-Yu; Sample, David J

    2014-05-01

    The application of floating treatment wetlands (FTWs) in point and non-point source pollution control has received much attention recently. Although the potential of this emerging technology is supported by various studies, quantifying FTW performance in urban retention ponds remains elusive due to significant research gaps. Actual urban retention pond water was utilized in this mesocosm study to evaluate phosphorus and nitrogen removal efficiency of FTWs. Multiple treatments were used to investigate the contribution of each component in the FTW system with a seven-day retention time. The four treatments included a control, floating mat, pickerelweed (Pontederia cordata L.), and softstem bulrush (Schoenoplectus tabernaemontani). The water samples collected on Day 0 (initial) and 7 were analyzed for total phosphorus (TP), total particulate phosphorus, orthophosphate, total nitrogen (TN), organic nitrogen, ammonia nitrogen, nitrate-nitrite nitrogen, and chlorophyll-a. Statistical tests were used to evaluate the differences between the four treatments. The effects of temperature on TP and TN removal rates of the FTWs were described by the modified Arrhenius equation. Our results indicated that all three FTW designs, planted and unplanted floating mats, could significantly improve phosphorus and nitrogen removal efficiency (%, E-TP and E-TN) compared to the control treatment during the growing season, i.e., May through August. The E-TP and E-TN was enhanced by 8.2% and 18.2% in the FTW treatments planted with the pickerelweed and softstem bulrush, respectively. Organic matter decomposition was likely to be the primary contributor of nutrient removal by FTWs in urban retention ponds. Such a mechanism is fostered by microbes within the attached biofilms on the floating mats and plant root surfaces. Among the results of the four treatments, the FTWs planted with pickerelweed had the highest E-TP, and behaved similarly with the other two FTW treatments for nitrogen removal

  4. Development of a constructed wetland water treatment system for selenium removal: use of mesocosms to evaluate design parameters.

    PubMed

    Huang, Jung-Chen; Passeport, Elodie; Terry, Norman

    2012-11-06

    The Salton Sea in California is an important habitat for fish and waterfowl. Its ecosystem is threatened due to diminishing water supplies and increasing salinity. An alternative source of water to support species conservation habitat may be obtained from local rivers (e.g., Alamo or New Rivers), provided that a wetland treatment system can be developed to remove selenium (Se), fertilizer nutrients, and other contaminants. Here, we used mesocosms to evaluate a number of potential design options (e.g., plant species selection, sediment composition and arrangement, forced aeration, organic amendments, etc.) to improve the efficiency of Se removal using treatment wetlands. Our results show that, of five different substrate arrangements tested for Se removal, the most efficient was obtained for cattails growing in a substrate of cattail litter overlying sand and peat moss sediment (water column Se was reduced from 15 μg Se/L to <0.1 μg Se/L in 72 h). The addition of organic amendments in the form of alfalfa hay or alfalfa meal was also helpful in lowering Se levels. These results suggest that it may be possible to design constructed wetland water treatment systems capable of reducing Se concentrations in river water to values below 1 μg Se/L.

  5. Effects on the Underlying Water Column by Extensive Floating Treatment Wetlands.

    PubMed

    Strosnider, W H; Schultz, S E; Strosnider, K A Johnson; Nairn, R W

    2017-01-01

    Floating treatment wetlands (FTWs) are an emerging engineering option with promise for simultaneous water quality improvement and habitat creation. Relatively little research has been published regarding their construction or effects on the underlying water column. In this field-scale experiment, four different extensive FTW designs were constructed using minimal materials, including drainpipe, burlap, mulch, utility netting, and reused polyethylene bottles. The FTWs were then planted with spp. (cattail) and L. (common rush). Over 28 mo, the water column beneath FTWs in two test ponds was compared to that in an open water control pond. The ponds (190 ± 10 m) were fed with well water enriched with nitrate to emulate agricultural ponds. Although observed differences were relatively small, statistically significant differences were noted. With respect to the control, waters underneath FTWs had lower dissolved oxygen, sulfate, nitrate, and pH, dampened diurnal temperature fluctuations, and greater alkalinity. The FTWs created habitat and were colonized by species of insects, birds, amphibians, snails, and spiders. Results indicated that spp. is suitable for FTW creation. However, a more supportive planting matrix is suggested to encourage faster plant growth and protect against wind and wave action damage. Although plant growth was limited, results suggest that FTWs may be applied to encourage less aerobic and more organic rich and thermally insulated conditions for water quality improvement in agricultural ponds and other aquatic systems while also creating valuable habitat. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. Assessing the effectiveness of pollutant removal by macrophytes in a floating wetland for wastewater treatment

    NASA Astrophysics Data System (ADS)

    Prajapati, Meera; van Bruggen, Johan J. A.; Dalu, Tatenda; Malla, Rabin

    2017-12-01

    The study aimed to evaluate the removal of pollutants by floating treatment wetlands (FTWs) using an edible floating plant, and emergent macrophytes. All experiments were performed under ambient conditions. Physico-chemical parameters were measured, along with microbiological analysis of biofilm within the roots, water column, and sludge and gravel zone. Nitrification and denitrification rates were high in the water zone of Azolla filiculoides, Lemna minor, Lactuca sativa, P. stratiotes, and Phragmites australis. Phosphate removal efficiencies were 23, 10, and 15% for the free-floating hydrophytes, emergent macrophytes, and control and edible plants, respectively. The microbial community was relatively more active in the root zone compared to other zones. Pistia stratiotes was found to be the efficient in ammonium (70%) and total nitrogen (59%) removal. Pistia stratiotes also showed the highest microbial activity of 1306 mg day-1, which was 62% of the total volume. Microbial activity was found in the water zone of all FTWs expect for P. australis. The use of P. stratiotes and the edible plant L. sativa could be a potential option to treat domestic wastewater due to relatively high nutrient and organic matter removal efficiency.

  7. Remediation of sewage and industrial effluent using bacterially assisted floating treatment wetlands vegetated with Typha domingensis.

    PubMed

    Ijaz, Amna; Iqbal, Zafar; Afzal, Muhammad

    2016-11-01

    This investigation reports the quantitative assessment of endophyte-assisted floating treatment wetlands (FTWs) for the remediation of sewage and industrial wastewater. Typha domingensis was used to vegetate FTWs that were subsequently inoculated with a consortium of pollutant-degrading and plant growth-promoting endophytic bacteria. T. domingensis, being an aquatic species, holds excellent potential to remediate polluted water. Nonetheless, investigation conducted on Madhuana drain carrying industrial and sewage water from Faisalabad City revealed the percentage reduction in chemical oxygen demand (COD) and biochemical oxygen demand (BOD 5 ) to be 87% and 87.5%, respectively, within 96 h on coupling the plant species with a consortium of bacterial endophytes. With the endophytes surviving in plant tissue, maximal reduction was obtained in not only the aforementioned pollution parameters but for other major environmental quality parameters including nutrients (N and P), ions (Na + and K + ), Cl - , and SO 4 2- as well, which showed percentage reductions up to 90%, 39%, 77%, 91.8%, 40%, and 60%, respectively. This significant improvement in polluted wastewater quality treated with the proposed method render it safe to be discharged freely in larger water bodies as per the National Environmental Quality Standards (NEQS) of Pakistan or to be reused safely for irrigation purposes; thus, FTWs provide a sustainable and affordable approach for in situ remediation of sewage and industrial wastewater.

  8. Measuring bulrush culm relationships to estimate plant biomass within a southern California treatment wetland

    USGS Publications Warehouse

    Daniels, Joan S. (Thullen); Cade, Brian S.; Sartoris, James J.

    2010-01-01

    Assessment of emergent vegetation biomass can be time consuming and labor intensive. To establish a less onerous, yet accurate method, for determining emergent plant biomass than by direct measurements we collected vegetation data over a six-year period and modeled biomass using easily obtained variables: culm (stem) diameter, culm height and culm density. From 1998 through 2005, we collected emergent vegetation samples (Schoenoplectus californicus andSchoenoplectus acutus) at a constructed treatment wetland in San Jacinto, California during spring and fall. Various statistical models were run on the data to determine the strongest relationships. We found that the nonlinear relationship: CB=β0DHβ110ε, where CB was dry culm biomass (g m−2), DH was density of culms × average height of culms in a plot, and β0 and β1 were parameters to estimate, proved to be the best fit for predicting dried-live above-ground biomass of the two Schoenoplectus species. The random error distribution, ε, was either assumed to be normally distributed for mean regression estimates or assumed to be an unspecified continuous distribution for quantile regression estimates.

  9. Performance of Free Water Surface Constructed Wetland Using Typhalatifolia and Canna Lilies for the Treatment of Domestic Wastewater.

    PubMed

    Shrikhande, Avinash N; Nema, P; Mhaisalkar, Vasant A

    2014-01-01

    Discharge of untreated wastewater or partially treated wastewater into surface water bodies or on to land is a major cause of surface and ground water pollution thereby posing health hazards. Conventional wastewater treatment is generally not preferred for small communities due to higher capital and maintenance costs and lack of skilled supervision required for operation and maintenance. A constructed wetland treatment appears to be an appropriate alternative that can be employed both in developed and developing countries. A constructed wetland system is simple to construct and operate with low cost, and hence worth considering for the treatment of municipal wastewaters, especially from small communities. In this context, the site for carrying out the studies related to wastewater treatment was chosen at Kavikulguru Institute of Technology and Science (KITS), Ramtek, Dist. Nagpur. A Free Water Surface Constructed Wetland (FWSCW) of size 22.00m x 6.50 m x 0.60m was constructed at KITS, Ramtek. The performance of FWS CW system was studied for domestic wastewater treatment with theoretical hydraulic retention times of 10 days, 7 days and 5 days. Important parameters, such as BOD5, COD, TSS, NH4-N, PO4-P, DO, pH and faecal coliforms in both raw and treated wastewaters were monitored during a macrophytes life cycle. Based on the studies, it is concluded that minimum 5 days HRT is necessary for the treatment of wastewater in FWSCW using Typhalatifolia or Canna Lilies. Typhalatifolia is better in removal of pollutants from the wastewater in comparison to Canna Lilies and hence, is recommended for use in constructed wetland. The nutrient uptake capacity of Typhalatifolia is also quite encouraging and hence has great potential for application in treating wastewater from fertilizer industry. During the application of kinetic model, the observed and predicted values in respect of BOD, TSS and NH4-N in case of Typhalatifolia and BOD, COD and TSS in case of Canna Lilies were

  10. Wetlands postcard

    USGS Publications Warehouse

    Ball, Lianne C.

    2016-05-25

    Research conducted by scientists at the U.S. Geological Survey provides reliable scientific information for the management of wetlands ranging from small freshwater alpine lakes in the Western United States to coastal wetlands of the Great Lakes and salt marshes along the Southeastern coast. Learn more about USGS wetlands research at: http://www.usgs.gov/ecosystems/environments/wetlands.html.

  11. Effect of vegetation type on treatment performance and bioelectric production of constructed wetland modules combined with microbial fuel cell (CW-MFC) treating synthetic wastewater.

    PubMed

    Saz, Çağdaş; Türe, Cengiz; Türker, Onur Can; Yakar, Anıl

    2018-03-01

    An operation of microcosm-constructed wetland modules combined with microbial fuel cell device (CW-MFC) was assessed for wastewater treatment and bioelectric generation. One of the crucial aims of the present experiment is also to determine effect of vegetation on wastewater treatment process and bioelectric production in wetland matrix with microbial fuel cell. Accordingly, CW-MFC modules with vegetation had higher treatment efficiency compared to unplanted wetland module, and average COD, NH 4 + , and TP removal efficiency in vegetated wetland modules were ranged from 85 to 88%, 95 to 97%, and 95 to 97%, respectively. However, the highest NO 3 - removal (63%) was achieved by unplanted control module during the experiment period. The maximum average output voltage, power density, and Coulombic efficiency were obtained in wetland module vegetated with Typha angustifolia for 1.01 ± 0.14 V, 7.47 ± 13.7 mWatt/m 2 , and 8.28 ± 10.4%, respectively. The results suggest that the presence of Typha angustifolia vegetation in the CW-MFC matrix provides the benefits for treatment efficiency and bioelectric production; thus, it increases microbial activities which are responsible for biodegradation of organic compounds and catalyzed to electron flow from anode to cathode. Consequently, we suggest that engineers can use vegetated wetland matrix with Typha angustifolia in CW-MFC module in order to maximize treatment efficiency and bioelectric production.

  12. Performance evaluation of planted and unplanted subsurface-flow constructed wetlands for the post-treatment of UASB reactor effluents.

    PubMed

    Dornelas, Filipe Lima; Machado, Matheus Boechat; von Sperling, Marcos

    2009-01-01

    A system comprised by a UASB (Upflow Anaerobic Sludge Blanket) reactor followed by two horizontal subsurface-flow constructed wetlands in parallel was evaluated for the treatment of the wastewater generated in the city of Belo Horizonte, Brazil (50 inhabitants each unit). One unit was planted (Typha latifolia) and the other was unplanted. Influent and effluent samples were collected for a period of seven months. The systems were able to produce final effluents with low concentrations of organic matter and suspended solids, but showed not to be efficient in the removal of nutrients. Mean effluent concentrations for the planted and unplanted units were, respectively: BOD: 15 and 19 mg/L; COD: 42 and 64 mg/L; TSS: 3 and 5 mg/L; TN: 27 and 33 mg/L; N-NH(3): 25 and 29 mg/L; P Total: 1.2 and 1.5 mg/L. The planted wetland presented effluent concentrations and removal efficiencies significantly (Wilcoxon matched-pairs test, 5% significance level) better than the unplanted unit for most constituents. The study shows that horizontal subsurface-flow constructed wetlands can be effectively used as a post-treatment option for the effluent from UASB reactors.

  13. The use of hybrid constructed wetlands for wastewater treatment with special attention to nitrogen removal: a review of a recent development.

    PubMed

    Vymazal, Jan

    2013-09-15

    The hybrid systems were developed in the 1960s but their use increased only during the late 1990 s and in the 2000s mostly because of more stringent discharge limits for nitrogen and also more complex wastewaters treated in constructed wetlands (CWs). The early hybrid CWs consisted of several stages of vertical flow (VF) followed by several stages of horizontal flow (HF) beds. During the 1990 s, HF-VF and VF-HF hybrid systems were introduced. However, to achieve higher removal of total nitrogen or to treat more complex industrial and agricultural wastewaters other types of hybrid constructed wetlands including free water surface (FWS) CWs and multistage CWs have recently been used as well. The survey of 60 hybrid constructed wetlands from 24 countries reported after 2003 revealed that hybrid constructed wetlands are primarily used on Europe and in Asia while in other continents their use is limited. The most commonly used hybrid system is a VF-HF constructed wetland which has been used for treatment of both sewage and industrial wastewaters. On the other hand, the use of a HF-VF system has been reported only for treatment of municipal sewage. Out of 60 surveyed hybrid systems, 38 have been designed to treat municipal sewage while 22 hybrid systems were designed to treat various industrial and agricultural wastewaters. The more detailed analysis revealed that VF-HF hybrid constructed wetlands are slightly more efficient in ammonia removal than hybrid systems with FWS CWs, HF-VF systems or multistage VF and HF hybrid CWs. All types of hybrid CWs are comparable with single VF CWs in terms of NH4-N removal rates. On the other hand, CWs with FWS units remove substantially more total nitrogen as compared to other types of hybrid constructed wetlands. However, all types of hybrid constructed wetlands are more efficient in total nitrogen removal than single HF or VF constructed wetlands. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Bacterial community dynamics in surface flow constructed wetlands for the treatment of swine waste.

    PubMed

    Ibekwe, A M; Ma, J; Murinda, Shelton; Reddy, G B

    2016-02-15

    Constructed wetlands are generally used for the removal of waste from contaminated water. In the swine production system, wastes are traditionally flushed into an anaerobic lagoon which is then sprayed on agricultural fields. However, continuous spraying of lagoon wastewater on fields can lead to high N and P accumulations in soil or lead to runoff which may contaminate surface or ground water with pathogens and nutrients. In this study, continuous marsh constructed wetland was used for the removal of contaminants from swine waste. Using pyrosequencing, we assessed bacterial composition within the wetland using principal coordinate analysis (PCoA) which showed that bacterial composition from manure influent and lagoon water were significantly different (P=0.001) from the storage pond to the final effluent. Canonical correspondence analysis (CCA) showed that different bacterial populations were significantly impacted by ammonium--NH4 (P=0.035), phosphate--PO4(3-) (P=0.010), chemical oxygen demand--COD (P=0.0165), total solids--TS (P=0.030), and dissolved solids--DS (P=0.030) removal, with 54% of the removal rate explained by NH4+PO4(3-) according to a partial CCA. Our results showed that different bacterial groups were responsible for the composition of different wetland nutrients and decomposition process. This may be the major reason why most wetlands are very efficient in waste decomposition. Published by Elsevier B.V.

  15. Life cycle assessment of constructed wetland systems for wastewater treatment coupled with microbial fuel cells.

    PubMed

    Corbella, Clara; Puigagut, Jaume; Garfí, Marianna

    2017-04-15

    The aim of this study was to assess the environmental impact of microbial fuel cells (MFCs) implemented in constructed wetlands (CWs). To this aim a life cycle assessment (LCA) was carried out comparing three scenarios: 1) a conventional CW system (without MFC implementation); 2) a CW system coupled with a gravel-based anode MFC, and 3) a CW system coupled with a graphite-based anode MFC. All systems served a population equivalent of 1500 p.e. They were designed to meet the same effluent quality. Since MFCs implemented in CWs improve treatment efficiency, the CWs coupled with MFCs had lower specific area requirement compared to the conventional CW system. The functional unit was 1m 3 of wastewater. The LCA was performed with the software SimaPro® 8, using the CML-IA baseline method. The three scenarios considered showed similar environmental performance in all the categories considered, with the exception of Abiotic Depletion Potential. In this impact category, the potential environmental impact of the CW system coupled with a gravel-based anode MFC was around 2 times higher than that generated by the conventional CW system and the CW system coupled with a graphite-based anode MFC. It was attributed to the large amount of less environmentally friendly materials (e.g. metals, graphite) for MFCs implementation, especially in the case of gravel-based anode MFCs. Therefore, the CW system coupled with graphite-based anode MFC appeared as the most environmentally friendly solution which can replace conventional CWs reducing system footprint by up to 20%. An economic assessment showed that this system was around 1.5 times more expensive than the conventional CW system. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Cell-to-cell pollution reduction effectiveness of subsurface domestic treatment wetlands.

    PubMed

    Steer, David N; Fraser, Lauchlan H; Seibert, Beth A

    2005-05-01

    Quarterly water quality data from 1998 to 2003 for eight single-family domestic systems serving 2-7 people in Ohio, USA, were studied to determine the cell-to-cell and system wide pathogen reduction efficiency and effectiveness of these systems in meeting compliance standards. Two-cell domestic wastewater treatment systems displayed significant variability in their cell-to-cell performance that directly impacted the overall ability of systems to meet effluent compliance standards. Fecal coliform was effectively reduced (approximately 99%) in these systems while two-thirds of the input biochemical oxygen demand was mitigated in each of the cells of these systems. Fecal coliform and biochemical oxygen demand were typically reduced below 2000 counts per 100 ml and 15 mg/l (respectively) before discharge to surface waters. Total suspended solids were reduced by approximately 80% overall with cell one retaining the majority of the solids (approximately 70%). These systems discharged more than 18 mg/l of suspended solids in less than 5% of the samples thus displaying a very high compliance rate. Ammonia and total phosphorus were less effectively treated (approximately 30-40% reductions in each cell) and exceeded standards (1.5 mg/l) more frequently. Analyses based on the number of occupants indicated that the two-cell design used here was most effective for smaller occupancy systems. More study is required to determine the value of this design for large occupancy systems. In the future, wetlands should be evaluated based on the total loads delivered to the watershed rather than by effluent concentrations.

  17. [Selection of winter plant species for wetlands constructed as sewage treatment systems and evaluation of their wastewater purification potentials].

    PubMed

    Chen, Yong-hua; Wu, Xiao-fu; Chen, Ming-li; Jiang, Li-juan; Li, Ke-lin; Lei, Dian; Wang, Hai-bin

    2010-08-01

    In order to establish an evaluation system for selection of winter wetland plants possessing high wastewater purification potentials in subtropics areas, designed sewage treatment experiments were carried out by introducing into the constructed wetlands 25 species of winter wetland plants. Cluster analysis was performed by including harmful environment-resistant enzyme and substrate enzyme activities into the commonly applied plant screening and assessment indexes system. The obtained results indicated that there were significant differences among the tested winter plants in their root length and vigor, leaf malonaldehyde (MDA), biomass, average nitrogen and phosphorus concentration and uptake, and urease and phosphoric acid enzyme activities in the root areas. Based on the established evaluation system, the tested plants were clustered into 3 groups. The plants in the 1st group possessing high purification potentials are Oenanthe javanica, Brassicacapestris, Juncus effusu, Saxifragaceae, Iris pseudoacorus, Osmanthus fragrans and Iris ensata; those in the 2nd group possessing moderate purification potentials are Brassica oleracea var acephala, Calendula officinalis, Aucuba japonica, Ligustrum lucidu, Beta vulgaris, Rhododendron simsii and Ilex latifolia; and those in the 3rd group with low purification potentials are Brassica oleracea var acephala, Calistephus chinensis, Rosa chinensis, Antirrhinums, Liriope palatyphylla, Zephyranthes candida, Fatshedera lizei, Petunia hybrida, Ilex quihoui, Dianthus caryophyllus and Loropetalum chinensis.

  18. Surface wetlands for the treatment of pathogens in stormwater: three case studies at Lake Macquarie, NSW, Australia.

    PubMed

    Méndez, H; Geary, P M; Dunstan, R H

    2009-01-01

    The treatment of stormwater using surface constructed wetlands has become common in the last decades. However, the use of constructed wetlands for stormwater management has not been thoroughly evaluated in their capacity to treat microbial loads. The case studies presented in this paper are situated at Lake Macquarie, a large estuarine lagoon located approximately 150 km north of Sydney, Australia. To protect the lake ecosystem from the impact of increasing urban development, the local Council constructed numerous stormwater quality improvement devices (SQIDs) at selected locations. The SQIDs typically consisted of trash racks, gross pollutant traps and surface constructed wetlands. To evaluate the effectiveness of three of these devices in reducing faecal contamination, water samples were collected for faecal coliforms (FC) during and following rainfall at inlets and outlets of the structures. Results indicated one of the SQIDs as the most efficient for bacterial reduction, while the other two provided low or non reduction of FC. Results also illustrated dependence of bacteria reduction on flow conditions. Comparison of devices suggested that hydraulic residence times and other design parameters strongly influenced the capacity of each device to reduce FC counts during different weather conditions.

  19. Comparison of the catabolic activity and catabolic profiles of rhizospheric, gravel-associated and interstitial microbial communities in treatment wetlands.

    PubMed

    Weber, Kela P; Legge, Raymond L

    2013-01-01

    Microbial communities play a critical role in degrading organic contaminants in treatment wetlands; however, an understanding of the different roles played by rhizospheric, gravel-associated and interstitial microbial communities is deficient due to a lack of data directly comparing these microbial communities. Community level physiological profiling (CLPP) was used to compare the catabolic capabilities of rhizospheric, gravel-associated and interstitial microbial communities in vertical-flow planted and unplanted wetland mesocosms. Wetland mesocosms were decommissioned to gather microbial community samples associated with the roots and gravel bed media taken from the top (10 cm depth), middle (30 cm depth) and bottom (60 cm depth). The catabolic capabilities of the rhizospheric microbial communities were seen to be much greater than those of the gravel-associated communities. A decrease in catabolic capability was seen with increasing depth, suggesting that communities near the surface play a larger role in the degradation of carbon-based compounds. A general difference in catabolic profiles based on plant presence/absence was observed for the interstitial water and all gravel-associated samples at all depths, suggesting that the presence of roots within part of the mesocosm not only has a localized effect on the attached microbial population, but also on gravel-associated microbial communities throughout the mesocosms.

  20. Application of constructed wetlands to the treatment of leachates from a municipal solid waste landfill in Ibadan, Nigeria.

    PubMed

    Aluko, Olufemi Oludare; Sridhar, M K C

    2005-06-01

    Leachates are wastewater generated principally from landfills and solid waste disposal sites. Leachates emanating from municipal wastes are a major source of surface and groundwater pollution worldwide. Globally, leachates have been implicated in low yield of farm produce, developmental anomalies, low birth weights, leukemia incidence, and other cancers in communities around the site. They have also been implicated in hazards to the environment, loss of biodiversity, and contamination of water sources. At Aba-Eku in Nigeria, leachates are being discharged into the Omi Stream without treatment. A study was conducted on a method of leachate treatment that passes the leachate through constructed wetlands using Ipomoea aquatica (Forsk), a locally available plant found close to the landfill site. The aim of the study was to evolve a sustainable and cost-effective method of treatment whose effluents can be discharged into the Omi Stream with no or minimal impact. The study was descriptive and analytical in design. Samples were collected and analyzed with standard methods for pH, suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia, nitrate, and trace metals. Raw leachates were turbid and amber in color and contained suspended solids (197.5 mg/L), ammonia (610.9 mg/L), lead (1.64 mg/L), iron (198.10 mg/L), and manganese (23.20 mg/L). When the leachates were passed through the constructed wetland with eight hours' detention time, effluents showed significant reductions in suspended solids (81.01 percent), BOD (86.03 percent), and ammonia (97.77 percent). The study shows that a constructed wetland is a feasible tool for the treatment of leachates before their disposal into the environment in Nigeria and can help safeguard environmental quality.

  1. Nitrogen dynamics of the aquatic system is an important driving force for efficient sewage purification in single pond natural treatment wetlands at East Kolkata Wetland.

    PubMed

    Das Gupta, Anirban; Sarkar, Subhasis; Singh, Jayprakash; Saha, Tapan; Sil, Alok Kumar

    2016-12-01

    At East Kolkata Wetlands, though the domestic city sewage is purified very rapidly, the mechanisms of treatment remains inadequately explored. In this context, the present study investigated nitrogen dynamics of the single pond treatment systems during purification and explored its potential role in sewage treatment. For this purpose the concentrations of different forms of nitrogen present both in water and soil at different time points of purification were measured. The organic nitrogen content decreased sharply, in the early phase, with an increase in ammonium concentration. Notably the reduction in organic nitrogen was significantly higher than the increase in NH 4 + which can be attributed to the volatilization of NH 4 + under alkaline pH. This volatilization results in reduced oxygen demand. The nitrate-N concentration decreased sharply from soil with a concomitant increase in water column. However the reduction of nitrate in soil was significantly higher than the increase in water column. It indicated the occurrence of denitrification under anoxic condition wherein nitrate serves as terminal electron acceptor. Additionally a part of the nitrate supported planktonic growth. Thus it describes another mechanism of reducing oxygen demand. The initial NH 4 + -N concentration in the soil was very low and it increased gradually during purification due to increasing soil cation exchange capacity. Thus by trapping NH 4 + ion soil contributes towards preventing contamination of water. Thus at EKW, the cumulative activities in water and soil involved in nitrogen dynamics lead to overall reduction of the oxygen demand and contribute towards efficient sewage purification. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Multistage treatment wetland for treatment of reject waters from digested sludge dewatering.

    PubMed

    Gajewska, M; Obarska-Pempkowiak, H

    2013-01-01

    The paper presents the influence of sewage composition on treatment in pilot-scale facility for reject waters (RW) from sewage sludge centrifugation. The facility consisted of mechanical (two tanks with 10 d retention each) and biological parts composed of three subsurface flow reed beds working in batch. Two years of monitoring of the facility proved high efficiency removal of predominant pollutants: chemical oxygen demand (COD) 75-80%, biochemical oxygen demand (BOD) 82.2-95.5% and total nitrogen 78.7-93.9% for low ratio of BOD5/COD in discharged RW. The differences in efficiency removal were correlated with the composition of organics and nitrogen compounds rather than with concentrations. It was assumed that high concentration of colloidal fraction of Org-N and COD in discharged RW led to a decrease in efficiency removal.

  3. Linking climate change to water provision: greywater treatment by constructed wetlands

    NASA Astrophysics Data System (ADS)

    Qomariyah, S.; Ramelan, AH; Setyono, P.; Sobriyah

    2018-03-01

    Climate change has been felt to take place in Indonesia, causing the temperature to increase, additional drought with more moisture evaporates from rivers, lakes, and other bodies of water, and intense rainfall in a shorter rainy season. One of the major concerns is the risk of severe drought leading to water shortages. It will affect water supply and agriculture yields. As a country extremely vulnerable to the climate change, Indonesia must adapt to the serious environmental issues. This paper aims to offer an effort of water provision by recycling and reusing of greywater applying constructed wetland systems. The treated greywater is useful as water provision for non-consumptive uses. A recent experiment was conducted on a household yard using a single horizontal subsurface flow type of constructed wetland. The experiments demonstrated that the constructed wetland systems reduced effectively the pollutants of TSS, BOD, COD, and detergent to the level that are compliant with regulatory standards. The constructed wetland has been established for almost two years however the system still works properly.

  4. Bacterial community dynamics in surface flow constructed wetlands for the treatment of swine waste

    USDA-ARS?s Scientific Manuscript database

    Constructed wetlands are generally used for the removal of waste from contaminated water. In the swine production system, wastes are traditionally flushed into an anaerobic lagoon which is then sprayed on agricultural fields. However, continuous spraying of lagoon wastewater on fields can lead to hi...

  5. Treatment of hypersaline hazardous landfill leachate using a baffled constructed wetland system: effect of granular packing media and vegetation.

    PubMed

    Meky, Naira; Fujii, Manabu; Tawfik, Ahmed

    2017-11-09

    Constructed wetland is an engineered system that attains more attention as a feasible technology for the treatment of municipal landfill leachate. However, its feasibility for treatment of toxic, hazardous, and hypersaline leachate remains unexplored. This study aimed to investigate the feasibility of using a baffled constructed wetland (BCW) system for the treatment of hypersaline hazardous landfill leachate. Furthermore, the effects of granular packing media, toxicity, and hyper salinity conditions on the removal efficiency of COD fractions (CODt, CODs, and CODp), nitrogen, heavy metals, and coarse solids were extensively investigated. Our findings indicated that BCWs were highly effective in removing heavy metals particularly Cu 2+ , Mn 2+ , Fe 2+ , and Zn 2+ and exhibited moderate efficiency for other contaminants (e.g. COD fractions, solids, and nitrogen species). Furthermore, use of a sand and gravel mixture for bed materials demonstrated higher performance over sand alone. However, we found that Phragmites australis is not tolerant enough to extreme toxicity and salinity conditions, and this reed could not survive for more than 27 and 33 days in sand BCW and sand/gravel BCW, respectively. Consequently, survivorship of reed and efficiency of treatment using vegetation were limited in the long-term operation with high salinity and toxicity conditions.

  6. Development of alum sludge-based constructed wetland: an innovative and cost effective system for wastewater treatment.

    PubMed

    Zhao, Y Q; Babatunde, A O; Zhao, X H; Li, W C

    2009-07-01

    This article describes a research attempt to integrate the dewatered alum sludge, a residual by-product of drinking water treatment process, into a constructed wetland (CW) system for the purpose of enhancing the wastewater treatment performance, thus developing a so called alum sludge-based constructed wetland system. A multi-dimensional research project including the batch tests of phosphorus (P) adsorption onto alum sludge followed by the model CWs trials of single and multi-stage CWs, has been conducted since 2004. It has been successfully demonstrated that the alum sludge-based CW is capable of enhanced and simultaneous removal of P and organic matter (in terms of BOD5 and COD), particularly from medium and high strength wastewater. The sludge cakes act as the carrier for developing biofilm for organics removal and also serve as adsorbent to enhance P immobilization. Batch P-adsorption tests revealed that the alum sludge tested possesses excellent P-adsorption ability of 14.3 mg-P/g x sludge (in dry solids) at pH 7.0 with the adsorption favored at lower pH. The results obtained in a 4-stage treatment wetland system suggest that high removal efficiencies of 90.4% for COD, 88.0% for BOD5, 90.6% for SS, 76.5% for TN and 91.9% for PO4(3-)-P under hydraulic loading of 0.36 m3/m2 x d can be achieved. The field demonstration study of this pioneering development is now underway.

  7. Rural domestic wastewater treatment in Norway and Poland: experiences, cooperation and concepts on the improvement of constructed wetland technology.

    PubMed

    Paruch, A M; Mæhlum, T; Obarska-Pempkowiak, H; Gajewska, M; Wojciechowska, E; Ostojski, A

    2011-01-01

    This article describes Norwegian and Polish experiences concerning domestic wastewater treatment obtained during nearly 20 years of operation for constructed wetland (CW) systems in rural areas and scattered settlements. The Norwegian CW systems revealed a high performance with respect to the removal of organic matter, biogenic elements and faecal indicator bacteria. The performance of the Polish CW systems was unstable, and varied between unsatisfied and satisfied treatment efficiency provided by horizontal and vertical flow CWs, respectively. Therefore, three different concepts related to the improvement of CW technology have been developed and implemented in Poland. These concepts combined some innovative solutions originally designed in Norway (e.g. an additional treatment step in biofilters) with Polish inspiration for new CWs treating rural domestic wastewater. The implementation of full-scale systems will be evaluated with regard to treatment efficiency and innovative technology; based on this, a further selection of the most favourable CW for rural areas and scattered settlements will be performed.

  8. Nitrogen removal on recycling water process of wastewater treatment plant effluent using subsurface horizontal wetland with continuous feed

    NASA Astrophysics Data System (ADS)

    Tazkiaturrizki, T.; Soewondo, P.; Handajani, M.

    2018-01-01

    Recycling water is a generic term for water reclamation and reuse to solve the scarcity of water. Constructed wetlands have been recognized as providing many benefits for wastewater treatment including water supply and control by recycling water. This research aims to find the best condition to significantly remove nitrogen using constructed wetland for recycling water of Bojongsoang Waste Water Treatment Plan (WWTP) effluent. Using media of soil, sand, gravel, and vegetation (Typha latifolia and Scirpus grossus) with an aeration system, BOD and COD parameters have been remarkably reduced. On the contrary, the removal efficiency for nitrogen is only between 50-60%. Modifications were then conducted by three step of treatment, i.e., Step I is to remove BOD/COD using Typha latifolia with an aeration system, Step II is todecrease nitrogen using Scirpus grossus with/without aeration, and Step III isto complete the nitrogen removal with denitrification process by Glycine max without aeration. Results of the research show that the nitrogen removal has been successfully increased to a high efficiency between 80-99%. The combination of aeration system and vegetation greatly affects the nitrogen removal. The vegetation acts as the organic nitrogen consumer (plant uptake) for amino acids, nitrate, and ammonium as nutrition, as well as theoxygen supplier to the roots so that aerobic microsites are formed for ammonification microorganisms.

  9. Hydrologic Education and Undergraduate Research in a Passive Wetland Treatment System

    NASA Astrophysics Data System (ADS)

    Fredrick, K. C.; Lohr, L.

    2012-12-01

    Legacy coal mine drainage has been found to impair surface water throughout southwestern Pennsylvania. Though few of our incoming students know what "acid mine drainage" is, nearly all have seen the orange streams and seeps that are its most obvious characteristic. On the other end of the spectrum, our geology majors are typically finding jobs in the oil and gas industry related to shale gas, or in environmental fields especially related to local and regional surface water. To take advantage of their early familiarity with local stream impacts and the likelihood they will have to deal with mine effluent during their post-academic careers, we have leveraged a local passive wetland treatment system to bring a relevant, real-life scenario into the classroom and lab. Moraine State Park, in western PA, is centered on Lake Arthur, an artificial reservoir of Muddy Creek. The park, particularly the lake, is a destination for recreational visitors, including boating and fishing enthusiasts. There is concern among visitors and park administrators about the health of the local streams and the lake. The area has been extensively undermined, with most coal mines sealed prior to the damming of the reservoir. One such instance of these sealed mine ports failed along one of the many embayments of Lake Arthur and a passive treatment system was installed. It was used as an example of the environmental impacts to the area for park guests, with an access road and signage. However, at this time, the three-pond system may be failing, five years beyond its projected life span and showing signs of stress and downstream contamination. Though the system is small, it provides a robust opportunity for hydrologic and geochemical analyses. We have used the pond system extensively for undergraduate research. Over the past five years, a Master's thesis was completed, and numerous undergraduate projects followed. Students have measured precipitate thickness and deposition rates, endeavored to

  10. Evaluation of the treatment performance and microbial communities of a combined constructed wetland used to treat industrial park wastewater.

    PubMed

    Xu, Ming; Liu, Weijing; Li, Chao; Xiao, Chun; Ding, Lili; Xu, Ke; Geng, Jinju; Ren, Hongqiang

    2016-06-01

    Constructed wetlands are ecosystems that use plants and microorganisms to remediate pollution in soil and water. In this study, two parallel pilot-scale vertical flow wetland and horizontal flow wetland (VF-HF) systems were implemented to investigate the treatment performance and microorganism community structure in the secondary effluent of an industrial park wastewater treatment plant (WWTP) with a loading rate of 100 mm/day near the Yangtze River in Suzhou City, East China. Removal efficiencies of 82.3, 69.8, 77.8, and 32.3 were achieved by the VF-HF systems for ammonium nitrogen (NH4 (+)-N), total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD), respectively. The VF system specialized in COD and NH4 (+)-N removal (73.6 and 79.2 %), whereas the HF system mainly contributed to TN removal (63.5 %). The effluents in all seasons are capable of achieving the "surface water environmental quality standard" (GB3838-2002) grade IV. In the VF system, the 16S gene and nirK gene were significantly correlated with depth, with the 16S gene showing significant correlations with the dissolved oxygen (DO) level (r = 0.954, p < 0.05), which was determined by real-time PCR and high-throughput sequencing. Many types of bacteria capable of biodegradation, including nitrifiers, denitrifiers, and polyaromatic hydrocarbon (PAH) degraders (improvement of the BOD5/COD ratio), were observed, and they contributed to approximately 90 % of the nitrogen removal in the VF-HF system.

  11. SU-D-18A-01: Tumor Motion Tracking with a Regional Deformable Registration Model for Four Dimensional Radiation Treatment of Lung Cancer

    SciTech Connect

    Chao, M; Lo, Y; Yuan, Y

    2014-06-01

    Purpose: To develop a tumor motion model from four-dimensional computed tomography (4DCT) of thoracic patients and demonstrate its impact on 4D radiation therapy simulation. Methods: A regional deformable image registration algorithm was introduced to extract tumor motion out of patient's breathing cycle. The gross target volume (GTV) was manually delineated on a selected phase of 4DCT and a subregion with 10mm margin supplemented to the GTV was created on the Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA). Together with 4DCT the structures were exported into an inhouse research platform. A free form B-Spline deformable registration was carriedmore » out to map the subregion to other respiratory phases. The displacement vector fields were employed to propagate GTV contours with which the center of mass (CoM) of the GTV was computed for each breathing phase of 4DCT. The resultant GTV motion and its volumetric shape are utilized to facilitate 4D treatment planning. Five lung cancer patients undergoing stereotactic body radiation therapy were enrolled and their 4DCT sets were included in the study. Results: Application of the algorithm to five thoracic patients indicates that clinically satisfactory outcomes were achievable with a spatial accuracy better than 2mm for GTV contour propagation between adjacent phases, and 3mm between opposite phases. The GTV CoM was found to be in the range of 2.0mm through 2.5cm, depending upon the tumor location. Compared to the traditional whole image based registration, the computation of the regional model was found to be an order of magnitude more efficient. Conclusion: A regional deformable registration model was implemented to extract tumor motion. It will have widespread application in 4D radiation treatment planning in the future to maximally utilize the available spatial-tempo information.« less

  12. Combining TiO2-photocatalysis and wetland reactors for the efficient treatment of pesticides.

    PubMed

    Araña, J; Garriga I Cabo, C; Fernández Rodríguez, C; Herrera Melián, J A; Ortega Méndez, J A; Doña Rodríguez, J M; Pérez Peña, J

    2008-03-01

    In the present work the photocatalytic and biological degradation of two commercial mixtures of pesticides (Folimat and Ronstar) and two fungicides (pyrimethanil and triadimenol) has been studied. The evolution of some components of these commercial products (dicofol, tetradifon and oxadiazon) and that of the two fungicides has been monitored by means of HPLC, GC-MS, TOC and toxicity (Lemna minor toxicity test) measurements. The photocatalytic method was able to degrade dicofol, tetradifon, pyrimethanil, triadimenol and the components of Ronstar with the exception of oxadiazon. In addition to this, the photocatalytic method eliminated pyrimethanil toxicity and reduced that of triadimenol by a 90%, Ronstar by a 78% and Folimat by an 87%. Nevertheless, the wetland reactors alone could reduce the toxicity of only the former. Finally, the proper dosage of the water containing the pesticides to a photocatalytic reactor followed by a wetland reactor resulted to be the most successful strategy for the detoxification of the studied compounds and their mixtures.

  13. Constructed Wetlands for Treatment of Organic and Engineered Nanomaterial Contaminants of Emerging Concerns (WaterRF Report 4334)

    EPA Science Inventory

    The goal of this project was to determine hydraulic and carbon loading rates for constructed wetlands required for achieving different levels of organic and nanomaterial contaminants of emerging concern (CECs) removal in constructed wetlands. Specific research objectives included...

  14. WE-D-18A-01: Evaluation of Three Commercial Metal Artifact Reduction Methods for CT Simulations in Radiation Therapy Treatment Planning

    SciTech Connect

    Huang, J; Kerns, J; Nute, J

    2014-06-15

    Purpose: To evaluate three commercial metal artifact reduction methods (MAR) in the context of radiation therapy treatment planning. Methods: Three MAR strategies were evaluated: Philips O-MAR, monochromatic imaging using Gemstone Spectral Imaging (GSI) dual energy CT, and monochromatic imaging with metal artifact reduction software (GSIMARs). The Gammex RMI 467 tissue characterization phantom with several metal rods and two anthropomorphic phantoms (pelvic phantom with hip prosthesis and head phantom with dental fillings), were scanned with and without (baseline) metals. Each MAR method was evaluated based on CT number accuracy, metal size accuracy, and reduction in the severity of streak artifacts. CTmore » number difference maps between the baseline and metal scan images were calculated, and the severity of streak artifacts was quantified using the percentage of pixels with >40 HU error (“bad pixels”). Results: Philips O-MAR generally reduced HU errors in the RMI phantom. However, increased errors and induced artifacts were observed for lung materials. GSI monochromatic 70keV images generally showed similar HU errors as 120kVp imaging, while 140keV images reduced errors. GSI-MARs systematically reduced errors compared to GSI monochromatic imaging. All imaging techniques preserved the diameter of a stainless steel rod to within ±1.6mm (2 pixels). For the hip prosthesis, O-MAR reduced the average % bad pixels from 47% to 32%. For GSI 140keV imaging, the percent of bad pixels was reduced from 37% to 29% compared to 120kVp imaging, while GSI-MARs further reduced it to 12%. For the head phantom, none of the MAR methods were particularly successful. Conclusion: The three MAR methods all improve CT images for treatment planning to some degree, but none of them are globally effective for all conditions. The MAR methods were successful for large metal implants in a homogeneous environment (hip prosthesis) but were not successful for the more complicated case of

  15. TH-C-17A-01: Imaging Sensor Comparison for Real-Time Cherenkov Signal Detection From Tissue for Treatment Verification

    SciTech Connect

    Andreozzi, J; Zhang, R; Glaser, A

    2014-06-15

    Purpose: To identify the optimum imaging sensor for a clinical system that would provide real-time imaging of the surface beam profile on patients as novel visual information to radiation therapy technologists, and more rapidly collect clinical data for large-scale studies of Cherenkov applications in radiotherapy. Methods: Four camera types, CMOS, CCD, ICCD and EMICCD, were tested to determine proficiency in the detection of Cherenkov signal in the clinical radiotherapy setting, and subsequent maximum supportable frame rate. Where possible, time-gating between the trigger signal from the LINAC and the intensifiers was implemented to detect signal with room lighting conditions comparable tomore » patient treatment scenarios. A solid water phantom was imaged by the EM-ICCD and ICCD to evaluate the minimum number of accumulations-on-chip required for adequate Cherenkov detection, defined as >200% electron counts per pixel over background signal. Additionally, an ICCD and EM-ICCD were used clinically to image patients undergoing whole-breast radiation therapy, to understand the impact of the resolution limitation of the EM-ICCD. Results: The intensifier-coupled cameras performed best at imaging Cherenkov signal, even with room lights on, which is essential for patient comfort. The tested EM-ICCD was able to support single-shot imaging and frame rates of 30 fps, however, the current maximum resolution of 512 × 512 pixels was restricting. The ICCD used in current clinical trials was limited to 4.7 fps at a 1024 × 1024 resolution. An intensifier with higher quantum efficiency at the entrance photocathode in the red wavelengths (30% QE vs current 7%) promises 16 fps at the same resolution at lower cost than the EM-ICCD. Conclusion: The ICCD with the better red wavelength QE intensifier was determined to be the best suited commercial-off-the-shelf camera to detect real-time Cherenkov signal and provide the best potential for real-time display of radiation dose on the

  16. Leachate treatment system using constructed wetlands, Town of Fenton sanitary landfill, Broome County, New York. Final report

    SciTech Connect

    Not Available

    1993-11-01

    Municipal sanitary landfills generate leachate that New York State regulations require to be collected and treated to avoid contaminating surface water and groundwater. One option for treating leachate is to haul it to municipal wastewater treatment facility. This option may be expensive, may require excessive energy for transportation, and may require pretreatment to protect the receiving facility`s processes. An alternative is on-site treatment and discharge. Personnel from the Town of Fenton, New York; Hawk Engineering, P.C.; Cornell University; and Ithaca College designed, built, and operated a pilot constructed wetland for treating leachate at the Town of Fenton`s municipal landfill. Themore » system, consisting of two overland flow beds and two subsurface flow beds has been effective for 18 months in reducing levels of ammonia (averaging 85% removal by volatilization and denitrification) and total iron (averaging 95% removal by precipitation and sedimentation), two key constituents of the Fenton landfill`s leachate. The system effects these reductions with zero chemical and energy inputs and minimal maintenance. A third key constituent of the leachate, manganese, apparently passes through the beds with minimal removal. Details and wetland considerations are described.« less

  17. Performance evaluation of semi continuous vertical flow constructed wetlands (SC-VF-CWs) for municipal wastewater treatment.

