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Sample records for a-01 wetland treatment

  1. WasteWater Treatment And Heavy Metals Removal In The A-01 Constructed Wetland 2003 Report

    SciTech Connect

    ANNA, KNOX

    2004-08-01

    The A-01 wetland treatment system (WTS) was designed to remove metals from the effluent at the A-01 NPDES outfall. The purpose of research conducted during 2003 was to evaluate (1) the ability of the A-01 wetland treatment system to remediate waste water, (2) retention of the removed contaminants in wetland sediment, and (3) the potential remobilization of these contaminants from the sediment into the water column. Surface water and sediment samples were collected and analyzed in this study.

  2. Baseline Hydrosoil Chemistry of the A-01 Wetland Treatment System, September 2001

    SciTech Connect

    Specht, W.L.

    2002-07-10

    The A-01 wetland treatment system was designed to remove metals from effluent from the A-01 NPDES outfall. Construction of the treatment system was completed in the summer of 2000 and all treatment cells were receiving A-01 effluent by July 2000. In September 2001, hydrosoil samples were collected from two of the treatment cells and analyzed for a suite of chemical parameters. The data indicate that copper and zinc are accumulating primarily in the surficial hydrosoils of the first treatment cells (A cells). Mercury was below the detection limit in most samples. However, the monthly data for mercury in water samples collected from the inflow and outflow of the treatment cells indicates that more mercury is removed in the A cells than in the B cells. The hydrosoils in the wetland treatment system have relatively low concentrations of organic carbon and a relatively low cation exchange capacity, due to the sandy nature of the hydrosoil and low organic content. Cation exchange capacity is expected to increase as organic matter produced by the wetland vegetation accretes in the wetland. Even though the wetland is removing metals from the A-01 effluent to concentrations that are below regulatory limits, as the treatment system matures, its ability to remove metals from the A-01 effluent is expected to increase. This report summarizes the hydrosoil chemistry data.

  3. Wetlands for Wastewater Treatment.

    PubMed

    Martinez-Guerra, Edith; Jiang, Yi; Lee, Gordon; Kokabian, Bahareh; Fast, Sara; Truax, Dennis D; Martin, James L; Magbanua, Benjamin S; Gude, Veera Gnaneswar

    2015-10-01

    This paper provides a review of the treatment technologies, which utilize natural processes or passive components in wastewater treatment. In particular, this paper primarily focuses on wetland systems and their applications in wastewater treatment (as an advanced treatment unit or decentralized system), nutrient and pollutant removal (single and multiple pollutants, and metals), and emerging pollutant removal (pharmaceuticals). A summary of studies involving the plant (vegetation) effects, wetland design and modeling, hybrid and innovative systems, storm water treatment and pathogen removal is also included.

  4. Wetlands for Wastewater Treatment.

    PubMed

    Jiang, Yi; Martinez-Guerra, Edith; Gnaneswar Gude, Veera; Magbanua, Benjamin; Truax, Dennis D; Martin, James L

    2016-10-01

    An update on the current research and development of the treatment technologies, which utilize natural processes or passive components in wastewater treatment, is provided in this paper. The main focus is on wetland systems and their applications in wastewater treatment (as an advanced treatment unit or decentralized system), nutrient and pollutant removal (metals, industrial and emerging pollutants including pharmaceutical compounds). A summary of studies involving the effects of vegetation, wetland design and modeling, hybrid and innovative systems, storm water treatment and pathogen removal is also included.

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

    SciTech Connect

    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) 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).

  6. Temperature effects in treatment wetlands.

    PubMed

    Kadlec, R H; Reddy, K R

    2001-01-01

    Several biogeochemical processes that regulate the removal of nutrients in wetlands are affected by temperature, thus influencing the overall treatment efficiency. In this paper, the effects of temperature on carbon, nitrogen, and phosphorus cycling processes in treatment wetlands and their implications to water quality are discussed. Many environmental factors display annual cycles that mediate whole system performance. Water temperature is one of the important cyclic stimuli, but inlet flow rates and concentrations, and several features of the annual biogeochemical cycle, also can contribute to the observed patterns of nutrient and pollutant removal. Atmospheric influences, including rain, evapotranspiration, and water reaeration, also follow seasonal patterns. Processes regulating storages in wetlands are active throughout the year and can act as seasonal reservoirs of nutrients, carbon, and pollutants. Many individual wetland processes, such as microbially mediated reactions, are affected by temperature. Response was much greater to changes at the lower end of the temperature scale (< 15 degrees C) than at the optimal range (20 to 35 degrees C). Processes regulating organic matter decomposition are affected by temperature. Similarly, all nitrogen cycling reactions (mineralization, nitrification, and denitrification) are affected by temperature. The temperature coefficient (theta) varied from 1.05 to 1.37 for carbon and nitrogen cycling processes during isolated conditions. Phosphorus sorption reactions are least affected by temperature, with theta values of 1.03 to 1.12. Physical processes involved in the removal of particulate carbon, nitrogen, and phosphorus are not affected much by temperature. In contrast, observed wetland removals may have different temperature dependence. Design models are oversimplified because of limitations of data for calibration. The result of complex system behavior and the simple model is the need to interpret whole ecosystem data