    PubMed

    Kumar, Manoj; Singh, Rajesh

    2017-05-01

    The present study demonstrated the understating of municipal wastewater treatment in five types of CWs operated under semi continuous vertical flow mode. All CWs treatment conditions show the significantly lower pollutants concentrations. The average NH 4 + -N, TN, NO 2 - -N, NO 3 - -N, SO 4 2- , and PO 4 3- removal efficiency in the ISs-CWs were 83.60%, 82.43%, 15.61%, 48.93%, 80.45%, and 78.94% respectively. The average NO 2 - -N removal efficiency shows that highest nitrite accumulation occurred in the Cont-CWs followed by C-CWs. The lowest increase in the biomass (127.5%) was observed in the Eichhornia crassipes planted in the ISs-CWs. The ISs filtration barrier created in the constructed wetlands was sufficient enough to remove all the pollutants. Principal components EFA 2D deformation plots show the distribution of the various nitrogenous species in the constructed wetlands along different components. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Mass Balance Assessment for Six Neonicotinoid Insecticides During Conventional Wastewater and Wetland Treatment: Nationwide Reconnaissance in United States Wastewater

    PubMed Central

    2016-01-01

    Occurrence and removal of six high-production high-volume neonicotinoids was investigated in 13 conventional wastewater treatment plants (WWTPs) and one engineered wetland. Flow-weighted daily composites were analyzed by isotope dilution liquid chromatography tandem mass spectrometry, revealing the occurrence of imidacloprid, acetamiprid, and clothianidin at ng/L concentrations in WWTP influent (60.5 ± 40.0; 2.9 ± 1.9; 149.7 ± 289.5, respectively) and effluent (58.5 ± 29.1; 2.3 ± 1.4; 70.2 ± 121.8, respectively). A mass balance showed insignificant removal of imidacloprid (p = 0.09, CI = 95%) and limited removal of the sum of acetamiprid and its degradate, acetamiprid-N-desmethyl (18 ± 4%, p = 0.01, CI = 95%). Clothianidin was found only intermittently, whereas thiamethoxam, thiacloprid, and dinotefuran were never detected. In the wetland, no removal of imidacloprid or acetamiprid was observed. Extrapolation of data from 13 WWTPs to the nation as a whole suggests annual discharges on the order of 1000–3400 kg/y of imidacloprid contained in treated effluent to surface waters nationwide. This first mass balance and first United States nationwide wastewater reconnaissance identified imidacloprid, acetamiprid, and clothianidin as recalcitrant sewage constituents that persist through wastewater treatment to enter water bodies at significant loadings, potentially harmful to sensitive aquatic invertebrates. PMID:27196423

  19. Operating a two-stage microbial fuel cell-constructed wetland for fuller wastewater treatment and more efficient electricity generation.

    PubMed

    Doherty, Liam; Zhao, Yaqian

    2015-01-01

    By integrating microbial fuel cells (MFCs) into constructed wetlands (CWs) the need and cost of building a reactor are eliminated, while CWs provide the simultaneous redox conditions required for optimum MFC performance. Two single-stage MFC-CWs, with dewatered alum sludge cake as the main wetland medium for enhanced phosphorus removal, were operated to determine the effects of electrode separation and flow regimes on power production and wastewater treatment. When the anode is buried and the cathode is at the air-water interface the system is inhibited by a large ohmic resistance resulting from the increased electrode separation. By placing the cathode directly above the anode and operating the system with simultaneous up-flow into the anode and down-flow into the cathode the ohmic resistance is reduced. The chemical oxygen demand (COD) removal efficiency was, however, reduced to 64% (compared with 79%). A two-stage system was subsequently run for fuller wastewater treatment and increased power production. The results indicate that a two-stage MFC-CW can increase the normalized energy recovery and improve removal efficiencies of COD, total nitrogen, NH4⁺, total phosphorus and reactive phosphorus to 93 ± 1.7%, 85 ± 5.2%, 90 ± 5.4%, 98 ± 5.3% and 99 ± 2.9%, respectively.

  20. Treatment of oil and grease in produced water by a pilot-scale constructed wetland system using biogeochemical processes.

    PubMed

    Pardue, Michael J; Castle, James W; Rodgers, John H; Huddleston, George M

    2014-05-01

    Constructed wetland treatment systems (CWTSs) can effectively remove many constituents that limit beneficial use of oilfield produced water. The objectives of this investigation were: (1) to assess the effect of mass loadings of oil and grease (O & G) on treatment performance in pilot-scale subsurface flow and free water surface CWTS series having sequential reducing and oxidizing cells, and (2) to evaluate effects on treatment performance of adding a pilot-scale oil-water separator. Increase in O & G mass loading from 5 to 20 mg min(-1) caused decreases in both dissolved oxygen concentration and sediment redox potential, which affected treatment performance. Biogeochemical pathways for removal of O & G, iron, and manganese operate under oxidizing conditions, and removal rate coefficients for these constituents decreased (0.905-0.514 d(-1) for O & G, 0.773-0.452 d(-1) for iron, and 0.970-0.518 d(-1) for manganese) because greater mass loading of O & G promoted reducing conditions. With increased mass loading, removal rate coefficients for nickel and zinc increased from 0.074 to 0.565 d(-1) and from 0.196 to 1.08 d(-1), respectively. Although the sequential reducing and oxidizing cells in the CWTS were very effective in treating the targeted constituents, an oil-water separator was added prior to wetland cells to enhance O & G removal at high inflow concentration (100 mg L(-1)). The oil-water separator removed approximately 50% of the O & G, and removal extents and efficiencies approximated those observed at 50 mg L(-1) inflow concentration during treatment without an oil-water separator. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Studies on sustainability of simulated constructed wetland system for treatment of urban waste: Design and operation.

    PubMed

    Upadhyay, A K; Bankoti, N S; Rai, U N

    2016-03-15

    New system configurations and wide range of treatability make constructed wetland (CW) as an eco-sustainable on-site approach of waste management. Keeping this view into consideration, a novel configured three-stage simulated CW was designed to study its performance efficiency and relative importance of plants and substrate in purification processes. Two species of submerged plant i.e., Potamogeton crispus and Hydrilla verticillata were selected for this study. After 6 months of establishment, operation and maintenance of simulated wetland, enhanced reduction in physicochemical parameters was observed, which was maximum in the planted CW. The percentage removal (%) of the pollutants in three-stage mesocosms was; conductivity (60.42%), TDS (67.27%), TSS (86.10%), BOD (87.81%), NO3-N (81.28%) and PO4-P (83.54%) at 72 h of retention time. Submerged macrophyte used in simulated wetlands showed a significant time dependent accumulation of toxic metals (p ≤ 0.05). P. crispus accumulated the highest Mn (86.36 μg g(-1) dw) in its tissue followed by Cr (54.16 μg g(-1) dw), Pb (31.56 μg g(-1) dw), Zn (28.06 μg g(-1) dw) and Cu (25.76 μg g(-1) dw), respectively. In the case of H. verticillata, it was Zn (45.29), Mn (42.64), Pb (22.62), Cu (18.09) and Cr (16.31 μg g(-1) dw). Thus, results suggest that the application of simulated CW tackles the water pollution problem more efficiently and could be exploited in small community level as alternative and cost effective tools of phytoremediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. On the fit of statistical and the k-C* models to projecting treatment performance in a constructed wetland system.

    PubMed

    Babatunde, A O; Zhao, Y Q; Doyle, R J; Rackard, S M; Kumar, J L G; Hu, Y S

    2011-01-01

    The objective of this study was to assess the suitability of statistical and the k-C* models to projecting treatment performance of constructed wetlands by applying the models to predict the final effluent concentrations of a pilot field-scale constructed wetlands system (CWs) treating animal farm wastewater. The CWs achieved removal rates (in g/m(2).d) ranging from 7.1-149.8 for BOD(5), 49.8-253.8 for COD and 7.1-47.0 for NH(4)-N. Generally, it was found that the statistical models developed from multiple regression analyses (MRA) were stronger in predicting final effluent concentrations than the k-C* model. However, both models were inadequate in predicting the final effluent concentrations of NO(3)-N. The first-order area-based removal rate constants (k, m/yr) determined from the experimental data were 200.5 for BOD(5), 80.1 for TP and 173.8 for NH(4)-N and these indicate a high rate of pollutant removal within the CWs.

  3. Rural Sewage Treatment by using Combined Process of Multi-layer Bio-filter and Constructed Wetland

    NASA Astrophysics Data System (ADS)

    Li, Xudong; Paul, Etienne; Qiu, Jiangping; Roustan, Michel; Wisniewski, Christelle; Mauviot, Patrice

    2010-11-01

    A combined process of multi-layer bio-filter and constructed wetland has been used to treat the rural sewage in eastern China. The capacity of the system was 60 m3/d, the hydraulic loading rate (HLR) of the bio-filter and the constructed wetland was 4.0 m3/(m3ṡd) and 0.50 m3/(m3ṡd), respectively. The system has been operated automatically for 2 years. The results showed that the average concentrations of COD, NH4+-N, TN and TP in the effluent were 58.2, 8.1, 12.1 and 0.9 mg/L with the removal efficiency of 79.2%, 62.8%, 55.1% and 77.1% respectively, which could meet the first grade of Chinese national pollutants discharge standard for municipal wastewater treatment plant (GB 18918-2002). The track studies showed that the organic pollutants were mainly removed in the first 4 layers and the ammonia was mainly removed in the 4th˜6th layers of the filter. It was observed that the COD removal efficiency in the whole system decreased from 84.6% to 73.3% following the sequences of summer, autumn, spring and winter. Comparing with traditional techniques, the combined process could provide a higher nitrogen and phosphorus removal capacity.

  4. The role of sand, marble chips and Typha latifolia in domestic wastewater treatment - a column study on constructed wetlands.

    PubMed

    Kadaverugu, Rakesh; Shingare, Rita P; Raghunathan, Karthik; Juwarkar, Asha A; Thawale, Prashant R; Singh, Sanjeev K

    2016-10-01

    The relative importance of sand, marble chips and wetland plant Typha latifolia is evaluated in constructed wetlands (CWs) for the treatment of domestic wastewater intended for reuse in agriculture. The prototype CWs for the experiments are realized in polyvinyl chloride columns, which are grouped into four treatments, viz. sand (<2 mm) + Typha latifolia (cattail), sand, marble chips (5-20 mm) + cattail and marble chips. The removal percentage of organic and nutritional pollutants from the wastewater is measured at varying hydraulic retention time in the columns. The statistical analysis suggests that the main effects of sand and cattail are found to be significant (p < .05) for the removal of biological oxygen demand and chemical oxygen demand from the wastewater. The presence of cattail significantly (p < .01) contributes to the conversion of total nitrogen in wastewater into [Formula: see text] by fostering the growth of favorable microbes for the nitrification. The removal of [Formula: see text] and turbidity from the wastewater is significantly (p < .01) influenced by sand than the presence of cattail. The maximum [Formula: see text] adsorption capacity of the sand is estimated to be 2.5 mg/g. Marble chips have significantly (p < .01) influenced the removal of [Formula: see text]and its maximum removal capacity is estimated to be 9.3 mg/g. The negative correlation between the filter media biofilm and column hydraulic conductivity is also reported for all the treatments. Thus, the findings of this study elucidate the role of low-cost and easily available filter media and it will guide the environmental practitioners in designing cost-effective CWs for wastewater treatment.

  5. Mass Balance of Fipronil and Total Toxicity of Fipronil-Related Compounds in Process Streams during Conventional Wastewater and Wetland Treatment

    PubMed Central

    2015-01-01

    Attenuation of the pesticide fipronil and its major degradates was determined during conventional wastewater treatment and wetland treatment. Analysis of flow-weighted composite samples by liquid and gas chromatography–tandem mass spectrometry showed fipronil occurrence at 12–31 ng/L in raw sewage, primary effluent, secondary effluent, chlorinated effluent, and wetland effluent. Mean daily loads of total fipronil related compounds in raw sewage and in plant effluent after chlorination were statistically indistinguishable (p = 0.29; n = 10), whereas fipronil itself was partially removed (25 ± 3%; p = 0.00025; n = 10); the associated loss in toxicity was balanced by the formation of toxic fipronil degradates, showing conventional treatment to be unfit for reducing overall toxicity. In contrast to these findings at the municipal wastewater treatment, both parental fipronil and the sum of fipronil-related compounds were removed in the wetland with efficiencies of 44 ± 4% and 47 ± 13%, respectively. Total fipronil concentrations in plant effluent (28 ± 6 ng/L as fipronil) were within an order of magnitude of half-maximal effective concentrations (EC50) of nontarget invertebrates. This is the first systematic assessment of the fate of fipronil and its major degradates during full-scale conventional wastewater and constructed wetland treatment. PMID:26710933

  6. Wetlands: Tidal

    USGS Publications Warehouse

    Conner, William H.; Krauss, Ken W.; Baldwin, Andrew H.; Hutchinson, Stephen

    2014-01-01

    Tidal wetlands are some of the most dynamic areas of the Earth and are found at the interface between the land and sea. Salinity, regular tidal flooding, and infrequent catastrophic flooding due to storm events result in complex interactions among biotic and abiotic factors. The complexity of these interactions, along with the uncertainty of where one draws the line between tidal and nontidal, makes characterizing tidal wetlands a difficult task. The three primary types of tidal wetlands are tidal marshes, mangroves, and freshwater forested wetlands. Tidal marshes are dominated by herbaceous plants and are generally found at middle to high latitudes of both hemispheres. Mangrove forests dominate tropical coastlines around the world while tidal freshwater forests are global in distribution. All three wetland types are highly productive ecosystems, supporting abundant and diverse faunal communities. Unfortunately, these wetlands are subject to alteration and loss from both natural and anthropogenic causes.

  7. Subsurface constructed wetlands for wastewater treatment and reuse in agriculture: five years of experiences in Sicily, Italy.

    PubMed

    Cirelli, G L; Consoli, S; Di Grande, V; Milani, M; Toscano, A

    2007-01-01

    The paper reports the results of an investigation on a H-SSF constructed wetland for tertiary treatment in a small community located in eastern Sicily, Italy. The system is designed to reuse wastewater for the irrigation of olive orchards covering about 150 hectares. From March 2001 to September 2005, wastewater samples were collected and the following chemical-physical parameters were determined according to Standard Methods: temperature, pH, EC, DO, TSS (105degrees C), BOD5, COD, TN, TP. The following microbiological parameters were also evaluated: total coliforms, faecal coliforms, Escherichia coli, faecal streptococci, Salmonella, helminth eggs. Mean removal efficiencies ranged from 77 to 92% (TSS), 37 to 72% (BOD5), 51 to 79% (COD), 97 to 99.5% (E. coli). Removal efficiency of Salmonella and helminth eggs was always 100% in all samples; however, only 150% of total samples matched the limit of E. coli (< 50 CFU/100 mL) fixed by Italian legislation for wastewater reuse.

  8. Nitrogen removal in Myriophyllum aquaticum wetland microcosms for swine wastewater treatment: 15 N-labelled nitrogen mass balance analysis.

    PubMed

    Zhang, Shunan; Liu, Feng; Xiao, Runlin; He, Yang; Wu, Jinshui

    2017-01-01

    Ecological treatments are effective for treating agricultural wastewater. In this study, wetland microcosms vegetated with Myriophyllum aquaticum were designed for nitrogen (N) removal from two strengths of swine wastewater, and 15 N-labelled ammonium (NH 4 + -N) was added to evaluate the dominant NH 4 + -N removal pathway. The results showed that 98.8% of NH 4 + -N and 88.3% of TN (TN: 248.6 mg L -1 ) were removed from low-strength swine wastewater (SW1) after an incubation of 21 days, with corresponding values for high-strength swine wastewater (SW2) being 99.2% of NH 4 + -N and 87.8% of TN (TN: 494.9 mg L -1 ). Plant uptake and soil adsorption respectively accounted for 24.0% and 15.6% of the added 15 N. Meanwhile, above-ground tissues of M. aquaticum had significantly higher biomass and TN content than below-ground (P < 0.05). 15 N mass balance analysis indicated that gas losses contributed 52.0% to the added 15 N, but the N 2 O flux constituted only 7.5% of total gas losses. The dynamics of NO 3 - -N and N 2 O flux revealed that strong nitrification and denitrification occurred in M. aquaticum microcosms, which was a dominant N removal pathway. These findings demonstrated that M. aquaticum could feasibly be used to construct wetlands for high N-loaded animal wastewater treatment. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  9. Influence of wetland type, hydrology, and wetland destruction on aquatic communities within wetland reservoir subirrigation systems in northwestern Ohio

    USDA-ARS?s Scientific Manuscript database

    Establishment of an agricultural water recycling system known as the wetland reservoir subirrigation system (WRSIS) results in the creation of two different types of wetlands adjacent to agricultural fields. Each WRSIS consists of one treatment wetland designed to process agricultural contaminants (...

  10. Wetland Hydrology

    EPA Science Inventory

    This chapter discusses the state of the science in wetland hydrology by touching upon the major hydraulic and hydrologic processes in these complex ecosystems, their measurement/estimation techniques, and modeling methods. It starts with the definition of wetlands, their benefit...

  11. Freshwater Wetlands.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Provides descriptions about freshwater wetlands, such as marshes, swamps, and bogs. Contains three learning activities which deal with unusual wetland plants, the animals and plants in a typical marsh, and the effects of a draught on a swamp. Included are reproducible handouts and worksheets for two of the activities. (TW)

  12. Effects of aeration and natural zeolite on ammonium removal during the treatment of sewage by mesocosm-scale constructed wetlands.

    PubMed

    Araya, F; Vera, I; Sáez, K; Vidal, G

    2016-01-01

    The objective was to evaluate the effects of intermittent artificial aeration cycles and natural zeolite as a support medium, in addition to the contribution of plants (Schoenoplectus californicus) on NH4(+)-N removal during sewage treatment by Constructed Wetlands (CW). Two lines of Mesocosm Constructed Wetland (MCW) were installed: (a) gravel line (i.e. G-Line) and (b) zeolite line (i.e. Z-Line). Aeration increased the NH4(+)-N removal efficiency by 20-45% in the G-Line. Natural zeolite increased the NH4(+)-N removal efficiency by up to 60% in the Z-Line. Plants contributed 15-30% of the NH4(+)-N removal efficiency and no difference between the G-Line and the Z-Line. Conversely, the NH4(+)-N removal rate was shown to only increase with the use of natural zeolite. However, the MCW with natural zeolite, the NH4(+)-N removal rate showed a direct relationship only with the NH4(+)-N influent concentration. Additionally, relationship between the oxygen, energy and area regarding the NH4(+)-N removal efficiency was established for 2.5-12.5 gO2/(kWh-m(2)) in the G-Line and 0.1-2.6 gO2/(kWh-m(2)) in the Z-Line. Finally, it was established that a combination of natural zeolite as a support medium and the aeration strategy in a single CW could regenerate the zeolite's adsorption sites and maintain a given NH4(+)-N removal efficiency over time.

  13. Marsh-pond-marsh wetland treatment of nitrogen and phosphorus in swine anaerobic lagoon wastewater: A case study

    USDA-ARS?s Scientific Manuscript database

    Constructed wetlands have been used to treat animal waste and are able to remove considerable amount of nitrogen (N), phosphorus (P), chemical oxygen demand (COD), biological oxygen demand (BOD), and solids. The removal mechanisms of N in constructed wetlands are sedimentation, adsorption, plant and...

  14. Microbial diversity of bacteria, archaea, and fungi communities in a continuous flow constructed wetland for the treatment of swine waste

    USDA-ARS?s Scientific Manuscript database

    Contaminant removal in constructed wetlands may largely be a function of many microbial processes. However, information about bacterial, archaea, and fungi communities in constructed wetlands for the removal of swine waste is limited. In this study, we used 454/GS-FLX pyrosequencing to assess bacter...

  15. Treatment of anaerobic digested effluent in biochar-packed vertical flow constructed wetland columns: Role of media and tidal operation.

    PubMed

    Kizito, Simon; Lv, Tao; Wu, Shubiao; Ajmal, Zeeshan; Luo, Hongzhen; Dong, Renjie

    2017-08-15

    Three types of vertical flow constructed wetland columns (VFCWs), packed with corn cob biochar (CB-CW), wood biochar (WB-CW) and gravel (G-CW) under tidal flow operations, were comparatively evaluated to investigate anaerobic digested effluent treatment performance and mechanisms. It was demonstrated that CB-CW and WB-CW provide significantly higher removal efficiencies for organic matter (>59%), NH 4 + -N (>76%), TN (>37%) and phosphorus (>71%), compared with G-CW (22%-49%). The higher pollutants removal ability of biochar-packed VFCWs was mainly attribute to the higher adsorption ability and microbial cultivation in the porous biochar media. Moreover, increasing the flooded/drained ratio from 4/8h to 8/4h of the tidal operation further improved around 10% of the removal of both organics and NH 4 + -N for biochar-packed VFCWs. The phosphorus removal was dependent on the media adsorption capacities through the whole experiment. However, the NH 4 + -N biodegradation by microbial communities was demonstrated to become the dominant removal mechanism in the long term treatment, which compensated the decreased adsorption capacities of the media. The study supported that the use of biochar would increase the treatment performance and elongate the lifespan of CWs under tidal operation. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Constructed wetlands and solar-driven disinfection technologies for sustainable wastewater treatment and reclamation in rural India: SWINGS project.

    PubMed

    Álvarez, J A; Ávila, C; Otter, P; Kilian, R; Istenič, D; Rolletschek, M; Molle, P; Khalil, N; Ameršek, I; Mishra, V K; Jorgensen, C; Garfi, A; Carvalho, P; Brix, H; Arias, C A

    2017-09-01

    SWINGS was a cooperation project between the European Union and India, aiming at implementing state of the art low-cost technologies for the treatment and reuse of domestic wastewater in rural areas of India. The largest wastewater treatment plant consists of a high-rate anaerobic system, followed by vertical and horizontal subsurface flow constructed wetlands with a treatment area of around 1,900 m 2 and a final step consisting of solar-driven anodic oxidation (AO) and ultraviolet (UV) disinfection units allowing direct reuse of the treated water. The implementation and operation of two pilot plants in north (Aligarh Muslim University, AMU) and central India (Indira Gandhi National Tribal University, IGNTU) are shown in this study. The overall performance of AMU pilot plant during the first 7 months of operation showed organic matter removal efficiencies of 87% total suspended solids, 95% 5-day biological oxygen demand (BOD 5 ) and 90% chemical oxygen demand, while Kjeldahl nitrogen removal reached 89%. The UV disinfection unit produces water for irrigation and toilet flushing with pathogenic indicator bacteria well below WHO guidelines. On the other hand, the AO disinfection unit implemented at IGNTU and operated for almost a year has been shown to produce an effluent of sufficient quality to be reused by the local population for agriculture and irrigation.

  17. Test study of the optimal design for hydraulic performance and treatment performance of free water surface flow constructed wetland.

    PubMed

    Guo, Changqiang; Cui, Yuanlai; Dong, Bin; Luo, Yufeng; Liu, Fangping; Zhao, Shujun; Wu, Huirong

    2017-08-01

    Orthogonal tests with mixed levels of design parameters of a free water surface flow constructed wetland were performed to assess their effect on hydraulic and treatment performance, and discover the relationship between the design parameters and the two performances. The results showed that water depth, plant spacing, and layout of in- and outlet mainly affected the two performances. Under 40cm depth, central pass of in- and outlet, 1.8m 3 /h flow rate, 20cm plant spacing, 2:1 aspect ratio, and Scripus tabernaemontani as the plant species, treatment performance of 5.3% TN, 6.1% TP and 15.6% TSS removal efficiencies and a high hydraulic performance of 0.854e, 0.602MI were achieved. There was no significant correlation between the design parameters and the two performances. The relationship among various hydraulic indicators and that among the purification indicators displayed extremely significant correlation. However, there was no significant correlation between hydraulic and treatment performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Hydrolytic anaerobic reactor and aerated constructed wetland systems for municipal wastewater treatment - HIGHWET project.

    PubMed

    Pascual, A; de la Varga, D; Arias, C A; Van Oirschot, D; Kilian, R; Álvarez, J A; Soto, M

    2017-01-01

    The HIGHWET project combines the hydrolytic up-flow sludge bed (HUSB) anaerobic digester and constructed wetlands (CWs) with forced aeration for decreasing the footprint and improving effluent quality. The HIGHWET plant in A Coruña (NW of Spain) treating municipal wastewater consists of a HUSB and four parallel subsurface horizontal flow (HF) CWs. HF1, HF2 and HF3 units are fitted with forced aeration, while the control HF4 is not aerated. All the HF units are provided with effluent recirculation, but different heights of gravel bed (0.8 m in HF1 and HF2, and 0.5 m in HF3 and HF4) are implemented. Besides, a tobermorite-enriched material was added in the HF2 unit in order to improve phosphorus removal. The HUSB 76-89% of total suspended solids (TSS) and about 40% of chemical oxygen demand (COD) and biological oxygen demand (BOD). Aerated HF units reached above 96% of TSS, COD and BOD at a surface loading rate of 29-47 g BOD 5 /m 2 ·d. An aeration regime ranging from 5 h on/3 h off to 3 h on/5 h off was found to be adequate to optimize nitrogen removal, which ranged from 53% to 81%. Average removal rates of 3.4 ± 0.4 g total nitrogen (TN)/m 2 ·d and 12.8 ± 3.7 g TN/m 3 ·d were found in the aerated units, being 5.5 and 4.1 times higher than those of the non-aerated system. The tobermorite-enriched HF2 unit showed a distinct higher phosphate (60-67%) and total phosphorus (54%) removal.

  19. Performance evaluation of hybrid treatment wetland for six years of operation in cold climate.

    PubMed

    Harada, June; Inoue, Takashi; Kato, Kunihiko; Uraie, Nana; Sakuragi, Hiroaki

    2015-09-01

    In Hokkaido, northern Japan, there are 12 hybrid subsurface constructed wetlands (HSCWs) and most of them are treating high concentrated organic wastewater. One of these systems is an HSCW situated in Embetsu, northern Hokkaido, and it has been in operation since November of 2006 to treat dairy milking parlor wastewater. The system is composed of two vertical flow beds and a horizontal flow bed. The influent and the effluent flow rates and pollutant concentrations and loads were extremely variable. Throughout its 6 years of operation, most of the pollutant removals were decently high. Removal efficiencies for COD, BOD5, and SS were ranging in the 90 %. Removal efficiencies for TN, NH4-N, and BOD5 were improving because of the development of the soil ecosystem and the Phragmites australis community. However, the removal efficiencies of TP were decreasing, presumably because of the declining adsorption ability. The accumulation of TP in the first and the second vertical beds had reached its plateau. Vertical beds had high removal efficiencies for TN, COD, BOD5, and SS. These high removal efficiencies of the first vertical bed may be caused from the efficient removal of solid material that is deposited as an organic layer of the first vertical bed. High NH4-N removal efficiencies exerted by the second vertical bed may be due to the recycling of wastewater. In conclusion, the HSCW was working excellently for its 6 years of operation, and it could be concluded that it has not reached its life yet.

  20. Synergistic effect of up-flow constructed wetland and microbial fuel cell for simultaneous wastewater treatment and energy recovery.

    PubMed

    Oon, Yoong-Ling; Ong, Soon-An; Ho, Li-Ngee; Wong, Yee-Shian; Dahalan, Farrah Aini; Oon, Yoong-Sin; Lehl, Harvinder Kaur; Thung, Wei-Eng

    2016-03-01

    This study demonstrated a successful operation of up-flow constructed wetland-microbial fuel cell (UFCW-MFC) in wastewater treatment and energy recovery. The goals of this study were to investigate the effect of circuit connection, organic loading rates, and electrode spacing on the performance of wastewater treatment and bioelectricity generation. The average influent of COD, NO3(-) and NH4(+) were 624 mg/L, 142 mg/L, 40 mg/L, respectively and their removal efficiencies (1 day HRT) were 99%, 46%, and 96%, respectively. NO3(-) removal was relatively higher in the closed circuit system due to lower dissolved oxygen in the system. Despite larger electrode spacing, the voltage outputs from Anode 2 (A2) (30 cm) and Anode 3 (A3) (45 cm) were higher than from Anode 1 (A1) (15 cm) as a result of insufficient fuel supply to A1. The maximum power density and Coulombic efficiency were obtained at A2, which were 93 mW/m(3) and 1.42%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Effects of simulated oilfield produced water on early seedling growth after treatment in a pilot-scale constructed wetland system.

    PubMed

    Pardue, Michael J; Castle, James W; Rodgers, John H; Huddleston, George M

    2015-01-01

    Seed germination and early seedling growth bioassays were used to evaluate phytotoxicity of simulated oilfield produced water (OPW) before and after treatment in a subsurface-flow, pilot-scale constructed wetland treatment system (CWTS). Responses to untreated and treated OPW were compared among seven plant species, including three monocotyledons: corn (Zea mays), millet (Panicum miliaceum), and sorghum (Sorghum bicolor); and four dicotyledons: lettuce (Lactuca sativa), okra (Abelmoschus esculents), watermelon (Citrullus lanatus), and soybean (Glycine max). Phytotoxicity was greater in untreated OPW than in treated OPW. Exposures to untreated and treated OPW enhanced growth in some plant species (sorghum, millet, okra, and corn) relative to a negative control and reduced growth in other plant species (lettuce, soybean, and watermelon). Early seedling growth parameters indicated that dicotyledons were more sensitive to test waters compared to monocotyledons, suggesting that morphological differences between plant species affected phytotoxicity. Results indicated the following sensitivity scale for plant species: lettuce>soybean>watermelon>corn>okra≈millet>sorghum. Phytotoxicity of the treated OPW to lettuce and soybean, although concentrations of COCs were less than irrigation guideline concentrations, suggests that chemical characterization and comparison to guideline concentrations alone may not be sufficient to evaluate water for use in growing crops.

  2. What Makes a Wetland a Wetland?

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Provides descriptions of and activities about various kinds of wetlands. Contains seven learning activities ranging from creating wetland scenes with picture cutouts to actually exploring a wetland. Includes reproducible handouts and worksheets for several of the activities. (TW)

  3. A comparative study of Cyperus papyrus and Miscanthidium violaceum-based constructed wetlands for wastewater treatment in a tropical climate.

    PubMed

    Kyambadde, Joseph; Kansiime, Frank; Gumaelius, Lena; Dalhammar, Gunnel

    2004-01-01

    The treatment efficiencies of constructed wetlands containing Cyperus papyrus L. (papyrus) and Miscanthidium violaceum (K. Schum.) Robyns (synonymous with Miscanthus violaceum (K. Schum) Pilg.) were investigated in a tropical climate (Kampala, Uganda). Papyrus showed higher ammonium-nitrogen and total reactive phosphorus (TRP) removal (75.3% and 83.2%) than Miscanthidium (61.5% and 48.4%) and unplanted controls (27.9% ammonium-nitrogen). No TRP removal was detected in control effluent. Nutrients (N and P) were significantly higher (p<0.015) in papyrus than Miscanthidium plant tissues. Plant uptake and storage was the major factor responsible for N and P removal in treatment line 2 (papyrus) where it contributed 69.5% N and 88.8% P of the total N and P removed. It however accounted for only 15.8% N and 30.7% P of the total N and P removed by treatment line 3 (Miscanthidium violaceum). In addition, papyrus exhibited a significantly larger (p=0.000) number of adventitious roots than Miscanthidium. Nitrifying bacteria attached to papyrus (2.15 x 10(6)+/-1.53 x 10(5) MPN/g DW) and Miscanthidium roots (1.30 x 10(4)+/-8.83 x 10(2) MPN/g DW) and the corresponding nitrification activities were consistent with this finding. Epiphytic nitrifiers appeared more important for total nitrification than those in peat or suspended in water. Papyrus root structures provided more microbial attachment sites, sufficient wastewater residence time, trapping and settlement of suspended particles, surface area for pollutant adsorption, uptake, assimilation in plant tissues and oxygen for organic and inorganic matter oxidation in the rhizosphere, accounting for its high treatment efficiency.

  4. Comparison of simple, small, full-scale sewage treatment systems in Brazil: UASB-maturation ponds-coarse filter; UASB-horizontal subsurface-flow wetland; vertical-flow wetland (first stage of French system).

    PubMed

    von Sperling, M

    2015-01-01

    This paper presents a comparison between three simple sewage treatment lines involving natural processes: (a) upflow anaerobic sludge blanket (UASB) reactor-three maturation ponds in series-coarse rock filter; (b) UASB reactor-horizontal subsurface-flow constructed wetland; and (c) vertical-flow constructed wetlands treating raw sewage (first stage of the French system). The evaluation was based on several years of practical experience with three small full-scale plants receiving the same influent wastewater (population equivalents of 220, 60 and 100 inhabitants) in the city of Belo Horizonte, Brazil. The comparison included interpretation of concentrations and removal efficiencies based on monitoring data (organic matter, solids, nitrogen, phosphorus, coliforms and helminth eggs), together with an evaluation of practical aspects, such as land and volume requirements, sludge production and handling, plant management, clogging and others. Based on an integrated evaluation of all aspects involved, it is worth emphasizing that each system has its own specificities, and no generalization can be made on the best option. The overall conclusion is that the three lines are suitable for sewage treatment in small communities in warm-climate regions.

  5. A preliminary study to design a floating treatment wetland for remediating acid mine drainage-impacted water using vetiver grass (Chrysopogon zizanioides).

    PubMed

    Kiiskila, Jeffrey D; Sarkar, Dibyendu; Feuerstein, Kailey A; Datta, Rupali

    2017-12-01

    Acid mine drainage (AMD) is extremely acidic, sulfate-rich effluent from abandoned or active mine sites that also contain elevated levels of heavy metals. Untreated AMD can contaminate surface and groundwater and pose severe ecological risk. Both active and passive methods have been developed for AMD treatment consisting of abiotic and biological techniques. Abiotic techniques are expensive and can create large amounts of secondary wastes. Passive biological treatment mainly consists of aerobic or anaerobic constructed wetlands. While aerobic wetlands are economical, they are not effective if the pH of the AMD is < 5. Anaerobic wetlands use organic-rich substrates to provide carbon source to iron- and sulfate-reducing bacteria. The efficiency of these systems declines overtime and requires continuous maintenance. Our objective is to develop an alternative, low-cost, and sustainable floating wetland treatment (FWT) system for AMD for the abandoned Tab-Simco coal mining site in Illinois using vetiver grass (Chrysopogon zizanioides). Tab-Simco AMD is highly acidic, with mean pH value of 2.64, and contains high levels of sulfate and metals. A greenhouse study was performed for a 30-day period in order to screen and optimize the necessary parameters to design a FWT system. Water quality and plant growth parameters were continuously monitored. Results show significant SO 4 2- removal, resulting in increased pH, particularly at higher planting densities. Vetiver also helped in metal removal; high amounts of Fe, Zn, and Cu were removed, with relatively lower amounts of Pb, Al, and Ni. Iron plaque formation on the root was observed, which increased metal stabilization in root and lowered root to shoot metal translocation. Vetiver was tolerant of AMD, showing minimal change in biomass and plant growth. Results obtained are encouraging, and a large scale mesocosm study is now in progress, as the next step to develop the vetiver-based system for AMD treatment.

  6. Potential for CSO treatment with horizontal flow constructed wetlands: influence of hydraulic load, plant presence and loading frequency.

    PubMed

    Pisoeiro, J; Galvão, A; Ferreira, F; Matos, J

    2016-10-01

    This study aimed at analysing the performance of horizontal subsurface flow constructed wetlands (CWs) to treat combined sewer overflow (CSO). Four horizontal subsurface flow CWs, organized in two groups (A and B) each with a planted (Phragmites australis) and a non-planted bed, were loaded with simulated CSO, with group B receiving twice the hydraulic load of group A. Beds were monitored for pH, dissolved oxygen, conductivity, redox potential, chemical oxygen demand (COD), total suspended solids (TSS) and enterococci. Porosity variations were also estimated. Monitoring was conducted during spring and wintertime, with regular and irregular loading frequencies. Results showed an average treatment efficiency of 90-100 % for TSS, 60-90 % for COD and 2-6 log for enterococci. Removal rates were especially relevant in the first 24 h for COD and TSS. TSS and enterococci removal did not exhibit the influence of macrophytes or the applied hydraulic load while COD's removal efficiency was lower in the higher load group and in planted beds.

  7. Complex interactions among nutrients, chlorophyll-a, and microcystins in three stormwater wet detention basins with floating treatment wetlands.

    PubMed

    Hartshorn, Nicholas; Marimon, Zachary; Xuan, Zhemin; Cormier, Jessica; Chang, Ni-Bin; Wanielista, Martin

    2016-02-01

    Stormwater wet detention ponds hold a permanent pool of water and offer many beneficial uses including flood mitigation, pollution prevention, downstream erosion control, increased aesthetics, and recreational uses. Although the removal of nutrients is generally low for stormwater wet detention ponds in urban areas, floating treatment wetlands (FTWs) can be installed to offer an innovative solution toward naturally removing excess nutrients and aiding in stormwater management. To improve the stormwater reuse potential, this study assessed nutrient, microcystin, and chlorophyll-a interactions in three Florida stormwater wet detention ponds with recently implemented FTWs. Both episodic (storm events) and routine (non-storm events) sampling campaigns were carried out at the three ponds located in Ruskin, Gainesville, and Orlando. The results showed a salient negative correlation between total phosphorus and microcystin concentrations for both storm and non-storm events across all three ponds. The dominant nutrient species in correlation seemed to be total phosphorus, which correlated positively with chlorophyll-a concentrations at all ponds and sampling conditions, with the exception of Orlando non-storm events. These results showed a correlation conditional to the candidate pond and sampling conditions for microcystin and chlorophyll-a concentrations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Treatment of a mixed wood preservative leachate by a hybrid constructed wetland and a willow planted filter.

    PubMed

    Lévesque, S; Demers, E; Brisson, J; Comeau, Y

    2017-07-01

    The performance and removal mechanisms of a hybrid constructed wetland (HCW) followed by a willow planted filter (WPF) were evaluated for the treatment of a leachate contaminated by wood pole preservatives (pentachlorophenol (PCP) and chromated copper arsenate) to reach the storm sewer discharge limits. The HCW aimed to dechlorinate the PCP and polychlorodibenzo-p-dioxins/polychlorodibenzofuran (PCDD/F) and to remove metals by adsorption and precipitation. The HCW was efficient in removing PCP (>98.6%), oil, arsenic (99.4%), chromium (>99.2%), copper (>99.6%%) and iron (29%) to under their discharge limits, but it was unable to reach those of Mn and PCDD/F, with residual concentrations of 0.11 mg Mn/L and 0.32 pg TEQ/L. Iron and manganese could be removed but were subsequently released by the HCW due to low redox conditions. No dechlorination of PCDD/F was observed since its chlorination profile remained the same in the different sections of the HCW. Adsorption was the most probable removal mechanism of PCDD/F. The WPF was able to remove some residual contamination, but it released Mn at a gradually decreasing rate. Total evapotranspiration of the leachate by a larger fertilized WPF and the construction of an underground retention basin are proposed to prevent any discharge of PCDD/F traces in the environment.

  9. Treatment of high organic content wastewater from food-processing industry with the French vertical flow constructed wetland system.

    PubMed

    Paing, J; Serdobbel, V; Welschbillig, M; Calvez, M; Gagnon, V; Chazarenc, F

    2015-01-01

    This study aimed at determining the treatment performances of a full-scale vertical flow constructed wetlands designed to treat wastewater from a food-processing industry (cookie factory), and to study the influence of the organic loading rate. The full-scale treatment plant was designed with a first vertical stage of 630 m², a second vertical stage of 473 m² equipped with a recirculation system and followed by a final horizontal stage of 440 m². The plant was commissioned in 2011, and was operated at different loading rates during 16 months for the purpose of this study. Treatment performances were determined by 24 hour composite samples. The mean concentration of the raw effluent was 8,548 mg.L(-1) chemical oxygen demand (COD), 4,334 mg.L(-1) biochemical oxygen demand (BOD5), and 2,069 mg.L(-1) suspended solids (SS). Despite low nutrients content with a BOD5/N/P ratio of 100/1.8/0.5, lower than optimum for biological degradation (known as 100/5/1), mean removal performances were very high with 98% for COD, 99% for BOD5 and SS for the two vertical stages. The increasing of the organic load from 50 g.m(-2).d(-1) COD to 237 g.m(-2).d(-1) COD (on the first stage) did not affect removal performances. The mean quality of effluent reached French standards (COD < 125 mg.L(-1), BOD5 < 25 mg.L(-1), SS < 35 mg.L(-1)).

  10. Autochthonous and Allochthonous Carbon Cycling in a Eutrophic Flow-Through Wetland

    EPA Science Inventory

    Wetland environments are important sites for the cycling and retention of terrestrially derived organic matter and nutrients, the influx of which subsidizes wetland C sequestration, as well as fueling autochthonous C productivity. Wetland treatment of agricultural runoff has been...

  11. Removal of Selected Endocrine Disrupting Chemicals During On-Site Wastewater Treatment Using A Constructed Wetland

    EPA Science Inventory

    Significant research has shown that domestic and industrial wastewater can be a source of endocrine disrupting chemicals (EDCs) to the environment. Much of this research has focused on municipal and industrial centralized wastewater treatment plants. These plants have been show...

  12. Wetlands ecology

    NASA Technical Reports Server (NTRS)

    Anderson, R. R. (Principal Investigator); Carter, V. L.; Mcginness, J. W., Jr.

    1972-01-01

    The author has identified the following significant results. The ERTS imagery analyzed provides approximately 2/3 coverage of the test site. Analysis was made using visual methods, density slicing, and multispectral analysis. Preliminary conclusions reached are that most, if not all, of the investigation objectives can be met. Saline and near-saline wetlands can be delineated from ERTS-1 images as the wetland-upland boundaries and land-water interface are clearly defined. Major plant species or communities such as Spartina alterniflora (high and low vigor forms), Spartina patens/Distichlis spicata, and Juncus roemarianus can be discriminated and spoil disposal areas identified.

  13. Greenhouse wastewater treatment by baffled subsurface-flow constructed wetlands supplemented with flower straws as carbon source in different modes.

    PubMed

    Chang, Junjun; Ma, Luyao; Chen, Jinquan; Lu, Yifeng; Wang, Xiaoyun

    2017-01-01

    Four laboratory-scale baffled subsurface-flow constructed wetlands (BSCWs) were established for the treatment of greenhouse wastewater containing high levels of nitrate and sulfate in the present study. Each BSCW microcosm involved a treatment zone and another post-treatment zone with a surface area ratio of 2:1. Evenly mixed straws of carnation and rose (w/w: 1/1), two common ornamental flowers, were supplemented as an organic carbon source into the treatment zone through a hydrolysis zone (CW 1), decentralized vertically installed perforated pipes (CW 2), and centralized pipes (CW 3 in the figures), except the blank system. Removals and transformations of nitrogen and sulfate as well as carbon release in the BSCWs were investigated and comparatively assessed. Results showed that the supplements of flower straws could greatly enhance both the nitrate and sulfate removals, and good performance was achieved during the beginning operation period of 30 days, followed by decline due to insufficient organic carbon supply. Nitrate removal efficiency was significantly higher and more stable compared to sulfate. The highest removal rates of nitrate and sulfate were achieved in the CW 3, with a mean value of 4.33 g NO 3 - -N·m -2  d -1 and 2.74 g SO 4 2- -S·m -2  d -1 , respectively, although the differences among the experimental microcosms were not statistically significant. However, almost the same TN removal rate (3.40-3.47 g N·m -2  d -1 ) was obtained due to the productions of NO 2 - -N and NH 4 + -N and leaching of organic N from the straws. High contents of organic carbon and colored substance were leached from the straws during the initial 10 days, but dropped rapidly to low levels, and could hardly determined after 30 days operation. The post-treatment zone could further eliminate various contaminants, but the capability was limited. Inorganic carbon (IC) concentration was detected to be a highly good indicator for the estimation of nitrate and

  14. Removal Of Endocrine Disrupting Chemicals By A Constructed Wetland For On-Site Domestic Wastewater Treatment

    EPA Science Inventory

    Research has shown that domestic and industrial wastewater can be a source of endocrine disrupting chemicals (EDCs) to the environment. Much of this research has focused on municipal and industrial centralized wastewater treatment plants (WWTPs). These WWTPs have been shown to ...

  15. Large-scale multi-stage constructed wetlands for secondary effluents treatment in northern China: Carbon dynamics.

    PubMed

    Wu, Haiming; Fan, Jinlin; Zhang, Jian; Ngo, Huu Hao; Guo, Wenshan

    2018-02-01

    Multi-stage constructed wetlands (CWs) have been proved to be a cost-effective alternative in the treatment of various wastewaters for improving the treatment performance as compared with the conventional single-stage CWs. However, few long-term full-scale multi-stage CWs have been performed and evaluated for polishing effluents from domestic wastewater treatment plants (WWTP). This study investigated the seasonal and spatial dynamics of carbon and the effects of the key factors (input loading and temperature) in the large-scale seven-stage Wu River CW polishing domestic WWTP effluents in northern China. The results indicated a significant improvement in water quality. Significant seasonal and spatial variations of organics removal were observed in the Wu River CW with a higher COD removal efficiency of 64-66% in summer and fall. Obvious seasonal and spatial variations of CH 4 and CO 2 emissions were also found with the average CH 4 and CO 2 emission rates of 3.78-35.54 mg m -2 d -1 and 610.78-8992.71 mg m -2 d -1 , respectively, while the higher CH 4 and CO 2 emission flux was obtained in spring and summer. Seasonal air temperatures and inflow COD loading rates significantly affected organics removal and CH 4 emission, but they appeared to have a weak influence on CO 2 emission. Overall, this study suggested that large-scale Wu River CW might be a potential source of GHG, but considering the sustainability of the multi-stage CW, the inflow COD loading rate of 1.8-2.0 g m -2 d -1 and temperature of 15-20 °C may be the suitable condition for achieving the higher organics removal efficiency and lower greenhouse gases (GHG) emission in polishing the domestic WWTP effluent. The obtained knowledge of the carbon dynamics in large-scale Wu River CW will be helpful for understanding the carbon cycles, but also can provide useful field experience for the design, operation and management of multi-stage CW treatments. Copyright © 2017 Elsevier Ltd. All rights

  16. An Analysis of Groundwater Flow Patterns in a Constructed Treatment Wetland Cell

    DTIC Science & Technology

    2008-03-01

    contaminants is not easy to track, capture, or treat completely. Common degreasing solvents used by industry and the United States Air Force (USAF) are...Environmental Protection Agency’s (EPA) regulations. One treatment option that could save millions for the USAF and the Department of Defense (DOD) is...identified and documented with the Ohio Environmental Protection Agency and there exists no current requirement for remediation. The location and the low

  17. Wetland history.

    PubMed

    Larson, J S

    1998-06-01

    Wetlands of the American Midwest: A Historical Geography of Changing Attitudes by Hugh Prince The University of Chicago Press (University of Chicago Geography Research Papers), 1997. $21.00/£16.75 pbk (xiii+395 pages) ISBN 0 226 68283 8.

  18. Inland Wetlands.

    ERIC Educational Resources Information Center

    Area Cooperative Educational Services, New Haven, CT. Environmental Education Center.

    This material includes student guide sheets, reference materials, and tape script for the audio-tutorial unit on Inland Wetlands. A set of 35mm slides and an audio tape are used with the material. The material is designed for use with Connecticut schools, but it can be adapted to other localities. The materials emphasize characteristics of inland…

  19. Saltwater Wetlands.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Provides information about saltwater wetlands. Contains seven learning activities which deal with "making" a mud snail, plants and animals of mangroves, and the effects of tides on salt marshes. Included are reproducible handouts and worksheets for several of the activities. (TW)

  20. Zambia Wetland

    Atmospheric Science Data Center

    2013-04-16

    ... these images is the prominent roundish shape of the Lukanga Swamp, another important wetland. The images along the left are natural ... plateau of the Kafue National Park, to the west of Lukanga Swamp, appears brighter in 2004 compared with 2003, which indicates weaker ...

  1. Vertical flow-constructed wetlands for domestic wastewater treatment under tropical conditions: effect of different design and operational parameters.

    PubMed

    Bohórquez, Eliana; Paredes, Diego; Arias, Carlos Alberto

    2017-01-01

    This study assessed the treatment of domestic wastewater to find the optimum vertical flow-constructed wetland (VFCW) configuration under tropical conditions. Eight pilot-scale configurations units were studied to compare between fine sand and medium gravel used as substrate, two feeding frequencies (20 pulses d -1 and 10 pulses d -1 ), and the presence or absence of tropical plants (Heliconia psittacorum). The results showed that the sand beds were significantly more efficient in the removal of organic matter, ammonia nitrogen, and total suspended solids than gravel beds, presenting average removal rates of 48 and 24 g m -2  d -1 of COD; 35 and 16 g m -2  d -1 of BOD 5 ; 7 and 4 g m -2  d -1 of [Formula: see text]; 9 and 0 g m -2  d -1 for sand and gravel, respectively. The oxygen consumption rates were calculated and a value of 65 g m -2  d -1 was obtained for sand beds while for the gravel beds the consumption rate was 30 g m -2  d -1 . The assessment of different kinds of nitrogen showed interesting dynamics in the nitrification processes. The presence of H. psittacorum showed positive effects in the total nitrogen (TN) removal. The different loading frequencies applied did not show significant statistical differences in the removal of the tested contaminants. Preliminary results were found in the pathogen removal, where the sand is favorable as the substrate. This work represents the first step in the research of optimum VFWC design and operation parameters for Colombia as well as the use of plants of the genus Heliconia.

  2. Pollutant removal in a multi-stage municipal wastewater treatment system comprised of constructed wetlands and a maturation pond, in a temperate climate.

    PubMed

    Rivas, A; Barceló-Quintal, I; Moeller, G E

    2011-01-01

    A multi-stage municipal wastewater treatment system is proposed to comply with Mexican standards for discharge into receiving water bodies. The system is located in Santa Fe de la Laguna, Mexico, an area with a temperate climate. It was designed for 2,700 people equivalent (259.2 m3/d) and consists of a preliminary treatment, a septic tank as well as two modules operating in parallel, each consisting of a horizontal subsurface-flow wetland, a maturation pond and a vertical flow polishing wetland. After two years of operation, on-site research was performed. An efficient biochemical oxygen demand (BOD5) (94-98%), chemical oxygen demand (91-93%), total suspended solids (93-97%), total Kjeldahl nitrogen (56-88%) and fecal coliform (4-5 logs) removal was obtained. Significant phosphorus removal was not accomplished in this study (25-52%). Evapotranspiration was measured in different treatment units. This study demonstrates that during the dry season wastewater treatment by this multi-stage system cannot comply with the limits established by Mexican standards for receiving water bodies type 'C'. However, it has demonstrated the system's potential for less restrictive uses such as agricultural irrigation, recreation and provides the opportunity for wastewater treatment in rural areas without electric energy.

  3. Albuquerque's constructed wetland pilot project for wastewater polishing

    Treesearch

    Michael D. Marcus; Shannon M. House; Nathan A. Bowles; Robert T. Sekiya; J. Steven Glass

    1999-01-01

    The City of Albuquerque has funded the Constructed Wetland Pilot Project (CWPP) since 1995 at the City's Southside Water Reclamation Plant (SWRP). Results from CWPP and other wetland treatment projects indicate that appropriately designed surface-flow wetlands could increase the cost-efficiencies of wastewater treatment, as well as help the City meet present and...

  4. Constructed wetland as a low cost and sustainable solution for wastewater treatment adapted to rural settlements: the Chorfech wastewater treatment pilot plant.

    PubMed

    Ghrabi, Ahmed; Bousselmi, Latifa; Masi, Fabio; Regelsberger, Martin

    2011-01-01

    The paper presents the detailed design and some preliminary results obtained from a study regarding a wastewater treatment pilot plant (WWTPP), serving as a multistage constructed wetland (CW) located at the rural settlement of 'Chorfech 24' (Tunisia). The WWTPP implemented at Chorfech 24 is mainly designed as a demonstration of sustainable water management solutions (low-cost wastewater treatment), in order to prove the efficiency of these solutions working under real Tunisian conditions and ultimately allow the further spreading of the demonstrated techniques. The pilot activity also aims to help gain experience with the implemented techniques and to improve them when necessary to be recommended for wide application in rural settlements in Tunisia and similar situations worldwide. The selected WWTPP at Chorfech 24 (rural settlement of 50 houses counting 350 inhabitants) consists of one Imhoff tank for pre-treatment, and three stages in series: as first stage a horizontal subsurface flow CW system, as second stage a subsurface vertical flow CW system, and a third horizontal flow CW. The sludge of the Imhoff tank is treated in a sludge composting bed. The performances of the different components as well as the whole treatment system were presented based on 3 months monitoring. The results shown in this paper are related to carbon, nitrogen and phosphorus removal as well as to reduction of micro-organisms. The mean overall removal rates of the Chorfech WWTPP during the monitored period have been, respectively, equal to 97% for total suspended solids and biochemical oxygen demand (BOD5), 95% for chemical oxygen demand, 71% for total nitrogen and 82% for P-PO4. The removal of E. coli by the whole system is 2.5 log units.

  5. Application of a horizontal subsurface flow constructed wetland on treatment of dairy parlor wastewater.

    PubMed

    Mantovi, Paolo; Marmiroli, Marta; Maestri, Elena; Tagliavini, Simona; Piccinini, Sergio; Marmiroli, Nelson

    2003-06-01

    Two horizontal subsurface flow reed beds of 75 m(2) each, treating dairy parlor effluent and domestic sewage (about 6.5 m(3)/day), were set-up to determine the efficiency of this system in reducing the polluting load in an isolated mountain rural settlement.A total suspended solids value of about 0.70 g/l and chemical oxygen demand (COD) and biological oxygen demand (BOD(5)) values of about 1200 and 450 mg/l O(2), respectively, were characteristic of the influent waters. Removal of suspended solids and organic load constantly remained at levels above 90%, while those of the nutrients N and P were about 50% and 60%, respectively. The total number of coliform bacteria and Escherichia coli was reduced by more than 99%, and faecal streptococci by more than 98%. Nitrates, chlorides, sulfates, anionic and non-ionic surface-active agents and heavy metals were detected only in low concentrations. Concentration and localization of metals was also quantified in Phragmites tissues by microanalysis.Results demonstrated the use of reed beds as an appropriate treatment to reduce pollutants in wastewater from rural activities to values acceptable for discharge into surface waters.

  6. The fate and risk of selected pharmaceutical and personal care products in wastewater treatment plants and a pilot-scale multistage constructed wetland system.

    PubMed

    Zhu, Saichang; Chen, Hong

    2014-01-01

    The removal of 12 pharmaceuticals and personal care products (PPCPs) in two full-scale wastewater treatment plants (WWTPs) and a tertiary treatment system was studied. The ecological risks of effluents from both secondary and tertiary treatment systems as well as excess sludge were evaluated. Primary treatment and ultraviolet light disinfection showed limited ability to remove most selected PPCPs. The combination of an anaerobic process and triple-oxidation ditches can eliminate DEET better than the anaerobic/anoxic/oxic process. Adsorption to sludge played a key role in the removal of triclocarban. Multistage constructed wetlands as a tertiary treatment efficiently removed caffeine and ibuprofen from wastewater and could decrease the risk of partial selected PPCPs. Selected PPCPs residues in excess sludge generally produced higher risks to the ecological environment than effluents from WWTPs.

  7. Denitrification of nitrified and non-nitrified swine lagoon wastewater in the suspended sludge layer of treatment wetlands

    USDA-ARS?s Scientific Manuscript database

    The management of N from animal wastes is important to global agriculture. One method for managing this N is the use of constructed wetlands to obtain substantial removal of N via denitrification. The objectives of this study were to 1) evaluate the denitrification enzyme activity (DEA) rates in wet...

  8. Riparian Wetlands: Mapping

    EPA Science Inventory

    Riparian wetlands are critical systems that perform functions and provide services disproportionate to their extent in the landscape. Mapping wetlands allows for better planning, management, and modeling, but riparian wetlands present several challenges to effective mapping due t...

  9. Our Valuable Wetlands.

    ERIC Educational Resources Information Center

    Texley, Juliana

    1988-01-01

    Defines wetlands and lists several types of wetland habitat. Describes explorations that can be done with secondary school students including the baby boom, a food pyramid, and microenvironments. Includes a classroom poster with text on the variety of wetlands. (CW)

  10. Nitrogen removal and nitrous oxide emission in surface flow constructed wetlands for treating sewage treatment plant effluent: Effect of C/N ratios.

    PubMed

    Li, Ming; Wu, Haiming; Zhang, Jian; Ngo, Huu Hao; Guo, Wenshan; Kong, Qiang

    2017-09-01

    In order to design treatment wetlands with maximal nitrogen removal and minimal nitrous oxide (N 2 O) emission, the effect of influent C/N ratios on nitrogen removal and N 2 O emission in surface flow constructed wetlands (SF CWs) for sewage treatment plant effluent treatment was investigated in this study. The results showed that nitrogen removal and N 2 O emission in CWs were significantly affected by C/N ratio of influent. Much higher removal efficiency of NH 4 + -N (98%) and TN (90%) was obtained simultaneously in SF CWs at C/N ratios of 12:1, and low N 2 O emission (8.2mg/m 2 /d) and the percentage of N 2 O-N emission in TN removal (1.44%) were also observed. These results obtained in this study would be utilized to determine how N 2 O fluxes respond to variations in C/N ratios and to improve the sustainability of CWs for wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Treatment of wastewater and restoration of aquatic systems through an eco-technology based constructed treatment wetlands - a successful experience in Central India.

    PubMed

    Billore, S K; Sharma, J K; Singh, N; Ram, H

    2013-01-01

    In the last couple of decades constructed wetlands (CWs) have drawn considerable interest in Central India. CWs offer an effective means of integrating wastewater treatment and resource enhancement, often at competitive cost in comparison to conventional wastewater treatments, with additional benefits of Green Urban Landscaping and wildlife habitat. This paper describes treatment performances and the design of some Sub Surface Flow CWs (SSFCW) and Artificial Floating Islands (AFIs) in Central India. Central Indian CWs show significant pollution reduction load for total suspended solids (TSS) (62-82%), biochemical oxygen demand (BOD) (40-75%), NH(4)-N (67-78%) and total Kjeldahl nitrogen (TKN) (59-78%). Field scale SSFCWs installed so far in Central India are rectangular, earthen, single/multiple celled having similar depths of 0.60-0.90 m, hydraulic retention capacity 18-221 m(3) with effective size 41.8-1,050 m(2). The major components of CWs incorporate puddled bottom/side walls, sealed with impermeable low-density polyethylene, a bed of locally available river gravel planted with Phragmites karka, and an inlet distribution and outlet collection system. A new variant on CWs are AFIs working under hydroponics. The field scale experimental AFIs installed in-situ in a slowly flowing local river were composed of hollow bamboo, a bed of coconut coir, floating arrangements and Phragmites karka as nutrient stripping plant species. The AFIs polish the aquatic system by reducing 46.6% of TSS, 45-55% of NH(4)-N, 33-45% of NO(3)-N, 45-50% of TKN and 40-50% of BOD. The study established that there is a need for further research and sufficient data to assist the development of CWs by instilling confidence in policymakers, planners and in the public.

  12. Microbial Community Structure and Diversity in an Integrated System of Anaerobic-Aerobic Reactors and a Constructed Wetland for the Treatment of Tannery Wastewater in Modjo, Ethiopia

    PubMed Central

    Desta, Adey Feleke; Assefa, Fassil; Leta, Seyoum; Stomeo, Francesca; Wamalwa, Mark; Njahira, Moses; Appolinaire, Djikeng

    2014-01-01

    A culture-independent approach was used to elucidate the microbial diversity and structure in the anaerobic-aerobic reactors integrated with a constructed wetland for the treatment of tannery wastewater in Modjo town, Ethiopia. The system has been running with removal efficiencies ranging from 94%–96% for COD, 91%–100% for SO42- and S2-, 92%–94% for BOD, 56%–82% for total Nitrogen and 2%–90% for NH3-N. 16S rRNA gene clone libraries were constructed and microbial community assemblies were determined by analysis of a total of 801 unique clone sequences from all the sites. Operational Taxonomic Unit (OTU) - based analysis of the sequences revealed highly diverse communities in each of the reactors and the constructed wetland. A total of 32 phylotypes were identified with the dominant members affiliated to Clostridia (33%), Betaproteobacteria (10%), Bacteroidia (10%), Deltaproteobacteria (9%) and Gammaproteobacteria (6%). Sequences affiliated to the class Clostridia were the most abundant across all sites. The 801 sequences were assigned to 255 OTUs, of which 3 OTUs were shared among the clone libraries from all sites. The shared OTUs comprised 80 sequences belonging to Clostridiales Family XIII Incertae Sedis, Bacteroidetes and unclassified bacterial group. Significantly different communities were harbored by the anaerobic, aerobic and rhizosphere sites of the constructed wetland. Numerous representative genera of the dominant bacterial classes obtained from the different sample sites of the integrated system have been implicated in the removal of various carbon- containing pollutants of natural and synthetic origins. To our knowledge, this is the first report of microbial community structure in tannery wastewater treatment plant from Ethiopia. PMID:25541981

  13. Microbial community structure and diversity in an integrated system of anaerobic-aerobic reactors and a constructed wetland for the treatment of tannery wastewater in Modjo, Ethiopia.

    PubMed

    Desta, Adey Feleke; Assefa, Fassil; Leta, Seyoum; Stomeo, Francesca; Wamalwa, Mark; Njahira, Moses; Djikeng, Appolinaire; Appolinaire, Djikeng

    2014-01-01

    A culture-independent approach was used to elucidate the microbial diversity and structure in the anaerobic-aerobic reactors integrated with a constructed wetland for the treatment of tannery wastewater in Modjo town, Ethiopia. The system has been running with removal efficiencies ranging from 94%-96% for COD, 91%-100% for SO4(2-) and S(2-), 92%-94% for BOD, 56%-82% for total Nitrogen and 2%-90% for NH3-N. 16S rRNA gene clone libraries were constructed and microbial community assemblies were determined by analysis of a total of 801 unique clone sequences from all the sites. Operational Taxonomic Unit (OTU)--based analysis of the sequences revealed highly diverse communities in each of the reactors and the constructed wetland. A total of 32 phylotypes were identified with the dominant members affiliated to Clostridia (33%), Betaproteobacteria (10%), Bacteroidia (10%), Deltaproteobacteria (9%) and Gammaproteobacteria (6%). Sequences affiliated to the class Clostridia were the most abundant across all sites. The 801 sequences were assigned to 255 OTUs, of which 3 OTUs were shared among the clone libraries from all sites. The shared OTUs comprised 80 sequences belonging to Clostridiales Family XIII Incertae Sedis, Bacteroidetes and unclassified bacterial group. Significantly different communities were harbored by the anaerobic, aerobic and rhizosphere sites of the constructed wetland. Numerous representative genera of the dominant bacterial classes obtained from the different sample sites of the integrated system have been implicated in the removal of various carbon- containing pollutants of natural and synthetic origins. To our knowledge, this is the first report of microbial community structure in tannery wastewater treatment plant from Ethiopia.

  14. Occurrence of 25 pharmaceuticals in Taihu Lake and their removal from two urban drinking water treatment plants and a constructed wetland.

    PubMed

    Hu, Xia-Lin; Bao, Yi-Fan; Hu, Jun-Jian; Liu, You-Yu; Yin, Da-Qiang

    2017-06-01

    Pharmaceuticals in drinking water sources have raised significant concerns due to their persistent input and potential human health risks. The seasonal occurrence of 25 pharmaceuticals including 23 antibiotics, paracetamol (PAR), and carbamazepine (CMZ) in Taihu Lake was investigated; meanwhile, the distribution and removal of these pharmaceuticals in two drinking water treatment plants (DWTPs) and a constructed wetland were evaluated. A high detection frequency (>70%) in the Taihu Lake was observed for nearly all the 25 pharmaceutics. Chlortetracycline (234.7 ng L -1 ), chloramphenicol (27.1 ng L -1 ), erythromycin (72.6 ng L -1 ), PAR (71.7 ng L -1 ), and CMZP (23.6 ng L -1 ) are compounds with both a high detection frequency (100%) and the highest concentrations, suggesting their wide use in the Taihu Basin. Higher concentrations of chloramphenicols, macrolides, PAR, and CMZP were observed in dry season than in wet season, probably due to the low flow conditions of the lake in winter and the properties of pharmaceuticals. The overall contamination levels of antibiotic pharmaceutics (0.2-74.9 ng L -1 ) in the Taihu Lake were lower than or comparable to those reported worldwide. However, for nonantibiotic pharmaceutics, PAR (45.0 ng L -1 ) and CMZP (14.5 ng L -1 ), significantly higher concentrations were observed in the Taihu Lake than at a global scale. High detection frequencies of 25 pharmaceuticals were observed in both the two DWTPs (100%) and the wetland (>60%) except for florfenicol and sulfapyridine. The removal efficacies of the studied pharmaceuticals in DWTP B with advanced treatment processes including ozonation and granular activated carbon filtration (16.7-100%) were superior to DWTP A with conventional treatment processes (2.9-100%), except for sulfonamides. Wetland C with the constructed root channel technology was efficient (24.2-100%) for removing most pharmaceuticals. This work suggests that the application of cost

  15. Application of vertical flow constructed wetland in treatment of heavy metals from pulp and paper industry wastewater.

    PubMed

    Arivoli, A; Mohanraj, R; Seenivasan, R

    2015-09-01

    The paper production is material intensive and generates enormous quantity of wastewater containing organic pollutants and heavy metals. Present study demonstrates the feasibility of constructed wetlands (CWs) to treat the heavy metals from pulp and paper industry effluent by using vertical flow constructed wetlands planted with commonly available macrophytes such as Typha angustifolia, Erianthus arundinaceus, and Phragmites australis. Results indicate that the removal efficiencies of the planted CWs for iron, copper, manganese, zinc, nickel, and cadmium were 74, 80, 60, 70, 71, and 70 %, respectively. On the other hand, the removal efficiency of the unplanted system was significantly lower ranging between 31 and 55 %. Among the macrophytes, T. angustifolia and E. arundinaceus exhibited comparatively higher bioconcentration factor (10(2) to 10(3)) than P. australis.

  16. In Situ Wetland Restoration Demonstration

    DTIC Science & Technology

    2014-07-28

    Soil Settings Completed AC and Biochar Field Pilots Site Contaminant Year initiated Treatment Applied in Intertidal Zone ? Key Findings Grasse...in freshwater wetland AC and Biochar Field Studies Underway Site Contaminant Year initiated Treatment Applied in Intertidal Zone ? Key Findings...BAZ Biologically Active Zone BC Black Carbon BSAF Biota Sediment Accumulation Factor CAS Columbia Analytical Services, Inc. CCSA Canal Creek Study

  17. Recovery and fractionation of phosphorus retained by lightweight expanded shale and masonry sand used as media in subsurface flow treatment wetlands.

    PubMed

    Forbes, Margaret G; Dickson, Kenneth L; Saleh, Farida; Waller, William T; Doyle, Robert D; Hudak, Paul

    2005-06-15

    Most subsurface flow treatment wetlands, also known as reed bed or root zone systems, use sand or gravel substrates to reduce organics, solids, and nutrients in septic tank effluents. Phosphorus (P) retention in these systems is highly variable and few studies have identified the fate of retained P. In this study, two substrates, expanded shale and masonry sand, were used as filter media in five subsurface flow pilot-scale wetlands (2.7 m3). After 1 year of operation, we estimated the annual rate of P sorption by taking the difference between total P (TP) of substrate in the pilot cells and TP of substrate not exposed to wastewater (control). Means and standard deviations of TP retained by expanded shale were 349 +/- 171 mg kg(-1), respectively. For a substrate depth of 0.9 m, aerial P retention by shale was 201 +/- 98.6 g of P m(-2) year(-1), respectively. Masonry sand retained an insignificant quantity of wastewater P (11.9 +/- 21.8 mg kg(-1)) and on occasion exported P. Substrate samples were also sequentially fractionated into labile P, microbial P, (Fe + Al) P, humic P, (Ca + Mg) P, and residual P. In expanded shale samples, the greatest increase in P was in the relatively permanent form of (Fe + Al) P (108 mg kg(-1)), followed by labile P (46.7 mg kg(-1)) and humic P (39.8 mg kg(-1)). In masonry sand, there was an increase in labile P (9.71 mg kg(-1)). Results suggest that sand is a poor candidate for long-term P storage, but its efficiency is similar to that reported for many sand, gravel, and rock systems. By contrast, expanded shale and similar products with high hydraulic conductivity and P sorption capacity could greatly improve performance of P retention in constructed wetlands.

  18. Constructed wetlands using aluminium-based drinking water treatment sludge as P-removing substrate: should aluminium release be a concern?

    PubMed

    Babatunde, Akintunde O; Kumar, Jeyakumar L G; Zhao, Yaqian

    2011-06-01

    This study investigated an important issue of aluminium (Al) release from a novel reuse of Al-based water treatment sludge (Al-WTS) in constructed wetland system (CWs) as alternative substrate for wastewater treatment. Al-WTS is an inevitable by-product of drinking water treatment plants that use Al-salt as coagulant for raw water purification. It has recently been demonstrated that Al-WTS can be reused as a low-cost phosphorus (P) adsorbent and biofilm carrier in CWs for wastewater treatment. However, to facilitate the large scale application of Al-WTS in CWs as wetland substrate, concerns about Al leaching during its reuse in CWs must be addressed as Al is a dominant constituent in Al-WTS. In this study, a desk review of literature on Al release during Al-WTS reuse was conducted. Furthermore, a 42-week Al monitoring was carried out on a pilot field-scale CWs employing Al-WTS as main substrate. Results show that 22 out of the 35 studies reviewed, reported Al release with levels of soluble Al reported ranging from 0.01 to about 20 mg L(-1). Monitoring of Al in the pilot field-scale CWs shows that there was Al leaching. However, except for the first three weeks of operation, effluents concentrations of both total- and soluble-Al were all below the general regulatory guideline limit of 0.2 mg L(-1). Overall, the study addresses a vital concern regarding the successful application of Al-WTS in CWs and shows that Al release during such novel reuse is quite low and should not preclude its use.

  19. Ohio Uses Wetlands Program Development Grants to Protect Wetlands

    EPA Pesticide Factsheets

    The wetland water quality standards require the use of ORAM score to determine wetland quality. OEPA has also used these tools to evaluate wetland mitigation projects, develop performance standards for wetland mitigation banks and In Lieu Fee programs an.

  20. Wetlands Survey

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Ducks Unlimited, Inc. is dedicated to preservation of the world's waterfowl. Current inventories of wetland resources are crucial to effective waterfowl management. They contracted with NASA to use data from the LANDSAT satellites Thematic Mapper (TM), an advanced Earth scanning instrument that collects data in seven bands of the spectrum utilizing the Earth Resources Laboratory Applications Software (ELAS). The TM measures and records six values of light energy reflected from Earth and one value of heat energy as it scans the Earth below. On each orbital sweep, sensors produce a series of digital scenes representing features of Earth segments measuring about 100 by 110 miles, each scene covering about eight million acres, and each containing some 40 million bits of information called picture elements or pixels. They are computer processed and the resulting mosaic is projected on a digital display device.

  1. Optimization of operating parameters of hybrid vertical down-flow constructed wetland systems for domestic sewerage treatment.

    PubMed

    Huang, Zhujian; Zhang, Xianning; Cui, Lihua; Yu, Guangwei

    2016-09-15

    In this work, three hybrid vertical down-flow constructed wetland (HVDF-CW) systems with different compound substrates were fed with domestic sewage and their pollutants removal performance under different hydraulic loading and step-feeding ratio was investigated. The results showed that the hydraulic loading and step-feeding ratio were two crucial factors determining the removal efficiency of most pollutants, while substrate types only significantly affected the removal of COD and NH4(+)-N. Generally, the lower the hydraulic loading, the better removal efficiency of all contaminants, except for TN. By contrast, the increase of step-feeding ratio would slightly reduce the removal rate of ammonium and TP but obviously promoted the TN removal. Therefore, the optimal operation of this CWs could be achieved with low hydraulic loading combined with 50% of step-feeding ratio when TN removal is the priority, whereas medium or low hydraulic loading without step-feeding would be suitable when TN removal is not taken into consideration. The obtained results in this study can provide us with a guideline for design and optimization of hybrid vertical flow constructed wetland systems to improve the pollutants removal from domestic sewage. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Wonderful Wetlands: An Environmental Education Curriculum Guide for Wetlands.

    ERIC Educational Resources Information Center

    King County Parks Div., Redmond, WA.

    This curriculum guide was designed to give teachers, students, and society a better understanding of wetlands in the hope that they learn why wetlands should be valued and preserved. It explores what is meant by wetlands, functions and values of wetlands, wetland activities, and wetland offerings which benefit animal and plant life, recreation,…

  3. Hydrogeology of wetlands

    USGS Publications Warehouse

    Winter, T.C.; Llamas, M.R.

    1993-01-01

    A collection of 10 papers presented at the Hydrogeology of Wetlands Symposium, 28th International Geological Congress in Washington, DC, in July 1989. The purpose of the symposium was to assemble papers describing hydrogeologic studies of wetlands representative of different geographic regions, wetland types, and study approaches. The papers presented at the Symposium ranged geographically from wetlands in the Arctic to the Subtropics. Different wetland types included coastal, riverine, depressional glacial terrane, and dunal depressions. Different study approaches included regional syntheses, analyses of groundwater flow systems, wetland-river interaction, and geomorphology-vegetation interaction. -from Editors

  4. Wetland Characteristics and Denitrification

    EPA Science Inventory

    This presentation serves as an initial summary of our wetland field work's watershed characteristics hydrologic characteristics, water quality measurements, and denitrification assays. We present our measurement results in the context of wetland type (Estuarine, Freshwater Mars...

  5. Why are wetlands important?

    EPA Pesticide Factsheets

    Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs. An immense variety of species of microbes, plants, insects, amphibians, reptiles, birds, fish, and mammals can be part of a wetland ecosystem.

  6. Acidification of experimental wetlands: Effects on wetland productivity and survival of juvenile black ducks

    USGS Publications Warehouse

    Haramis, G.M.; Chu, D.S.; Bunck, C.M.; Mingo, T.M.; Schaffner, W.W.R.

    1997-01-01

    Six man-made wetlands (0.02 ha each) and pen-reared broods of American black ducks (Anas rubripes) were used to assess the effects of reduced pH on the quality of fish- free, palustrine habitat for brood rearing. Acid treatment was assigned randomly among newly constructed wetlands during April through June 1984-85, to simulate depressed pH from snowmelt and spring rain. Sampling of chlorophyll epiphytic growth, zooplankton and macroinvertebrates confirmed reduced productivity of acidified (pH 5.0) versus control (pH 6.8) wetlands. Primary productivity was particularly reduced in acidified wetlands in early spring as indicated by high water transparency and low chlorophyll a concentrations. Chlrophyll a concentrations showed treatment (p = 0.01) and date (p = 0.05) effects, but no interaction, and dry weight of epiphytic growth was lower (p = 0.03) in acidified versus control wetlands. Numbers of zooplankton were similar in experimental wetlands, although controls generally exceeded acidified wetlands in abundance; only a single treatment effect for cladocerans (p = 0.1) was detected. Sweep net samples yielded greater numbers (p = 0.03), taxa (p = 0.01) and biomass (p = 0.07) of macroinvertebrates in control wetlands with gastropods, pelecypods and leeches notably reduced by acidification. Placement of 18 broods (female with four 10-day-old ducklings) for 10-day trials on experimental wetlands revealed limited growth, altered behaviour and marked reduction in survival of ducklings on acidified wetlands. An inadequate number of invertebrates is indicated as the cause for poor duckling productivity on acidified wetlands

  7. The use of constructed wetlands for the treatment and reuse of urban wastewater for the irrigation of two warm-season turfgrass species under Mediterranean climatic conditions.

    PubMed

    Licata, Mario; Tuttolomondo, Teresa; Leto, Claudio; La Bella, Salvatore; Virga, Giuseppe

    2017-07-01

    Constructed wetlands (CWs) represent low-cost technology for the treatment and reuse of wastewater in urban areas. This study aimed to evaluate the pollutant removal efficiency of a CW system and to assess the effects of irrigation using treated urban wastewater on soil and on two warm-season turf species. The research was carried out in Sicily (Italy) on a pilot-scale horizontal subsurface flow system which was fed with treated urban wastewater following secondary treatment from an activated-sludge wastewater treatment plant. The pilot system was located in an open urban park and comprised two separate parallel planted units. Experimental fields of Cynodon dactylon (L.) Pers. and Paspalum vaginatum Sw. were set up close to the system and irrigated with both treated wastewater (TWW) and freshwater (FW). Irrigation with TWW did not result in a significant variation in soil pH and soil salinity in the topsoil. The turf species tolerated high sodium levels in the soil due to TWW irrigation. Savings in FW and mineral fertilizers were deemed significant. The results highlight the fact that use of CW systems for the treatment and reuse of wastewater can represent a sustainable way to obtain alternative water resources for turfgrass irrigation in urban areas.

  8. Effects of herbicide mixture on microbial communities in prairie wetland ecosystems: a whole wetland approach.

    PubMed

    Sura, Srinivas; Waiser, Marley; Tumber, Vijay; Farenhorst, Annemieke

    2012-10-01

    Wetlands in the prairie pothole region of Saskatchewan and Manitoba serve an important role in providing wildlife habitat, water storage and water filtration. These wetlands are regularly interspersed among agricultural operations where multiple pesticides are commonly used. Although mixtures of pesticides are often detected in these important aquatic ecosystems, very little information is known, regarding their effects. In this study, a curtained wetland approach was used to investigate the effects of a herbicide mixture (2,4-D, MCPA, clopyralid, dicamba, dichlorprop, mecoprop, bromoxynil, and glyphosate) on the structure and function of microbial communities in an ephemeral wetland and a semi-permanent wetland. In the two studied wetlands, located in Manitoba Zero Till Research Association Farm, Brandon, Manitoba, Canada, herbicide treatment based on maximum-exposure scenarios had a significant effect on pelagic and biofilm phytoplankton productivity over relatively short time periods. The stimulation of phytoplankton productivity in the ephemeral wetland appeared to be the result of a hormonal effect of the auxin-type herbicides present in the mixture, similar to naturally occurring auxins. Herbicidal effects of auxin-type herbicides were also noticed in the semi-permanent wetland where phytoplankton productivity was suppressed during the first week as a result of the concentration addition effect of the auxin-type herbicides present in the mixture. BIOLOG and pigment profiles of the biofilm community suggested a change in the community structure in both wetlands. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  9. Sedimentation of prairie wetlands

    USGS Publications Warehouse

    Gleason, Robert A.; Euliss, Ned H.

    1998-01-01

    Many wetlands in the prairie pothole region are embedded within an agricultural landscape where they are subject to varying degrees of siltation. Cultivation of wetland catchment areas has exacerbated soil erosion; wetlands in agricultural fields receive more sediment from upland areas than wetlands in grassland landscapes and hence are subject to premature filling (i.e., they have shorter topographic lives). Associated impacts from increased turbidity, sediment deposition, and increased surface water input likely have impaired natural wetland functions. Although trapping of sediments by wetlands is often cited as a water quality benefit, sediment input from agricultural fields has potential to completely fill wetlands and shorten their effective life-span. Thus, the value placed on wetlands to trap sediments is in conflict with maximizing the effective topographic life of wetlands. Herein, we provide an overview of sedimentation, identify associated impacts on wetlands, and suggest remedial management strategies. We also highlight the need to evaluate the impact of agricultural practices on wetland functions from an interdisciplinary approach to facilitate development of best management practices that benefit both wetland and agricultural interests.

  10. Wetlands, Wildlife, and People.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Discusses the problems created when wetlands are drained or altered by humans. Provides a brief case study of the Everglades as an example of the effects of human intervention. Presents four learning activities (along with reproducible worksheets) that deal with the benefits of wetlands, and some debated issues over wetlands. (TW)

  11. Wetlands: An Interdisciplinary Exploration

    ERIC Educational Resources Information Center

    Czerniak, Charlene M.

    2004-01-01

    The topic of wetlands provides a rich context for curriculum integration. This unit contains seven activities that integrate environmental science with math, technology, social studies, language arts, and other disciplines. In this series, students will identify plants and animals found in wetlands, understand the function of wetlands through the…

  12. Are isolated wetlands isolated?

    USGS Publications Warehouse

    Smith, Loren M.; Euliss, Ned H.; Haukos, David A.

    2011-01-01

    While federal regulations during the past 10 years have treated isolated wetlands as unconnected to aquatic resources protected by the Clean Water Act, they provide critical ecosystem services to society that extend well beyond their wetland boundaries. The authors offer well-documented examples from the scientific literature on some of the ecosystem services provided by isolated wetlands to society and other ecosystems.

  13. Long-term assessment at field scale of Floating Treatment Wetlands for improvement of water quality and provision of ecosystem services in a eutrophic urban pond.

    PubMed

    Olguín, Eugenia J; Sánchez-Galván, Gloria; Melo, Francisco J; Hernández, Víctor J; González-Portela, Ricardo E

    2017-04-15

    Pollution of urban water bodies requires stringent control measures and the development of low-cost and highly efficient alternative technologies. In contrast to Constructed Wetlands, Floating Treatment Wetlands (FTWs) have the advantage of not requiring large surface of land since they operate in situ. However, there is limited information about their long-term evaluation while operating at field scale. The aim of this work was to assess the performance of FTWs using a combination of Pontederia sagittata and Cyperus papyrus for the improvement of the water quality and provision of ecosystem services of a eutrophic urban pond. The FTWs were built with low-cost material easy to acquire and to ensemble. Two FTWs (17.5m 2 and 33m 2 ) located in Pond 1 within a complex of 4 urban artificial ponds were evaluated for two years. They promoted an increase in the dissolved oxygen (D.O.) within a range of 15 to 67%, a removal of fecal coliforms in the range of 9 to 86% and a nitrate removal in the range of 9 to 76%. The plant productivity reached a maximum of 363g dm m -2 d -1 in the FTW1 and 536g dm m -2 d -1 in the FTW2 during the period March-June 2016. The TKN and the TP content in the plant were in the range of 18.3 to 28.1 and of 0.05 to 0.196gkg -1 dry matter, respectively. In conclusion, the tested FTWs have proved to be a very beneficial low-cost technology for the improvement of water quality and provision of ecosystem services. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Pollutant removal performance of an integrated upflow-constructed wetland filled with haydites made of Al-based drinking water treatment residuals.

    PubMed

    Wang, Wendong; Han, Yu; Liu, Hui; Zhang, Ke; Yue, Qiang; Bo, Longli; Wang, Xiaochang

    2017-05-01

    This study examined the pollutants removal performance of an integrated upflow-constructed wetland (IUCW) system in a 1.5 years' continuous operation. The average concentrations of chemical oxygen demand (COD), NH 4 -N, total nitrogen (TN), and total phosphorus (TP) in the effluent were 21.9, 1.47, 2.63, and 0.18 mg/L, respectively, which corresponded to 90.1%, 23.3%, 86.1%, and 97.2% removals from the raw water, respectively. The residual concentration of COD was 219 mg/L at start-up and decreased notably to 52.8 mg/L after 50 days of operation. NH 4 -N was difficult to remove because the average concentration of dissolved oxygen in the IUCW system was lower than 0.6 mg/L. In contrast, the residual concentrations of both TN and TP in the effluent were stable, with average removal rates as high as 89% and 99%, respectively, at start-up of the system. Changing the organic loading rates from 45.0 g/(m 2 ·day) to 20.0 or 60.0 g/(m 2 ·day) both inhibited the removal of TN. Further study showed that the removal of organic matter mainly occurred within 10-20 cm of the wetland cell. Considering its strong organic, nitrogen, and phosphate removal capacity, the IUCW system was determined to be effective in decentralized wastewater treatment.

  15. Performance of a pilot demonstration-scale hybrid constructed wetland system for on-site treatment of polluted urban river water in Northwestern China.

    PubMed

    Zheng, Yucong; Wang, Xiaochang C; Dzakpasu, Mawuli; Ge, Yuan; Zhao, Yaqian; Xiong, Jiaqing

    2016-01-01

    Hybrid constructed wetland (HCW) systems have been used to treat various wastewaters across the world. However, large-scale applications of HCWs are scarce, particularly for on-site improvement of the water quality of highly polluted urban rivers in semi-arid regions. In this study, a large pilot-scale HCW system was constructed to improve the water quality of the Zaohe River in Xi'an, China. With a total area of about 8000 m(2), the pilot HCW system, composed of different configurations of surface and subsurface flow wetlands, was operated for 2 years at an average inflow volume rate of 362 m(3)/day. Local Phragmites australis and Typha orientalis from the riverbank were planted in the HCW system. Findings indicate a higher treatment efficiency for organics and suspended solids than nutrients. The inflow concentrations of 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), suspended solids (SS), total nitrogen (TN), NH3-N, and total phosphorus (TP) were 125.6, 350.9, 334.2, 38.5, 27.2, and 3.9 mg/L, respectively. Average removal efficiencies of 94.4, 74.5, 92.0, 56.3, 57.5, and 69.2%, respectively, were recorded. However, the pollutant removal rates were highly seasonal especially for nitrogen. Higher removals were recorded for all pollutants in the autumn while significantly lower removals were recorded in the winter. Plant uptake and assimilation accounted for circa 19-29 and 16-23% of the TN and TP removal, respectively. Moreover, P. australis demonstrated a higher nutrient uptake ability and competitive potential. Overall, the high efficiency of the pilot HCW for improving the water quality of such a highly polluted urban river provided practical evidence of the applicability of the HCW technology for protecting urban water environments.

  16. Is wetland mitigation successful in Southern California?

    NASA Astrophysics Data System (ADS)

    Cummings, D. L.; Rademacher, L. K.

    2004-12-01

    Wetlands perform many vital functions within their landscape position; they provide unique habitats for a variety of flora and fauna and they act as treatment systems for upstream natural and anthropogenic waste. California has lost an estimated 91% of its wetlands. Despite the 1989 "No Net Loss" policy and mitigation requirements by the regulatory agencies, the implemented mitigation may not be offsetting wetlands losses. The "No Net Loss" policy is likely failing for numerous reasons related to processes in the wetlands themselves and the policies governing their recovery. Of particular interest is whether these mitigation sites are performing essential wetlands functions. Specific questions include: 1) Are hydric soil conditions forming in mitigation sites; and, 2) are the water quality-related chemical transformations that occur in natural wetlands observed in mitigation sites. This study focuses on success (or lack of success) in wetlands mitigation sites in Southern California. Soil and water quality investigations were conducted in wetland mitigation sites deemed to be successful by vegetation standards. Observations of the Standard National Resource Conservation Service field indicators of reducing conditions were made to determine whether hydric soil conditions have developed in the five or more years since the implementation of mitigation plans. In addition, water quality measurements were performed at the inlet and outlet of these mitigation sites to determine whether these sites perform similar water quality transformations to natural wetlands within the same ecosystem. Water quality measurements included nutrient, trace metal, and carbon species measurements. A wetland location with minimal anthropogenic changes and similar hydrologic and vegetative features was used as a control site. All sites selected for study are within a similar ecosystem, in the interior San Diego and western Riverside Counties, in Southern California.

  17. Multiple antibiotic resistance patterns of rhizospheric bacteria isolated from Phragmites australis growing in constructed wetland for distillery effluent treatment.