  7. 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.

  8. 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...

  9. 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...

  10. Organic phosphorus sequestration in subtropical treatment wetlands.

    PubMed

    Turner, Benjamin L; Newman, Susan; Newman, Jana M

    2006-02-01

    Diffuse phosphorus pollution is commonly remediated by diverting runoff through treatment wetlands to sequester phosphorus into soil layers. Much of the sequestered phosphorus occurs in organic forms, yet our understanding of its chemical nature is limited. We used NaOH-EDTA extraction and solution 31P NMR spectroscopy to speciate organic phosphorus sequestered in a large treatment wetland (STA-1W) in Florida, USA. The wetland was constructed on previously farmed peat and was designed to remove phosphorus from agricultural runoff prior to discharge into the Everglades. Unconsolidated benthic floc that had accumulated during the 9-year operation of the wetland was sampled along transects through two connected cells dominated by cattail (Typha dominigensis Pers.) and an additional cell colonized by submerged aquatic vegetation, including southern water nymph (Najas guadalupensis(Spreng.) Magnus) and coontail (Ceratophyllum demersum L.). Organic phosphorus was a greater proportion of the sequestered phosphorus in the cattail marsh compared to the submerged aquatic vegetation wetland, but occurred almost exclusively as phosphate diesters and their alkaline hydrolysis products. Itwas therefore markedly different from the organic phosphorus in mineral soils, which is dominated typically by inositol phosphates. Phosphate diesters are readily degradable in most soils, raising concern about the long-term fate of organic phosphorus in treatment wetlands. Further studies are now necessaryto assess the stability of the sequestered organic phosphorus in response to biogeochemical and hydrological perturbation.

  11. Elemental composition of native wetland plants in constructed mesocosm treatment wetlands.

    PubMed

    Collins, Beverly S; Sharitz, Rebecca R; Coughlin, Daniel P

    2005-05-01

    Plants that accumulate a small percentage of metals in constructed treatment wetlands can contribute to remediation of acidic, metal contaminated runoff waters from coal mines or processing areas. We examined root and shoot concentrations of elements in four perennial wetland species over two seasons in mesocosm wetland systems designed to remediate water from a coal pile runoff basin. Deep wetlands in each system contained Myriophyllum aquaticum and Nymphaea odorata; shallow wetlands contained Juncus effusus and Pontederia cordata. Shoot elemental concentrations differed between plants of deep and shallow wetlands, with higher Zn, Al, and Fe concentrations in plants in shallow wetlands and higher Na, Mn, and P concentrations in plants in deep wetlands. Root and shoot concentrations of most elements differed between species in each wetland type. Over two seasons, these four common wetland plants did help remediate acidic, metal-contaminated runoff from a coal storage pile.

  12. Modeling Vertical Flow Treatment Wetland Hydraulics to Optimize Treatment Efficiency

    DTIC Science & Technology

    2011-03-24

    wetlands. Ecological Engineering. 35: 754-768, 2009. Lorah, M.M., E.H. Majcher, E.J. Jones, and M.A. Voytek. Microbial Consortia Development and...Abstract An upward Vertical Flow Treatment Wetland (uVFTW) has been designed to use anaerobic and aerobic microbial processes to bioremediate...Wetland (uVFTW) has been designed to use anaerobic and aerobic microbial processes to bioremediate groundwater contaminated with chlorinated

  13. Wetland treatment systems: FY91-96 research plan for the US EPA wetlands research program

    SciTech Connect

    Olson, R.

    1990-10-01

    The Wetlands Research Program of the U.S. Environmental Protection Agency through the Clean Water Act, is working to provide technical guidance for protecting the chemical and biological integrity of U.S. surface waters. Towards this goal, a six year research plan has been developed for a Wetland Treatment Systems Project (WTS Project) with three main objectives: evaluate the relationships between the design and structure of wetland treatment systems, and water quality improvement, evaluate the relationships between water quality in wetland treatment systems, and ecological condition including bioaccumulation of toxics, productivity, species diversity, habitat quality, and evaluate the relationships between the placement of wetland treatment systems, and landscape water quality functions.