    PubMed

    Chaturvedi, Sonal; Chandra, Ram; Rai, Vibhuti

    2008-01-01

    Susceptibility patterns of 12 different antibiotics were investigated against rhizospheric bacteria isolated from Phragmites australis from three different zones i.e. upper (0-5 cm), middle (5-10 cm), lower (10-15 cm) in constructed wetland system with and without distillery effluent. The major pollutants of distillery effluent were phenols, sulphide, heavy metals, and higher levels of biological oxygen demand (BOD), chemical oxygen demand (COD) etc. The antibiotic resistance properties of bacteria were correlated with the heavy metal tolerance (one of distillery pollutant). Twenty-two species from contaminated and seventeen species from non-contaminated site were tested by agar disc-diffusion method. The results revealed that more than 63% of total isolates were resistance towards one or more antibiotics tested from all the three different zones of contaminated sites. The multiple-drug resistance property was shown by total 8 isolates from effluent contaminated region out of which 3 isolates were from upper zone, 3 isolates from middle zone and 2 isolates were from lower zone. Results indicated that isolates from contaminated rhizosphere were found more resistant to antibiotics than isolates from non-contaminated rhizosphere. Further this study produces evidence suggesting that tolerance to antibiotics was acquired by isolates for the adaptation and detoxification of all the pollutants present in the effluent at contaminated site. This consequently facilitated the phytoremediation of effluent, which emerges the tolerance and increases resistance to antibiotics.

  18. National Wetlands Inventory products

    USGS Publications Warehouse

    ,

    1998-01-01

    control. These predominantly wet areas, or wetlands as they are commonly called, now represent only about 5 percent of the land surface of the lower 48 States. Out of 221 million acres of wetlands that once existed in the conterminous United States, the U.S. Fish and Wildlife Service (FWS) estimates that only about 103.3 million acres remain. Each year, development, drainage, and agriculture eliminate another 290,000 acres-an area a little less than half the size of Rhode Island. From the 1950's to the 1970's, conversion of wetlands to farmland caused 87 percent of all wetland losses. The FWS has long recognized the importance of America's wetlands because they form breeding and wintering grounds for great numbers of migratory birds. In 1977, the FWS began the National Wetlands Inventory (NWI), a systematic effort to classify and map America's remaining wetlands.

  19. Basic Oxygen Furnace steel slag aggregates for phosphorus treatment. Evaluation of its potential use as a substrate in constructed wetlands.

    PubMed

    Blanco, Ivan; Molle, Pascal; Sáenz de Miera, Luis E; Ansola, Gemma

    2016-02-01

    Basic Oxygen Furnace (BOF) steel slag aggregates from NW Spain were tested in batch and column experiments to evaluate its potential use as a substrate in constructed wetlands (CWs). The objectives of this study were to identify the main P removal mechanisms of BOF steel slag and determine its P removal capacity. Also, the results were used to discuss the suitability of this material as a substrate to be used in CWs. Batch experiments with BOF slag aggregates and increasing initial phosphate concentrations showed phosphate removal efficiencies between 84 and 99% and phosphate removal capacities from 0.12 to 8.78 mg P/g slag. A continuous flow column experiment filled with BOF slag aggregates receiving an influent synthetic solution of 15 mg P/L during 213 days showed a removal efficiency greater than 99% and a phosphate removal capacity of 3.1 mg P/g slag. In both experiments the main P removal mechanism was found to be calcium phosphate precipitation which depends on Ca(2+) and OH(-) release from the BOF steel slag after dissolution of Ca(OH)2 in water. P saturation of slag was reached within the upper sections of the column which showed phosphate removal capacities between 1.7 and 2.5 mg P/g slag. Once Ca(OH)2 was completely dissolved in these column sections, removal efficiencies declined gradually from 99% until reaching stable outlet concentrations with P removal efficiencies around 7% which depended on influent Ca(2+) for limited continuous calcium phosphate precipitation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Assessment of the technological reliability of a hybrid constructed wetland for wastewater treatment in a mountain eco-tourist farm in Poland.

    PubMed

    Jucherski, Andrzej; Nastawny, Maria; Walczowski, Andrzej; Jóźwiakowski, Krzysztof; Gajewska, Magdalena

    2017-06-01

    The aim of the present study was to assess the technological reliability of a domestic hybrid wastewater treatment installation consisting of a classic three-chambered (volume 6 m 3 ) septic tank, a vertical flow trickling bed filled with granules of a calcinated clay material (KERAMZYT), a special wetland bed constructed on a slope, and a permeable pond used as a receiver. The test treatment plant was located at a mountain eco-tourist farm on the periphery of the spa municipality of Krynica-Zdrój, Poland. The plant's operational reliability in reducing the concentration of organic matter, measured as biochemical oxygen demand (BOD 5 ) and chemical oxygen demand (COD), was 100% when modelled by both the Weibull and the lognormal distributions. The respective reliability values for total nitrogen removal were 76.8% and 77.0%, total suspended solids - 99.5% and 92.6%, and PO 4 -P - 98.2% and 95.2%, with the differences being negligible. The installation was characterized by a very high level of technological reliability when compared with other solutions of this type. The Weibull method employed for statistical evaluation of technological reliability can also be used for comparison purposes. From the ecological perspective, the facility presented in the study has proven to be an effective tool for protecting local aquifer areas.

  1. Performance of an Ultraviolet Mutagenetic Polyphosphate-Accumulating Bacterium PZ2 and Its Application for Wastewater Treatment in a Newly Designed Constructed Wetland.

    PubMed

    Tian, Jiang; Yu, Chenlei; Liu, Jiafeng; Ye, Chaoran; Zhou, Xiangjun; Chen, Lanzhou

    2017-02-01

    Total phosphorus (TP) removal performance and application for wastewater treatment of polyphosphate-accumulating bacteria (PAB) in constructed wetlands (CWs) were investigated. In this study, a novel isolated ultraviolet (UV) mutant PZ2 with phosphate-accumulating ability was screened from domestic wastewater and identified as Pseudomonas putida by 16S ribosomal DNA (rDNA) sequencing analysis. The TP removal performance of PZ2 in the synthetic wastewater reached the highest of 93.95 % within 45 h. Two vertical subsurface flow CWs planted with two aquatic macrophytes Canna indica and Acorus calamus were newly designed. After inoculating PZ2 into two CWs within 45 h, the average chemical oxygen demand (COD), TP, and ammonia-nitrogen (NH 3 -N) removal efficiencies reached 68.50, 60.22, and 66.81 %, respectively. Vegetation type and filter size significantly influenced the TP removal capability of PZ2 in CWs. Meanwhile, considerable qualitative differences were found in the pollutant removal efficiencies of PZ2 with and without CWs in synthetic wastewater. These results could also indicate potential applications of the UV mutagenesis in PAB isolation and the newly designed CWs in wastewater treatments.

  2. Role of macrophyte and effect of supplementary aeration in up-flow constructed wetland-microbial fuel cell for simultaneous wastewater treatment and energy recovery.

    PubMed

    Oon, Yoong-Ling; Ong, Soon-An; Ho, Li-Ngee; Wong, Yee-Shian; Dahalan, Farrah Aini; Oon, Yoong-Sin; Lehl, Harvinder Kaur; Thung, Wei-Eng; Nordin, Noradiba

    2017-01-01

    This study investigates the role of plant (Elodea nuttallii) and effect of supplementary aeration on wastewater treatment and bioelectricity generation in an up-flow constructed wetland-microbial fuel cell (UFCW-MFC). Aeration rates were varied from 1900 to 0mL/min and a control reactor was operated without supplementary aeration. 600mL/min was the optimum aeration flow rate to achieve highest energy recovery as the oxygen was sufficient to use as terminal electron acceptor for electrical current generation. The maximum voltage output, power density, normalized energy recovery and Coulombic efficiency were 545.77±25mV, 184.75±7.50mW/m 3 , 204.49W/kg COD, 1.29W/m 3 and 10.28%, respectively. The variation of aeration flow rates influenced the NO 3 - and NH 4 + removal differently as nitrification and denitrification involved conflicting requirement. In terms of wastewater treatment performance, at 60mL/min aeration rate, UFCW-MFC achieved 50 and 81% of NO 3 - and NH 4 + removal, respectively. E. nuttallii enhanced nitrification by 17% and significantly contributed to bioelectricity generation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. [Problems and countermeasures in the application of constructed wetlands].

    PubMed

    Huang, Jin-Lou; Chen, Qin; Xu, Lian-Huang

    2013-01-01

    Constructed wetlands as a wastewater eco-treatment technology are developed in recent decades. It combines sewage treatment with the eco-environment in an efficient way. It treats the sewage effectively, and meanwhile beautifies the environment, creates ecological landscape, and brings benefits to the environment and economics. The unique advantages of constructed wetlands have attracted intensive attention since developed. Constructed wetlands are widely used in treatment of domestic sewage, industrial wastewater, and wastewater from mining and petroleum production. However, many problems are found in the practical application of constructed wetland, e. g. they are vulnerable to changes in climatic conditions and temperature, their substrates are easily saturated and plugged, they are readily affected by plant species, they often occupy large areas, and there are other problems including irrational management, non-standard design, and a single function of ecological service. These problems to a certain extent influence the efficiency of constructed wetlands in wastewater treatment, shorten the life of the artificial wetland, and hinder the application of artificial wetland. The review presents correlation analysis and countermeasures for these problems, in order to improve the efficiency of constructed wetland in wastewater treatment, and provide reference for the application and promotion of artificial wetland.

  4. Freshwater Wetlands: A Citizen's Primer.

    ERIC Educational Resources Information Center

    Catskill Center for Conservation and Development, Inc., Hobart, NY.

    The purpose of this "primer" for the general public is to describe the general characteristics of wetlands and how wetland alteration adversely affects the well-being of humans. Particular emphasis is placed on wetlands in New York State and the northeast. Topics discussed include wetland values, destruction of wetlands, the costs of…

  5. Aquatic and wetland vascular plants of the northern Great Plains

    Treesearch

    Gary E. Larson

    1993-01-01

    A taxonomic treatment of aquatic and wetland vascular plants has been developed as a tool for identifying over 500 plant species inhabiting wetlands of the northern Great Plains region. The treatment provides dichotomous keys and botanical descriptions to facilitate identification of all included taxa. Illustrations are also provided for selected species. Geographical...

  6. A LOW-COST THREE-DIMENSIONAL SAMPLE COLLECTION ARRAY TO EVALUATE AND MONITOR CONSTRUCTED WETLANDS

    USDA-ARS?s Scientific Manuscript database

    Artificially constructed wetlands are gaining acceptance as a low cost treatment alternative to remove a number of undesirable constituents from water. Wetlands can be used to physically remove compounds such as suspended solids through sedimentation. Dissolved nutrients, biochemical oxygen demand, ...

  7. The Economics of Wetland Drainage in Agricultural Minnesota.

    DTIC Science & Technology

    1981-04-01

    programs have been established to influence wetlands management decisions. Executive Order 11990 directs Federal agencies to avoid, as much as possible...ties may affect decisions on private wetlands management . Income tax treatment of drainage investments and the availability of an investment tax credit... wetlands management as the "most emotional and pervasive issue in Minnesota’s management of water resources" and has recommended in its Framework Water

  8. Constructed wetlands for stormwater management.

    DOT National Transportation Integrated Search

    1998-07-01

    This report presents the results of research to evaluate the potential of utilizing mitigated wetlands as stormwater Best Management Practices (BMPs). Results of wetland monitoring, wetland modeling, and geographic information system (GIS) developmen...

  9. Pipeline corridors through wetlands

    SciTech Connect

    Zimmerman, R.E.; Wilkey, P.L.; Isaacson, H.R.

    1992-12-01

    This paper presents preliminary findings from six vegetational surveys of gas pipeline rights-of-way (ROW) through wetlands and quantifies the impacts of a 20-year-old pipeline ROW through a boreal forest wetland. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the Row approximated or exceeded those in the adjacent natural area. The boreal forest study showed that (1) adjacent natural wetland areas were not altered in type; (2) water sheet flow restriction had been reversed by nature; (3) nomore » nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity.« less

  10. Pipeline corridors through wetlands

    SciTech Connect

    Zimmerman, R.E.; Wilkey, P.L.; Isaacson, H.R.

    1992-01-01

    This paper presents preliminary findings from six vegetational surveys of gas pipeline rights-of-way (ROW) through wetlands and quantifies the impacts of a 20-year-old pipeline ROW through a boreal forest wetland. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the Row approximated or exceeded those in the adjacent natural area. The boreal forest study showed that (1) adjacent natural wetland areas were not altered in type; (2) water sheet flow restriction had been reversed by nature; (3) nomore » nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity.« less

  11. Electrode and azo dye decolorization performance in microbial-fuel-cell-coupled constructed wetlands with different electrode size during long-term wastewater treatment.

    PubMed

    Fang, Zhou; Cao, Xian; Li, Xuexiao; Wang, Hui; Li, Xianning

    2017-08-01

    Microbial-fuel-cell-coupled constructed wetlands (CW-MFCs) with various cathode layers were used for long-term azo dye wastewater treatment. Their performance was assessed using cathode diameters ranging from 20 to 27.5cm and the influence of plants at the cathode was also examined. Bioelectricity generation, ABRX3 decolorization, and chemical oxygen demand (COD) removal performances first increased and then decreased with increasing cathode diameter. The CW-MFCs with larger cathodes had an anoxic region at the cathode where ABRX3 was decolorized. This phenomenon has not been reported in previous research on MFCs using traditional air cathodes. Anode performance was influenced by the cathode. The CW-MFC with a cathode diameter of 25cm showed the best electrode performance, and the highest voltage and power density were 560mV and 0.88W/m 3 , respectively. The highest ABRX3 decolorization and COD removal volumes were 271.53mg/L and 312.17mg/L, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Performance comparison and economics analysis of waste stabilization ponds and horizontal subsurface flow constructed wetlands treating domestic wastewater: a case study of the Juja sewage treatment works.

    PubMed

    Mburu, Njenga; Tebitendwa, Sylvie M; van Bruggen, Johan J A; Rousseau, Diederik P L; Lens, Piet N L

    2013-10-15

    The performance, effluent quality, land area requirement, investment and operation costs of a full-scale waste stabilization pond (WSP) and a pilot scale horizontal subsurface flow constructed wetland (HSSF-CW) at Jomo Kenyatta University of Agriculture and Technology (JKUAT) were investigated between November 2010 to January 2011. Both systems gave comparable medium to high levels of organic matter and suspended solids removal. However, the WSP showed a better removal for Total Phosphorus (TP) and Ammonium (NH4(+)-N). Based on the population equivalent calculations, the land area requirement per person equivalent of the WSP system was 3 times the area that would be required for the HSSF-CW to treat the same amount of wastewater. The total annual cost estimates consisting of capital, operation and maintenance (O&M) costs were comparable for both systems. However, the evaluation of the capital cost of either system showed that it is largely influenced by the size of the population served, local cost of land and the construction materials involved. Hence, one can select either system in terms of treatment efficiency. When land is available other factor including the volume of wastewater or the investment, and O&M costs determine the technology selection. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Treatment of a sulfate-rich groundwater contaminated with perchloroethene in a hydroponic plant root mat filter and a horizontal subsurface flow constructed wetland at pilot-scale.

    PubMed

    Chen, Zhongbing; Kuschk, Peter; Paschke, Heidrun; Kästner, Matthias; Müller, Jochen A; Köser, Heinz

    2014-12-01

    A hydroponic plant root mat filter (HPRMF) was compared over 7months with a horizontal subsurface flow constructed wetland (HSSF CW) regarding the removal of perchloroethene (PCE) (about 2 mg L(-1)) from a sulfate- (850 mg L(-1)) and ammonia-rich (50 mg L(-1)) groundwater with a low TOC content. At a mean area specific inflow PCE load of 56 mg m(-2)d(-1), after 4m from inlet, the mean PCE removal during summer time reached 97% in the HPRMF and almost 100% in the HSSF CW. Within the first 2m in the HSSF CW metabolites like dichloroethenes, vinyl chloride and ethene accumulated, their concentrations decreased further along the flow path. Moreover, the tidal operation (a 7-d cycle) in the HSSFCW decreased the accumulation of PCE metabolites within the first 1m of the bed. The carcinogenic degradation metabolite vinyl chloride was not detected in the HPRMF. The smaller accumulation of the degradation metabolites in the HPRMF correlated with its higher redox potential. It can be concluded from this study that HPRMF appears an interesting alternative for special water treatment tasks and that tidal operation will show some positive effects on the removal of the accumulated PCE metabolites in HSSF CW. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Impacts of vegetation and temperature on the treatment of domestic sewage in constructed wetlands incorporated with Ferric-Carbon micro-electrolysis material.

    PubMed

    Zhou, Qingwei; Zhu, Hui; Bañuelos, Gary; Yan, Baixing; Liang, Yinxiu; Yu, Jing; Li, Huai

    2017-10-03

    Ferric-Carbon Micro-Electrolysis (Fe/C-M/E) material had been widely used for the pretreatment of wastewater. Therefore, we hypothesized that Fe/C-M/E material could enhance the treatment of domestic sewage when it was integrated into constructed wetlands (CWs). In this study, CWs integrated with Fe/C-M/E material were developed. Druing the experiment of effect of vegetation on the performance of CWs, percentages of NH 4 + -N, NO 3 - -N, total nitrogen (TN), and Chemical Oxygen Demand (COD) removed in polyculture (W1) were up to 91.8%, 97.0%, 92.3%, and 85.4%, respectively, which were much higher than those in Lythrum salicaria monoculture (W2) and Canna indica monoculture (W3). In the experiment of temperature influences on the removal efficiency of CWs, temperature substantially influenced the performance of CWs. For example, NO 3 - -N removal percentages of W1, W2, and W3 at high temperature (25.5°C and 19.8°C) were relatively stable and greater than 85.4%. At 8.9°C, however, a sharp decline of NO 3 - -N removal percentage was observed in all CWs. Temperature also influenced the Chemical Oxygen Demand (COD) removal and soil microbial activity and biomass. Overall, the polyculture (Lythrum salicaria +Canna indica) showed the best performance during most of the operating time, at an average temperature ≥ 19.8°C, due to the functional complementarity between vegetation. All the CWs consistently achieved high removal efficiency (above 96%) for TP in all experiments, irrespective of vegetation types, phosphorous loadings, and temperatures. In conclusion, polyculture was an attractive solution for the treatment of domestic sewage during most of the operating time (average temperature ≥ 19.8°C). Furthermore, CWs with Fe/C-M/E material were ideally suitable for domestic sewage treatment, especially for TP removal.

  15. Nitrogen removal capacity of wetlands: sediment versus epiphytic biofilms.

    PubMed

    Bourgues, S; Hart, B T H

    2007-01-01

    Wetlands are important sinks for nutrients and constructed wetlands are current practice for stormwater treatment. For nitrogen, the main removal process is denitrification (microbial reduction of nitrate to nitrogen gas). The bacteria responsible for this process are mostly found in the sediments and in epiphytic biofilms growing on wetland macrophytes. This paper reports on a project which aimed at measuring denitrification potential in sediments and epiphyton in urban wetlands. This study showed that wetland sediments could support high rates of denitrification. Interestingly, the most polluted of the wetlands studied had the highest denitrification potential. The management implication from this result is that indicators of pollution, such as hydrocarbon levels, will not necessarily reflect the ability of a wetland to denitrify. Two of the wetlands were studied in more detail. Here the denitrification potential of the epiphyton on dominant macrophytes and sediments were measured. The results indicated that the potential denitrification activity of the epiphyton was comparable to those measured in the sediments. Hence, biofilms could play a significant part in removing nitrogen loads. This work contributes to a better knowledge of the functioning of wetlands. This will lead to improved design and management of wetlands used for treating stormwater.

  16. Vertical redox profiles in treatment wetlands as function of hydraulic regime and macrophytes presence: surveying the optimal scenario for microbial fuel cell implementation.

    PubMed

    Corbella, Clara; Garfí, Marianna; Puigagut, Jaume

    2014-02-01

    Sediment microbial fuel cell (sMFC) represents a variation of the typical configuration of a MFC in which energy can be harvested via naturally occurring electropotential differences. Moreover, constructed wetlands show marked redox gradients along the depth which could be exploited for energy production via sMFC. In spite of the potential application of sMFC to constructed wetlands, there is almost no published work on the topic. The main objective of the present work was to define the best operational and design conditions of sub-surface flow constructed wetlands (SSF CWs) under which energy production with microbial fuel cells (MFCs) would be maximized. To this aim, a pilot plant based on SSF CW treating domestic sewage was operated during six months. Redox gradients along the depth of SSF CWs were determined as function of hydraulic regime (continuous vs discontinuous) and the presence of macrophytes in two sampling campaigns (after three and six months of plant operation). Redox potential (EH) within the wetlands was analysed at 5, 15 and 25 cm. Results obtained indicated that the maximum redox gradient was between the surface and the bottom of the bed for continuous planted wetlands (407.7 ± 73.8 mV) and, to a lesser extent, between the surface and the middle part of the wetland (356.5 ± 76.7 mV). Finally, the maximum redox gradients obtained for planted wetlands operated under continuous flow regime would lead to a power production of about 16 mW/m(2). © 2013.

  17. Wetlands: Earth's Kidneys

    EPA Science Inventory

    Wetlands are unique, diverse, and productive habitats that emerge at the fringe of aquatic and upland land systems. The U.S. Environmental Protection Agency (EPA) defines wetlands as "areas that are regularly inundated by surface water or groundwater and characterized by a preva...

  18. Wetlands and Web Pages.

    ERIC Educational Resources Information Center

    Tisone-Bartels, Dede

    1998-01-01

    Argues that the preservation of areas like the Shoreline Park (California) wetlands depends on educating students about the value of natural resources. Describes the creation of a Web page on the wetlands for third-grade students by seventh-grade art and ecology students. Outlines the technical process of developing a Web page. (DSK)

  19. Effects of agricultural, industrial, and municipal pollutants on wetlands and wildlife and wildlife health

    USGS Publications Warehouse

    Converse, Kathryn A.

    1995-01-01

    Wetlands accumulate pollutants from adjacent areas through intentional discharge of sewage or industrial wastes, runoff of agricultural fertilizers and pesticides, and discharge from municipal storm drains.  Coastal wetlands receive more pollutants indirectly as the endpoint for upland drainage systems and directly through petroleum spills and insect abatement.  Wetlands that serve as evaporation basins during seasonally high water, especially in more arid climates, concentrate natural compounds and as well as pollutants.  The ability of wetlands to be effective filtration systems for wastewater nutrients through microbial transformations, uptake by plants, and deposition of particulate matter, and the shortage of water in arid climates has resulted in revision of wetland regulations.  Wetlands can now be developed for wastewater treatment and natural wetlands can be restored or converted to wastewater treatment systems.  The effect of these accumulation pollutants on wetland ecology and wildlife health needs to be recognized.

  20. Remote sensing of wetlands

    NASA Technical Reports Server (NTRS)

    Roller, N. E. G.

    1977-01-01

    The concept of using remote sensing to inventory wetlands and the related topics of proper inventory design and data collection are discussed. The material presented shows that aerial photography is the form of remote sensing from which the greatest amount of wetlands information can be derived. For extensive, general-purpose wetlands inventories, however, the use of LANDSAT data may be more cost-effective. Airborne multispectral scanners and radar are, in the main, too expensive to use - unless the information that these sensors alone can gather remotely is absolutely required. Multistage sampling employing space and high altitude remote sensing data in the initial stages appears to be an efficient survey strategy for gathering non-point specific wetlands inventory data over large areas. The operational role of remote sensing insupplying inventory data for application to several typical wetlands management problems is illustrated by summary descriptions of past ERIM projects.

  1. Forested wetland habitat

    USGS Publications Warehouse

    Duberstein, Jamie A.; Krauss, Ken W.; Kennish, Michael J.

    2015-01-01

    A forested wetland (swamp) is a forest where soils are saturated or flooded for at least a portion of the growing season, and vegetation, dominated by trees, is adapted to tolerate flooded conditions. A tidal freshwater forested wetland is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity of soil porewater less than 0.5 g/l. It is known locally as tidal várzea in the Amazon delta, Brazil. A tidal saltwater forested wetland (mangrove forest) is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity often exceeding 3 g/l and reaching levels that can exceed seawater. Mangrove ecosystems are composed of facultative halophytes that generally experience better growth at moderate salinity concentrations.

  2. Aluminum-based water treatment residual use in a constructed wetland for capturing urban runoff phosphorus: Column study

    USDA-ARS?s Scientific Manuscript database

    Aluminum-based water treatment residuals (Al-WTR) have a strong affinity to sorb phosphorus. In a proof-of-concept greenhouse column study, Al-WTR was surface-applied at 0, 62, 124, and 248 Mg/ha to 15 cm of soil on top of 46 cm of sand; Al-WTR rates were estimated to capture 0, 10, 20, and 40 year...

  3. HISTORIC WETLANDS OF PRUDENCE ISLAND

    EPA Science Inventory

    Ten wetland sites around Narragansett Bay, Rhode Island have been selected for a multidisciplinary study. These wetland sites are being studied to develop indicators of "wetland health." The study includes assessing the ecological conditions of the wetlands in the past, and the c...

  4. National Wetlands Inventory products

    USGS Publications Warehouse

    ,

    1999-01-01

    Marshes, swamps, ponds, and bogs are teeming biological nurseries for migratory birds, fish, and aquatic plants. They also provide natural flood and erosion control. These predominantly wet areas, or wetlands as they are commonly called, now represent only about 5 percent of the land surface of the lower 48 States. Out of 221 million acres of wetlands that once existed in the conterminous United States, the U.S. Fish and Wildlife Service (FWS) estimates that only about 103.3 million acres remain. Each year, development, drainage, and agriculture eliminate another 290,000 acres - an area a little less than half the size of Rhode Island. From the 1950's to the 1970's, conversion of wetlands to farmland caused 87 percent of all wetland losses. The FWS has long recognized the importance of America's wetlands because they form breeding and wintering grounds for great numbers of migratory birds. In 1977, the FWS began the National Wetlands Inventory (NWI), a systematic effort to classify and map America's remaining wetlands.

  5. Neotropical coastal wetlands

    USGS Publications Warehouse

    McKee, Karen L.; Batzer, Darold P.; Baldwin, Andrew H.

    2012-01-01

    The Neotropical region, which includes the tropical Americas, is one of the world's eight biogeographic zones. It contains some of the most diverse and unique wetlands in the world, some of which are still relatively undisturbed by humans. This chapter focuses on the northern segment of the Neotropics (south Florida, the Caribbean islands, Mexico, and Central America), an area that spans a latitudinal gradient from about 7 N to 29 N and 60 W to 112 W. Examples of coastal wetlands in this realm include the Everglades (Florida, USA), Ten Thousand Islands (Florida, USA), Laguna de Terminos (Mexico), Twin Cays (Belize), and Zapata Swamp (Cuba). Coastal wetlands are dominated by mangroves, which will be emphasized here, but also include freshwater swamps and marshes, saline marshes, and seagrass beds. The aim of this chapter is to provide a broad overview of Neotropical coastal wetlands of the North American continent, with an emphasis on mangroves, since this is the dominant vegetation type and because in-depth coverage of all wetland types is impossible here. Instead, the goal is to describe the environmental settings, plant and animal communities, key ecological controls, and some conservation concerns, with specific examples. Because this book deals with wetlands of North America, this chapter excludes coastal wetlands of South America. However, much of the information is applicable to mangrove, marsh, and seagrass communities of other tropicaI regions.

  6. Use of Constructed Wetlands for Polishing Recharge Wastewater

    NASA Astrophysics Data System (ADS)

    Cardwell, W.

    2009-12-01

    The use of constructed wetlands for waste water treatment is becoming increasingly popular as more focus is being shifted to natural means of waste treatment. These wetlands employ processes that occur naturally and effectively remove pollutants and can greatly minimize costs when compared to full scale treatment plants. Currently, wetland design is based on basic “rules-of-thumb,” meaning engineers have a general understanding but not necessarily a thorough knowledge of the intricate physical, biological, and chemical processes involved in these systems. Furthermore, there is very little consideration given to use the wetland as a recharge pond to allow the treated water to percolate and recharge the local groundwater aquifers. The City of Foley, located in Alabama, and the Utilities Board of the City of Foley partnered with Wolf Bay Watershed Watch to evaluate alternative wastewater effluent disposal schemes. Rather than discharging the treated water into a local stream, a pilot program has been developed to allow water from the treatment process to flow into a constructed wetlands area where, after natural treatment, the treated water will then be allowed to percolate into a local unconfined aquifer. The goal of this study is to evaluate how constructed wetlands can be used for “polishing” effluent as well as how this treated water might be reused. Research has shown that constructed wetlands, with proper design and construction elements, are effective in the treatment of BOD, TSS, nitrogen, phosphorous, pathogens, metals, sulfates, organics, and other substances commonly found in wastewater. Mesocosms will be used to model the wetland, at a much smaller scale, in order to test and collect data about the wetland treatment capabilities. Specific objectives include: 1. Determine optimum flow rates for surface flow wetlands where water treatment is optimized. 2. Evaluate the capabilities of constructed wetlands to remove/reduce common over the counter

  7. The effect of phorate on wetland macroinvertebrates

    USGS Publications Warehouse

    Dieter, Charles D.; Flake, Lester D.; Duffy, Walter G.

    1996-01-01

    The effects of phorate, an organophosphorus insecticide, on aquatic macroinvertebrates was studied in littoral mesocosms in South Dakota wetlands. In 1991 and 1992, four mesocosms were constructed in each of three wetlands. In each wetland, one mesocosm was a reference and phorate concentrations of 1.2, 2.4, and 4.8 kg/ha were applied to treatment mesocosms. Phorate caused mortality to amphipods and chironomids throughout the study. Leeches and snails were resistant to phorate. Few living macroinvertebrates were present in mesocosms after phorate treatment and populations recovered only slightly after 1 month. Macroinvertebrate taxa that were sensitive to phorate included: Odonata, Hemiptera, Culicidae, Heliidae, Ephemeroptera, Acarina, Coleoptera, Stratio-myidae, and Hydracarina. Taxa that were tolerant to phorate included: Hirudinea, Gastropoda, Oligochaeta, and Ostracoda.

  8. Control of non-point source pollution by a natural wetland.

    PubMed

    Kao, C M; Wu, M J

    2001-01-01

    Wetland creation and restoration is a reliable and efficient technology for the remediation of contaminated water. Knowledge from the natural wetland systems would be necessary to enhance the operational efficiency of constructed wetlands. In this study, a mountainous wetland located in McDowell County, North Carolina, USA was selected to demonstrate the effects of the natural filtration and restoration system on the maintenance of surface water quality. The hydraulic retention time (HRT) for the wetland was 10.5 days based on the results from a dye release study. Water quality monitoring of the wetland was conducted from May to August 1997. One major storm event and baseline water quality samples were collected and analyzed. Analytical results indicate that this wetland removed a significant amount of non-point source (NPS) pollutants [more than 80% N removal, 91% of total suspended solid removal, 59% of total phosphorus removal, and 66% of chemical oxygen demand (COD) removal] caused by the studied storm event. Sediment accretion monitoring results indicate that the accretion rate in the wetland was only 4 mm/year. Therefore, the wetland would require 100 years to fill at the measured sediment accretion rate. The high organic content of sediments (16%) indicates that the wetland is building the characteristic organic layer on the bottom of the wetland. Results from this study would be very useful in the maintenance of natural wetlands and design of constructed wetlands for water treatment.

  9. Response of aquatic invertebrates to ecological rehabilitation of Southeastern USA depressional wetlands.

    SciTech Connect

    Batzer, Donald P.; Taylor, Barbera E.

    2015-07-02

    Abstract We assessed aquatic invertebrate response to ecological rehabilitation treatment in 20 depression wetlands on the Savannah River Site, South Carolina, USA. All wetlands had been ditched for 50+ years. Sixteen of the 20 wetlands received rehabilitation treatment, and four wetlands remained untreated as a control group. Treatment included logging of all trees, plugging drainage ditches, and planting wetland trees and grasses. Hydroperiods were consequently extended in most of the treatment wetlands. As part a larger study, we sampled macroinvertebrates and microcrustaceans during the pre-habilitation (1998–2000) and rehabilitation (2001–2003) phases. Our study spanned 2 years of high rainfall (1998 andmore » 2003) and 4 years of low rainfall (1999–2002). Samples were collected bimonthly from any wetlands holding water. Macroinvertebrate assemblages in treatment wetlands in 2003 had changed from previous years (1998–2002) and compared to control wetlands (1998–2003), with abundances of Baetidae, Coenagrionidae, Dytiscidae, Chironomidae, and Chaoboridae driving variation. For microcrustaceans (Copepoda and Branchiopoda, including Cladocera, Anostraca and Laevicaudata), assemblage composition and species richness responded mainly to hydrologic conditions. Rehabilitation efforts in these wetlands induced diverse and abundant invertebrate communities to develop, but some responses appeared opportunistic; several taxa that benefitted were not typical residents of depressional wetlands in the region.« less

  10. Response of Aquatic Invertebrates to Ecological Rehabilitation of Southeastern USA Depressional Wetlands

    SciTech Connect

    Batzer, Darold P.; Taylor, Barbara E.; DeBiase, Adrienne E.

    2015-07-02

    We assessed aquatic invertebrate response to ecological rehabilitation treatment in 20 depression wetlands on the Savannah River Site, South Carolina, USA. All wetlands had been ditched for 50+ years. Sixteen of the 20 wetlands received rehabilitation treatment, and four wetlands remained untreated as a control group. Treatment included logging of all trees, plugging drainage ditches, and planting wetland trees and grasses. Hydroperiods were consequently extended in most of the treatment wetlands. As part a larger study, we sampled macroinvertebrates and microcrustaceans during the pre-habilitation (1998–2000) and rehabilitation (2001–2003) phases. Our study spanned 2 years of high rainfall (1998 and 2003)more » and 4 years of low rainfall (1999–2002). Samples were collected bimonthly from any wetlands holding water. Macroinvertebrate assemblages in treatment wetlands in 2003 had changed from previous years (1998–2002) and compared to control wetlands (1998–2003), with abundances of Baetidae, Coenagrionidae, Dytiscidae, Chironomidae, and Chaoboridae driving variation. For microcrustaceans (Copepoda and Branchiopoda, including Cladocera, Anostraca and Laevicaudata), assemblage composition and species richness responded mainly to hydrologic conditions. Rehabilitation efforts in these wetlands induced diverse and abundant invertebrate communities to develop, but some responses appeared opportunistic; several taxa that benefitted were not typical residents of depressional wetlands in the region.« less

  11. Effects of vegetations and temperature on nutrient removal and microbiology in horizontal subsurface low constructed wetland for treatment of domestic sewage

    USDA-ARS?s Scientific Manuscript database

    The direct discharge of untreated domestic wastewater represents a major source of nutrients entering into aquatic environments, which may cause serious ecological problems, e.g., eutrophication. In this regard, low-cost and easily managed technologies such as constructed wetlands (CWs) provide a go...

  12. Review of Constructed Subsurface Flow vs. Surface Flow Wetlands

    SciTech Connect

    HALVERSON, NANCY

    2004-09-01

    The purpose of this document is to use existing documentation to review the effectiveness of subsurface flow and surface flow constructed wetlands in treating wastewater and to demonstrate the viability of treating effluent from Savannah River Site outfalls H-02 and H-04 with a subsurface flow constructed wetland to lower copper, lead and zinc concentrations to within National Pollutant Discharge Elimination System (NPDES) Permit limits. Constructed treatment wetlands are engineered systems that have been designed and constructed to use the natural functions of wetlands for wastewater treatment. Constructed wetlands have significantly lower total lifetime costs and often lower capital costs thanmore » conventional treatment systems. The two main types of constructed wetlands are surface flow and subsurface flow. In surface flow constructed wetlands, water flows above ground. Subsurface flow constructed wetlands are designed to keep the water level below the top of the rock or gravel media, thus minimizing human and ecological exposure. Subsurface flow wetlands demonstrate higher rates of contaminant removal per unit of land than surface flow (free water surface) wetlands, therefore subsurface flow wetlands can be smaller while achieving the same level of contaminant removal. Wetlands remove metals using a variety of processes including filtration of solids, sorption onto organic matter, oxidation and hydrolysis, formation of carbonates, formation of insoluble sulfides, binding to iron and manganese oxides, reduction to immobile forms by bacterial activity, and uptake by plants and bacteria. Metal removal rates in both subsurface flow and surface flow wetlands can be high, but can vary greatly depending upon the influent concentrations and the mass loading rate. Removal rates of greater than 90 per cent for copper, lead and zinc have been demonstrated in operating surface flow and subsurface flow wetlands. The constituents that exceed NPDES limits at outfalls H-02

  13. Physiological response curves reveal differences among season advancement and timing of grazing experimental treatments in a coastal Alaskan wetland

    NASA Astrophysics Data System (ADS)

    Leffler, A. J.; Kelsey, K.; Beard, K. H.; Choi, R. T.; Welker, J. M.

    2016-12-01

    The phenology of northern ecosystems is rapidly changing as high latitude regions warm. Spring green-up has advanced 1-3 days per decade since the early 1980's and sea ice retreat is likely to further accelerate the arrival of spring in coastal Alaska. One result of spring advancement is a phenological mismatch with the arrival of migratory geese that bread in the region. As green-up advances, geese arrive into a phenologically older system where vegetation has a higher C:N ratio than younger grasses with potential consequences for goose nutrition and C and N cycling. In 2014 and 2015 we established a season advancement X timing of grazing experiment to examine the ecosystem consequences of this mismatch. We used a LI-Cor 8100 automated, chamber-based C flux system to monitor hourly net ecosystem exchange (NEE) in eight plots: four were warmed in June to advance the growing season, four received ambient temperatures; two each experienced early, typical, late, or no grazing. The experiment is replicated six times, but the automated system is capable of measuring only one block; other blocks are measured twice weekly with a portable system. We fit physiological light response curves to weekly data and used incident sunlight to estimate daily NEE. Results suggest that daily carbon uptake ranged from ca. 0.6 to 4.5 g m-2 d-1 in the different treatments. Carbon uptake in the season advancement plots was lower than in the ambient plots by ca. 0.5 g m-2 d-1 averaged during the summer. Delaying grazing into the later season, the expectation of climate change, greatly increased NEE to 4.5 g m-2 d-1, a value much greater than the typical grazing period in 2015. Completely eliminating grazing from the system resulted in NEE of 2.9 g m-2 d-1. Differences were likely driven by warmer soils enhancing respiration, removal of photosynthetic biomass, and grazing maintaining tissue in a young, highly photosynthetic form. Overall our results suggest that timing of grazing in the

  14. Principles of Wetland Restoration

    EPA Pesticide Factsheets

    the return of a degraded ecosystem to a close approximation of its remaining natural potential - is experiencing a groundswell of support across the United States. The number of stream, river, lake, wetland and estuary restoration projects grows yearly

  15. Excellence in Wetland Programs

    EPA Pesticide Factsheets

    States and tribes play important roles in protecting and restoring wetlands and other water resources by adopting practices within our Core Elements Framework (CEF) to complete various projects. restoration and protection, monitoring and assessment

  16. National Wetland Condition Assessment

    EPA Pesticide Factsheets

    The NWCA is a collaborative, statistical survey of the nation's wetlands. It is one of four national surveys that EPA and its partners conduct to assess the condition and health of the nation's water resources.

  17. The Constructed Wetland Association UK database of constructed wetland systems.

    PubMed

    Cooper, P

    2007-01-01

    There are now more than 1,000 constructed wetland systems (CWs) in the UK. The first UK CW database was constructed by Water Research Centre (WRc) and Severn Trent Water Ltd to accompany a book on the design and performance of these systems. In that database, constructed by Gareth Job et al., only 154 beds were listed, most of which were tertiary sewage treatment sites in Severn Trent Water. The Constructed Wetland Association (CWA) was formed in 2000 as a UK water industry body in response to problems caused by unscrupulous constructors. A group of experienced, reputable designers and constructors formed the CWA to bring together best UK practice in order to counteract this problem. The group contains major water companies, designers, constructors, academics, plant growers and operators. They decided that one of the best ways of countering the problem was to assemble a database of design and performance from well-designed systems. After negotiation the CWA group took over responsibility for the database from WRc. The CWA has produced eight updates of the database which now contains information from more than 900 beds. It contains examples of the different variants of CWs in use in the UK. Most of these sites treat sewage/domestic wastewater but the database also includes examples of systems for the treatment of minewater, sludge, landfill leachate, industrial effluents, surface runoff and road runoff. Particular treatment applications are illustrated by case studies which are summary articles describing design, construction and performance.

  18. Wetlands may clean geothermal water

    NASA Astrophysics Data System (ADS)

    Development of geothermal resources may help to ease energy problems, but water quality problems could result from the disposal of spent geothermal brines. Research by EG&G Idaho shows that man-made wetlands may provide a more economic disposal system than do conventional treatment and disposal methods.Most geothermal water contains high concentrations of dissolved solids and trace elements, including fluoride and boron, which can be harmful to water quality and organisms. Because of these high concentrations, only a limited number of methods can be used to dispose of used geothermal water. These include injection wells, evaporation ponds, and disposal into surface waterways.

  19. Effect of by-pass and effluent recirculation on nitrogen removal in hybrid constructed wetlands for domestic and industrial wastewater treatment.

    PubMed

    Torrijos, V; Gonzalo, O G; Trueba-Santiso, A; Ruiz, I; Soto, M

    2016-10-15

    Hybrid constructed wetlands (CWs) including subsurface horizontal flow (HF) and vertical flow (VF) steps look for effective nitrification and denitrification through the combination of anaerobic/anoxic and aerobic conditions. Several CW configurations including several configurations of single pass systems (HF + HF, VF + VF, VF + HF), the Bp(VF + HF) arrangement (with feeding by-pass) and the R(HF + VF) system (with effluent recirculation) were tested treating synthetic domestic wastewater. Two HF/VF area ratios (AR) were tested for the VF + HF and Bp(VF + HF) systems. In addition, a R(VF + VF) system was tested for the treatment of a high strength industrial wastewater. The percentage removal of TSS, COD and BOD5 was usually higher than 95% in all systems. The single pass systems showed TN removal below the threshold of 50% and low removal rates (0.6-1.2 g TN/m(2) d), except the VF + VF system which reached 63% and 3.5 g TN/m(2) d removal but only at high loading rates. Bp(VF + HF) systems required by-pass ratios of 40-50% and increased TN removal rates to approximately 50-60% in a sustainable manner. Removal rates depended on the AR value, increasing from 1.6 (AR 2.0) to 5.2 g TN/m(2) d (AR 0.5), both working with synthetic domestic wastewater. On real domestic wastewater the Bp (VF + HF) (AR 0.5 and 30% by-pass) reached 2.5 g TN/m(2) d removal rate. Effluent recirculation significantly improved the TN removal efficiency and rate. The R(HF + VF) system showed stable TN removals of approximately 80% at loading rates ranging from 2 to 8 g TN/m(2) d. High TN removal rates (up to 73% TN and 8.4 g TN/m(2) d) were also obtained for the R(VF + VF) system treating industrial wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. A study on the effects of different hydraulic loading rates (HLR) on pollutant removal efficiency of subsurface horizontal-flow constructed wetlands used for treatment of domestic wastewaters.

    PubMed

    Çakir, Recep; Gidirislioglu, Ali; Çebi, Ulviye

    2015-12-01

    The research into the treatment of domestic wastewaters originating from Büyükdöllük village in Edirne Province was carried out over a 3 year experimental period. The wastewaters of the settlement were treated using a constructed wetland with subsurface horizontal flow, and the effects of different hydraulic loading levels on removal efficiency were studied. In order to achieve this goal, three equal chambers (ponds) of 300 m(2) each were constructed and planted with Phragmites australis. Each of the chambers was loaded with domestic wastewater with average flow discharge creating hydraulic loading rates of 0. m(3) day(-1) m(-2); 0.075 m(3) day(-1) m(-2) and 0.125 m(3) day(-1) m(-2), respectively. According to the results of the study, the inlet levels of the pollutant parameters with carbon origin in the water samples taken from the system entrance are high and the average values for three years are respectively: Biological Oxygen Demand, BOD5 -324.5 mg L(-1); Chemical Oxygen Demand, COD -484,0 mg L(-1); suspended solids (TSS) -147.3 mg L(-1) and Oil and Grease -0.123 mg L(-1). It was also determined that the removal rates of the system were closely dependent on the applied hydraulic loading levels and the highest removal rates of 64.9%, 62.5%, 86.3% and 80.34% for BOD5, COD, TSS and Oil and Grease, respectively, were determined in the pond with a hydraulic loading rate of 0.050 m(3) day(-1) m(-2). Lower removal of 57.9%, 55.5%, 81.4% and 74.5% for BOD5, COD, TSS and Oil and Grease were recorded in the pond with a hydraulic loading rate of 0.075 m(3) day(-1) m(-2); and these values were 49.1%, 47.8%, 70.9% and 62.1% for the pond with a hydraulic loading rate of 0.125 m(3) day(-1) m(-2). High removal rates were also recorded for the other investigated pollution parameters. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Coastal wetlands of Chesapeake Bay

    USGS Publications Warehouse

    Baldwin, Andrew H.; Kangas, Patrick J.; Megonigal, J. Patrick; Perry, Matthew C.; Whigham, Dennis F.; Batzer, Darold P.; Batzer, Darold P.; Baldwin, Andrew H.

    2012-01-01

    Wetlands are prominent landscapes throughout North America. The general characteristics of wetlands are controversial, thus there has not been a systematic assessment of different types of wetlands in different parts of North America, or a compendium of the threats to their conservation. Wetland Habitats of North America adopts a geographic and habitat approach, in which experts familiar with wetlands from across North America provide analyses and syntheses of their particular region of study. Addressing a broad audience of students, scientists, engineers, environmental managers, and policy makers, this book reviews recent, scientifically rigorous literature directly relevant to understanding, managing, protecting, and restoring wetland ecosystems of North America.

  2. [Research progress on wetland ecotourism].

    PubMed

    Wang, Li-Long; Lu, Lin

    2009-06-01

    Wetland is rich in biodiversity and cultural diversity, possessing higher tourism value and environmental education and community participation functions. Wetland ecotourism reflects the sustainable development of tourism economy and wetland protection, having received great concern from governments and scholars at home and abroad. This paper summarized the related theories and practices, discussed the research advances in wetland ecotourism from the aspects of significance, progress, contents, methods and results, and pointed out the important research fields in the future, aimed to accelerate the development of wetland ecotourism research and to provide reference about the resources exploitation, environment protection, and scientific administration of wetland and related scenic areas.

  3. Constructed wetlands as biofuel production systems

    NASA Astrophysics Data System (ADS)

    Liu, Dong; Wu, Xu; Chang, Jie; Gu, Baojing; Min, Yong; Ge, Ying; Shi, Yan; Xue, Hui; Peng, Changhui; Wu, Jianguo

    2012-03-01

    Clean biofuel production is an effective way to mitigate global climate change and energy crisis. Progress has been made in reducing greenhouse-gas (GHG) emissions and nitrogen fertilizer consumption through biofuel production. Here we advocate an alternative approach that efficiently produces cellulosic biofuel and greatly reduces GHG emissions using waste nitrogen through wastewater treatment with constructed wetlands in China. Our combined experimental and literature data demonstrate that the net life-cycle energy output of constructed wetlands is higher than that of corn, soybean, switchgrass, low-input high-diversity grassland and algae systems. Energy output from existing constructed wetlands is ~237% of the input for biofuel production and can be enhanced through optimizing the nitrogen supply, hydrologic flow patterns and plant species selection. Assuming that all waste nitrogen in China could be used by constructed wetlands, biofuel production can account for 6.7% of national gasoline consumption. We also find that constructed wetlands have a greater GHG reduction than the existing biofuel production systems in a full life-cycle analysis. This alternative approach is worth pursuing because of its great potential for straightforward operation, its economic competitiveness and many ecological benefits.

  4. Graywater Treatment Using Constructed Wetlands

    EPA Science Inventory

    Mounting pressure to conserve water resources has prompted the notion that the separation of graywater from sewerage through the use of dual-plumbed systems may enable graywater to be reused at the household level for such non-potable demands as landscape irrigation or toilet flu...

  5. Do created wetlands replace the wetlands that are destroyed?

    USGS Publications Warehouse

    Hunt, Randall J.

    1997-01-01

    Wetlands, once perceived as worthless land, are now recognized as a necessary component of a vital landscape. However, due to draining and filling we have lost many of our wetlands. The loss of wetlands can have undesirable effects on the landscape, such as erosion, flooding, habitat loss and deterioration of water quality. While natural wetland systems are being destroyed nationwide, the wetlands restored or created to compensate for these losses are commonly not evaluated or contain large percentages of non-wetland acreage. At the present time we do not have established methodology that can uniformly evaluate a wetland's function, or that is useful for providing guidelines that enhance wetland restoration/creation success.

  6. Assessment of nutrient retention by Natete wetland Kampala, Uganda

    NASA Astrophysics Data System (ADS)

    Kanyiginya, V.; Kansiime, F.; Kimwaga, R.; Mashauri, D. A.

    Natete wetland which is located in a suburb of Kampala city in Uganda is dominated by C yperus papyrus and covers an area of approximately 1 km 2. The wetland receives wastewater and runoff from Natete town which do not have a wastewater treatment facility. The main objective of this study was to assess nutrient retention of Natete wetland and specifically to: determine the wastewater flow patterns in the wetland; estimate the nutrient loads into and out of the wetland; determine the nutrient retention by soil, plants and water column in the wetland; and assess the above and belowground biomass density of the dominant vegetation. Soil, water and plant samples were taken at 50 m intervals along two transects cut through the wetland; soil and water samples were taken at 10 cm just below the surface. Physico-chemical parameters namely pH, electrical conductivity and temperature were measured in situ. Water samples were analyzed in the laboratory for ammonium-nitrogen, nitrate-nitrogen, total nitrogen, orthophosphate and total phosphorus. Electrical conductivity ranged between 113 μS/cm and 530 μS/cm and the wastewater flow was concentrated on the eastern side of the wetland. pH varied between 6 and 7, temperature ranged from 19 °C to 24 °C. NH 4-N, NO 3-N, and TN concentrations were retained by 21%, 98%, and 35% respectively. Phosphorus concentration was higher at the outlet of the wetland possibly due to release from sediments and leaching. Nutrient loads were higher at the inlet (12,614 ± 394 kgN/day and 778 ± 159 kgP/day) than the outlet (2368 ± 425 kgN/day and 216 ± 56 kgP/day) indicating retention by the wetland. Plants stored most nutrients compared to soil and water. The belowground biomass of papyrus vegetation in the wetland was higher (1288.4 ± 8.3 gDW/m 2) than the aboveground biomass (1019.7 ± 13.8 gDW/m 2). Plant uptake is one of the important routes of nutrient retention in Natete wetland. It is recommended that harvesting papyrus can be an

  7. Influence of UV radiation on chlorophyll, and antioxidant enzymes of wetland plants in different types of constructed wetland.

    PubMed

    Xu, Defu; Wu, Yinjuan; Li, Yingxue; Howard, Alan; Jiang, Xiaodong; Guan, Yidong; Gao, Yongxia

    2014-09-01

    A surface- and vertical subsurface-flow-constructed wetland were designed to study the response of chlorophyll and antioxidant enzymes to elevated UV radiation in three types of wetland plants (Canna indica, Phragmites austrail, and Typha augustifolia). Results showed that (1) chlorophyll content of C. indica, P. austrail, and T. augustifolia in the constructed wetland was significantly lower where UV radiation was increased by 10 and 20 % above ambient solar level than in treatment with ambient solar UV radiation (p < 0.05). (2) The malondialdehyde (MDA) content, guaiacol peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities of wetland plants increased with elevated UV radiation intensity. (3) The increased rate of MDA, SOD, POD, and CAT activities of C. indica, P. australis, and T. angustifolia by elevated UV radiation of 10 % was higher in vertical subsurface-flow-constructed wetland than in surface-flow-constructed wetland. The sensitivity of MDA, SOD, POD, and CAT activities of C. indica, P. austrail, and T. augustifolia to the elevated UV radiation was lower in surface-flow-constructed wetland than in the vertical subsurface-flow-constructed wetland, which was related to a reduction in UV radiation intensity through the dissolved organic carbon and suspended matter in the water. C. indica had the highest SOD and POD activities, which implied it is more sensitive to enhanced UV radiation. Therefore, different wetland plants had different antioxidant enzymes by elevated UV radiation, which were more sensitive in vertical subsurface-flow-constructed wetland than in surface-flow-constructed wetland.

  8. Association between wetland disturbance and biological attributes in floodplain wetlands

    USGS Publications Warehouse

    Chipps, S.R.; Hubbard, D.E.; Werlin, K.B.; Haugerud, N.J.; Powell, K.A.; Thompson, John; Johnson, T.

    2006-01-01

    We quantified the influence of agricultural activities on environmental and biological conditions of floodplain wetlands in the upper Missouri River basin. Seasonally-flooded wetlands were characterized as low impact (non-disturbed) or high impact (disturbed) based on local land use. Biological data collected from these wetlands were used to develop a wetland condition index (WCI). Fourteen additional wetlands were sampled to evaluate the general condition of seasonally-flooded floodplain wetlands. Structural and functional attributes of macrophyte, algae, and macroinvertebrate communities were tested as candidate metrics for assessing biotic responses. The WCI we developed used six biological metrics to discriminate between disturbed and non-disturbed wetlands: 1) biomass of Culicidae larvae, 2) abundance of Chironomidae larvae, 3) macroinvertebrate diversity, 4) total number of plant species, 5) the proportion of exotic plant species, and 6) total number of sensitive diatom species. Disturbed wetlands had less taxa richness and species diversity and more exotic and nuisance (e.g., mosquitoes) species. Environmental differences between low and high impact wetlands included measures of total potassium, total phosphorus, total nitrogen, alkalinity, conductance, and sediment phosphorus concentration. Canonical analyses showed that WCI scores were weakly correlated (P = 0.057) with environmental variables in randomly selected wetlands. In addition, mean WCI score for random wetlands was higher than that for high impact wetlands, implying that floodplain wetlands were less impacted by the types of agricultural activities affecting high impact sites. Inter-year sampling of some wetlands revealed that WCI metrics were correlated in 2000 and 2001, implying that biological metrics provided useful indicators of disturbance in floodplain wetlands. ?? 2006, The Society of Wetland Scientists.

  9. Effect of a constructed wetland on disinfection byproducts: Removal processes and production of precursors

    USGS Publications Warehouse

    Rostad, C.E.; Martin, B.S.; Barber, L.B.; Leenheer, J.A.; Daniel, S.R.

    2000-01-01

    The fate of halogenated disinfection byproducts (DBPs) in treatment wetlands and the changes in the DBP formation potential as wastewater treatment plant (WWTP)-derived water moves through the wetlands were investigated. Wetland inlet and outlet samples were analyzed for total organic halide (TOX), trihalomethanes (TH M), haloacetic acids (HAA), dissolved organic carbon (DOC), and UV absorbance. Removal of DBPs by the wetland ranged from 13 to 55% for TOX, from 78 to 97% for THM, and from 67 to 96% for HAA. The 24-h and 7-day nonpurgeable total organic halide (NPTOX), THM, and HAA formation potential yields were determined at the inlet and outlet of these wetlands. The effect of wetlands on the production of DBP precursors and their DBP-formation potential yield from wastewater was dramatic. The wetlands increased DBP yield up to a factor of almost 30. Specific changes in the DOC precursors were identified using 13C NMR spectroscopy.The fate of halogenated disinfection byproducts (DBPs) in treatment wetlands and the changes in the DBP formation potential as wastewater treatment plant (WWTP)-derived water moves through the wetlands were investigated. Wetland inlet and outlet samples were analyzed for total organic halide (TOX), trihalomethanes (THM), haloacetic acids (HAA), dissolved organic carbon (DOC), and UV absorbance. Removal of DBPs by the wetland ranged from 13 to 55% for TOX, from 78 to 97% for THM, and from 67 to 96% for HAA. The 24-h and 7-day nonpurgeable total organic halide (NPTOX), THM, and HAA formation potential yields were determined at the inlet and outlet of these wetlands. The effect of wetlands on the production of DBP precursors and their DBP-formation potential yield from wastewater was dramatic. The wetlands increased DBP yield up to a factor of almost 30. Specific changes in the DOC precursors were identified using 13C NMR spectroscopy.

  10. North Atlantic Coastal Tidal Wetlands

    EPA Science Inventory

    The book chapter provides college instructors, researchers, graduate and advanced undergraduate students, and environmental consultants interested in wetlands with foundation information on the ecology and conservation concerns of North Atlantic coastal wetlands. The book c...

  11. National Wetlands Mitigation Action Plan

    EPA Pesticide Factsheets

    On December 26, 2002, EPA and the Corps of Engineers announced the release of a comprehensive, interagency National Wetlands Mitigation Action Plan to further achievement of the goal of no net loss of wetlands.

  12. Wetlands Restoration Definitions and Distinctions

    EPA Pesticide Factsheets

    Ecological restoration is a valuable endeavor that has proven very difficult to define. The term indicates that degraded and destroyed natural wetland systems will be reestablished to sites where they once existed. But, what wetland ecosystems are we talki

  13. Wetland Management - A Success Story In Transition - Restoration of Bhoj Wetland, India

    NASA Astrophysics Data System (ADS)

    Mudgal, M. K.; Tech, B. M.; Miwwa

    Wetlands are beautiful, biologically diverse, hydrologically disperse and ecological vibrant landscape world wide, embracing soils, water, plants, animals and human be- ing. The population growth in the catchment of wetlands led to multifarious human interventions for deriving maximum benefit from the wetlands and their catchments neglecting and disrespecting the principles of sustainability. This act of destruction has been pronounced in developing countries which are under the grip of poverty, illiteracy and lack of environmental education. SBhoj WetlandS is a Lake situated ´ in Central India, Earthen Dam across the river KOLANS in 1061 AD by then ruler king BHOJ. Till 1950 this Wetland was served as a principal source of water supply, even not requiring filtration. As the city grew and the wetland started getting encir- cled by habitation and urban development, the anthropogenic pressures on the lake increased, thus accelerating the process of eutrophication, making the water unfit for human consumption without due treatment due to deterioration of quality of water. For the conservation and management of Bhoj Wetland (Lake Bhopal) a project is under- taken in the financial assistance from Japan Bank for International Cooperation (JBIC, Japan). The project envisages tackle various issues of conservation and management ofn the wetlands under a multi prongs strategies and manner. Although these issues are deeply interrelated and interlinked but for operational and management ease, these issues have been divided into various sub projects which are being tackled indepen- dently, albeit with undercurrent knowledge and understanding of the related issues and interconnectivity with each other. The Project itself is an apt example of the spectrum of varied problems and issues that come to light when attempts are made for sustain- able conservation and management of a wetland. The Project as envisaged intends to conserve and manage through 14 sub projects as under:- Sub

  14. Wetland Mapping: History and Trends

    USDA-ARS?s Scientific Manuscript database

    Historically, the biologic, aesthetic, and economic values of wetlands were largely unappreciated. Wetlands within the United States have been and are continuing to disappear at a rapid rate. Efforts are being made to conserve remaining wetlands and many regulatory policies have been adopted in su...

  15. Developing a New Wetland Habitat

    ERIC Educational Resources Information Center

    Bernard, Rosalie

    2006-01-01

    This article features a project at Ohio's Miami Valley Career Technology Center (MVCTC) which has made a real difference in the wetland environment on campus. The goals of the wetland project were to replace a poorly functioning tile system and develop two wetland areas for local and migratory wildlife. The environmental/natural resources students…

  16. Wetland soils, hydrology and geomorphology

    Treesearch

    C. Rhett Jackson; James A. Thompson; Randall K. Kolka

    2014-01-01

    The hydrology, soils, and watershed processes of a wetland all interact with vegetation and animals over time to create the dynamic physical template upon which a wetland's ecosystem is based (Fig. 2.1). With respect to many ecosystem processes, the physical factors defining a wetland environment at any particular time are often treated as independent variables,...

  17. Wetlands: water, wildlife, plants, & people

    USGS Publications Warehouse

    Vandas, Stephen; Farrar, Frank

    1996-01-01

    Wetlands are part of all our lives. They can generally be described as transitional areas between land and deepwater habitats. There are many different kinds of wetlands, and they can be found in many different habitat types, from forests to deserts; some are maintained by saltwater, others by freshwater. This poster shows general types of diverse wetlands and demonstrates how people and wetlands can benefit by living together. The diversity of plants and animals is shown in cartooned pictures. As with plants and animals, there are many different common names for the various wetland types. The common names used on this poster were used by the U.S. Fish and Wildlife Service in the publication "Wetlands-Status and Trends in the Conterminous United States, Mid-1970's to Mid-1980's." Estuarine wetland types--salt marshes and mangrove swamps--are labeled in red letters. The estuary is where ocean saltwater and river freshwater mix. The estuary is labeled in orange letters. The inland wetland types-inland marshes and wet meadows, forested wetlands, and shrub wetlands-are labeled in yellow. Other wetlands are present in rivers, lakes, and reservoirs. The water bodies associated with these wetlands are labeled in black. The poster is folded into 8.5" x 11" panels; front and back panels can easily be photocopied.

  18. Evaluating the significance of wetland restoration scenarios on phosphorus removal.

    PubMed

    Daneshvar, Fariborz; Nejadhashemi, A Pouyan; Adhikari, Umesh; Elahi, Behin; Abouali, Mohammad; Herman, Matthew R; Martinez-Martinez, Edwin; Calappi, Timothy J; Rohn, Bridget G

    2017-05-01

    Freshwater resources are vital for human and natural systems. However, anthropogenic activities, such as agricultural practices, have led to the degradation of the quality of these limited resources through pollutant loading. Agricultural Best Management Practices (BMPs), such as wetlands, are recommended as a valuable solution for pollutant removal. However, evaluation of their long-term impacts is difficult and requires modeling since performing in-situ monitoring is expensive and not feasible at the watershed scale. In this study, the impact of natural wetland implementation on total phosphorus reduction was evaluated both at the subwatershed and watershed levels. The study area is the Saginaw River Watershed, which is largest watershed in Michigan. The phosphorus reduction performances of four different wetland sizes (2, 4, 6, and 8 ha) were evaluated within this study area by implementing one wetland at a time in areas identified to have the highest potential for wetland restoration. The subwatershed level phosphorus loads were obtained from a calibrated Soil and Water Assessment Tool (SWAT) model. These loads were then incorporated into a wetland model (System for Urban Stormwater Treatment and Analysis IntegratioN-SUSTAIN) to evaluate phosphorus reduction at the subwatershed level and then the SWAT model was again used to route phosphorus transport to the watershed outlet. Statistical analyses were performed to evaluate the spatial impact of wetland size and placement on phosphorus reduction. Overall, the performance of 2 ha wetlands in total phosphorus reduction was significantly lower than the larger sizes at both the subwatershed and watershed levels. Regarding wetland implementation sites, wetlands located in headwaters and downstream had significantly higher phosphorus reduction than the ones located in the middle of the watershed. More specifically, wetlands implemented at distances ranging from 200 to 250 km and 50-100 km from the outlet had the

  19. Field test results for nitrogen removal by the constructed wetland component of an agricultural water recycling system

    USDA-ARS?s Scientific Manuscript database

    Wetland Reservoir Subirrigation Systems (WRSIS) are innovative agricultural water recycling systems that can provide economic and environmental benefits. A constructed wetland is a main component of WRSIS, and an important function of this constructed wetland is drainage water treatment of nitrog...

  20. Nitrogen compounds in drain sewage after constructed wetlands.

    PubMed

    Paweska, K; Malczewska, B

    2009-01-01

    Constructed wetlands, commonly known as ground filters, are well suited mostly for wastewater treatment in areas with no central sewage system. The basic difficulty with exploitation of constructed wetlands is connected with irregular hydraulic overload of its surface. However, irregular wastewater inflow can be reduced by cyclical irrigation which increases efficiency. The unquestionable advantage of the constructed wetlands is inexpensive construction and exploitation as well as low energy consumption. The constructed wetlands also fit very well in surrounding area. The investigation concerned the analysis of two constructed wetlands which are composed of mechanical separation (septic tank) and a filter bed with subsurface flow. The research has been undertaken in a period from July to December 2008, with regard to concentration distribution of nitrogen compounds in municipal sewage after constructed wetlands. The preliminary investigation on constructed wetland which has been exploited for 10 years showed variable removal efficiency of nitrogen compounds. The continuation of the research can indicate the efficiency of wastewater treatment in summer and winter season.

  1. Wetland and water supply

    USGS Publications Warehouse

    Baker, John Augustus

    1960-01-01

    The Geological Survey has received numerous inquiries about the effects of proposed changes in the wetland environment. The nature of the inquiries suggests a general confusion in the public mind as to wetland values and an increasing concern by the public with the need for facts as a basis for sound decisions when public action is required. Perhaps the largest gap in our knowledge is in regard to the role played by the wetland in the natural water scheme. Specialists in such fields as agriculture and conservation have studied the wetland in relation to its special uses and values for farming and as a habitat for fish and wildlife. However, except as studied incidentally by these specialists, the role of the wetland with respect to water has been largely neglected. This facet of the wetland problem is of direct concern to the Geological Survey. We commonly speak of water in terms of its place in the hydrologic environment---as, for example, surface water or ground water. These terms imply that water can be neatly pigeonholed. With respect to the wetland environment nothing can be further from the truth. In fact, one objective of this discussion is to demonstrate that for the wetland environment surface water, ground water, and soil water cannot be separated realistically, but are closely interrelated and must be studied together. It should be noted that this statement holds true for the hydrologic environment in general, and that the wetland environment is by no means unique in this respect. Our second and principal objective is to identify some of the problems that must be studied in order to clarify the role of the wetland in relation to water supply. We have chosen to approach these objectives by briefly describing one area for which we have some information, and by using this example to point out some of the problems that need study. First, however, let us define what we, as geohydrologists, mean by wetland and briefly consider wetland classifications. For our

  2. Remote sensing of wetlands

    NASA Technical Reports Server (NTRS)

    Butera, M. K.

    1983-01-01

    Results are given for three separate investigations of remote sensing over wetlands, including the delineations of roseau cane and mangrove from both Landsat and aircraft MSS data, and the delineation of wetland communities for potential waste assimilation in a coastal river floodplain from Landsat MSS data only. Attention is also given to data processing and analysis techniques of varying levels of sophistication, which must increase with surface cover diversity. All computer processing in these studies was performed on a minicomputer configured with the adequate memory, image display capability, and associated peripherals, using state-of-the-art digital MSS data analysis software.

  3. 77 FR 63326 - Huron Wetland Management District, Madison Wetland Management District, and Sand Lake Wetland...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ..., consistent with sound principles of fish and wildlife management, conservation, legal mandates, and our... FXRS1265066CCP0] Huron Wetland Management District, Madison Wetland Management District, and Sand Lake Wetland Management District, SD; Final Comprehensive Conservation Plan and Finding of No Significant Impact for...

  4. Greenhouse gas emissions from constructed wetlands treating dairy wastewater

    NASA Astrophysics Data System (ADS)

    Glass, Vimy M.

    In Nova Scotia, constructed wetland systems are widely considered as effective treatment systems for agricultural wastewater. Although research has examined the water quality treatment attributes, there has been limited focus on the air quality effects of these systems. Six operational pilot-scale constructed wetlands were built with flow-through chambers for quantifying greenhouse gas (GHG) emissions in Truro, NS. Utilized within this facility were three gas analyzers to monitor GHG emissions (CO2, N 2O, CH4) and the gaseous fluxes could then be determined using the mass balance micrometeorological technique. Prior to data collection, the site underwent testing to ensure valid conclusions and replicated responses from the wetland systems. Those wetlands receiving wastewater at a typical HLR (10.6 mm d-1) and with ample vegetation displayed the best concentration reductions. During the growing season (GS), average CO 2 consumption was large (approximately -44 g CO2m -2 d-1) for wetlands with dense vegetation (approximately 100% cover) at the typical loading rate. For those wetlands at higher loading rates, CO2 emissions were observed to be as high as +9.2 g CO 2m-2 d-1. Wetlands with typical loading rates and healthy aquatic vegetation produced average CH4 fluxes of approximately 43 g CO2 eq. m-2d-1, while higher loaded systems with little vegetation approached 90 g CO 2 eq. m-2d-1. During the non-growing season (NGS), all vegetated wetlands exhibited higher CH4 emissions than the non-vegetated systems (˜15 to 20% higher). Vegetation maturity played a strong role in the GHG balance. The average CO2consumption for wetlands with established vegetation was ˜ -36 g CO2 m -2 d-1 during the GS. Wetland 4, which had been newly transplanted in 2004, had the highest single day CO2 consumption of -152 g CO2m-2 d-1 . Methane emissions from wetlands with two-year-old vegetation followed the same pattern but were approximately half of the emissions recorded from 2003. The

  5. Response of ammonium removal to growth and transpiration of Juncus effusus during the treatment of artificial sewage in laboratory-scale wetlands.

    PubMed

    Wiessner, A; Kappelmeyer, U; Kaestner, M; Schultze-Nobre, L; Kuschk, P

    2013-09-01

    The correlation between nitrogen removal and the role of the plants in the rhizosphere of constructed wetlands are the subject of continuous discussion, but knowledge is still insufficient. Since the influence of plant growth and physiological activity on ammonium removal has not been well characterized in constructed wetlands so far, this aspect is investigated in more detail in model wetlands under defined laboratory conditions using Juncus effusus for treating an artificial sewage. Growth and physiological activity, such as plant transpiration, have been found to correlate with both the efficiency of ammonium removal within the rhizosphere of J. effusus and the methane formation. The uptake of ammonium by growing plant stocks is within in a range of 45.5%, but under conditions of plant growth stagnation, a further nearly complete removal of the ammonium load points to the likely existence of additional nitrogen removal processes. In this way, a linear correlation between the ammonium concentration inside the rhizosphere and the transpiration of the plant stocks implies that an influence of plant physiological activity on the efficiency of N-removal exists. Furthermore, a linear correlation between methane concentration and plant transpiration has been estimated. The findings indicate a fast response of redox processes to plant activities. Accordingly, not only the influence of plant transpiration activity on the plant-internal convective gas transport, the radial oxygen loss by the plant roots and the efficiency of nitrification within the rhizosphere, but also the nitrogen gas released by phytovolatilization are discussed. The results achieved by using an unplanted control system are different in principle and characterized by a low efficiency of ammonium removal and a high methane enrichment of up to a maximum of 72.7% saturation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. An assessment of the performance of municipal constructed wetlands in Ireland.

    PubMed

    Hickey, Anthony; Arnscheidt, Joerg; Joyce, Eadaoin; O'Toole, James; Galvin, Gerry; O' Callaghan, Mark; Conroy, Ken; Killian, Darran; Shryane, Tommy; Hughes, Francis; Walsh, Katherine; Kavanagh, Emily

    2018-03-15

    While performance assessments of constructed wetlands sites around the world have appraised their capacity for effective removal of organics, a large variance remains in these sites' reported ability to retain nutrients, which appears to depend on differences in design, operation and climate factors. Nutrient retention is a very important objective for constructed wetlands, to avoid eutrophication of aquatic environments receiving their effluents. This study assessed the performance of constructed wetlands in terms of nutrient retention and associated parameters under the humid conditions of Ireland's temperate maritime climate. A review of the performance of 52 constructed wetland sites from 17 local authorities aimed to identify the best performing types of constructed wetlands and the treatment factors determining successful compliance with environmental standards. Data analysis compared effluent results from constructed wetlands with secondary free surface flow or tertiary horizontal subsurface flow, hybrid systems and integrated constructed wetlands with those from small-scale mechanical wastewater treatment plants of the same size class. Nutrient concentrations in effluents of constructed wetlands were negatively correlated (p < .01) with specific area, i.e. the ratio of surface area and population equivalents. The latest generation of integrated constructed wetlands, which had applied design guidelines issued by the Department of the Environment, performed best. Storm management design features improved treatment performance of constructed wetlands significantly (p < .05) for total suspended solids concentrations and exceedance frequency of limit values for total nitrogen. Mechanical wastewater treatment plants, secondary free surface water and tertiary horizontal subsurface flow wetlands showed a very large variance in effluent concentrations for organic and nutrient parameters. E. coli numbers in effluents were lowest for integrated constructed

  7. Carbon storage in US wetlands

    PubMed Central

    Nahlik, A. M.; Fennessy, M. S.

    2016-01-01

    Wetland soils contain some of the highest stores of soil carbon in the biosphere. However, there is little understanding of the quantity and distribution of carbon stored in our remaining wetlands or of the potential effects of human disturbance on these stocks. Here we use field data from the 2011 National Wetland Condition Assessment to provide unbiased estimates of soil carbon stocks for wetlands at regional and national scales. We find that wetlands in the conterminous United States store a total of 11.52 PgC, much of which is within soils deeper than 30 cm. Freshwater inland wetlands, in part due to their substantial areal extent, hold nearly ten-fold more carbon than tidal saltwater sites—indicating their importance in regional carbon storage. Our data suggest a possible relationship between carbon stocks and anthropogenic disturbance. These data highlight the need to protect wetlands to mitigate the risk of avoidable contributions to climate change. PMID:27958272

  8. Carbon storage in US wetlands

    NASA Astrophysics Data System (ADS)

    Nahlik, A. M.; Fennessy, M. S.

    2016-12-01

    Wetland soils contain some of the highest stores of soil carbon in the biosphere. However, there is little understanding of the quantity and distribution of carbon stored in our remaining wetlands or of the potential effects of human disturbance on these stocks. Here we use field data from the 2011 National Wetland Condition Assessment to provide unbiased estimates of soil carbon stocks for wetlands at regional and national scales. We find that wetlands in the conterminous United States store a total of 11.52 PgC, much of which is within soils deeper than 30 cm. Freshwater inland wetlands, in part due to their substantial areal extent, hold nearly ten-fold more carbon than tidal saltwater sites--indicating their importance in regional carbon storage. Our data suggest a possible relationship between carbon stocks and anthropogenic disturbance. These data highlight the need to protect wetlands to mitigate the risk of avoidable contributions to climate change.

  9. Ecological and Landscape Drivers of Neonicotinoid Insecticide Detections and Concentrations in Canada's Prairie Wetlands.

    PubMed

    Main, Anson R; Michel, Nicole L; Headley, John V; Peru, Kerry M; Morrissey, Christy A

    2015-07-21

    Neonicotinoids are commonly used seed treatments on Canada's major prairie crops. Transported via surface and subsurface runoff into wetlands, their ultimate aquatic fate remains largely unknown. Biotic and abiotic wetland characteristics likely affect neonicotinoid presence and environmental persistence, but concentrations vary widely between wetlands that appear ecologically (e.g., plant composition) and physically (e.g., depth) similar for reasons that remain unclear. We conducted intensive surveys of 238 wetlands, and documented 59 wetland (e.g., dominant plant species) and landscape (e.g., surrounding crop) characteristics as part of a novel rapid wetland assessment system. We used boosted regression tree (BRT) analysis to predict both probability of neonicotinoid analytical detection and concentration. BRT models effectively predicted the deviance in neonicotinoid detection (62.4%) and concentration (74.7%) from 21 and 23 variables, respectively. Detection was best explained by shallow marsh plant species identity (34.8%) and surrounding crop (13.9%). Neonicotinoid concentration was best explained by shallow marsh plant species identity (14.9%) and wetland depth (14.2%). Our research revealed that plant composition is a key indicator and/or driver of neonicotinoid presence and concentration in Prairie wetlands. We recommend wetland buffers consisting of diverse native vegetation be retained or restored to minimize neonicotinoid transport and retention in wetlands, thereby limiting their potential effects on wetland-dependent organisms.

  10. Inland wetland mineral soils

    Treesearch

    Kimberly P. Wickland; Alex V. Krusche; Randall K. Kolka; Ayaka W. Kishimoto-Mo; Rodney A. Chimner; Stephen Ogle; Nalin. Srivastava

    2013-01-01

    This chapter provides supplementary guidance for estimating and reporting greenhouse gas (GHG) emissions and removals from managed lands with Inland Wetland Mineral Soils (IWMS) for all land-use categories (see Chapter 1 and decision tree in Chapter 1 in this supplement for what is specifically covered in this chapter in relationship to other chapters in this...

  11. Wetlands, Chapter 17

    Treesearch

    T.L. Greaver; L. Liu; R. Bobbink

    2011-01-01

    The U.S. Clean Water Act defines wetlands as "those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions".

  12. Wetlands Mitigation Banking Concepts

    DTIC Science & Technology

    1992-07-01

    Naval Amphibious Bas Eslgrss Mit. Bank CA, San Diego Co. dredging & facilities Dept of the Navy SeaWorld Eelgras Mitigation Dank CA, San Diego Co...shore development, private projects SeaWorld 8 Table 2. WETLAND MITIGATION BANKS UNDER PLANNING, Institute for Water Resources Preliminary Survey Data

  13. Wading into Wetlands.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1986-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Wading into Wetlands." Contents are organized into the following…

  14. Effects of temperature on metal tolerance and the accumulation of Zn and Pb by metal-tolerant fungi isolated from urban runoff treatment wetlands.

    PubMed

    Purchase, D; Scholes, L N L; Revitt, D M; Shutes, R B E

    2009-04-01

    To investigate the ability of two fungi to accumulate Zn and Pb, the effect of temperature on their metal tolerance and possible mechanisms involved in metal accumulation. Beauveria bassiana and Rhodotorula mucilaginosa isolated from constructed wetlands receiving urban runoff were grown in modified glycerol asparagine medium containing elevated levels of Zn and Pb at 30 degrees C. Beauveria bassiana accumulated up to 0.64% of available Zn and 8.44% of Pb. The corresponding values for R. mucilaginosa were up to 2.05% for Zn and 16.55% for Pb. Radial growth of colonies grown at 4 degrees and 30 degrees C on agar containing Zn or Pb indicated that metal tolerance was not seriously affected by a decrease in temperature. Transmission electron microscopy and emission dispersion x-ray spectrophotometry suggested that the mechanism of resistance in B. bassiana may be associated with the precipitation of Pb (possibly in the form of oxalates). The processes of biosorption could potentially occur throughout the year with both living and dead cells able to accumulate metals. Identified precipitation processes could be an important mechanism in metal removal in wetland substrates serving as long-term storage sinks.

  15. Wetland biogeochemistry and ecological risk assessment

    NASA Astrophysics Data System (ADS)

    Bai, Junhong; Huang, Laibin; Gao, Haifeng; Zhang, Guangliang

    2017-02-01

    Wetlands are an important ecotone between terrestrial and aquatic ecosystems and can provide great ecological service functions. Soils/sediments are one of the important components of wetland ecosystems, which support wetland plants and microorganisms and influence wetland productivity. Moreover, wetland soils/sediments serve as sources, sinks and transfers of carbon, nitrogen, phosphorus and chemical contaminants such as heavy metals. In natural wetland ecosystems, wetland soils/sediments play a great role in improving water quality as these chemical elements can be retained in wetland soils/sediments for a long time. Moreover, the biogeochemical processes of the abovementioned elements in wetland soils/sediments can drive wetland evolution and development, and their changes will considerably affect wetland ecosystem health. Therefore, a better understanding of wetland soil biogeochemistry will contribute to improving wetland ecological service functions.

  16. Accumulation of Cd, Pb and Zn by 19 wetland plant species in constructed wetland.

    PubMed

    Liu, Jianguo; Dong, Yuan; Xu, Hai; Wang, Deke; Xu, Jiakuan

    2007-08-25

    Uptake and distribution of Cd, Pb and Zn by 19 wetland plant species were investigated with experiments in small-scale plot constructed wetlands, into which artificial wastewater dosed with Cd, Pb and Zn at concentrations of 0.5, 2.0 and 5.0mgl(-1) was irrigated. The results showed that the removal efficiency of Cd, Pb and Zn from the wastewater were more than 90%. Generally, there were tens differences among the 19 plant species in the concentrations and quantity accumulations of the heavy metals in aboveground part, underground part and whole plants. The distribution ratios into aboveground parts for the metals absorbed by plants varied also largely from about 30% to about 90%. All the plants accumulated, in one harvest, 19.85% of Cd, 22.55% of Pb and 23.75% of Zn that were added into the wastewater. Four plant species, e.g. Alternanthera philoxeroides, Zizania latifolia, Echinochloa crus-galli and Polygonum hydropiper, accumulated high amounts of Cd, Pb and Zn. Monochoria vaginalis was capable for accumulating Cd and Pb, Isachne globosa for Cd and Zn, and Digitaria sanguinalis and Fimbristylis miliacea for Zn. The results indicated that the plants, in constructed wetland for the treatment of wastewater polluted by heavy metals, can play important roles for removal of heavy metals through phytoextraction. Selection of plant species for use in constructed wetland will influence considerably removal efficiency and the function duration of the wetland.

  17. Molecular Characterization of Wetland Soil Bacterial Community in Constructed Mesocosms

    DTIC Science & Technology

    2006-06-01

    promise. In order to better understand this process and test its legitimacy, a treatment wetland was constructed at Wright-Patterson AFB, Dayton, Ohio...fruition. Dr. Smith, without your patient instruction in the process of DNA extraction, PCR amplification, cloning, sequencing, and analysis those...then, wetlands have also been designed and constructed to treat process waters from industry (Kadlec and Knight, 1996) and are being used more and

  18. A Wetland Camp for Upland Teachers.

    ERIC Educational Resources Information Center

    Soniat, Lyle; Duggan, Suzanne

    1995-01-01

    Discusses a workshop to provide an opportunity for north Louisiana teachers to learn firsthand about Louisiana's coastal wetlands. The multidisciplinary sessions focused on coastal wetland ecosystems, covering wetland productivity, the functions and value of wetlands, current wetland issues, water quality, botany, geology, fisheries management,…

  19. Effects of wastewater on forested wetlands

    USGS Publications Warehouse

    Doyle, Thomas W.

    2002-01-01

    Cycling nutrient-enriched wastewater from holding ponds through natural, forested wetlands is a practice that municipal waste treatment managers are considering as a viable option for disposing of wastewater. In this wastewater cycling process, sewer effluent that has been circulated through aerated ponds is discharged into neighboring wetland systems. To understand how wastewater cycling affects forest and species productivity, researchers at the USGS National Wetlands Research Center conducted dendroecological investigations in a swamp system and in a bog system that have been exposed to wastewater effluent for many decades. Dendroecology involves the study of forest changes over time as interpreted from tree rings. Tree-ring chronologies describe the pattern and history of growth suppression and release that can be associated with aging and disturbances such as hurricanes, floods, and fires. But because of limited monitoring, little is known about the potential for long-term effects on forested wetlands as a result of wastewater flooding. USGS researchers used tree rings to detect the effect of wastewater cycling on tree growth. Scientists expected to find that tree-ring width would be increased as a result of added nutrients.

  20. A review on removing pharmaceutical contaminants from wastewater by constructed wetlands: design, performance and mechanism.

    PubMed

    Li, Yifei; Zhu, Guibing; Ng, Wun Jern; Tan, Soon Keat

    2014-01-15

    This paper presents a comprehensive review of the current state of research activities on the application of constructed wetlands for removing pharmaceutical contaminants from wastewater. The focus of the review was placed on the application of constructed wetlands as an alternative secondary wastewater treatment system or as a wastewater polishing treatment system. The design parameters of the reported constructed wetlands including the physical configuration, hydraulic mode, vegetation species, and targeting pharmaceuticals were summarized. The removal efficiencies of pharmaceuticals under different conditions in the wetlands were evaluated at the macroscopic level. In addition, the importance of the three main components of constructed wetlands (substrate, plants and microbes) for pharmaceutical removal was analyzed to elucidate the possible removal mechanisms involved. There is a general consensus among many researchers that constructed wetlands hold great potential of being used as an alternative secondary wastewater treatment system or as a wastewater polishing treatment system for the removal of pharmaceuticals, but relevant reported studies are scarce and are not conclusive in their findings. Current knowledge is limited on the removal efficiencies of pharmaceuticals in constructed wetlands, the removal mechanisms involved, the toxicity to constructed wetlands caused by pharmaceuticals, and the influences of certain important parameters (configuration design, hydraulic mode, temperature and seasonality, pH, oxygen and redox potential, etc.). This review promotes further research on these issues to provide more and better convincing evidences for the function and performance of larger laboratory-scale, pilot-scale or full-scale constructed wetlands. © 2013.

  1. Post-treatment of UASB reactor effluent in waste stabilization ponds and in horizontal flow constructed wetlands: a comparative study in pilot scale in Southeast Brazil.

    PubMed

    Bastos, R K X; Calijuri, M L; Bevilacqua, P D; Rios, E N; Dias, E H O; Capelete, B C; Magalhães, T B

    2010-01-01

    The results of a 20-month period study in Brazil were analyzed to compare horizontal-flow constructed wetlands (CW) and waste stabilization pond (WSP) systems in terms of land area requirements and performance to produce effluent qualities for surface water discharge, and for wastewater use in agriculture and/or aquaculture. Nitrogen, E. coli and helminth eggs were more effectively removed in WSP than in CW. It is indicated that CW and WSP require similar land areas to achieve a bacteriological effluent quality suitable for unrestricted irrigation (10(3) E. coli per 100 mL), but CW would require 2.6 times more land area than ponds to achieve quite relaxed ammonia effluent discharge standards (20 mg NH(3) L(-1)), and, by far, more land than WSP to produce an effluent complying with the WHO helminth guideline for agricultural use (< or =1 egg per litre).

  2. Evaluating Wetland Expansion in a Tallgrass Prairie-Wetland Restoration

    NASA Astrophysics Data System (ADS)

    Engelmann, Katie Mae

    Remote sensing is an effective tool to inventory and monitor wetlands at large spatial scales. This study examined the effect of wetland restoration practices at Glacial Ridge National Wildlife Refuge (GRNWR) in northwest Minnesota on the distribution, location, size and temporal changes of wetlands. A Geographic Object-Based Image Analysis (GEOBIA) land cover classification method was applied that integrated spectral data, LiDAR elevation, and LiDAR derived ancillary data of slope, aspect, and TWI. Accuracy of remote wetland mapping was compared with onsite wetland delineation. The GEOBIA method produced land cover classifications with high overall accuracy (88 - 91 percent). Wetland area from a June 12, 2007 classified image was 20.09 km2 out of a total area of 147.3 km 2. Classification of a July 22, 2014 image, showed wetlands covering an area of 37.96 km2. The results illustrate how wetland areas have changed spatially and temporally within the study landscape. These changes in hydrologic conditions encourage additional wetland development and expansion as plant communities colonize rewetted areas, and soil conditions develop characteristics typical of hydric soils.

  3. Influence of hydraulic retention time and plant species on performance of mesocosm subsurface constructed wetlands during municipal wastewater treatment in super-arid areas.

    PubMed

    Vera, Ismael; Verdejo, Nathaly; Chávez, Wladimir; Jorquera, Camila; Olave, Jorge

    2016-01-28

    A constructed wetland (CW) in arid areas requires special knowledge given the particular climatic conditions. Among other aspects, the Hydraulic Retention Time (HRT) and plant species may be two important design parameters in hyper- and super-arid areas. Therefore, the study aimed to evaluate the influence of both variables in the application of CW in super-arid areas. Two HRT, 3.5 d and 7 d, and plant species classified by their origin: (a) native, Festuca Orthopylla, Cortaderia atacamensis and Schoenoplectus americanus, and (b) foreign, Cyperus papyrus, were evaluated in four Mesocosm Constructed Wetlands (MCW) operated in a super-arid area. The results showed that the HRT significantly increased (α < 0.05) in more than 10% the removal efficiency of nitrogen and phosphorus forms (TN, NH 4 + -N, TP, PO 4 -3 -P). These results were the same for the two groups of plants assessed. Moreover, Cyperus papyrus significantly increased (α < 0.05) above 30% the removal efficiency, but only for nitrogen and phosphorus forms. MCW with this plant species showed a water loss above 25% and significantly increased (α < 0.05) the Electrical Conductivity (EC) of effluents. MCW planted with Schoenoplectus americanus showed water losses of around 25% for the both HRT evaluated, and its influence was not significant (α > 0.05) on the EC of the effluents. These results suggest that Schoenoplectus americanus would be an ideal candidate species for use in CW with subsurface flow in super-arid areas, with HRT varying between 3.5 d and 7 d.

  4. Towards the development of a novel construction solid waste (CSW) based constructed wetland system for tertiary treatment of secondary sewage effluents.

    PubMed

    Yang, Y; Zhang, L; Zhao, Y Q; Wang, S P; Guo, X C; Guo, Y; Wang, L; Ren, Y X; Wang, X C

    2011-01-01

    This study was conducted to examine the possibility of using construction solid waste (CSW), an inevitable by-product of the construction and demolition process, as the main substrate in a laboratory scale multi-stage constructed wetland system (CWs) to improve phosphorus (P) removal from secondary sewage effluent. A tidal-flow operation strategy was employed to enhance the wetland aeration. This will stimulate aerobic biological processes and benefit the organic pollutants decomposition and nitrification process for ammoniacal-nitrogen (NH(+)(4)-N) removal. The results showed that the average P concentration in the secondary sewage effluent was reduced from 1.90 mg-P/L to 0.04 mg-P/L. CSW presents excellent P removal performance. The average NH(+)(4)-N concentration was reduced from 9.94 mg-N/L to 1.0 mg-N/L through nitrification in the system. The concentration of resultant nitrite and nitrate in the effluent of the CSW based CWs ranged from 0.1 to 2.4 mg-N/L and 0.01 to 0.8 mg-N/L, respectively. The outcome of this study has shown that CSW can be successfully used to act as main substrate in CWs. The application of CSW based CWs on improving N and P removals from secondary sewage effluent presents a win-win scenario. Such the reuse of CSW will benefit both the CSW disposal and nutrient control from wastewater. More significantly, such the application can transfer the CSW from a 'waste' to 'useful' material and can ease the pressure of construction waste solid management. Meanwhile, the final effluent from the CSW-based CWs can be used as non-potable water source in landscape irrigation, agriculture and industrial process.