  14. 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 ...

  15. 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 ...

  16. 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.

  17. CONSTRUCTED WETLAND TREATMENT SYSTEMS FOR WATER QUALITY IMPROVEMENT

    SciTech Connect

    Nelson, E.

    2010-07-19

    The Savannah River National Laboratory implemented a constructed wetland treatment system (CWTS) in 2000 to treat industrial discharge and stormwater from the Laboratory area. The industrial discharge volume is 3,030 m{sup 3} per day with elevated toxicity and metals (copper, zinc and mercury). The CWTS was identified as the best treatment option based on performance, capital and continuing cost, and schedule. A key factor for this natural system approach was the long-term binding capacity of heavy metals (especially copper, lead, and zinc) in the organic matter and sediments. The design required that the wetland treat the average daily discharge volume and be able to handle 83,280 m{sup 3} of stormwater runoff in a 24 hour period. The design allowed all water flow within the system to be driven entirely by gravity. The CWTS for A-01 outfall is composed of eight one-acre wetland cells connected in pairs and planted with giant bulrush to provide continuous organic matter input to the system. The retention basin was designed to hold stormwater flow and to allow controlled discharge to the wetland. The system became operational in October of 2000 and is the first wetland treatment system permitted by South Carolina DHEC for removal of metals. Because of the exceptional performance of the A-01 CWTS, the same strategy was used to improve water quality of the H-02 outfall that receives discharge and stormwater from the Tritium Area of SRS. The primary contaminants in this outfall were also copper and zinc. The design for this second system required that the wetland treat the average discharge volume of 415 m{sup 3} per day, and be able to handle 9,690 m{sup 3} of stormwater runoff in a 24 hour period. This allowed the building of a system much smaller than the A-01 CWTS. The system became operational in July 2007. Metal removal has been excellent since water flow through the treatment systems began, and performance improved with the maturation of the vegetation during

  18. Acid mine water treatment using engineered wetlands

    NASA Astrophysics Data System (ADS)

    Kleinmann, Robert L. P.

    1990-03-01

    During the last two decades, the United States mining industry has greatly increased the amount it spends on pollution control. The application of biotechnology to mine water can reduce the industry's water treatment costs (estimated at over a million dollars a day) and improve water quality in streams and rivers adversely affected by acidic mine water draining from abandoned mines. Biological treatment of mine waste water is typically conducted in a series of small excavated ponds that resemble, in a superficial way, a small marsh area. The ponds are engineered to first facilitate bacterial oxidation of iron; ideally, the water then flows through a composted organic substrate that supports a population of sulfate-reducing bacteria. The latter process raises the pH. During the past four years, over 400 wetland water treatment systems have been built on mined lands as a result of research by the U.S. Bureau of Mines. In general, mine operators find that the wetlands reduce chemical treatment costs enough to repay the cost of wetland construction in less than a year. Actual rates of iron removal at field sites have been used to develop empirical sizing criteria based on iron loading and pH. If the pH is 6 or above, the wetland area (m2) required is equivalent to the iron load (grams/day) divided by 10. Theis requirement doubles at a pH of 4 to 5. At a pH below 4, the iron load (grams/day) should be divided by 2 to estimate the area required (m2).

  19. FULL-SCALE TREATMENT WETLANDS FOR METAL REMOVAL FROM INDUSTRIAL WASTEWATER

    SciTech Connect

    Nelson, E; John Gladden, J

    2007-03-22

    The A-01 NPDES outfall at the Savannah River Site receives process wastewater discharges and stormwater runoff from the Savannah River National Laboratory. Routine monitoring indicated that copper concentrations were regularly higher than discharge permit limit, and water routinely failed toxicity tests. These conditions necessitated treatment of nearly one million gallons of water per day plus storm runoff. Washington Savannah River Company personnel explored options to bring process and runoff waters into compliance with the permit conditions, including source reduction, engineering solutions, and biological solutions. A conceptual design for a constructed wetland treatment system (WTS) was developed and the full-scale system was constructed and began operation in 2000. The overall objective of our research is to better understand the mechanisms of operation of the A-01 WTS in order to provide better input to design of future systems. The system is a vegetated surface flow wetland with a hydraulic retention time of approximately 48 hours. Copper, mercury, and lead removal efficiencies are very high, all in excess of 80% removal from water passing through the wetland system. Zinc removal is 60%, and nickel is generally unaffected. Dissolved organic carbon in the water column is increased by the system and reduces toxicity of the effluent. Concentrations of metals in the A-01 WTS sediments generally decrease with depth and along the flow path through the wetland. Sequential extraction results indicate that most metals are tightly bound to wetland sediments.