  5. Factors affecting biological recovery of wetland restorations

    DOT National Transportation Integrated Search

    1999-06-01

    This report describes a long-term study to monitor and evaluate the ecosystem recovery of seven wetland restorations in south central Minnesota. The study looks at the impact of planting on wetland restoration success in inland wetlands and develops ...

  6. Hydrologic budget for a wetland system.

    DOT National Transportation Integrated Search

    1998-07-01

    An important functional indicator of the success of a constructed wetland as a replacement for a natural system is the hydrology of : a site and whether it is adequate to support wetland vegetation and habitats. For constructed wetlands with potentia...

  7. Assessing and measuring wetland hydrology

    USGS Publications Warehouse

    Rosenberry, Donald O.; Hayashi, Masaki; Anderson, James T.; Davis, Craig A.

    2013-01-01

    Virtually all ecological processes that occur in wetlands are influenced by the water that flows to, from, and within these wetlands. This chapter provides the “how-to” information for quantifying the various source and loss terms associated with wetland hydrology. The chapter is organized from a water-budget perspective, with sections associated with each of the water-budget components that are common in most wetland settings. Methods for quantifying the water contained within the wetland are presented first, followed by discussion of each separate component. Measurement accuracy and sources of error are discussed for each of the methods presented, and a separate section discusses the cumulative error associated with determining a water budget for a wetland. Exercises and field activities will provide hands-on experience that will facilitate greater understanding of these processes.

  8. 7 CFR 12.30 - NRCS responsibilities regarding wetlands.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... approve wetland determinations, delineations and certifications, functional assessments, mitigation plans... wetland determinations and wetland delineations. (1) Certification of a wetland determination means that... determination and wetland delineation shall be certified as final by the NRCS official 30 days after providing...

  9. 7 CFR 12.30 - NRCS responsibilities regarding wetlands.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... approve wetland determinations, delineations and certifications, functional assessments, mitigation plans... wetland determinations and wetland delineations. (1) Certification of a wetland determination means that... determination and wetland delineation shall be certified as final by the NRCS official 30 days after providing...

  10. 7 CFR 12.30 - NRCS responsibilities regarding wetlands.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... approve wetland determinations, delineations and certifications, functional assessments, mitigation plans... wetland determinations and wetland delineations. (1) Certification of a wetland determination means that... determination and wetland delineation shall be certified as final by the NRCS official 30 days after providing...

  11. Native plants for effective coastal wetland restoration

    USGS Publications Warehouse

    Howard, Rebecca J.

    2003-01-01

    Plant communities, along with soils and appropriate water regimes, are essential components of healthy wetland systems. In Louisiana, the loss of wetland habitat continues to be an issue of major concern. Wetland loss is caused by several interacting factors, both natural and human-induced (e.g., erosion and saltwater intrusion from the construction of canals and levees). Recent estimates of annual coastal land loss rates of about 62 km2 (24 mi2 ) over the past decade emphasize the magnitude of this problem. In an attempt to slow the rate of loss and perhaps halt the overall trend, resource managers in Louisiana apply various techniques to restore damaged or degraded habitats to functioning wetland systems.Researchers at the U.S. Geological Survey’s National Wetlands Research Center (NWRC) have cooperated with the Louisiana Department of Natural Resources in studies that address effective restoration strategies for coastal wetlands. The studies have identified differences in growth that naturally exist in native Louisiana wetland plant species and genetic varieties (i.e., clones) within species. Clones of a species have a distinctive genetic identity, and some clones may also have distinctive growth responses under various environmental conditions (i.e., preferences). Indeed, large areas of coastal marsh are typically populated by several clones of a plant species, each growing in a microenvironment suited to its preferences.These studies will provide information that will assist resource managers in selecting plant species and clones of species with known growth characteristics that can be matched to environmental conditions at potential restoration sites. Before the studies began, a collection of several clones from four plant species native to coastal Louisiana was established. The species collected included saltgrass (Distichlis spicata), common reed (Phragmites australis), giant bulrush (Schoenoplectus californicus), and saltmarsh bulrush (Schoenoplectus

  12. Management of wetlands for wildlife

    USGS Publications Warehouse

    Matthew J. Gray,; Heath M. Hagy,; J. Andrew Nyman,; Stafford, Joshua D.

    2013-01-01

    Wetlands are highly productive ecosystems that provide habitat for a diversity of wildlife species and afford various ecosystem services. Managing wetlands effectively requires an understanding of basic ecosystem processes, animal and plant life history strategies, and principles of wildlife management. Management techniques that are used differ depending on target species, coastal versus interior wetlands, and available infrastructure, resources, and management objectives. Ideally, wetlands are managed as a complex, with many successional stages and hydroperiods represented in close proximity. Managing wetland wildlife typically involves manipulating water levels and vegetation in the wetland, and providing an upland buffer. Commonly, levees and water control structures are used to manipulate wetland hydrology in combination with other management techniques (e.g., disking, burning, herbicide application) to create desired plant and wildlife responses. In the United States, several conservation programs are available to assist landowners in developing wetland management infrastructure on their property. Managing wetlands to increase habitat quality for wildlife is critical, considering this ecosystem is one of the most imperiled in the world.

  13. Unit Process Wetlands for Removal of Trace Organic Contaminants and Pathogens from Municipal Wastewater Effluents.

    PubMed

    Jasper, Justin T; Nguyen, Mi T; Jones, Zackary L; Ismail, Niveen S; Sedlak, David L; Sharp, Jonathan O; Luthy, Richard G; Horne, Alex J; Nelson, Kara L

    2013-08-01

    Treatment wetlands have become an attractive option for the removal of nutrients from municipal wastewater effluents due to their low energy requirements and operational costs, as well as the ancillary benefits they provide, including creating aesthetically appealing spaces and wildlife habitats. Treatment wetlands also hold promise as a means of removing other wastewater-derived contaminants, such as trace organic contaminants and pathogens. However, concerns about variations in treatment efficacy of these pollutants, coupled with an incomplete mechanistic understanding of their removal in wetlands, hinder the widespread adoption of constructed wetlands for these two classes of contaminants. A better understanding is needed so that wetlands as a unit process can be designed for their removal, with individual wetland cells optimized for the removal of specific contaminants, and connected in series or integrated with other engineered or natural treatment processes. In this article, removal mechanisms of trace organic contaminants and pathogens are reviewed, including sorption and sedimentation, biotransformation and predation, photolysis and photoinactivation, and remaining knowledge gaps are identified. In addition, suggestions are provided for how these treatment mechanisms can be enhanced in commonly employed unit process wetland cells or how they might be harnessed in novel unit process cells. It is hoped that application of the unit process concept to a wider range of contaminants will lead to more widespread application of wetland treatment trains as components of urban water infrastructure in the United States and around the globe.

  14. Unit Process Wetlands for Removal of Trace Organic Contaminants and Pathogens from Municipal Wastewater Effluents

    PubMed Central

    Jasper, Justin T.; Nguyen, Mi T.; Jones, Zackary L.; Ismail, Niveen S.; Sedlak, David L.; Sharp, Jonathan O.; Luthy, Richard G.; Horne, Alex J.; Nelson, Kara L.

    2013-01-01

    Abstract Treatment wetlands have become an attractive option for the removal of nutrients from municipal wastewater effluents due to their low energy requirements and operational costs, as well as the ancillary benefits they provide, including creating aesthetically appealing spaces and wildlife habitats. Treatment wetlands also hold promise as a means of removing other wastewater-derived contaminants, such as trace organic contaminants and pathogens. However, concerns about variations in treatment efficacy of these pollutants, coupled with an incomplete mechanistic understanding of their removal in wetlands, hinder the widespread adoption of constructed wetlands for these two classes of contaminants. A better understanding is needed so that wetlands as a unit process can be designed for their removal, with individual wetland cells optimized for the removal of specific contaminants, and connected in series or integrated with other engineered or natural treatment processes. In this article, removal mechanisms of trace organic contaminants and pathogens are reviewed, including sorption and sedimentation, biotransformation and predation, photolysis and photoinactivation, and remaining knowledge gaps are identified. In addition, suggestions are provided for how these treatment mechanisms can be enhanced in commonly employed unit process wetland cells or how they might be harnessed in novel unit process cells. It is hoped that application of the unit process concept to a wider range of contaminants will lead to more widespread application of wetland treatment trains as components of urban water infrastructure in the United States and around the globe. PMID:23983451

  15. Modeling and Understanding BOD Removal Processes in Free-Water Surface Constructed Wetlands

    NASA Astrophysics Data System (ADS)

    Deng, Z.

    2016-12-01

    Free-water surface constructed wetlands have proven to be effective systems for removal of various pollutants in wastewater and agricultural drainage water. Modeling tools are needed for understanding the processes and mechanisms responsible for the removal of pollutants and for the design of new constructed wetlands. This paper presents a new model for mimicking the processes and mechanisms controlling the removal of BOD (biochemical oxygen demand) in free-water surface constructed wetlands. The processes and mechanisms, simulated in the model, include advection, dispersion, diffusion, monod kinetics of bacterial growth, water gains (via precipitation) and losses (evaporation and seepage) and mass exchange between water column and root layers of a wetland. A novel feature of the new model is the incorporation of a dynamic diffusive root-zone. Sensitivity analysis of the model input vaiables indicates that the BOD removal in free water surface constructed wetlands is most sensitive to the biological removal process of BOD in the root zone, controlled by acetic acid and anaerobic bacteria in root zone, and the flow velocity (controlling mean hydraulic residence time) and organic carbon in the water column. The application of the new model is demonstrated through two case studies involving two distinct constructed wetlands with one (Gustine Wetland) for treatment of secondary wastewater located in the USA and another (Lake Manzala Engineered Wetland) for treatment of agricultural drainage water in Egypt. The model is relatively simple yet effective, as evidenced by the high coefficient of determination of 0.73 - 0.99 for the Gustine Wetland and 0.98 for Manzala Wetland. The model is a reliable and efficient tool for designing constructed wetlands and for understanding effects of various processes and mechanisms on the treatment efficiency of wastewater in constructed wetlands.

  16. EPA METHODS FOR EVALUATING WETLAND CONDITION, WETLANDS CLASSIFICATION

    EPA Science Inventory

    In 1999, the U.S. Environmental Protection Agency (EPA) began work on this series of reports entitled Methods for Evaluating Wetland Condition. The purpose of these reports is to help States and Tribes develop methods to evaluate 1) the overall ecological condition of wetlands us...

  17. Mitigation of two pyrethroid insecticides in a Mississippi Delta constructed wetland.

    PubMed

    Moore, M T; Cooper, C M; Smith, S; Cullum, R F; Knight, S S; Locke, M A; Bennett, E R

    2009-01-01

    Constructed wetlands are a suggested best management practice to help mitigate agricultural runoff before entering receiving aquatic ecosystems. A constructed wetland system (180 m x 30 m), comprising a sediment retention basin and two treatment cells, was used to determine the fate and transport of simulated runoff containing the pyrethroid insecticides lambda-cyhalothrin and cyfluthrin, as well as suspended sediment. Wetland water, sediment, and plant samples were collected spatially and temporally over 55 d. Results showed 49 and 76% of the study's measured lambda-cyhalothrin and cyfluthrin masses were associated with vegetation, respectively. Based on conservative effects concentrations for invertebrates and regression analyses of maximum observed wetland aqueous concentrations, a wetland length of 215 m x 30 m width would be required to adequately mitigate 1% pesticide runoff from a 14 ha contributing area. Results of this experiment can be used to model future design specifications for constructed wetland mitigation of pyrethroid insecticides.

  18. Effect of constructed wetlands receiving agricultural return flows on disinfection byproduct precursors.

    PubMed

    Díaz, Francisco J; Chow, Alex T; O'Geen, Anthony T; Dahlgren, Randy A; Wong, Po-Keung

    2009-06-01

    The effects of wetland treatment on disinfection byproduct precursors were evaluated for six constructed wetlands receiving agricultural return flows in the Central Valley of California. Wetlands varied in size, age, vegetation, hydrologic residence time (0.9-20 days) and water management (continuous flow vs. flood pulse). The effects of wetland treatment were determined by analyzing input and outflow waters for dissolved organic carbon concentration and quality, bromide concentration, and formation potentials for nine disinfection byproduct species, including trihalomethanes, haloacetronitriles, chloral hydrate, and haloketones. We hypothesized that hydraulic residence time was a key factor governing differences in disinfection byproduct precursors. Small wetlands (<3 ha) with short hydraulic residence times (<2 days) did not produce significant changes in disinfection byproduct precursor concentrations with respect to the agricultural return flows input to the wetlands. In these wetlands hydraulic residence times were not long enough to promote processes that adversely affect dissolved organic carbon and bromide quantity, such as evapoconcentration and leaching from vegetation. Thus, less negative effects were associated with disinfection byproduct formation. In contrast, larger wetlands (>100 ha) with long hydraulic residence times (>10 days) resulted in higher dissolved organic carbon and bromide levels, increasing disinfection byproduct formation by factors ranging between 1.7 and 10.2 compared to agricultural return flows. Results from this study provide important information for optimizing the design and management of constructed wetlands to effectively combine control of disinfection byproduct precursors with other water quality parameters.

  19. High Pb concentration stress on Typha latifolia growth and Pb removal in microcosm wetlands.

    PubMed

    Han, Jianqiu; Chen, Fengzhen; Zhou, Yumei; Wang, Chaohua

    2015-01-01

    When constructed wetlands are used to treat high-Pb wastewater, Pb may become a stress to wetland plants, which subsequently reduces treatment performance and the other ecosystem services. To facilitate the design and operation of constructed wetlands for treatment of Pb-rich wastewater, we investigated the irreversible inhibitory level of Pb for Typha latifolia through experiments in microcosm wetlands. Seven horizontal subsurface flow constructed wetlands were built with rectangular plastic tanks and packed with marble chips and sand. All wetlands were transplanted with nine stems of Typha latifolia each. The wetlands were batch operated in a greenhouse with artificial wastewater (10 L each) for 12 days. Influent to the seven wetlands had different concentrations of Pb: 0 mg/L, 10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 200 mg/L, and 500 mg/L, respectively. The results suggested that leaf chlorophyll relative content, relative growth rate, photosynthetic characteristics, activities of superoxide dismutase, peroxidase, and content of malondialdehyde were not affected when initial Pb concentration was at 100 mg/L and below. But when initial Pb concentration was above 100 mg/L, all of them were seriously affected. We conclude that high Pb concentrations wastewater could inhibit the growth of Typha latifolia and decrease the removal rate of wetlands.

  20. Design and performance of hybrid constructed wetland systems for high-content wastewater treatment in the cold climate of Hokkaido, northern Japan.

    PubMed

    Kato, K; Inoue, T; Ietsugu, H; Sasaki, H; Harada, J; Kitagawa, K; Sharma, P K

    2013-01-01

    The performance of six multistage hybrid constructed wetland systems was evaluated. The systems were designed to treat four kinds of high-content wastewater: dairy wastewater (three systems, average inflow content 2,400-5,000 mg·COD l(-1), 3-6 years of operation); pig farm wastewater, including liquid food washing wastewater (one system, 9,500 mg·COD l(-1), 3 years); potato starch processing wastewater (one system, 20,000-60,000 mg·COD l(-1), 3 years); and wastewater containing pig farm swine urine (one system, 6,600 mg·COD l(-1), 2.8 years) (COD = chemical oxygen demand). The systems contained three or four vertical (V) flow beds with self-priming siphons and surface partitions and no or one horizontal (H) flow bed (three to five beds). In some V flow beds, treated effluents were recirculated (Vr) through the inlet to improve performance. Mean annual temperature was 5-8 °C at all locations. To overcome clogging due to the high load in a cold climate, we applied a safety bypass structure and floating cover material to the V flow beds. Calculated average oxygen transfer rates (OTRs) increased proportionally with the influent load, and the OTR value was Vr > V> H. The relations of load-OTR, COD-ammonium, and a Arrhenius temperature-dependent equation enable the basic design of a reed bed system.

  1. Discover Wetlands. A Curriculum Guide.

    ERIC Educational Resources Information Center

    Lynn, Brian

    Teaching about wetlands fits well into curriculum goals for science, social studies, environmental education, and even English/language arts. Given their numerous ecological values, the history of their losses and the fact that they are a current, often controversial environmental issue, wetlands provide an ideal topic for a variety of…

  2. Carbon Storage in US Wetlands.

    EPA Science Inventory

    Background/Question/Methods Wetland soils contain some of the highest stores of soil carbon in the biosphere. However, there is little understanding of the quantity and distribution of carbon stored in US wetlands or of the potential effects of human disturbance on these stocks. ...

  3. Critical Questions in Wetland Science

    EPA Science Inventory

    Wetlands are transitional between terrestrial and aquatic environments. As such, they perform important ecological functions (e.g., nutrient cycling, flood abatement) providing a variety of ecosystem services on which humans rely. Wetlands are also one of the world’s most e...

  4. Wetlands management at CERCLA sites

    SciTech Connect

    Harman, C.R.; Romaine, W.M.; D'Alleinne, C.P.

    1993-01-01

    Wetlands have historically been viewed as dumping grounds for a wide range of waste products. The uncontrolled introduction of hazardous and toxic waste materials into these sensitive ecosystems has prompted the US Environmental Protection Agency (USEPA) to oversee many investigatory and remediation activities in wetlands, as mandated by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). USEPA documents, in fact, note that approximately 72% of the CERCLA sites in USEPA Regions 1,2,3 and 4 are associated, to some degree, with wetlands. However, CERCLA activities in these areas are often complicated by the very regulatory measures designed to preserve andmore » protect wetlands from anthropogenic disturbances. The ability of a Potentially Responsible Party (PRP) to effectively respond to issues at a CERCLA site, while still being responsive to both Federal and State wetlands regulations, requires the utmost in both technical and management expertise.« less

  5. Regulatory Implications of Using Constructed Wetlands to Treat Selenium-Laden Wastewater

    Treesearch

    A. Dennis Lemly; Harry M. Ohlendorf

    2002-01-01

    The practice of using constructed wetlands to treat selenium-laden wastewater is gaining popularity in the linited States and elsewhere. However, proponents of treatment wetlands often overlook important ecological liabilities and regulatory implications when developing new methods and applications. Their research studies typically seek to answer a basic performance...

  6. Vegetation Changes and Partitioning of Selenium in 4-Year-Old Constructed Wetlands Treating Agricultural Drainage

    USDA-ARS?s Scientific Manuscript database

    The knowledge of vegetation management and the partitioning of selenium (Se) in treatment wetlands is essential for long-term effective operation of constructed wetlands treating Se-laden agricultural tile-drainage water in the San Joaquin Valley, California. Vegetation changes in six vegetated wetl...

  7. Erosion and restoration of two headwater wetlands following an extreme wildfire

    Treesearch

    Jonathan Long; Javis Davis

    2016-01-01

    Wildfire can damage headwater wetlands, yet the value of post-fire restoration treatments in channels has been contested. Staff from the White Mountain Apache Tribe, students from the local Cibecue Community School, and researchers from the U.S. Forest Service collaboratively recorded channel responses over 13 years at two headwater wetlands lying within watersheds...

  8. Using Refined Regression Analysis To Assess The Ecological Services Of Restored Wetlands

    EPA Science Inventory

    A hierarchical approach to regression analysis of wetland water treatment was conducted to determine which factors are the most appropriate for characterizing wetlands of differing structure and function. We used this approach in an effort to identify the types and characteristi...

  9. USE OF WETLANDS TO TREAT SEPTIC TANK EFFLUENT FROM A CONFERENCE FACILITY

    EPA Science Inventory

    The Grailville Retreat Center near Loveland, OH built a wastewater treatment wetland under an experimental permit from OEPA to eliminate overflow from a failing leach field. Grailville allowed the USEPA Risk Management Research Lab in Cincinnati to subdivide the wetland into fiv...

  10. Organic Matter Decomposition following Harvesting and Site Preparation of a Forested Wetland

    Treesearch

    Carl C. Trettin; M. Davidian; M.F. Jurgensen; R. Lea

    1996-01-01

    Organic matter accumulation is an important process that affects ecosystem function in many northern wetlands. The cotton strip assay (CSA)was used to measure the effect of harvesting and two different site preparation treatments, bedding and trenching, on organic matter decomposition in a forested wetland. A Latin square experimental design was used to determine the...

  11. 7 CFR 12.33 - Use of wetland and converted wetland.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... continue to farm such wetlands under natural conditions or as they did prior to December 23, 1985. However... wetlands under this section means any natural wetland, farmed wetland, farmed-wetland pasture, or any... woody vegetation, and the history of use. In accordance with § 12.5(b)(1)(iii), participation in a USDA...

  12. 7 CFR 12.33 - Use of wetland and converted wetland.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... continue to farm such wetlands under natural conditions or as they did prior to December 23, 1985. However... wetlands under this section means any natural wetland, farmed wetland, farmed-wetland pasture, or any... woody vegetation, and the history of use. In accordance with § 12.5(b)(1)(iii), participation in a USDA...

  13. 7 CFR 12.33 - Use of wetland and converted wetland.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... continue to farm such wetlands under natural conditions or as they did prior to December 23, 1985. However... wetlands under this section means any natural wetland, farmed wetland, farmed-wetland pasture, or any... woody vegetation, and the history of use. In accordance with § 12.5(b)(1)(iii), participation in a USDA...

  14. Climate Change and Intertidal Wetlands

    PubMed Central

    Ross, Pauline M.; Adam, Paul

    2013-01-01

    Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause—the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the “squeeze” experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change. PMID:24832670

  15. Climate change and intertidal wetlands.

    PubMed

    Ross, Pauline M; Adam, Paul

    2013-03-19

    Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause-the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the "squeeze" experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change.

  16. Hydrology of Mid-Atlantic Freshwater Wetlands

    EPA Science Inventory

    Hydrology is a key variable in the structure and function of a wetland; it is a primary determinant of wetland type, and it drives many of the functions a wetland performs and in turn the services it provides. However, wetland hydrology has been understudied. Efforts by Riparia s...

  17. Wetlands: Water, Wildlife, Plants, and People.

    ERIC Educational Resources Information Center

    Vandas, Steve

    1992-01-01

    Describes wetlands and explains their importance to man and ecology. Delineates the role of water in wetlands. Describes how wetlands are classified: estuarine, riverine, lacustrine, palustrine, and marine. Accompanying article is a large, color poster on wetlands. Describes an activity where metaphors are used to explore the functions of…

  18. Factors influencing wetland use by Canada geese

    USGS Publications Warehouse

    Naugle, D.E.; Gleason, J.S.; Jenks, J.A.; Higgins, K.F.; Mammenga, P.W.; Nusser, S.M.

    1997-01-01

    Seasonal and semi-permanent wetlands in eastern South Dakota were surveyed in 1995 and 1996 to identify habitat characteristics influencing wetland use by Canada geese (Branta canadensis maxima). Position of a wetland within the landscape and its area were important landscape-scale features influencing wetland use by geese. Our delineation of potential Canada goose habitat using a wetland geographic information system indicated that distribution and area of semi-permanent wetlands likely limit Canada goose occurrence in regions outside the Prairie Coteau. Periodicity in hydrologic cycles within landscapes also may influence goose use of wetlands in eastern South Dakota.

  19. Emergy-based evaluation of system sustainability and ecosystem value of a large-scale constructed wetland in North China.

    PubMed

    Zhang, Yiran; Liu, Jian; Zhang, Jian; Wang, Renqing

    2013-07-01

    Constructed wetland has been widely adopted to deal with degraded natural wetlands and water bodies; thus, more attention should be focused on ecological-economic sustainability and ecological efficiency of these projects for long-term success. Emergy accounting was conducted to investigate the energy and resource flows in constructed wetlands during the restoration process. Emergy-based indexes were adopted to evaluate the sustainability of a pilot large-scale constructed wetland in a large wetland restoration project in North China, carried out to enhance the river water quality and offset the degradation of natural wetland. Emergy and emdollar values for ecosystem services and natural capital were also calculated. The results showed that when outflow was considered as the product, the studied large-scale constructed wetland was more self-supporting and could be operated with lesser financial investment, although the waste treatment efficiency and the sustainability index were lower than conventional small-scale treatment constructed wetlands. Compared with natural wetlands, more visits from tourists and lesser financial investment coming in as feedback into the wetland would reduce system environment loading and promote system self-support ability, ultimately generating sustainability. In addition, the studied large-scale constructed wetland can effectively simulate energy and resource flows of natural wetland ecosystem and contribute a roughly equal value of ecosystem services in term of gross primary production. The studied large-scale constructed wetland can successfully achieve ecosystem functions as replacement for natural wetland and hasten the restoration process, although the restoration effectiveness of ecosystem structures in terms of living biomass and water using emergy-value accounting is still inconclusive.

  20. Using Bayesian Belief Networks to Explore the Effects of Nitrogen Inputs on Wetland Ecosystem Services

    NASA Astrophysics Data System (ADS)

    Spence, P. L.; Jordan, S. J.

    2011-12-01

    Increased reactive nitrogen (Nr) inputs to freshwater wetlands resulting from infrastructure development due to population growth along with intensive agricultural practices associated with food production can threaten regulating (i.e. climate change, water purification, and waste treatment) and supporting (i.e. nutrient cycling) ecosystem services. Wetlands generally respond both by sequestering Nr (i.e. soil accumulation and biomass assimilation) and converting Nr into inert gaseous forms via biogeochemical processes. It is important for wetlands to be efficient in removing excessive Nr inputs from polluted waters to reduce eutrophication in downstream receiving water bodies while producing negligible amounts of nitrous oxide (N2O), a potent greenhouse gas, which results from incomplete denitrification. Wetlands receiving excessive Nr lose their ability to provide a constant balance between regulating water quality and mitigating climate change. The purpose of this study is to explore the effects of Nr inputs on ecosystem services provided by wetlands using a Bayesian Belief Network (BBN). The network was developed from established relationships between a variety of wetland function indicators and biogeochemical process associated with Nr removal. Empirical data for 34 freshwater wetlands were gathered from a comprehensive review of published peer-reviewed and gray literature. The BBN was trained using 30 wetlands (88% of the freshwater wetland case file) and tested using 4 wetlands (12% of the freshwater wetland case file). Sensitivity analysis suggested that Nr removal, water quality, soil Nr accumulation and N2O emissions had the greatest influence on ecosystem service tradeoffs. The magnitude of Nr inputs did not affect ecosystem services. The network implies that Nr removal efficiency has a greater influence on final ecosystem services associated with water quality impairment and atmospheric pollution. A very low error rate, which was based on 4 wetland

  1. [Impact on nitrogen and phosphorous export of wetlands in Tianmu Lake watershed].

    PubMed

    Li, Zhao-Fu; Liu, Hong-Yu; Li, Heng-Peng

    2012-11-01

    Focused on understanding the function of wetland in improving water quality, Pingqiao watershed and Zhongtian watershed in Tianmu Lake drinking water sources area were selected as the research region. We integrated remote sensing, GIS techniques with field investigation and chemical analysis to analyze the relationship between wetland and water quality in watershed scale. Results show: (1) There are many wetland patches in Pingqiao and Zhongtian watershed, wetlands patch densities were respectively 7.5 km(-2) and 7.1 km(-2). Wetlands widely distributed in the Pingqiao watershed with mostly located away from the river of 500 m, whereas wetlands relatively concentrated in the lower reach within 500 meters of riverside in Zhongtian watershed. (2) Nitrogen and phosphorus nutrient retention of wetland in watershed scale was significant. The annual mean TN and DTN concentration had a strong relationship with percent area of wetlands in Zhongtian watershed while the weakest relationship was found with TP and DTP concentrations, especially, the mean TN and DTN concentrations in spring and winter had the significantly negative relationship with wetland areas of watershed. The negative relationship was existed for nitrogen in autumn of Pingqiao watershed, which suggested that watersheds varying in area of wetlands have the different nutrient reducing efficiency in seasonal periods. (3) A certain number and area of wetland will improve river water quality in watershed scale, which can instruct water environment treatment. However, considering the complexity of nutrient transport processes in watershed, wetland-related factors such as area, location, density, ecosystem structure and watershed-related factors such as temporal interval, spatial scales, slope and land use will impact on the transport processes, and related theoretical and practical problems need further research.

  2. Performance of a pilot showcase of different wetland systems in an urban setting in Singapore.

    PubMed

    Quek, B S; He, Q H; Sim, C H

    2015-01-01

    The Alexandra Wetlands, part of PUB's Active, Beautiful, Clean Waters (ABC Waters) Programme, showcase a surface flow wetland, an aquatic pond and a sub-surface flow wetland on a 200 m deck built over an urban drainage canal. Water from the canal is pumped to a sedimentation basin, before flowing in parallel to the three wetlands. Water quality monitoring was carried out monthly from April 2011 to December 2012. The order of removal efficiency is sub-surface flow (81.3%) >aquatic pond (58.5%) >surface flow (50.7%) for total suspended solids (TSS); sub-surface (44.9%) >surface flow (31.9%) >aquatic pond (22.0%) for total nitrogen (TN); and surface flow (56.7%) >aquatic pond (39.8%) >sub-surface flow (5.4%) for total phosphorus (TP). All three wetlands achieved the Singapore stormwater treatment objectives (STO) for TP removal, but only the sub-surface flow wetland met the STO for TSS, and none met the STO for TN. Challenges in achieving satisfactory performance include inconsistent feed water quality, undesirable behaviour such as fishing, release of pets and feeding of animals in the wetlands, and canal dredging during part of the monitoring period. As a pilot showcase, the Alexandra Wetlands provide useful lessons for implementing multi-objective wetlands in an urban setting.

  3. Design, construction and performance of a horizontal subsurface flow wetland system in Australia.

    PubMed

    Bolton, Lise M W; Bolton, Keith G E

    2013-01-01

    Malabugilmah is a remote Aboriginal community located in Clarence Valley, Northern NSW, Australia. In 2006, seven horizontal subsurface flow wetland clusters consisting of 3 m × 2 m wetland cells in series were designed and constructed to treat septic tank effluent to a secondary level (Total Suspended Solids (TSS) < 30 mg/L and Biochemical Oxygen Demand (BOD5) <20 mg/L) and achieve >50% Total Nitrogen (TN) reduction, no net Total Phosphorus (TP) export and ≥99.9% Faecal Coliform (FC) reduction. The wetland cell configuration allowed the wetlands to be located on steeper terrain, enabling effluent to be treated to a secondary level without the use of pumps. In addition to the water quality targets, the wetlands were designed and constructed to satisfy environmental, economic and social needs of the community. The wetland systems were planted with a local Australian wetland tree species which has become well established. Two wetland clusters have been monitored over the last 4 years. The wetlands have demonstrated to be robust over time, providing a high level of secondary treatment over an extended period.

  4. Identification of an antifungal metabolite produced by a potential biocontrol Actinomyces strain A01

    PubMed Central

    Lu, Cai Ge; Liu, Wei Cheng; Qiu, Ji Yan; Wang, Hui Min; Liu, Ting; De Liu, Wen

    2008-01-01

    Actinomyces strain A01 was isolated from soil of a vegetable field in the suburb of Beijing, China. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain A01 was identified as Streptomyces lydicus. In the antimicrobial spectrum test strain A01 presented a stable and strong inhibitory activity against several plant pathogenic fungi such as Fusarium oxysporum, Botrytis cinerea, Monilinia laxa, etc. However, no antibacterial activity was found. In pot experiments in greenhouse, the development of tomato gray mold was markedly suppressed by treatment with the fermentation broth of the strain A01, and the control efficacy was higher than those of Pyrimethanil and Polyoxin. A main antifungal compound (purity 99.503%) was obtained from the fermentation broth of strain A01 using column chromatography and HPLC. The chemical structural analysis with U V, IR, MS, and NMR confirmed that the compound produced by the strain A01 is natamycin, a polyene antibiotic produced by S. chattanovgensis, S. natalensis, and S. gilvosporeus, widely used as a natural biological preservative for food according to previous reports. The present study revealed a new producing strain of natamycin and its potential application as a biological control agent for fungal plant diseases. PMID:24031293

  5. Wetland Program Development Grants: Building State and Tribal Capacity to Protect Wetlands

    EPA Pesticide Factsheets

    This brochure highlights just a few examples of the progress being made by states and tribes through the use of the Wetland Program Development Grant funds. Wetland Program Development Grants: Building State and Tribal Capacity to Protect Wetlands

  6. 7 CFR 12.33 - Use of wetland and converted wetland.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... before December 23, 1985, unless NRCS determines the effect on losing remaining wetland values would be... the circulation and flow of water made to a farmed wetland or farmed-wetland pasture would not cause a...

  7. 7 CFR 12.33 - Use of wetland and converted wetland.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... before December 23, 1985, unless NRCS determines the effect on losing remaining wetland values would be... the circulation and flow of water made to a farmed wetland or farmed-wetland pasture would not cause a...

  8. Using Tradtional Ecological Knowledge to Protect Wetlands: the Swinomish Tribe's Wetland Cultural Assessment Project

    NASA Astrophysics Data System (ADS)

    Mitchell, T.

    2017-12-01

    "Traditional" wetland physical assessment modules do not adequately identify Tribal cultural values of wetlands and thus wetlands may not be adequately protected for cultural uses. This Swinomish Wetlands Cultural Assessment Project has developed a cultural resource scoring module that can be incorporated into wetland assessments to better inform wetland protections. Local native knowledge was gathered about the traditional uses of 99 native wetland plant species. A cultural scoring matrix was developed based on the presence of traditionally used plants in several use categories including: construction, ceremonial, subsistence, medicinal, common use, plant rarity, and place of value for each wetland. The combined score of the cultural and physcial modules provides an overall wetland score that relates to proscribed buffer protection widths. With this local native knowledge incorporated into wetland assessments, we are protecting and preserving Swinomish Reservation wetlands for both cultural uses and ecological functionality through the Tribe's wetland protection law.

  9. Methane Fluxes from Subtropical Wetlands

    NASA Astrophysics Data System (ADS)

    DeLucia, N.; Gomez-Casanovas, N.; Bernacchi, C.

    2013-12-01

    It is well documented that green house gas concentrations have risen at unequivocal rates since the industrial revolution but the disparity between anthropogenic sources and natural sources is uncertain. Wetlands are one example of a natural ecosystem that can be a substantial source or sink for methane (CH4) depending on climate conditions. Due to strict anaerobic conditions required for CH4-generating microorganisms, natural wetlands are one of the main sources for biogenic CH4. Although wetlands occupy less than 5% of total land surface area, they contribute approximately 20% of total CH4 emissions to the atmosphere. The processes regulating CH4 emissions are sensitive to land use and management practices of areas surrounding wetlands. Variation in adjacent vegetation or grazing intensity by livestock can, for example, alter CH4 fluxes from wetland soils by altering nutrient balance, carbon inputs and hydrology. Therefore, understanding how these changes will affect wetland source strength is essential to understand the impact of wetland management practices on the global climate system. In this study we quantify wetland methane fluxes from subtropical wetlands on a working cattle ranch in central Florida near Okeechobee Lake (27o10'52.04'N, 81o21'8.56'W). To determine differences in CH4 fluxes associated with land use and management, a replicated (n = 4) full factorial experiment was designed for wetlands where the surrounding vegetation was (1) grazed or un-grazed and (2) composed of native vegetation or improved pasture. Net exchange of CH4 and CO2 between the land surface and the atmosphere were sampled with a LICOR Li-7700 open path CH4 analyzer and Li-7500A open path CO2/H20 analyzer mounted in a 1-m3 static gas-exchange chamber. Our results showed and verified that CH4 emissions from subtropical wetlands were larger when high soil moisture was coupled with high temperatures. The presence of cattle only amplified these results. These results help quantify

  10. Process-Based Modeling of Constructed Wetlands

    NASA Astrophysics Data System (ADS)

    Baechler, S.; Brovelli, A.; Rossi, L.; Barry, D. A.

    2007-12-01

    Constructed wetlands (CWs) are widespread facilities for wastewater treatment. In subsurface flow wetlands, contaminated wastewater flows through a porous matrix, where oxidation and detoxification phenomena occur. Despite the large number of working CWs, system design and optimization are still mainly based upon empirical equations or simplified first-order kinetics. This results from an incomplete understanding of the system functioning, and may in turn hinder the performance and effectiveness of the treatment process. As a result, CWs are often considered not suitable to meet high water quality-standards, or to treat water contaminated with recalcitrant anthropogenic contaminants. To date, only a limited number of detailed numerical models have been developed and successfully applied to simulate constructed wetland behavior. Among these, one of the most complete and powerful is CW2D, which is based on Hydrus2D. The aim of this work is to develop a comprehensive simulator tailored to model the functioning of horizontal flow constructed wetlands and in turn provide a reliable design and optimization tool. The model is based upon PHWAT, a general reactive transport code for saturated flow. PHWAT couples MODFLOW, MT3DMS and PHREEQC-2 using an operator-splitting approach. The use of PHREEQC to simulate reactions allows great flexibility in simulating biogeochemical processes. The biogeochemical reaction network is similar to that of CW2D, and is based on the Activated Sludge Model (ASM). Kinetic oxidation of carbon sources and nutrient transformations (nitrogen and phosphorous primarily) are modeled via Monod-type kinetic equations. Oxygen dissolution is accounted for via a first-order mass-transfer equation. While the ASM model only includes a limited number of kinetic equations, the new simulator permits incorporation of an unlimited number of both kinetic and equilibrium reactions. Changes in pH, redox potential and surface reactions can be easily incorporated

  11. Distribution and mass balance of hexavalent and trivalent chromium in a subsurface, horizontal flow (SF-h) constructed wetland operating as post-treatment of textile wastewater for water reuse.

    PubMed

    Fibbi, Donatella; Doumett, Saer; Lepri, Luciano; Checchini, Leonardo; Gonnelli, Cristina; Coppini, Ester; Del Bubba, Massimo

    2012-01-15

    In this study, during a two-year period, we investigated the fate of hexavalent and trivalent chromium in a full-scale subsurface horizontal flow constructed wetland planted with Phragmites australis. The reed bed operated as post-treatment of the effluent wastewater from an activated sludge plant serving the textile industrial district and the city of Prato (Italy). Chromium speciation was performed in influent and effluent wastewater and in water-suspended solids, at different depths and distances from the inlet; plants were also analyzed for total chromium along the same longitudinal profile. Removals of hexavalent and trivalent chromium equal to 72% and 26%, respectively were achieved. The mean hexavalent chromium outlet concentration was 1.6 ± 0.9 μg l(-1) and complied with the Italian legal limits for water reuse. Chromium in water-suspended solids was in the trivalent form, thus indicating that its removal from wastewater was obtained by the reduction of hexavalent chromium to the trivalent form, followed by accumulation of the latter inside the reed bed. Chromium in water-suspended solids was significantly affected by the distance from the inlet. Chromium concentrations in the different plant organs followed the same trend of suspended solids along the longitudinal profile and were much lower than those found in the solid material, evidencing a low metal accumulation in P. australis. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Transfers and transformations of zinc in flow-through wetland microcosms.

    PubMed

    Gillespie, W B; Hawkins, W B; Rodgers, J H; Cano, M L; Dorn, P B

    1999-06-01

    Two microcosm-scale wetlands (570-liter containers) were integratively designed and constructed to investigate transfers and transformations of zinc associated with an aqueous matrix, and to provide future design parameters for pilot-scale constructed wetlands. The fundamental design of these wetland microcosms was based on biogeochemical principles regulating fate and transformations of zinc (pH, redox, etc.). Each wetland consisted of a 45-cm hydrosoil depth inundated with 25 cm of water, and planted with Scirpus californicus. Zinc ( approximately 2 mg/liter) as ZnCl2 was amended to each wetland for 62 days. Individual wetland hydraulic retention times (HRT) were approximately 24 h. Total recoverable zinc was measured daily in microcosm inflow and outflows, and zinc concentrations in hydrosoil and S. californicus tissue were measured pre- and post-treatment. Ceriodaphnia dubia and Pimephales promelas7-day aqueous toxicity tests were performed on wetland inflows and outflows, and Hyalella azteca whole sediment toxicity tests (10-day) were performed pre- and post-treatment. Approximately 75% of total recoverable zinc was transferred from the water column. Toxicity decreased from inflow to outflow based on 7-day C. dubia tests, and survival of H. azteca in hydrosoil was >80%. Data illustrate the ability of integratively designed wetlands to transfer and sequester zinc from the water column while concomitantly decreasing associated toxicity. Copyright 1999 Academic Press.

  13. Hydrologic regime controls soil phosphorus fluxes in restoration and undisturbed wetlands

    USGS Publications Warehouse

    Aldous, A.; McCormick, P.; Ferguson, C.; Graham, S.; Craft, C.

    2005-01-01

    Many wetland restoration projects occur on former agricultural soils that have a history of disturbance and fertilization, making them prone to phosphorus (P) release upon flooding. To study the relationship between P release and hydrologic regime, we collected soil cores from three restoration wetlands and three undisturbed wetlands around Upper Klamath Lake in southern Oregon, U.S.A. Soil cores were subjected to one of three hydrologic regimes - flooded, moist, and dry - for 7.5 weeks, and P fluxes were measured upon reflooding. Soils from restoration wetlands released P upon reflooding regardless of the hydrologic regime, with the greatest releases coming from soils that had been flooded or dried. Undisturbed wetland soils released P only after drying. Patterns in P release can be explained by a combination of physical and biological processes, including the release of iron-bound P due to anoxia in the flooded treatment and the mineralization of organic P under aerobic conditions in the dry treatment. Higher rates of soil P release from restoration wetland soils, particularly under flooded conditions, were associated with higher total P concentrations compared with undisturbed wetland soils. We conclude that maintaining moist soil is the means to minimize P release from recently flooded wetland soils. Alternatively, prolonged flooding provides a means of liberating excess labile P from former agricultural soils while minimizing continued organic P mineralization and soil subsidence. ?? 2005 Society for Ecological Restoration International.

  14. Mitigation of Impacts to Wetlands

    DOT National Transportation Integrated Search

    1996-06-17

    In accordance with the President's Regulatory Reinvention : Initiative, the FHWA proposes to amend its regulation outlining the : procedures to be followed in mitigating the impacts of Federal-aid : highway projects and programs to wetlands. The curr...

  15. Tropical Wetlands as Carbon Sinks

    NASA Astrophysics Data System (ADS)

    Jones, M. B.; Saunders, M.

    2007-12-01

    This presentation focuses on the tropical wetlands of sub-Saharan Africa. These are an understudied ecosystem in which large emergent grasses and sedges normally dominate and which have the potential to sequester significant amounts of carbon. Measurements of Net Primary Production of these wetlands show that they are some of the highest values recorded for any ecosystem. We have used eddy covariance to measure Net Ecosystem Exchange of pristine and disturbed wetlands and show that pristine systems can have sink strengths as strong as tropical forests while disturbed systems that have been reclaimed for agricultural purposes have a very much reduced carbon sink activity and may be net carbon sources. The management issues surrounding the use of these wetlands illustrate a direct conflict between the production of food crops for the local population and the maintenance of carbon sequestration as an ecosystem service.

  16. Wetlands Law Tests Government Power.

    ERIC Educational Resources Information Center

    McGregor, Gregor I.

    1992-01-01

    Discusses how working definitions of wetlands vary in different statutes and the controversy this has created. Focuses on these definition differences in relationship to federal, state and local government control of environmental protection and development decisions. (MCO)

  17. REMOTE SENSING AND GIS WETLANDS

    EPA Science Inventory

    Learn how photographs and computer sensor generated images can illustrate conditions of hydrology, extent, change over time, and impact of events such as hurricanes and tornados. Other topics include: information storage and modeling, and evaluation of wetlands for managing reso...

  18. [Effect of water depths on hydraulic performance of pond wetlands].