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

    PubMed

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

    2001-12-15

    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 wastewater-derived organic contaminants such as linear alkylbenzene sulfonate, caffeine, and ethylenediaminetetraacetic acid were significantly attenuated by wetland treatment and were not contributed by internal loading.

  1. 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.

  2. 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.

  3. Technical and Regulatory Guidance Document for Constructed Treatment Wetlands

    DTIC Science & Technology

    2003-12-01

    Wetlands Research Program Technical Report WRP-DE-4. Brix , H., 1993, “Wastewater Treatment in Constructed Wetlands: System Design, Removal...Opelousas, La. Constituents of Concern Influent BOD, 500– 3000 mg/L Regulatory Contact Name Robert Crawford, Louisiana DEQ Plant Hardiness Deep South

  4. 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.

  5. Application of constructed wetlands for wastewater treatment in Nepal.

    PubMed

    Shrestha, R R; Haberl, R; Laber, J; Manandhar, R; Mader, J

    2001-01-01

    Surface water pollution is one of the serious environmental problems in urban centers in Nepal due to the discharge of untreated wastewater into the river-system, turning them into open sewers. Wastewater treatment plants are almost non-existent in the country except for a few in the Kathmandu Valley and even these are not functioning well. Successful implementation of a few constructed wetland systems within the past three years has attracted attention to this promising technology. A two-staged subsurface flow constructed wetland for hospital wastewater treatment and constructed wetlands for treatment of greywater and septage is now becoming a demonstration site of constructed wetland systems in Nepal. Beside these systems, five constructed wetlands have already been designed and some are under construction for the treatment of leachate and septage in Pokhara municipality, wastewater in Kathmandu University, two hospitals and a school. This paper discusses the present condition and treatment performance of constructed wetlands that are now in operation. Furthermore, the concept of the treatment wetlands under construction is also described here. With the present experience, several recommendations are pointed out for the promotion of this technology in the developing countries.

  6. Hydraulic analysis of cell-network treatment wetlands

    NASA Astrophysics Data System (ADS)

    Wang, Huaguo; Jawitz, James W.

    2006-11-01

    SummaryWhen individual cells of a multiple-cell treatment wetland are hydraulically connected, the wetland has a cell-network structure. The hydraulic performance of treatment wetlands is often characterized using tracer residence time distributions (RTDs) measured between the wetland inlet and outlet, such that the wetland is considered as a single hydraulic unit, regardless of the extent of networking between individual internal cells. This work extends the single hydraulic unit approach to enable the specification of moments and RTD parameters for individual cells, or clusters of cells, within the cell-network based on inert tracer tests with injection only at the network inlet. Hydraulic performance is quantified in terms of hydraulic efficiency and travel time dimensionless variance using both the method of moments and RTD modeling. Cell-network analysis was applied to a case study from the Orlando Easterly Wetland (OEW), demonstrating the improvement in hydraulic performance of individual wetland cells following wetland restoration activities. Furthermore, cell-network analysis indicated that the location of water quality sampling station locations within the cell network can significantly affect the accuracy of pollutant removal effectiveness estimation when the individual sample station RTD does not represent the hydraulic unit RTD. At the OEW, it was determined that historical nutrient removal effectiveness estimation may be underestimated for one area and overestimated for another, and recommendations were provided for sample station locations to minimize future performance estimation errors.

  7. ``Living off the land'': resource efficiency of wetland wastewater treatment

    NASA Astrophysics Data System (ADS)

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

    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™) 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 1/5 the electrical energy of conventional sewage treatment (package plants), and save 2/3 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