    PubMed

    Guo, Chang-Qiang; Dong, Bin; Liu, Jun-Jie; Liu, Chun-Guo; Feng, Da-Peng; Liu, Fang-Ping

    2014-11-01

    Pond wetlands have been widely used in the treatment of drainage water from paddy fields. However, wetland hydraulic performance and purification effects are affected by many factors, such as water depth, flow rate, aspect ratio and vegetation distribution, and the better understanding of these factors would be helpful to improve the quality of wetland design, operation and management. This paper analyzed the effect of three different water depths (20, 40 and 60 cm) on the hydraulic performance of pond wetland through the dye tracer experiments with Rhodamine WT. The hydraulic indices, i. e., effective volume ratio, nominal serial complete mixing tanks (N), hydraulic efficiency (λ), were selected for analysis through the hydraulic residence time distribution (RTD) curve. The results showed that the effective volume rate rose from 0.421 to 0.844 and the hydraulic efficiency from 0.281 to 0.604 when the water depth declined from 60 cm to 20 cm. This indicated that the wetland hydraulic performance improved as the water depth decreased. In addition, the hydraulic performance of the first half of the wetland was significantly better than that of the second half. The flow regime of the first half approached complete mixing because of the mixing index (N) approaching 1 and its effective volume rate was above 0.9 when the water depth was relatively low (20 and 40 cm). The normalized RTD curves demonstrated a good agreement between moment analysis parameters and hydraulic parameters, and a great consistency between the hydraulic parameters and moment index which was not affected by tail truncation error. The experimental study concluded that a lower water depth was favorable to improve the hydraulic performance of pond wetlands.

  19. Louisiana coastal wetlands: a resource at risk

    USGS Publications Warehouse

    Williams, S. Jeffress

    Approximately half the Nation's original wetland habitats have been lost over the past 200 years. In part, this has been a result of natural evolutionary processes, but human activities, such as dredging wetlands for canals or draining and filling for agriculture, grazing, or development, share a large part of the responsibility for marsh habitat alteration and destruction. Louisiana's wetlands today represent about 40 percent of the wetlands of the continental United States, but about 80 percent of the losses. The State's wetlands extend as much as 130 kilometers inland and along the coast for about 300 kilometers. Not all the wetlands are receding; in fact some wetlands are stable, and others are growing. But, at the present net rate of wetlands loss, Louisiana will have lost this crucial habitat in about 200 years. Considerable effort has been expended, and will continue to be expended, on understanding the processes that control wetlands evolution.

  20. Ecohydraulics and Estuarine Wetland Rehabilitation

    NASA Astrophysics Data System (ADS)

    Rodriguez, J. F.; Howe, A.; Saintilan, N.; Spencer, J.

    2004-12-01

    The hydraulics or water flow in wetlands is known to be a key factor influencing ecosystem development in estuarine wetland environments. The relationship is indirect, with the hydraulics of wetlands influencing a host of factors including soil salinity, waterlogging, sediment transport, sediment chemistry, vegetation dispersal and growth and nutrient availability and cycling. The relationship is also not one way, with the hydraulics of wetlands being influenced by plant and animal activity. Understanding these complex interactions is fundamental for the adequate management of estuarine wetlands. Listed as a Wetland of International Importance under the 1971 Ramsar Convention, the Hunter River estuary is regarded as the most significant site for migratory shorebirds in New South Wales, Australia. Over the past 20 years, the number of migratory shorebirds in the estuary has sharply declined from 8,000 to 4,000 approx. Alteration of bird habitat is believed to be one of the reasons for this alarming trend. In 2004 we started a three-year program to investigate the links between hydraulics, sediment, benthic invertebrates, vegetation and migratory shorebird habitat in the estuary. During the first year we have focused on a highly disturbed part of the Hunter estuary wetlands located on Ash Island. The area is one of the major roosting sites in the estuary and is characterized by a complex hydraulic regime due to a restricted tidal interchange with the Hunter River and the presence of infrastructure for the maintenance of power lines (i.e., roads, bridges, culverts). Salt marshes, mudflat and mangroves are the dominant vegetation types. The monitoring program includes measurements of water levels, salinity, discharge, velocity, turbulence, sediment transport and deposition, plant species and density, soil composition and benthic invertebrates coordinated with observations of bird habitat utilization on a number of locations throughout the wetland and for different flow

  1. Integrating geographically isolated wetlands into land management decisions

    EPA Science Inventory

    Wetlands across the globe provide extensive ecosystem services. However, many wetlands – especially those surrounded by uplands, often referred to as geographically isolated wetlands (GIWs) – remain poorly protected. Protection and restoration of wetlands frequently r...

  2. Artificial wetlands performance: nitrogen removal.

    PubMed

    Durán-de-Bazúa, Carmen; Guido-Zárate, Alejandro; Huanosta, Thalía; Padrón-López, Rosa Martha; Rodríguez-Monroy, Jesús

    2008-01-01

    Artificial wetlands (AW) are a promising option for wastewater treatment in small communities due to their high performance in nutrients removal and low operation and maintenance costs. Nitrogen can favour the growth of algae in water bodies causing eutrophication when present at high concentrations. Nitrogen can be removed through different mechanisms (e.g. nitrification-denitrification, adsorption and plant uptake). Environmental conditions such as temperature and relative humidity can play an important role in the performance of these systems by promoting the growth of macrophytes such as reeds and cattails (e.g. Phragmites australis, Typha latifolia respectively). In this paper, two AW systems were compared, one located in Mexico City, Mexico at an altitude higher than 2,000 m above the sea level, and the second one located in Villahermosa, Tabasco, Mexico at an a altitude near the sea level (27 m). Both systems comprised five reactors (147-L plastic boxes) filled with volcanic slag and gravel and intermittently fed with synthetic water. The removal nitrogen efficiency found for the system located in Mexico City was higher than that of the Tabasco system (90 and 80% as TKN respectively). The higher temperatures in the Tabasco system did not enhanced the nitrogen removal as expected. Copyright IWA Publishing 2008.

  3. Hydrologic indices for nontidal wetlands

    USGS Publications Warehouse

    Lent, Robert M.; Weiskel, Peter K.; Lyford, Forest P.; Armstrong, David S.

    1997-01-01

    Two sets of hydrologic indices were developed to characterize the water-budget components of nontidal wetlands. The first set consisted of six water-budget indices for input and output variables, and the second set consisted of two hydrologic interaction indices derived from the water-budget indices. The indices then were applied to 19 wetlands with previously published water-budget data. Two trilinear diagrams for each wetland were constructed, one for the three input indices and another for the three output indices. These two trilinear diagrams then were combined with a central quadrangle to form a Piper-type diagram, with data points from the trilinear diagrams projected onto the quadrangle. The quadrangle then was divided into nine fields that summarized the water-budget information. Two quantitative "interaction indices" were calculated from two of the six water-budget indices (precipitation and evapotranspiration). They also were obtained graphically from the water-budget indices, which were first projected to the central quadrangle of a Piper-type diagram from the flanking trilinear plots. The first interaction index (l) defines the strength of interaction between a wetland and the surrounding ground- and surface-water system. The second interaction index (S) defines the nature of the interaction between the wetland and the surrounding ground- and surface-water system (source versus sink). Evaluation of these indices using published wetland water-budget data illustrates the usefulness of the technique.

  4. A wetland hydrology and water quality model incorporating surface water/groundwater interactions

    NASA Astrophysics Data System (ADS)

    KazezyıLmaz-Alhan, Cevza Melek; Medina, Miguel A.; Richardson, Curtis J.

    2007-04-01

    In the last two decades the beneficial aspects of constructed treatment wetlands have been studied extensively. However, the importance of restored wetlands as a best management practice to improve the water quality of storm water runoff has only recently been appreciated. Furthermore, investigating surface water/groundwater interactions within wetlands is now acknowledged to be essential in order to better understand the effect of wetland hydrology on water quality. In this study, the development of a general comprehensive wetland model Wetland Solute Transport Dynamics (WETSAND) that has both surface flow and solute transport components is presented. The model incorporates surface water/groundwater interactions and accounts for upstream contributions from urbanized areas. The effect of restored wetlands on storm water runoff is also investigated by routing the overland flow through the wetland area, collecting the runoff within the stream, and transporting it to the receiving water using diffusion wave routing techniques. The computed velocity profiles are subsequently used to obtain water quality concentration distributions in wetland areas. The water quality component solves the advection-dispersion equation for several nitrogen and phosphorus constituents, and it also incorporates the surface water/groundwater interactions by including the incoming/outgoing mass due to the groundwater recharge/discharge. In addition, output from the Storm Water Management Model (SWMM5) is incorporated into this conceptual wetland model to simulate the runoff quantity and quality flowing into a wetland area from upstream urban sources. Additionally, the model can simulate a water control structure using storage routing principles and known stage-discharge spillway relationships.

  5. Framework Guidance Manual for In Situ Wetland Restoration Demonstration

    DTIC Science & Technology

    2013-08-26

    Remediation of Contaminated Sediments ASTM American Society for Testing and Materials AVS Acid Volatile Sulfide BAZ Biologically Active Zone ...exposures in Biologically Active Zone (BAZ). - Limited short term risk from treatment application. - Will not significantly alter soil elevations or...situ wetland remediation is intended for surface applications within the biologically active zone (BAZ) to limit uptake by the local benthos (Ghosh

  6. H. R. 2594: This Act may be cited as the Wetlands Stewardship Trusts Act of 1991, introduced in the US House of Representatives, One Hundred Second Congress, First Session, June 7, 1991

    SciTech Connect

    Not Available

    1991-01-01

    This bill was introduced into the US House of Representatives on June 7, 1991 to provide for the designation of Wetlands Stewardship Trusts. This legislation amended the Internal Revenue Code of 1986 to establish special rules for contributions of wetlands and riparian lands to Wetlands Stewardship Trusts. Key features of the bill address the following: tax treatment of donations of wetlands and riparian lands to Wetlands Stewardship Trusts; amortization of expenditures to restore wetlands and riparian lands; expenditures for restoring wetlands and riparian lands; exclusion from gross income for amounts received from compatible uses of wetlands or riparian lands; andmore » income from compatible uses of wetlands or riparian lands.« less

  7. Removal and factors influencing removal of sulfonamides and trimethoprim from domestic sewage in constructed wetlands.

    PubMed

    Dan A; Yang, Yang; Dai, Yu-nv; Chen, Chun-xing; Wang, Su-yu; Tao, Ran

    2013-10-01

    Twelve pilot-scale constructed wetlands with different configurations were set up in the field to evaluate the removal and factors that influence removal of sulfonamides (sulfadiazine, sulfapyridine, sulfacetamide, sulfamethazine and sulfamethoxazole) and trimethoprim from domestic sewage. The treatments included four flow types, three substrates, two plants and three hydraulic loading rates across two seasons (summer and winter). Most target antibiotics were efficiently removed by specific constructed wetlands; in particular, all types of constructed wetlands performed well for the degradation of sulfapyridine. Flow types were the most important influencing factor in this study, and the best removal of sulfonamides was achieved in vertical subsurface-flow constructed wetlands; however, the opposite phenomenon was found with trimethoprim. Significant relationships were observed between antibiotic degradation and higher temperature and redox potential, which indicated that microbiological pathways were the most probable degradation route for sulfonamides and trimethoprim in constructed wetlands. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Wetland Hydrology | Science Inventory | US EPA

    EPA Pesticide Factsheets

    This chapter discusses the state of the science in wetland hydrology by touching upon the major hydraulic and hydrologic processes in these complex ecosystems, their measurement/estimation techniques, and modeling methods. It starts with the definition of wetlands, their benefits and types, and explains the role and importance of hydrology on wetland functioning. The chapter continues with the description of wetland hydrologic terms and related estimation and modeling techniques. The chapter provides a quick but valuable information regarding hydraulics of surface and subsurface flow, groundwater seepage/discharge, and modeling groundwater/surface water interactions in wetlands. Because of the aggregated effects of the wetlands at larger scales and their ecosystem services, wetland hydrology at the watershed scale is also discussed in which we elaborate on the proficiencies of some of the well-known watershed models in modeling wetland hydrology. This chapter can serve as a useful reference for eco-hydrologists, wetland researchers and decision makers as well as watershed hydrology modelers. In this chapter, the importance of hydrology for wetlands and their functional role are discussed. Wetland hydrologic terms and the major components of water budget in wetlands and how they can be estimated/modeled are also presented. Although this chapter does not provide a comprehensive coverage of wetland hydrology, it provides a quick understanding of the basic co

  9. Indicator pathogens, organic matter and LAS detergent removal from wastewater by constructed subsurface wetlands

    PubMed Central

    2014-01-01

    Background Constructed wetland is one of the natural methods of municipal and industrial wastewater treatments with low initial costs for construction and operation as well as easy maintenance. The main objective of this study is to determine the values of indicator bacteria removal, organic matter, TSS, ammonia and nitrate affecting the wetland removal efficiency. Results The average concentration of E. coli and total coliform in the input is 1.127 × 1014 and 4.41 × 1014 MPN/100 mL that reached 5.03 × 1012 and 1.13 × 1014 MPN/100 mL by reducing 95.5% and 74.4% in wetland 2. Fecal streptococcus reached from the average 5.88 × 1014 in raw wastewater to 9.69 × 1012 in the output of wetland 2. Wetland 2 could reduce 1.5 logarithmic units of E. coli. The removal efficiency of TSS for the wetlands is 68.87%, 71.4%, 57.3%, and 66% respectively. Conclusions The overall results show that wetlands in which herbs were planted had a high removal efficiency about the indicator pathogens, organic matter, LAS detergent in comparison to a control wetland (without canes) and could improve physicochemical parameters (DO, ammonia, nitrate, electrical conductivity, and pH) of wastewater. PMID:24581277

  10. Morphological response of Typha domingensis to an industrial effluent containing heavy metals in a constructed wetland.

    PubMed

    Hadad, H R; Mufarrege, M M; Pinciroli, M; Di Luca, G A; Maine, M A

    2010-04-01

    Typha domingensis had become the dominant species after 2 years of operation of a wetland constructed for metallurgical effluent treatment. Therefore, the main purpose of this study was to investigate its ability to tolerate the effluent and to maintain the contaminant removal efficiency of the constructed wetland. Plant, sediment, and water at the inlet and outlet of the constructed wetland and in two natural wetlands were sampled. Metal concentration (Cr, Ni, and Zn) and total phosphorus were significantly higher in tissues of plants growing at the inlet in comparison with those from the outlet and natural wetlands. Even though the chlorophyll concentration was sensitive to effluent toxicity, biomass and plant height at the inlet and outlet were significantly higher than those in the natural wetlands. The highest root and stele cross-sectional areas, number of vessels, and biomass registered in inlet plants promoted the uptake, transport, and accumulation of contaminants in tissues. The modifications recorded accounted for the adaptability of T. domingensis to the conditions prevailing in the constructed wetland, which allowed this plant to become the dominant species and enabled the wetland to maintain a high contaminant retention capacity.

  11. A Framework for Wetlands Research: Development of a Wetlands Data Base

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Issues related to the assembly of a comprehensive global wetlands data base are presented. A strategy to collect relevant data for wetland ecosystems through remote sensing inventories of wetland distribution was discussed. Elements of a research program on biogenic gas fluxes were identified. The major wetland parameters and their functional importance to material exchange mechanisms are summarized.

  12. Vegetation of Upper Coastal Plain Depression Wetlands: Environmental Templates and Wetland Dynamics Within A Landscape Framework

    Treesearch

    Diane De Steven; Maureen M. Toner

    2004-01-01

    Reference wetlands play an important role in efforts to protect wetlands and assess wetland condition. Because wetland vegetation integrates the influence of many ecological factors, a useful reference system would identify natural vegetation types and include models relating vegetation to important regional geomorphic, hydrologic, and geochemical properties. Across...

  13. Michigan Wetlands: Yours To Protect. A Citizen's Guide to Local Involvement in Wetland Protection. Second Edition.

    ERIC Educational Resources Information Center

    Cwikiel, Wilfred

    This guidebook is designed to assist concerned Michigan citizens, local governments, conservation organizations, landowners, and others in their efforts to initiate wetlands protection activities. Chapter 1 focuses on wetland functions, values, losses, and the urgent need to protect wetland resources. Chapter 2 discusses wetland identification and…

  14. Restoration of Bhoj Wetlands At Bhopal, India

    NASA Astrophysics Data System (ADS)

    Shukla, S. S.; Kulshrestha, M.; Wetland Project, Bhoj

    financial savings as well as devel- opment of in-house expertise. The works have also been taken up manually as far as possible, giving employment opportunities to thousands of poor residents of Bhopal City and nearby villages. This also has ensured participation of masses by default. The project had at the time of its inception envisaged a sum of Rs. 2470 millions. As a result of manual pursuance of work, development of in-house expertise and due to various other cost reduction exercises adopted by the project authorities and engineers the project has so far spent only Rs. 1100 millions thus resulting in huge savings. A part of savings (Rs. 500 millions) has been invested to form a Lake Conservation Authority U a Government body which will look after all the lakes in the entire state 1 of Madhya Pradesh, thus contributing immensely to the cause of lake conservation. One of the special features of this project has been the involvement of masses in its various developmental schemes. This has been ensured by involving more than 55 NGOs and dozens of local educational institutions. Millions of Rupees have been ear- marked for ensuring public participation in various sub-projects. The project on its completion within the next 4 months will contribute immensely to the conservation of both the lakes which can them become role models for other similar wetlands. The paper also details out the various project works like diversion and treatment of nearly 56 MLD of sewage, reduction of harmful inflows of chemicals from activities such as washing activity, idol immersions etc., reduction measures for silt inflow to the lakes, desilting and dredging operations to increase the lake capacity by more than 2.5 M.Cum, improvement in the water quality by reduction of pollution, deweeding oper- ations, nutrient removal by dredging, increased aquaculture activities etc., large scale afforestation (1.6 million trees have been planted in the catchment) and implementa- tion of solid waste

  15. 40 CFR 258.12 - Wetlands.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... contribute to significant degradation of wetlands. The owner or operator must demonstrate the integrity of...) Erosion, stability, and migration potential of native wetland soils, muds and deposits used to support the...

  16. 40 CFR 257.9 - Wetlands.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... degradation of wetlands. The owner/operator must demonstrate the integrity of the unit and its ability to... potential of native wetland soils, muds and deposits used to support the unit; (ii) Erosion, stability, and...

  17. 40 CFR 257.9 - Wetlands.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... degradation of wetlands. The owner/operator must demonstrate the integrity of the unit and its ability to... potential of native wetland soils, muds and deposits used to support the unit; (ii) Erosion, stability, and...

  18. 40 CFR 257.9 - Wetlands.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... degradation of wetlands. The owner/operator must demonstrate the integrity of the unit and its ability to... potential of native wetland soils, muds and deposits used to support the unit; (ii) Erosion, stability, and...

  19. 40 CFR 258.12 - Wetlands.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... contribute to significant degradation of wetlands. The owner or operator must demonstrate the integrity of...) Erosion, stability, and migration potential of native wetland soils, muds and deposits used to support the...

  20. 40 CFR 257.9 - Wetlands.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... degradation of wetlands. The owner/operator must demonstrate the integrity of the unit and its ability to... potential of native wetland soils, muds and deposits used to support the unit; (ii) Erosion, stability, and...

  1. 40 CFR 258.12 - Wetlands.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... contribute to significant degradation of wetlands. The owner or operator must demonstrate the integrity of...) Erosion, stability, and migration potential of native wetland soils, muds and deposits used to support the...

  2. 40 CFR 258.12 - Wetlands.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... contribute to significant degradation of wetlands. The owner or operator must demonstrate the integrity of...) Erosion, stability, and migration potential of native wetland soils, muds and deposits used to support the...

  3. [Wetland landscape ecological classification: research progress].

    PubMed

    Cao, Yu; Mo, Li-jiang; Li, Yan; Zhang, Wen-mei

    2009-12-01

    Wetland landscape ecological classification, as a basis for the studies of wetland landscape ecology, directly affects the precision and effectiveness of wetland-related research. Based on the history, current status, and latest progress in the studies on the theories, indicators, and methods of wetland landscape classification, some scientific wetland classification systems, e.g., NWI, Ramsar, and HGM, were introduced and discussed in this paper. It was suggested that a comprehensive classification method based on HGM and on the integral consideration of wetlands spatial structure, ecological function, ecological process, topography, soil, vegetation, hydrology, and human disturbance intensity should be the major future direction in this research field. Furthermore, the integration of 3S technologies, quantitative mathematics, landscape modeling, knowledge engineering, and artificial intelligence to enhance the automatization and precision of wetland landscape ecological classification would be the key issues and difficult topics in the studies of wetland landscape ecological classification.

  4. Wetland mitigation in abandoned gravel pits.

    DOT National Transportation Integrated Search

    2010-03-01

    It is becoming increasingly difficult to provide on-site mitigation for wetland impacts due to road construction in : northeastern Minnesota counties that retain greater than 80 percent of their pre-settlement wetlands. Abandoned : gravel pits are on...

  5. Industry and forest wetlands: Cooperative research initiatives

    SciTech Connect

    Shepard, J.P.; Lucier, A.A.; Haines, L.W.

    1993-05-01

    In 1989 the forest products industry responded to a challenge of the National Wetlands Policy Forum to initiate a cooperative research program on forest wetlands management organized through the National Council of the Paper Industry for Air and Stream Improvement (NCASI). The objective is to determine how forest landowners can manage wetlands for timber production while protecting other wetland functions such as flood storage, water purification, and food chain/wildlife habitat support. Studies supported by the NCASI in 9 states are summarized. Technical support on wetland regulatory issues to member companies is part of the research program. Since guidelines for recognizingmore » wetlands for regulatory proposed have changed frequently, the NCASI has recommend an explicit link between wetland delineation and a classification system that considers difference among wetland types in vegetation, soils, hydrology, appearance, landscape position, and other factors. 16 refs.« less

  6. Quantifying The Water Quality Services Of Wetlands

    EPA Science Inventory

    Wetlands are well recognized for their potential for providing a wide range of important ecological services including their ability to provide water quality protection. Watershed-scale water quality trading could create market driven incentives to restore and construct wetlands...

  7. Mycorrhizae in Bottomland Hardwood (BLH) Wetland Forests

    DTIC Science & Technology

    1999-01-01

    This technical note describes the distribution of mycorrhizae in several BLH wetland forests of the Southeast and their potential importance in restoration of BLH wetland forests from agricultural lands.

  8. Constructed wetlands for nonpoint source pollution control.

    DOT National Transportation Integrated Search

    1998-01-01

    Wetland mitigation and stormwater management provisions in the 1987 Clean Water Act (CWA) significantly impact transportation agencies. CWA Section 404 stipulates that when highway construction results in the displacement of natural wetlands, the hig...

  9. Reciprocating constructed wetlands for treating industrial, municipal and agricultural wastewater.

    PubMed

    Behrends, L; Houke, L; Bailey, E; Jansen, P; Brown, D

    2001-01-01

    Scientists at the Tennessee Valley Authority (TVA), and in collaboration with the U.S. Environmental Protection Agency (EPA), are continuing to develop and refine an innovative wastewater treatment system referred to as reciprocating subsurface-flow constructed wetlands. Reciprocation relates to patented improvements in the design and operation of paired subsurface-flow constructed wetlands, such that contiguous cells are filled and drained on a frequent and recurrent basis. This operating technique turns the entire wetland system into a fixed-film biological reactor, in which it is possible to control redox potential in alternating aerobic and anaerobic zones. Reciprocating systems enable manipulation of wastewater treatment functions by controlling such parameters as hydraulic retention time, frequency of reciprocation, reciprocation cycle time, depth of reciprocation, and size and composition of substrate. These improved wetland technologies have been used for treating municipal/domestic wastewater, high strength animal wastewater, and mixed wastewater streams containing acids, recalcitrant compounds, solvents, antifreeze compounds, heavy metals, explosives, and fertilizer nutrients. Results from selected treatability studies and field demonstrations will be summarized with respect to conceptual design and treatment efficacy.

  10. Stochastic modeling of reactive transport in wetlands

    NASA Astrophysics Data System (ADS)

    Carleton, James N.; Montas, Hubert J.

    2009-11-01

    This study describes the development of a general model for reaction in and performance of spatially heterogeneous bioreactors such as treatment wetlands. The modeled domain possesses local-scale velocities, reaction rates and transverse dispersion coefficients that are functions of an underlying heterogeneity variate representing one or more controlling biophysical attributes, for example, reactive surface area (submerged plant) density. Reaction rate coefficients are treated as related to local velocities in an inverse square fashion via their mutual dependence upon the variate. The study focuses on the solution for the steady-state case with constant inlet concentration. Results compare well with exact solutions developed for laterally-bounded systems in which the heterogeneity is represented explicitly. Employing the bicontinuum analogue of a second-order model, an expression for an effective longitudinal dispersion coefficient as a function of travel distance is developed using the method of moments. The result provides insights into the behavior of concentration as transverse mixing drives the system asymptotically toward Fickian longitudinal dispersion. The model may represent an improvement over other approaches for characterizing treatment wetland performance because it accounts for evolving shear flow dispersion, and because parameters are few in number, physically based, and invariant with mean velocity.

  11. The treatment of wastewater containing pharmaceuticals in microcosm constructed wetlands: the occurrence of integrons (int1-2) and associated resistance genes (sul1-3, qacEΔ1).

    PubMed

    Nowrotek, Monika; Kotlarska, Ewa; Łuczkiewicz, Aneta; Felis, Ewa; Sochacki, Adam; Miksch, Korneliusz

    2017-06-01

    The aim of this study was to analyze the occurrence of sulfonamide resistance genes (sul1-3) and other genetic elements as antiseptic resistance gene (qacEΔ1) and class 1 and class 2 integrons (int1-2) in the upper layer of substrate and in the effluent of microcosm constructed wetlands (CWs) treating artificial wastewater containing diclofenac and sulfamethoxazole (SMX), which is a sulfonamide antibiotic. The bacteria in the substrate and in the effluents were equipped with the sul1-2, int1, and qacEΔ1 resistance determinants, which were introduced into the CW system during inoculation with activated sludge and with the soil attached to the rhizosphere of potted seedlings of Phalaris arundinacea 'Picta' roots (int1). By comparing the occurrence of the resistance determinants in the upper substrate layer and the effluent, it can be stated that they neither were lost nor emerged along the flow path. The implications of the presence of antibiotic resistance genes in the effluent may entail a risk of antibiotic resistance being spread in the receiving environment. Additionally, transformation products of SMX were determined. According to the obtained results, four (potential) SMX transformation products were identified. Two major metabolites of SMX, 2,3,5-trihydroxy-SMX and 3,5-dihydroxy-SMX, indicated that SMX may be partly oxidized during the treatment. The remaining two SMX transformation products (hydroxy-glutathionyl-SMX and glutathionyl-SMX) are conjugates with glutathione, which suggests the ability of CW bacterial community to degrade SMX and resist antimicrobial stress.

  12. North Dakota Wetlands Discovery Guide. Photocopy Booklet.

    ERIC Educational Resources Information Center

    Dietz, Nancy J., Ed.; And Others

    This booklet contains games and activities that can be photocopied for classroom use. Activities include Wetland Terminology, Putting on the Map, Erosional Forces, Water in...Water out, Who Lives Here?, Wetlands in Disguise, Dichotomous Plant Game, Algae Survey, Conducting an Algal Survey, Water Quality Indicators Guide, Farming Wetlands, Wetlands…

  13. Using hydrogeology to site wetland compensation

    USGS Publications Warehouse

    Miller, Michael V.; Fucciolo, Christine S.; Miner, James J.

    1998-01-01

    The Illinois State Geological Survey has designed an initial site evaluation (ISE) procedure to rapidly separate candidate sites that have favorable hydrogeologic characteristics for wetland restoration or creation from sites where success is doubtful or difficult. ISE aims to focus compensation efforts on sites where former wetland hydrology can be restored or where the hydrogeology of wetlands in similar landscape positions can be reproduced.

  14. 76 FR 777 - National Wetland Plant List

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-06

    ... Plant List AGENCY: U. S. Army Corps of Engineers, Department of Defense. ACTION: Notice. SUMMARY: The National Wetland Plant List (NWPL) is used to delineate wetlands for purposes of the Clean Water Act and... Conservation Service (NRCS), is announcing the availability of the draft National Wetland Plant List (NWPL) and...

  15. Conservation of Louisiana's coastal wetland forests

    Treesearch

    Jim L. Chambers; Richard F. Keim; William H. Conner; John W. Jr. Day; Stephen P. Faulkner; Emile S. Gardiner; Melinda s. Hughes; Sammy L. King; Kenneth W. McLeod; Craig A. Miller; J. Andrew Nyman; Gary P. Shaffer

    2006-01-01

    Large-scale efforts to protect and restore coastal wetlands and the concurrent renewal of forest harvesting in cypress-tupelo swamps have brought new attention to Louisiana's coastal wetland forests in recent years. Our understanding of these coastal wetland forests has been limited by inadequate data and the lack of a comprehensive review of existing information...

  16. Hydrology of a natural hardwood forested wetland

    Treesearch

    George M. Chescheir; Devendra M. Amatya; R. Wayne Skaggs

    2008-01-01

    This paper documents the hydrology of a natural forested wetland near Plymouth, NC, USA. The research site was located on one of the few remaining, undrained non-riverine, palustrine forested hardwood wetlands on the lower coastal plain of North Carolina. A 137 ha watershed within the 350ha wetland was selected for intensive field study. Water balance components...

  17. Enrichment of elements in detritus from a constructed wetland and consequent toxicity to Hyalella azteca.

    PubMed

    Sundberg, Sarah E; Hassan, Sayed M; Rodgers, John H

    2006-07-01

    In a pilot constructed wetland treatment system specifically designed to treat constituents of flue gas desulfurization wastewater, detritus adsorbs significantly high concentrations of Hg, Se, and As. Results of this research indicate that Hg, Se, and As were enriched in detritus from Schoenoplectus californicus and Typha angustifolia collected from the constructed wetland by factors up to 4600, 26,300, and 15,600, respectively. As an important food source for many organisms, element enrichment makes the detritus an even greater source of contaminants to the food web. Results demonstrate that the natural decomposition of plants in this constructed wetland treatment system produces detritus enriched with Hg, Se, and As at levels potentially hazardous to aquatic organisms. To completely assess ecological risks associated with the use of constructed wetland treatment systems, contaminant enrichment, bioavailability, and toxicity in detritus must be considered.

  18. Remote sensing of coastal wetlands

    NASA Technical Reports Server (NTRS)

    Hardisky, M. A.; Klemas, V.; Gross, M. F.

    1986-01-01

    Various aircraft and satellite sensors for detecting and mapping wetlands properties are examined. The uses of color IR photography to map coastal vegetation, and of Landsat MSS and TM and SPOT data to quantify biomass and productivity for large wetland areas are discussed. For spectral estimation of biomass and productivity, the relation between radiance and biomass needs to be studied; the quantity and orientation of dead biomass and the amount of soil reflectance in comparison with vegetation reflectance in a given target area affect the spectral estimation of biomass. The radiometric evaluation of brackish wetland, and remote sensing in mangroves are described. The collection of images in narrow, contiguous spectral band using imaging spectrometry is considered.

  19. Intensification of constructed wetlands for land area reduction: a review.

    PubMed

    Ilyas, Huma; Masih, Ilyas

    2017-05-01

    The large land area requirement of constructed wetlands (CWs) is a major limitation of its application especially in densely populated and mountainous areas. This review paper provides insights on different strategies applied for the reduction of land area including stack design and intensification of CWs with different aeration methods. The impacts of different aeration methods on the performance and land area reduction were extensively and critically evaluated for nine wetland systems under three aeration strategies such as tidal flow (TF), effluent recirculation (ER), and artificial aeration (AA) applied on three types of CWs including vertical flow constructed wetland (VFCW), horizontal flow constructed wetland (HFCW), and hybrid constructed wetland (HCW). The area reduction and pollutant removal efficiency showed substantial variation among different types of CWs and aeration strategies. The ER-VFCW designated the smallest footprint of 1.1 ± 0.5 m 2 PE -1 (population equivalent) followed by TF-VFCW with the footprint of 2.1 ± 1.8 m 2 PE -1 , and the large footprint was of AA-HFCW (7.8 ± 4.7 m 2 PE -1 ). When footprint and removal efficiency both are the major indicators for the selection of wetland type, the best options for practical application could be TF-VFCW, ER-HCW, and AA-HCW. The data and results outlined in this review could be instructive for futures studies and practical applications of CWs for wastewater treatment, especially in land-limited regions.

  20. Constructed wetlands as a component of the agricultural landscape: Mitigation of herbicides in simulated runoff from upland drainage areas

    USDA-ARS?s Scientific Manuscript database

    Constructed wetlands are a recommended practice for buffering pollutant source areas and receiving waters. A wetland consisting of a sediment trap and two treatment cells was constructed in a Mississippi Delta lake watershed. A 3-h simulated runoff event was initiated (2003) to evaluate fate and tr...

  1. Using constructed wetlands to treat biochemical oxygen demand and ammonia associated with a refinery effluent.

    PubMed

    Huddleston, G M; Gillespie, W B; Rodgers, J H

    2000-02-01

    This study evaluated the effectiveness of constructed wetlands for tertiary treatment of a petroleum refinery effluent. Specific performance objectives were to decrease 5-day biochemical oxygen demand (BOD(5)) and ammonia by at least 50% and to reduce toxicity associated with this effluent. Two bench-scale wetlands (replicates) were constructed in a greenhouse to provide tertiary treatment of effluent samples shipped from the refinery to the study site. Integrated wetland features included Typha latifolia Linnaeus planted in low organic (0.2%), sandy sediment, 48-h nominal hydraulic retention time, and 15-cm overlying water depth. Targeted constituents and aqueous toxicity were monitored in wetland inflows and outflows for 3 months. Following a 2 to 3-week stabilization period, effective and consistent removal of BOD(5) and ammonia (as NH(3)-N) from the effluent was observed. Average BOD(5) removal was 80%, while NH(3)-N decreased by an average of 95%. Survival of Pimephales promelas Rafinesque and Ceriodaphnia dubia Richard (7-day, static, renewal exposures) increased by more than 50% and 20%, respectively. Reproduction of C. dubia increased from zero in undiluted wetland inflow to 50% of controls in undiluted wetland outflow. This study demonstrated the potential for constructed wetlands to decrease BOD(5), ammonia, and toxicity in this refinery effluent. Copyright 2000 Academic Press.

  2. Regulatory implications of using constructed wetlands to treat selenium-laden wastewater.

    PubMed

    Lemly, A Dennis; Ohlendorf, Harry M

    2002-05-01

    The practice of using constructed wetlands to treat selenium-laden wastewater is gaining popularity in the United States and elsewhere. However, proponents of treatment wetlands often overlook important ecological liabilities and regulatory implications when developing new methods and applications. Their research studies typically seek to answer a basic performance question--are treatment wetlands effective in improving water quality--rather than answering an implicit safety question-are they hazardous to wildlife. Nevertheless, wetland owners are responsible for both the operational performance of treatment wetlands and the health of animals that use them. This is true even if wetlands were not created with the intent of providing wildlife habitat; the owner is still legally responsible for toxic hazards. If poisoning of fish and wildlife occurs, the owner can be prosecuted under a variety of federal and state laws, for example, the Migratory Bird Treaty Act and the Endangered Species Act. In considering this type of treatment technology it is important to document the selenium content of the wastewater, understand how it cycles and accumulates in the environment, and evaluate the threat it may pose to fish and wildlife before deciding whether or not to proceed with construction. Many of the potential hazards may not be obvious to project planners, particularly if there is no expressed intention for the wetland to provide wildlife habitat. Ecological risk assessment provides an approach to characterizing proposed treatment wetlands with respect to wildlife use, selenium contamination, and possible biological impacts. Proper application of this approach can reveal potential problems and the associated liabilities, and form the basis for selection of an environmentally sound treatment option.

  3. Regulators of coastal wetland methane production and responses to simulated global change

    NASA Astrophysics Data System (ADS)

    Vizza, Carmella; West, William E.; Jones, Stuart E.; Hart, Julia A.; Lamberti, Gary A.

    2017-01-01

    Wetlands are the largest natural source of methane (CH4) emissions to the atmosphere, which vary along salinity and productivity gradients. Global change has the potential to reshape these gradients and therefore alter future contributions of wetlands to the global CH4 budget. Our study examined CH4 production along a natural salinity gradient in fully inundated coastal Alaska wetlands. In the laboratory, we incubated natural sediments to compare CH4 production rates between non-tidal freshwater and tidal brackish wetlands, and quantified the abundances of methanogens and sulfate-reducing bacteria in these ecosystems. We also simulated seawater intrusion and enhanced organic matter availability, which we predicted would have contrasting effects on coastal wetland CH4 production. Tidal brackish wetlands produced less CH4 than non-tidal freshwater wetlands probably due to high sulfate availability and generally higher abundances of sulfate-reducing bacteria, whereas non-tidal freshwater wetlands had significantly greater methanogen abundances. Seawater addition experiments with freshwater sediments, however, did not reduce CH4 production, perhaps because the 14-day incubation period was too short to elicit a shift in microbial communities. In contrast, increased organic matter enhanced CH4 production in 75 % of the incubations, but this response depended on the macrophyte species added, with half of the species treatments having no significant effect. Our study suggests that CH4 production in coastal wetlands, and therefore their overall contribution to the global CH4 cycle, will be sensitive to increased organic matter availability and potentially seawater intrusion. To better predict future wetland contributions to the global CH4 budget, future studies and modeling efforts should investigate how multiple global change mechanisms will interact to impact CH4 dynamics.

  4. Effects of wetlands creation on groundwater flow

    USGS Publications Warehouse

    Hensel, B.R.; Miller, M.V.

    1991-01-01

    Changes in groundwater flow were observed near four Experimental Wetland Areas (EWAs) constructed along a reach of the Des Plaines River in northeastern Illinois. These changes were observed during monthly monitoring of groundwater elevation in nested piezometers and shallow observation wells before and after the wetlands were filled with water. A numerical model was calibrated with observed data and used to estimate seepage from the wetlands into the Des Plaines River. After the wetlands became operational, groundwater levels in adjacent wells increased by about 0.5m, while water levels in wells distant from the wetlands decreased. The increase in groundwater levels near the wetlands is a result of seepage from the wetlands. Numerical predictions of seepage from the wetlands are 60-150 m3 day-1 for two wetlands situated over sand and gravel and less than 1 m3 day-1 for two wetlands situated over clayey till. The difference in seepage rates is attributed to two factors. First, the hydraulic conductivity of the sand and gravel unit is greater than that of the till, and thus there is less mounding and a greater capacity for transmitting water beneath the wetlands overlying this deposit. Secondly, the wetlands located over till are groundwater flow-through ponds, whereas the wetlands over the sand and gravel are primarily groundwater recharge areas. The model was used to estimate that seepage from the wetlands will double groundwater discharge into the Des Plaines River and a tributary relative to pre-operational discharge from the study area. Overall, the wetlands have acted as a constant head boundary, stabilizing groundwater flow patterns. ?? 1991.

  5. Understanding Broadscale Drivers of Coastal Wetland Extent

    NASA Astrophysics Data System (ADS)

    Braswell, A. E.; Heffernan, J. B.

    2014-12-01

    Coastal wetlands provide valuable ecosystem services, but are threatened by sea level rise, anthropogenic disturbance, and changing sediment supply. Watershed characteristics, such as watershed area and upland land use, can mediate suspended sediment concentration; while estuarine characteristics, such as fetch, can determine the wave energy and erosion in a coastal area. These combined effects are mediated by local biogeomorphic feedbacks within wetlands to determine wetland extent. There has been little empirical or theoretical study of how broad-scale features of estuaries and watersheds influence wetland formation, persistence, and loss. As such, we cannot predict how wetland extent and resilience to sea level rise will respond to land use change and other human alterations. In this study, we ask, what factors control the broad-scale distribution of coastal wetlands? We examined relationships between coastal wetland extent and watershed/estuarine characteristics at multiple scales along the Eastern and Gulf coasts of the United States. Using existing GIS resources, we delineated the absolute and relative extents of coastal wetlands, and generated watershed and estuarine characteristics to serve as proxies of sediment input, the estuarine energy environment, and local wetland alteration. We found that present coastal wetland distributions reflect interactions across a wide range of spatial scales, ranging from local biogeomorphic processes, to estuarine-scale morphology that governs hydrodynamics, and to past and present watershed processes that influence sediment delivery. Coastal wetland extent scales with estuary size to the half power and the residuals reflect a bimodal distribution. The wetland extent distribution also displays multiple clusters, possibly signaling that local feedbacks drive wetland extent at some scales. When the results are broken up by region, this pattern is stronger in Northeastern United States. Using continental-scale variation in

  6. Wetland mitigation banking for the petroleum industry

    SciTech Connect

    Crookshank, S.L.

    1996-08-01

    Wetland policies aimed at achieving a no-overall-net-loss goal are likely to increase the cost of petroleum operations conducted in wetlands. This paper argues that wetland mitigation banking is the key to minimizing the costs associated with these wetland policies. Noting the limited opportunities for banking by the petroleum industry currently, the paper examines how wetland mitigation banking regulations should be structured in order to make banking a viable option for industry. It argues that the Army Corps of Engineers should allow banks with proper safety mechanisms in place to sell credits before mitigation projects are completed.

  7. The treatment of run-off from a fertiliser plant for nitrification, denitrification and phosphorus removal by use of constructed wetlands: a demonstration study.

    PubMed

    Cooper, P F; McBarnet, W; O'Donnell, D; McMahon, A; Houston, L; Brian, M

    2010-01-01

    The paper describes an evaluation carried out on demonstration scale to show that it was possible to use a Hybrid Reed Bed System comprising a Horizontal flow and a Vertical Flow Bed for treating the high strength run-off from a fertiliser packaging plant. The site is located close to an estuary which is sensitive to nutrients. The environmental regulators were therefore concerned that excessive mass flows of nitrate, ammoniacal nitrogen and phosphate, potentially arising from the site run-off, were not discharged into the estuary. The fertiliser manufacturing company required a simple, low maintenance system for removing nitrogen and phosphorus. A series of experimental runs were carried out to characterise the performance of the Hybrid System, establishing the effluent quality that could be achieved and the mass removal rate which was appropriate for acceptable treatment. These tests showed that it was possible to achieve a reduction of 79% in Total N whilst using molasses as a carbon source for denitrification. When using a 4:1 recycle ratio this produced an effluent with concentrations of 14 mg NH(4)-N/litre and 18 mg NO(3)-N/litre from treating site run-off containing concentrations in the order of 75 mg/litre of both NH(3)N and NO(3)-N. Chemical dosing with an iron salt brought the P concentration down to around 0.5 mg PO(4)-P/litre.

  8. A Review of Wetland Remote Sensing.

    PubMed

    Guo, Meng; Li, Jing; Sheng, Chunlei; Xu, Jiawei; Wu, Li

    2017-04-05

    Wetlands are some of the most important ecosystems on Earth. They play a key role in alleviating floods and filtering polluted water and also provide habitats for many plants and animals. Wetlands also interact with climate change. Over the past 50 years, wetlands have been polluted and declined dramatically as land cover has changed in some regions. Remote sensing has been the most useful tool to acquire spatial and temporal information about wetlands. In this paper, seven types of sensors were reviewed: aerial photos coarse-resolution, medium-resolution, high-resolution, hyperspectral imagery, radar, and Light Detection and Ranging (LiDAR) data. This study also discusses the advantage of each sensor for wetland research. Wetland research themes reviewed in this paper include wetland classification, habitat or biodiversity, biomass estimation, plant leaf chemistry, water quality, mangrove forest, and sea level rise. This study also gives an overview of the methods used in wetland research such as supervised and unsupervised classification and decision tree and object-based classification. Finally, this paper provides some advice on future wetland remote sensing. To our knowledge, this paper is the most comprehensive and detailed review of wetland remote sensing and it will be a good reference for wetland researchers.

  9. Factors affecting coastal wetland loss and restoration

    USGS Publications Warehouse

    Cahoon, D.R.; Phillips, S.W.

    2007-01-01

    Opening paragraph: Tidal and nontidal wetlands in the Chesapeake Bay watershed provide vital hydrologic, water-quality, and ecological functions. Situated at the interface of land and water, these valuable habitats are vulnerable to alteration and loss by human activities including direct conversion to non-wetland habitat by dredge-and-fill activities from land development, and to the effects of excessive nutrients, altered hydrology and runoff, contaminants, prescribed fire management, and invasive species. Processes such as sea-level rise and climate change also impact wetlands. Although local, State, and Federal regulations provide for protection of wetland resources, the conversion and loss of wetland habitats continue in the Bay watershed. Given the critical values of wetlands, the Chesapeake 2000 Agreement has a goal to achieve a net gain in wetlands by restoring 25,000 acres of tidal and nontidal wetlands by 2010. The USGS has synthesized findings on three topics: (1) sea-level rise and wetland loss, (2) wetland restoration, and (3) factors affecting wetland diversity.

  10. Flooding Frequency Alters Vegetation in Isolated Wetlands

    USGS Publications Warehouse

    Haag, Kim H.; Lee, Terrie M.

    2006-01-01

    Many isolated wetlands in central Florida occur as small, shallow depressions scattered throughout the karst topography of the region. In these wetlands, the water table approaches land surface seasonally, and water levels and flooding frequency are largely determined by differences between precipitation and evapotranspiration. Because much of the region is flat with little topographic relief, small changes in wetland water levels can cause large changes in wetland surface area. Persistent changes in wetland flooding frequencies, as a result of changes in rainfall or human activity, can cause a substantial change in the vegetation of thousands of acres of land. Understanding the effect that flooding frequency has on wetland vegetation is important to assessing the overall ecological status of wetlands. Wetland bathymetric mapping, when combined with water-level data and vegetation assessments, can enable scientists to determine the frequency of flooding at different elevations in a wetland and describe the effects of flooding frequency on wetland vegetation at those elevations. Five cypress swamps and five marshes were studied by the U.S. Geological Survey (USGS) during 2000-2004, as part of an interdisciplinary study of isolated wetlands in central Florida (Haag and others, 2005). Partial results from two of these marshes are described in this report.

  11. A Review of Wetland Remote Sensing

    PubMed Central

    Guo, Meng; Li, Jing; Sheng, Chunlei; Xu, Jiawei; Wu, Li

    2017-01-01

    Wetlands are some of the most important ecosystems on Earth. They play a key role in alleviating floods and filtering polluted water and also provide habitats for many plants and animals. Wetlands also interact with climate change. Over the past 50 years, wetlands have been polluted and declined dramatically as land cover has changed in some regions. Remote sensing has been the most useful tool to acquire spatial and temporal information about wetlands. In this paper, seven types of sensors were reviewed: aerial photos coarse-resolution, medium-resolution, high-resolution, hyperspectral imagery, radar, and Light Detection and Ranging (LiDAR) data. This study also discusses the advantage of each sensor for wetland research. Wetland research themes reviewed in this paper include wetland classification, habitat or biodiversity, biomass estimation, plant leaf chemistry, water quality, mangrove forest, and sea level rise. This study also gives an overview of the methods used in wetland research such as supervised and unsupervised classification and decision tree and object-based classification. Finally, this paper provides some advice on future wetland remote sensing. To our knowledge, this paper is the most comprehensive and detailed review of wetland remote sensing and it will be a good reference for wetland researchers. PMID:28379174

  12. Lake Superior Coastal Wetland Fish Assemblages and ...

    EPA Pesticide Factsheets

    The role of the coastal margin and the watershed context in defining the ecology of even very large lakes is increasingly being recognized and examined. Coastal wetlands are both important contributors to the biodiversity and productivity of large lakes and important mediators of the lake-basin connection. We explored wetland-watershed connections and their relationship to wetland function and condition using data collected from 37 Lake Superior wetlands spanning a substantial geographic and geomorphic gradient. While none of these wetlands are particularly disturbed, there were nevertheless clear relationships between watershed landuse and wetland habitat and biota, and these varied consistently across wetland type categories that reflected the strength of connection to the watershed. For example, water clarity and vegetation structure complexity declined with decreasing percent natural land cover, and these effects were strongest in riverine wetlands (having generally large watersheds and tributary-dominated hydrology) and weakest in lagoon wetlands (having generally small watersheds and lake-dominate hydrology). Fish abundance and species richness both increased with decreasing percent natural land cover while species diversity decreased, and again the effect was strongest in riverine wetlands. Lagoonal wetlands, which lack any substantial tributary, consistently harbored the fewest species of fish and a composition different from the more watershed-lin

  13. Performance of a constructed wetland treating intensive shrimp aquaculture wastewater under high hydraulic loading rate.

    PubMed

    Lin, Ying-Feng; Jing, Shuh-Ren; Lee, Der-Yuan; Chang, Yih-Feng; Chen, Yi-Ming; Shih, Kai-Chung

    2005-04-01

    A water treatment unit, mainly consisting of free water surface (FWS) and subsurface flow (SF) constructed wetland cells, was integrated into a commercial-scale recirculating aquaculture system for intensive shrimp culture. This study investigated performance of the treatment wetlands for controlling water quality. The results showed that the FWS-SF cells effectively removed total suspended solids (55-66%), 5-day biochemical oxygen demand (37-54%), total ammonia (64-66%) and nitrite (83-94%) from the recirculating water under high hydraulic loading rates (1.57-1.95 m/day). This led to a water quality that was suitable for shrimp culture and effluent that always satisfied the discharge standards. The area ratios of wetlands to culture tank being demonstrated (0.43) and calculated (0.096) in this study were both significantly lower than the reported values. Accordingly, a constructed wetland was technically and economically feasible for managing water quality of an intensive aquaculture system.

  14. Remote Sensing of Global Wetland Dynamics

    NASA Technical Reports Server (NTRS)

    Matthews, Elaine; Prigent, Catherine; Birkett, Charon; Coe, Mike; Hasen, James E. (Technical Monitor)

    2000-01-01

    Although natural wetlands only cover about 4% of the earth's ice-free land surface, they are the world's largest methane (CH4) source and the only one dominated by climate. In addition, wetlands affect climate by modulating temperatures and heat fluxes, storing water, increasing evaporation, and altering the seasonality of runoff and river discharge to the oceans. Current CH4 emissions from wetlands are relatively well understood but the sensitivity of wetlands and their emissions to climate variations remains the largest uncertainty in the global CH4 cycle and could strongly influence predictions of future climate. Therefore, characterizing climate-sensitive processes prevailing in the world's wetlands is crucial to understanding and predicting physical and biogeochemical responses of wetlands to interannual and longer-term climate variations. Recent research has resulted in the first generation of models to predict methane emissions from wetlands but the models must still be applied to static data on wetland distributions. Moreover, no models currently exist to realistically predict the distribution and dynamics of wetlands themselves for the current, or any other, climate. The dominant obstacle to modeling wetland dynamics has been lack of remote sensing techniques and data useful for characterizing quantitatively the seasonal and interannual variations of wetlands. We report on initial remote sensing studies undertaken to validate a global hydrological model linking rivers, takes and wetlands. Using a combination of SSM/I microwave and TOPEX Poseidon altimetry data sets, we developed and applied techniques to quantify inundation extent and duration for several large wetlands in tropical Africa and South America. Our initial results indicate that seasonally-inundated wetlands can be well characterized over large spatial scales and at monthly time scales using these remote sensing data. The results also confirm that currently available remote sensing products can

  15. Environmental Education in Wetland Ecosystems

    ERIC Educational Resources Information Center

    Papapanagou, Eirini; Tiniakou, Argyro; Georgiadis, Theodoros

    2005-01-01

    An educational package based on the Messolongi wetland area and designed to develop environmental awareness amongst Greek secondary students is described. The package includes a book and a pedagogical guide for the teacher, as well as a hypermedia application/CD-ROM and worksheets for the student. The entire educational package combines recent…

  16. 76 FR 22785 - Wetland Conservation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-25

    ... Wetland Conservation AGENCY: Office of the Secretary, United States Department of Agriculture (USDA... Conservation Service's (NRCS) coordination responsibilities. DATES: Effective Date: The rule is effective April..., U.S. Department of Agriculture, Natural Resources Conservation Service, Room 6819, South Building, P...

  17. A Hydrogeomorphic Classification for Wetlands

    DTIC Science & Technology

    1993-08-01

    factors like fire, herbivory , frost, and other variables were necessary to further characterize specific wetlands and their vegeta- tion (Figure 5c). During...Heinselman, M. L. (1970). "Landscape evolution , peatland types, and the environment in the Lake Agassiz Peatlands Natural Area, Minnesota," Ecological

  18. The National Wetland Condition Assessment

    EPA Science Inventory

    The first National Wetland Condition Assessment (NWCA) was conducted in 2011 by the US Environmental Protection Agency (USEPA). Vegetation, algae, soil, water chemistry,and hydrologic data were collected at each of 1138 sites across the contiguous US. Ecological condition was ass...

  19. Constructed wetlands as sustainable ecotechnologies in decentralization practices: a review.

    PubMed

    Valipour, Alireza; Ahn, Young-Ho

    2016-01-01

    Recently, a range of novel and cost-effective engineered wetland technologies for decentralization practices of domestic wastewater treatment have been developed with ecological process modification, the use of functionalized plants, and advanced biofilm formation. However, selecting the one that can be more appreciated for on-site sanitation is still uncertain. This paper reviews the role of plants, media materials, microorganisms, and oxygen transfer in domestic wastewater purification through constructed wetlands (CWs). The effectiveness of traditional and recently developed CWs and the necessity of an induced biofilm attachment surface (BAS) in these systems for the treatment of domestic sewage are presented. This review also elucidates the idea of CWs for domestic wastewater characteristics highly stressed by total dissolved solids and the adaptive strategies in mitigating the cold climate impacts on their efficiencies. Further research needed to enhance the stability and sustainability of CWs is highlighted. By a more advanced investigation, BAS CWs can be specified as an ideal treatment process in decentralization.

  20. Organic matter and nitrogen removal at planted wetlands treating domestic septage with varying operational strategies.

    PubMed

    Jong, Valerie Siaw Wee; Tang, Fu Ee

    2014-01-01

    A two-staged engineered wetland-based system was designed and constructed to treat raw domestic septage. Hydraulic loading rates (HLRs) of 8.75 and 17.5 cm/d were studied with four and eight daily dosings at the second stage of the system to investigate the influence of the regimes on septage treatment. Removal of organic matter (OM) was found to be HLR dependent, where the results indicated that the increase of HLR from 8.75 to 17.5 cm/d impaired the overall level of treatment in the wetland units. Effluent of wetland fed at HLR 17.5 cm/d presented significantly lower oxygen reduction potential and dissolved oxygen values than wetland fed at 8.75 cm/d, indicative of the occurrence of less aerobic and reductive conditions in the bed. The reoxygenation capability of the wetland units was found to be heavily affected by the dosing frequency especially under high hydraulic load (17.5 cm/d). NH3-N degradation was found to decrease with statistical importance when the wetland was flushed two times more frequently with smaller batches of influent. The number of hydraulic load fractionings did not seem to affect the level of treatments of OM and ammonia for both the wetlands fed under the lower HLR of 8.75 cm/d. Prediction of hydraulic limits and management of the feeding strategies are important in the vertical type of engineered wetlands to guarantee the treatment performance and minimize the chances of filter clogging.

  1. Nesting and foraging behavior of red-winged blackbirds in stormwater wetlands

    USGS Publications Warehouse

    Sparling, D.W.; Eisemann, J.; Kuenzel, W.

    2007-01-01

    Stormwater wetlands are a common part of urban and suburban landscapes. These constructed wetlands provide first-order treatment of effluent from roads, parking lots, lawns and other surfaces. They also provide habitat for wetland-associated birds. Thus, there is a concern that birds may be attracted to potentially toxic habitats. This study assesses nesting success and forging behavior of Red-winged Blackbirds (Agelaius phoeniceus) in retention stormwater wetlands based on drainage type. Drainage categories included residential, commercial, and highway sites. Commercial sites had the lowest nesting success and the lowest diversity of invertebrate foods. Mean nest success values for all three types of wetlands, especially for highway drainages, were comparable to published values from natural wetlands. Over two years of study highway ponds collectively served as source populations whereas residential and commercial sites were population sinks in one year and sources in the other. Red-wings using highway sites had the highest foraging efficiency as determined by the frequency and duration of forays. Residential sites had the greatest human disturbance and generally had intermediate-quality habitat and nesting success. We conclude that while stormwater wetlands collect run off and accompanying pollutants, they can still be valuable habitats for nesting birds in urban and suburban areas. We recommend a few management strategies that can increase avian use of these habitats. ?? Springer Science+Business Media, LLC 2007.

  2. Effects of a herbicide mixture on primary and bacterial productivity in four prairie wetlands with varying salinities: an enclosure approach.

    PubMed

    Sura, Srinivas; Waiser, Marley J; Tumber, Vijay; Raina-Fulton, Renata; Cessna, Allan J

    2015-04-15

    Wetlands in the Prairie pothole region of Saskatchewan and Manitoba serve an important role in providing wildlife habitat, water storage and water filtration. They display a wide range of water quality parameters such as salinity, nutrients and major ions with sulfate as the dominant ion for the most saline wetlands. The differences in these water quality parameters among wetlands are reflected in the composition of aquatic plant communities and their productivity. Interspersed within an intensely managed agricultural landscape where pesticides are commonly used, mixtures of herbicides are often detected in these wetlands as well as in rivers, and drinking water reservoirs. One freshwater and three wetlands of varying salinity in the St. Denis National Wildlife Area, Saskatchewan, Canada were selected to study the effects of a mixture of eight herbicides (2,4-D, MCPA, dicamba, clopyralid, bromoxynil, mecoprop, dichlorprop, and glyphosate) on wetland microbial communities using an outdoor enclosure approach. Six enclosures (three controls and three treatments) were installed in each wetland and the herbicide mixture added to the treatment enclosures. The concentration of each herbicide in the enclosure water was that which would have resulted from a direct overspray of a 0.5-m deep wetland at its recommended field application rate. After herbicide addition, primary and bacterial productivity, and algal biomass were measured in both planktonic and benthic communities over 28 days. The herbicide mixture had a stimulatory effect on primary productivity in the nutrient-sufficient freshwater wetland while no stimulatory effect was observed in the nutrient-deficient saline wetlands. The differences observed in the effects of the herbicide mixture appear to be related to the nutrient bioavailability in these wetlands. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  3. China's natural wetlands: past problems, current status, and future challenges

    Treesearch

    Shuqing An; Harbin Li; Baohua Guan; Changfang Zhou; Zhongsheng Wang; Zifa Deng; Yingbiao Zhi; Yuhong Liu; Chi Xu; Shubo Fang; Jinhui Jiang; Hongli Li

    2007-01-01

    Natural wetlands, occupying 3.8% of China's land and providing 54.9% of ecosystem services, are unevenly distributed among eight wetland regions. Natural wetlands in China suffered great loss and degradation (e.g., 23.0% freshwater swamps, 51.2% coastal wetlands) because of the wetland reclamation during China's long history of civilization, and the...

  4. Forestry Best Management Practices for Wetlands in Minnesota

    Treesearch

    Michael J. Phillips

    1997-01-01

    Wetlands are a common landscape feature in Minnesota in spite of significant losses of wetlands to agriculture and development. Prior to European settlement, Minnesota contained 7.5 million ha of wetlands, including both wet, mineral and peat soils. These wetlands covered approximately 35 percent of the state. The current extent of wetlands for Minnesota is...

  5. Wetlands and agriculture: Are we heading for confrontation or conservation

    Treesearch

    Brij Gopal

    2000-01-01

    Wetlands and agriculture are closely linked. Historically, agriculture had its beginning in riparian wetland habitats and expanded into other wetlands. Later, large areas of riverine, palustrine, and coastal wetlands were converted into paddy fields or drained for agriculture. Agriculture has grown most at the expense of natural wetlands. Today, the intensive...

  6. Methane Cycling in a Warming Wetland

    NASA Astrophysics Data System (ADS)

    Noyce, G. L.; Megonigal, P.; Rich, R.; Kirwan, M. L.; Herbert, E. R.

    2017-12-01

    Coastal wetlands are global hotspots of carbon (C) storage, but the future of these systems is uncertain. In June 2016, we initiated an in-situ, active, whole-ecosystem warming experiment in the Smithsonian's Global Change Research Wetland to quantify how warming and elevated CO2 affect the stability of coastal wetland soil C pools and contemporary rates of C sequestration. Transects are located in two plant communities, dominated by C3 sedges or C4 grasses. The experiment has a gradient design with air and soil warming treatments ranging from ambient to +5.1 °C and heated plots consistently maintain their target temperature year-round. In April 2017, an elevated CO2 treatment was crossed with temperature in the C3community. Ongoing measurements include soil elevation, C fluxes, porewater chemistry and redox potential, and above- and below-ground growth and biomass. In both years, warming increased methane (CH4) emissions (measured at 3-4 week intervals) from spring through fall at the C3 site, but had little effect on emissions from the C4 site. Winter (Dec-Mar) emissions showed no treatment effect. Stable isotope analysis of dissolved CH4 and DIC also indicated that warming had differing effects on CH4 pathways in the two vegetation communities. To better understand temperature effects on rates of CH4 production and oxidation, 1 m soil cores were collected from control areas of the marsh in summer 2017 and incubated at temperatures ranging from 4 °C to 35 °C. Warming increased CH4 production and oxidation rates in surface samples and oxidation rates in the rooting zone samples from both sites, but temperature responses in deep (1 m) soil samples were minimal. In the surface and rooting zone samples, production rates were also consistently higher in C3 soils compared to C4 soils, but, contrary to our expectations, the temperature response was stronger in the C4 soils. However, oxidation in C3 rooting zone samples did have a strong temperature response. The

  7. Spatial distribution of metals in the constructed wetlands.

    PubMed

    Kongroy, Porntawee; Tantemsapya, Netnapid; Lin, Ying-Feng; Jing, Shuh Ren; Wirojanagud, Wanpen

    2012-02-01

    Investigation of the spatial distribution of metals was conducted for two constructed wetlands used as tertiary treatment in Chia Nan University of Pharmacy and Science (CNU) and Metal Processing Industries (MPI) located in Tainan, Taiwan. These two distinguished sites were selected to compare the distribution of metals for constructed wetlands treating different types of wastewater. Along the distance, samples of water, sediment, and macrophytes were analyzed for metals including Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. Additionally, measurements of water quality including temperature, pH, EC, ORP, DO, TSS, BOD, COD, and turbidity were performed. Results show that, at CNU, wastewater contained higher organic consititute (BOD 29.3 +/- 11.7 mg/, COD 46.7 +/- 33.6 mg/L) with low metals content. Wastewater at MPI contained low level of organic consititute (BOD 7.1 +/- 3.3 mg/L, and COD 66.0 +/- 56.5 mg/L) and higher metals content. Metals distribution of both sites showed similar results where metals in the sediments in the inlet zone have greater concentrations than other areas. The constructed wetlands can remove Cd, Cu, Ni, Pb, and Zn. However, there was no removal of Al, Cr, Fe, and Mn. A distance along the constructed wetlands had no effect on metal concentrations in macrophyte and water.

  8. The National Wetland Condition Assessment: National Data on Wetland Quality to Inform and Improve Wetlands Protection

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA), in collaboration with states, tribes, the US Fish and Wildlife Service (US FWS), and other federal partners will conduct the first-ever National Wetland Condition Assessment (NWCA) in 2011. The NWCA is designed to build on the succ...

  9. Flow patterns of dairy wastewater constructed wetlands in a cold climate.

    PubMed

    Muñoz, Pete; Drizo, Aleksandra; Cully Hession, W

    2006-10-01

    Conservative tracer experiments, and spatial temperature and dissolved oxygen mapping within four subsurface treatment wetlands employed in this study demonstrated the importance of supplemental aeration and vegetation in reducing preferential flows in cold climate treatment wetlands. Four constructed wetlands, employing horizontal subsurface flow were used to treat dairy wastewater in a 2 x 2 factorial design consisting of two wetland cells with vegetation and two with supplemental aeration. Four tracer studies were conducted between November 2004 and May 2005. Two key observations were made, demonstrating that vegetation and aeration can be utilized in cold regions to prevent clogging and freezing, thereby reducing preferential flow paths which can reduce treatment efficiencies: (1) vegetation contributed to thermal protection and (2) aeration increased temperature and mixing. A comparison of multiple wetland cells with varying flow rates showed that the use of pore volume in tracer response curves was a better indicator of preferential flows than other indicators including volumetric efficiency, hydraulic efficiency and number of continuosly stirred tank reactors (CSTRs). This research helps further establish how constructed wetlands are a viable tool for treating wastewater in cold climates.

  10. Wetland restoration, flood pulsing, and disturbance dynamics

    USGS Publications Warehouse

    Middleton, Beth A.

    1999-01-01

    While it is generally accepted that flood pulsing and disturbance dynamics are critical to wetland viability, there is as yet no consensus among those responsible for wetland restoration about how best to plan for those phenomena or even whether it is really necessary to do so at all. In this groundbreaking book, Dr. Beth Middleton draws upon the latest research from around the world to build a strong case for making flood pulsing and disturbance dynamics integral to the wetland restoration planning process.While the initial chapters of the book are devoted to laying the conceptual foundations, most of the coverage is concerned with demonstrating the practical implications for wetland restoration and management of the latest ecological theory and research. It includes a fascinating case history section in which Dr. Middleton explores the restoration models used in five major North American, European, Australian, African, and Asian wetland projects, and analyzes their relative success from the perspective of flood pulsing and disturbance dynamics planning.Wetland Restoration also features a wealth of practical information useful to all those involved in wetland restoration and management, including: * A compendium of water level tolerances, seed germination, seedling recruitment, adult survival rates, and other key traits of wetland plant species * A bibliography of 1,200 articles and monographs covering all aspects of wetland restoration * A comprehensive directory of wetland restoration ftp sites worldwide * An extensive glossary of essential terms

  11. WE-G-9A-01: Radiation Oncology Outcomes Informatics

    SciTech Connect

    Mayo, C; Miller, R; Sloan, J

    2014-06-15

    The construction of databases and support software to enable routine and systematic aggregation, analysis and reporting of patient outcomes data is emerging as an important area. “How have results for our patients been affected by the improvements we have made in our practice and in the technologies we use?” To answer this type of fundamental question about the overall pattern of efficacy observed, it is necessary to systematically gather and analyze data on all patients treated within a clinic. Clinical trials answer, in great depth and detail, questions about outcomes for the subsets of patients enrolled in a given trial.more » However, routine aggregation and analysis of key treatment parameter data and outcomes information for all patients is necessary to recognize emergent patterns that would be of interest from a public health or practice perspective and could better inform design of clinical trials or the evolution of best practice principals. To address these questions, Radiation Oncology outcomes databases need to be constructed to enable combination essential data from a broad group of data types including: diagnosis and staging, dose volume histogram metrics, patient reported outcomes, toxicity metrics, performance status, treatment plan parameters, demographics, DICOM data and demographics. Developing viable solutions to automate aggregation and analysis of this data requires multidisciplinary efforts to define nomenclatures, modify clinical processes and develop software and database tools requires detailed understanding of both clinical and technical issues. This session will cover the developing area of Radiation Oncology Outcomes Informatics. Learning Objectives: Audience will be able to speak to the technical requirements (software, database, web services) which must be considered in designing an outcomes database. Audience will be able to understand the content and the role of patient reported outcomes as compared to traditional toxicity

  12. Importance of hydrogeochemical processes in the coastal wetlands: A case study from Edremit-Dalyan coastal wetland, Balıkesir-Turkey

    NASA Astrophysics Data System (ADS)

    Somay, Melis A.

    2016-11-01

    Investigating the hydrogeochemical properties of wetlands allow us to protect them in a sustainable fashion in global scale. Edremit-Dalyan coastal wetland (EDCW) is located in southern part of Biga Peninsula (Mount Ida) which is the most important eco-tourism center in Turkey. Water sampling was done from the hydrologic basin of coastal wetland that consists of a geothermal site, ore deposits area, treatment facility area and olive tree breeding area. EC values of wetland vary between 440 and 2190 μS/cm and water type shows a shift from CaHCO3 to NaClSO4. Al, As, Cd, Cu, Fe, Pb and Zn concentrations exceed the tolerance limits in wetland area probably due to ore deposits around the Edremit Plain. Concentrations of As are high in wetland area exceeding both aquatic life and drinking water As standards of 10 μg/L by as much as 3 times are observed. The dominant As species is As (III). For the living organisms, this situation can be dangerous. Oxygen-18 and deuterium composition of the samples between -7.18 and -6.13‰, and between -42.6 and -34.4‰, respectively in the study area and all the waters are of meteoric origin. Oxygen-18 enrichment can be observed around Derman and coastal zone due to the geothermal activity and evaporation, respectively.

  13. TH-C-9A-01: Lean Tools and Methods

    SciTech Connect

    Rangaraj, D; Chan, K; Boddu, S

    2014-06-15

    Lean thinking has revolutionized the manufacturing industry. Toyota has pioneered and leveraged this aspect of Lean thinking. Application of Lean thinking and Lean Six Sigma techniques into Healthcare and in particular in Radiation Oncology has its merits and challenges. To improve quality, safety and patient satisfaction with available resources or reducing cost in terms of time, staff and resources is demands of today's healthcare. Radiation oncology treatment involves many processes and steps, identifying and removing the non-value added steps in a process can significantly improve the efficiency. Real projects undertaken in radiation oncology department in cutting down the procedure timemore » for MRI guided brachytherapy to 40% less using lean thinking will be narrated. Simple Lean tools and techniques such as Gemba walk, visual control, daily huddles, standard work, value stream mapping, error-proofing, etc. can be applied with existing resources and how that improved the operation in a Radiation Oncology department's two year experience will be discussed. Lean thinking focuses on identifying and solving the root-cause of a problem by asking “Why” and not “Who” and this requires a culture change of no blame. Role of leadership in building lean culture, employee empowerment and trains and develops lean thinkers will be presented. Why Lean initiatives fail and how to implement lean successfully in your clinic will be discussed. Learning Objectives: Concepts of lean management or lean thinking. Lean tools and techniques applied in Radiation Oncology. Implement no blame culture and focus on system and processes. Leadership role in implementing lean culture. Challenges for Lean thinking in healthcare.« less

  14. Soil organic carbon of degraded wetlands treated with freshwater in the Yellow River Delta, China.

    PubMed

    Wang, Hui; Wang, Renqing; Yu, Yue; Mitchell, Myron J; Zhang, Lianjun

    2011-10-01

    Supplying freshwater is one of the important methods to help restore degraded wetlands. Changes in soil properties and plant community biomass were evaluated by comparing sites with freshwater treatment versus reference sites following freshwater addition to wetlands of the Yellow River Delta for 7 years. The results indicated that soil organic carbon (SOC) was significantly increased in all wetland sites that were treated with freshwater compared to the reference sites. The treatment wetlands had greater total nitrogen (TN), lower pH and electrical conductivity and higher water content in the soil compared to the reference wetlands. In general, the upper soil layer (0-20 cm) had greater SOC than the lower soil layer (20-40 cm). The increase of SOC in the freshwater reintroduction wetlands was higher in the Suaeda salsa plant community (mean ± standard error) (6.89 ± 0.63 g/kg) and Phragmites communis plant community (4.11 ± 0.12 g/kg) than in the Tamarix chinensis plant community (1.40 ± 0.31 g/kg) in the upper soil layer. The differences were especially marked between the treated and reference wetlands for SOC and TN in the P. communis plant communities. The C:N ratio of the soil was significantly greater in the treated compared to the reference wetlands for the S. salsa plant community. Although the C: N ratios increased after treatment, they were all <25 suggesting that N availability was not limiting soil organic matter decomposition. Our results indicate that freshwater addition and the concomitant increase in soil moisture content enhances the accumulation of SOC in the Yellow River Delta. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Introduction to the Wetland Book 1: Wetland structure and function, management, and nethods

    USGS Publications Warehouse

    Davidson, Nick C.; Middleton, Beth A.; McInnes, Robert J.; Everard, Mark; Irvine, Kenneth; Van Dam, Anne A.; Finlayson, C. Max; Finlayson, C. Max; Everard, Mark; Irvine, Kenneth; McInnes, Robert J.; Middleton, Beth A.; Van Dam, Anne A.; Davidson, Nick C.

    2016-01-01

    The Wetland Book 1 is designed as a ‘first port-of-call’ reference work for information on the structure and functions of wetlands, current approaches to wetland management, and methods for researching and understanding wetlands. Contributions by experts summarize key concepts, orient the reader to the major issues, and support further research on such issues by individuals and multidisciplinary teams. The Wetland Book 1 is organized in three parts - Wetland structure and function; Wetland management; and Wetland methods - each of which is divided into a number of thematic Sections. Each Section starts with one or more overview chapters, supported by chapters providing further information and case studies on different aspects of the theme.

  16. Forested wetlands constructed for mitigation of destroyed natural wetlands

    USGS Publications Warehouse

    Perry, M.C.; Pugh, S.B.; Deller, A.S.

    1995-01-01

    Forested wetlands constructed for mitigation were evaluated at six sites in Maryland to determine the success of these areas for providing suitable wildlife habitat. Natural forested wetlands were used as reference sites. Initial mortality of planted woody shrubs and trees was high (avg. 55%) and mostly attributed to excessive moisture. The number of woody seedlings from natural regeneration was inversely proportional to the amount of grass cover on the site, which was planted for erosion control. The number of volunteer woody seedlings was also inversely proportional to the distance from adjacent natural forests. Preliminary data indicate that cost does not support use of transplants and that enhancement of soil with organic supplements, followed by widespread and heavy seeding of woody plants would be more efficient and effective. Wildlife use of areas measured by avian surveys and trapping of mammals, reptiles, and amphibians showed that in general wildlife species were more representative of open grassland areas than forested habitats. Natural succession of the sites probably will take at least 20-30 years before typical values and functions of forested wetlands are obtained.

  17. Efficient removal of antibiotics in surface-flow constructed wetlands, with no observed impact on antibiotic resistance genes.

    PubMed

    Berglund, Björn; Khan, Ghazanfar Ali; Weisner, Stefan E B; Ehde, Per Magnus; Fick, Jerker; Lindgren, Per-Eric

    2014-04-01

    Recently, there have been growing concerns about pharmaceuticals including antibiotics as environmental contaminants. Antibiotics of concentrations commonly encountered in wastewater have been suggested to affect bacterial population dynamics and to promote dissemination of antibiotic resistance. Conventional wastewater treatment processes do not always adequately remove pharmaceuticals causing environmental dissemination of low levels of these compounds. Using constructed wetlands as an additional treatment step after sewage treatment plants have been proposed as a cheap alternative to increase reduction of wastewater contaminants, however this means that the natural microbial community of the wetlands becomes exposed to elevated levels of antibiotics. In this study, experimental surface-flow wetlands in Sweden were continuously exposed to antibiotics of concentrations commonly encountered in wastewater. The aim was to assess the antibiotic removal efficiency of constructed wetlands and to evaluate the impact of low levels of antibiotics on bacterial diversity, resistance development and expression in the wetland bacterial community. Antibiotic concentrations were measured using liquid chromatography-mass spectrometry and the effect on the bacterial diversity was assessed with 16S rRNA-based denaturing gradient gel electrophoresis. Real-time PCR was used to detect and quantify antibiotic resistance genes and integrons in the wetlands, during and after the exposure period. The results indicated that the antibiotic removal efficiency of constructed wetlands was comparable to conventional wastewater treatment schemes. Furthermore, short-term treatment of the constructed wetlands with environmentally relevant concentrations (i.e. 100-2000 ng×l(-1)) of antibiotics did not significantly affect resistance gene concentrations, suggesting that surface-flow constructed wetlands are well-suited for wastewater treatment purposes. Copyright © 2014 Elsevier B.V. All rights

  18. 77 FR 71820 - Meeting Announcement: North American Wetlands Conservation Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ...] Meeting Announcement: North American Wetlands Conservation Council AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of meeting. SUMMARY: The North American Wetlands Conservation Council (Council) will meet to select North American Wetlands Conservation Act (NAWCA) grant proposals for recommendation...

  19. 77 FR 39252 - Meeting Announcement: North American Wetlands Conservation Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ...] Meeting Announcement: North American Wetlands Conservation Council AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of meetings. SUMMARY: The North American Wetlands Conservation Council (Council) will meet to select North American Wetlands Conservation Act (NAWCA) grant proposals for recommendation...

  20. 76 FR 31626 - Meeting Announcement; North American Wetlands Conservation Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ...] Meeting Announcement; North American Wetlands Conservation Council AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of meeting. SUMMARY: The North American Wetlands Conservation Council (Council) will meet to select North American Wetlands Conservation Act (NAWCA) grant proposals for recommendation...

  1. 75 FR 34479 - Meeting Announcement: North American Wetlands Conservation Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ...] Meeting Announcement: North American Wetlands Conservation Council AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of meeting. SUMMARY: The North American Wetlands Conservation Council (Council) will meet to select North American Wetlands Conservation Act (NAWCA) grant proposals for recommendation...

  2. 75 FR 68378 - Meeting Announcement: North American Wetlands Conservation Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-05

    ...] Meeting Announcement: North American Wetlands Conservation Council AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of meeting. SUMMARY: The North American Wetlands Conservation Council (Council) will meet to select North American Wetlands Conservation Act (NAWCA) grant proposals for recommendation...

  3. 78 FR 11220 - Meeting Announcement: North American Wetlands Conservation Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ...] Meeting Announcement: North American Wetlands Conservation Council AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of meeting. SUMMARY: The North American Wetlands Conservation Council (Council) will meet to select North American Wetlands Conservation Act (NAWCA) grant proposals for recommendation...

  4. 78 FR 71637 - Meeting Announcement: North American Wetlands Conservation Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-29

    ...] Meeting Announcement: North American Wetlands Conservation Council AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of meeting. SUMMARY: The North American Wetlands Conservation Council (Council) will meet to select North American Wetlands Conservation Act (NAWCA) grant proposals for recommendation...

  5. EVALUATION OF BIOREMEDIATION STRATEGIES OF A CONTROLLED OIL RELEASE IN A WETLAND

    EPA Science Inventory

    A controlled petroleum release was conducted to evaluate bioremediation in a wetland near Houston, Texas. The 140-day study was conducted using a randomized, complete block design to test three treatments with six replicates per treatment. The three treatment strategies were in...

  6. Are wetlands the reservoir for avian cholera?

    USGS Publications Warehouse

    Samuel, M.D.; Shadduck, D.J.; Goldberg, Diana R.

    2004-01-01

    Wetlands have long been suspected to be an important reservoir for Pasteurella multocida and therefore the likely source of avian cholera outbreaks. During the fall of 1995a??98 we collected sediment and water samples from 44 wetlands where avian cholera epizootics occurred the previous winter or spring. We attempted to isolate P. multocida in sediment and surface water samples from 10 locations distributed throughout each wetland. We were not able to isolate P. multocida from any of the 440 water and 440 sediment samples collected from these wetlands. In contrast, during other investigations of avian cholera we isolated P. multocida from 20 of 44 wetlands, including 7% of the water and 4.5% of the sediment samples collected during or shortly following epizootic events. Our results indicate that wetlands are an unlikely reservoir for the bacteria that causes avian cholera.

  7. Are wetlands the reservoir for avian cholera?

    PubMed

    Samuel, Michael D; Shadduck, Daniel J; Goldberg, Diana R

    2004-07-01

    Wetlands have long been suspected to be an important reservoir for Pasteurella multocida and therefore the likely source of avian cholera outbreaks. During the fall of 1995-98 we collected sediment and water samples from 44 wetlands where avian cholera epizootics occurred the previous winter or spring. We attempted to isolate P. multocida in sediment and surface water samples from 10 locations distributed throughout each wetland. We were not able to isolate P. multocida from any of the 440 water and 440 sediment samples collected from these wetlands. In contrast, during other investigations of avian cholera we isolated P. multocida from 20 of 44 wetlands, including 7% of the water and 4.5% of the sediment samples collected during or shortly following epizootic events. Our results indicate that wetlands are an unlikely reservoir for the bacteria that causes avian cholera.

  8. Aquatic macroinvertebrates associated with Schoenoplectus litter in a constructed wetland in California (USA)

    USGS Publications Warehouse

    Nelson, S.M.; Thullen, J.S.

    2008-01-01

    Culm processing characteristics were associated with differences in invertebrate density in a study of invertebrates and senesced culm packs in a constructed treatment wetland. Invertebrate abundance differed by location within the wetland and there were differences between the two study years that appeared to be related to water quality and condition of culm material. Open areas in the wetland appeared to be critical in providing dissolved oxygen (DO) and food (plankton) to the important invertebrate culm processor, Glyptotendipes. As culm packs aged, invertebrate assemblages became less diverse and eventually supported mostly tubificid worms and leeches. It appears from this study that wetland design is vital to processing of plant material and that designs that encourage production and maintenance of high DO's will encourage microbial and invertebrate processing of material.

  9. Biogeochemial modeling of biodegradation and stable isotope fractionation of DCE in a small-scale wetland

    NASA Astrophysics Data System (ADS)

    Alvarez-Zaldívar, Pablo; Imfeld, Gwenaël; Maier, Uli; Centler, Florian; Thullner, Martin

    2013-04-01

    In recent years, the use of (constructed) wetlands has gained significant attention for the in situ remediation of groundwater contaminated with (chlorinated) organic hydrocarbons. Although many sophisticated experimental methods exist for the assessment of contaminant removal in such wetlands the understanding how changes in wetland hydrochemistry affect the removal processes is still limited. This knowledge gap might be reduced by the use of biogeochemical reactive transport models. This study presents the reactive transport simulation of a small-scale constructed wetland treated with groundwater containing cis-1,2-dichloroethene (cDCE). Simulated processes consider different cDCE biodegradation pathways and the associated carbon isotope fractionation, a set of further (bio)geochemical processes as well as the activity of the plant roots. Spatio-temporal hydrochemical and isotope data from a long-term constructed wetland experiment [1] are used to constrain the model. Simulation results for the initial oxic phase of the wetland experiment indicate carbon isotope enrichment factors typical for cometabolic DCE oxidation, which suggests that aerobic treatment of cDCE is not an optimal remediation strategy. For the later anoxic phase of the experiment model derived enrichment factors indicate reductive dechlorination pathways. This degradation is promoted at all wetland depths by a sufficient availability of electron donor and carbon sources from root exudates, which makes the anoxic treatment of groundwater in such wetlands an effective remediation strategy. In combination with the previous experimental data results from this study suggest that constructed wetlands are viable remediation means for the treatment of cDCE contaminated groundwater. Reactive transport models can improve the understanding of the factors controlling chlorinated ethenes removal, and the used model approach would also allow for an optimization of the wetland operation needed for a complete

  10. Integrated wetlands for food production.

    PubMed

    Chen, Ray Zhuangrui; Wong, Ming-Hung

    2016-07-01

    The widespread use of compound pelleted feeds and chemical fertilizers in modern food production contribute to a vast amount of residual nutrients into the production system and adjacent ecosystem are major factors causing eutrophication. Furthermore, the extensive development and application of chemical compounds (such as chemical pesticides, disinfectants and hormones used in enhancing productivity) in food production process are hazardous to the ecosystems, as well as human health. These unsustainable food production patterns cannot sustain human living in the long run. Wetlands are perceived as self-decontamination ecosystems with high productivities. This review gives an overview about wetlands which are being integrated with food production processes, focusing on aquaculture. Copyright © 2016. Published by Elsevier Inc.

  11. Hydrogeomorphic classification for Great Lakes coastal wetlands

    USGS Publications Warehouse

    Albert, Dennis A.; Wilcox, Douglas A.; Ingram, Joel W.; Thompson, Todd A.

    2005-01-01

    A hydrogeomorphic classification scheme for Great Lakes coastal wetlands is presented. The classification is hierarchical and first divides the wetlands into three broad hydrogeomorphic systems, lacustrine, riverine, and barrier-protected, each with unique hydrologic flow characteristics and residence time. These systems are further subdivided into finer geomorphic types based on physical features and shoreline processes. Each hydrogeomorphic wetland type has associated plant and animal communities and specific physical attributes related to sediment type, wave energy, water quality, and hydrology.

  12. Wetland features and landscape context predict the risk of wetland habitat loss

    Treesearch

    Kevin J. Gutzwiller; Curtis H. Flather

    2011-01-01

    Wetlands generally provide significant ecosystem services and function as important harbors of biodiversity. To ensure that these habitats are conserved, an efficient means of identifying wetlands at risk of conversion is needed, especially in the southern United States where the rate of wetland loss has been highest in recent decades. We used multivariate adaptive...

  13. Wetlands reserve program: a partnership to restore wetlands and associated habitat

    Treesearch

    Randall L. Gray

    2005-01-01

    The 1990 Farm Bill created the Wetlands Reserve Program (WRP) to restore and protect wetland, which as of 2002 has enrolled over 1.4 million acres of wetland and upland habitat in 49 states and Puerto Rico. The program is administered by the U. S. Department of Agriculture Natural Resource Conservation Service and delivered in cooperation with many partners from the...

  14. Characteristic community structure of Florida's subtropical wetlands: the Florida wetland condition index

    EPA Science Inventory

    Depending upon the classification scheme applied, there are between 10 and 45 different wetland types in Florida. Land use and land cover change has a marked effect on wetland condition, and different wetland types are affected differentially depending on many abiotic and biotic ...

  15. Diverse characteristics of wetlands restored under the Wetlands Reserve Program in the Southeastern United States

    Treesearch

    Diane De Steven; Joel M. Gramling

    2012-01-01

    The Wetlands Reserve Program (WRP) restores converted or degraded wetlands on private working lands; however, the nature and outcomes of such efforts are undocumented in the Southeastern U.S. Identification of wetland types is needed to assess the program's conservation benefits, because ecological functions differ with hydrogeomorphic (HGM) type. We reviewed...

  16. SLOSS or Not? Factoring Wetland Size Into Decisions for Wetland Conservation, Enhancement, Restoration, and Creation

    EPA Science Inventory

    Mitigation or replacement of several small impacted wetlands or sites with fewer large wetlands can occur deliberately through the application of functional assessment methods (e.g., Adamus 1997) or coincidentally as the result of market-based mechanisms for wetland mitigation ba...

  17. Application of the EPA Wetland Research Program Approach to a floodplain wetland restoration assessment

    Treesearch

    R. K. Kolka; C. C. Trettin; E. A. Nelson; C. D. Barton; D. E. Fletcher

    2002-01-01

    Forested wetland restoration assessment is difficult because of the timeframe necessary for the development of a forest ecosystem. The development of a forested wetland ecosystem includes the recovery of hydrology, soils, vegetation, and faunal communities. To assess forested wetland restoration projects, measures need to be developed that are sensitive to early...

  18. Application of the EPA wetland research program approach to a floodplain wetland restoration assessment

    Treesearch

    R.K. Kolka; Carl C. Trettin; E.A. Nelson; C.D. Barton; D.E. Fletcher

    2002-01-01

    Forested wetland restoration assessment is difficult because of the timeframe necessary for the development of a forest ecosystem. The development of a forested wetland ecosystem includes the recovery of hydrology, soils, vegetation, and faunal communities. To assess forested wetland restoration projects, measures need to be developed that are sensitive to early...

  19. Bat response to carolina bays and wetland restoration in the southeastern U.S. Coastal Plain.

    SciTech Connect

    Menzel, Jennifer M.; Michael A. Menzel; John C. Kilgo

    2005-09-01

    Abstract: Bat activity in the southeastern United States is concentrated over riparian areas and wetland habitats. The restoration and creation of wetlands for mitigation purposes is becoming common in the Southeast. Understanding the effects of these restoration efforts on wetland flora and fauna is thus becoming increasingly important. Because bats (Order: Chiroptera) consist of many species that are of conservation concern and are commonly associated with wetland and riparian habitats in the Southeast (making them a good general indicator for the condition of wetland habitats), we monitored bat activity over restored and reference Carolina bays surrounded by pine savanna (Pinusmore » spp.) or mixed pine-hardwood habitat types at the Savannah River Site in South Carolina. In order to determine how wetland restoration efforts affected the bat community, we monitored bat activity above drained Carolina bays pre- and post-restoration. Our results indicate that bat activity was greater over reference (i.e., undrained) than drained bays prior to the restorative efforts. One year following combined hydrologic and vegetation treatment, however, bat activity was generally greater over restored than reference bays. Bat activity was also greater over both reference and restored bays than in random, forested interior locations. We found significantly more bat activity after restoration than prior to restoration for all but one species in the treatment bays, suggesting that Carolina bay restoration can have almost immediate positive impacts on bat activity.« less

  20. 'Halophyte filters': the potential of constructed wetlands for application in saline aquaculture.

    PubMed

    De Lange, H J; Paulissen, M P C P; Slim, P A

    2013-01-01

    World consumption of seafood continues to rise, but the seas and oceans are already over-exploited. Land-based (saline) aquaculture may offer a sustainable way to meet the growing demand for fish and shellfish. A major problem of aquaculture is nutrient waste, as most of the nutrients added through feed are released into the environment in dissolved form. Wetlands are nature's water purifiers. Constructed wetlands are commonly used to treat contaminated freshwater effluent. Experience with saline systems is more limited. This paper explores the potential of constructed saline wetlands for treating the nutrient-rich discharge from land-based saline aquaculture systems. The primary function of constructed wetlands is water purification, but other ancillary benefits can also be incorporated into treatment wetland designs. Marsh vegetation enhances landscape beauty and plant diversity, and wetlands may offer habitat for fauna and recreational areas. Various approaches can be taken in utilizing plants (halophytes, macro-algae, micro-algae) in the treatment of saline aquaculture effluent. Their strengths and weaknesses are reviewed here, and a conceptual framework is presented that takes into account economic and ecological benefits as well as spatial constraints. Use of the framework is demonstrated for assessing various saline aquaculture systems in the southwestern delta region of the Netherlands.