  8. Denitrification in constructed wetlands used for treatment of swine wastewater.

    PubMed

    Hunt, Patrick G; Matheny, Terry A; Szögi, Ariel A

    2003-01-01

    Constructed wetland treatment of swine wastewater probably involves substantial denitrification. Our objective was to assess denitrification and denitrification enzyme activity (DEA) in such wetlands in relation to plant communities, N loading, carbon or nitrogen limitations, and water depth. Two wetland cells each 3.6 m wide and 33.5 m long were connected in series. One set of cells was planted with rushes and bulrushes, including soft rush (Juncus effusus L.), softstem bulrush [Schoenoplectus tabernaemontani (K.C. Gmel.) Pallal, American bulrush [Schoenoplectus americanus (Pers.) Volkart ex Schinz & R. Keller], and woolgrass bulrush [Scirpus cyperinus (L.) Kunth]. Another set was planted with bur-reeds and cattails, including American bur-reed (Sparganium americanum Nutt.), broadleaf cattail (Typha latifolia L.), and narrowleaf cattail (Typha angustifolia L.). The sets will be referred to herein as bulrush and cattail wetlands, respectively. Denitrification and DEA were measured via the acetylene inhibition method in intact soil cores and disturbed soil samples that were taken during four years (1994-1997). Although DEA in the disturbed samples was greater than denitrification in the core samples, the measurements were highly correlated (r2 > or = 0.82). The DEA was greater in the bulrush wetlands than the cattail wetlands, 0.516 and 0.210 mg N kg(-1) soil h(-1), respectively; and it increased with the cumulative applied N. The DEA mean was equivalent to 9.55 kg N ha(-1) d(-1) in the bulrush wetlands. We hypothesized and confirmed that DEA was generally limited by nitrate rather than carbon. Moreover, we determined that one of the most influential factors in DEA was wetland water depth. In bulrush wetlands, the slope and r2 values of the control treatment were -0.013 mg N kg(-1) soil h(-1) mm(-1) depth and r2 = 0.89, respectively. Results of this investigation indicate that DEA can be very significant in constructed wetlands used to treat swine wastewater.

  9. METAL REMOVAL FROM PROCESS AND STORMWATER DISCHARGES BY CONSTRUCTED TREATMENT WETLANDS

    SciTech Connect

    NELSON, ERIC

    2004-11-02

    The A-01 NPDES outfall at the Savannah River Site receives process wastewater and stormwater which passes through a wetland treatment system (WTS) prior to discharge. The overall objective of our research is to better understand the mechanisms of operation of the A-01 WTS in order to provide better input to the design of future systems. The system is a vegetated surface flow wetland and has a retention time of approximately 48 hours. Sampling conducted during the fourth year of operation validated continued wetland performance, and assessed the fate of a larger suite of metals present in the water. Copper and mercury removal efficiencies were still very high, both in excess of 80 per cent removal from the water after passage through the wetland system. Lead removal from the water by the system was 83 per cent, zinc removal was 60 per cent, and nickel was generally unaffected. Nitrates entering into the wetland cells are almost immediately removed from the water column and generally no nitrates are discharged from the A cells. The wetland cells are very anaerobic and the sediments have negative redox potentials. As a result, manganese and iron mineral phases in the sediments have been reduced to soluble forms and increase in the water during passage through the wetland system. Dissolved organic carbon in the water column is also increased by the system and reduces toxicity of the effluent. Operation and maintenance of the system is minimal, and consists of checking for growth of the vegetation and free flow of the water through the system.

  10. Groundwater Flow Through a Constructed Treatment Wetland

    DTIC Science & Technology

    2003-03-01

    should be constructed in an area where the contaminated water can be efficiently pumped into the wetland. Locating the wetland near the... water into the piezometer, and then back out again repeatedly. Pumping water in and out of the piezometer clears the screen of any clogging by...tests where the rate of receding water was so quick so as to allow gathering only a few head measurements, amounting to about half of all the pump

  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. Evaluation of constructed wetland treatment performance for winery wastewater.

    PubMed

    Grismer, Mark E; Carr, Melanie A; Shepherd, Heather L

    2003-01-01

    Rapid expansion of wineries in rural California during the past three decades has created contamination problems related to winery wastewater treatment and disposal; however, little information is available about performance of on-site treatment systems. Here, the project objective was to determine full-scale, subsurface-flow constructed wetland retention times and treatment performance through assessment of water quality by daily sampling of total dissolved solids, pH, total suspended solids, chemical oxygen demand (COD), tannins, nitrate, ammonium, total Kjeldahl nitrogen, phosphate, sulfate, and sulfide across operating systems for winery wastewater treatment. Measurements were conducted during both the fall crush season of heavy loading and the spring following bottling and racking operations at the winery. Simple decay model coefficients for these constituents as well as COD and tannin removal efficiencies from winery wastewater in bench-scale reactors are also determined. The bench-scale study used upward-flow, inoculated attached-growth (pea-gravel substrate) reactors fed synthetic winery wastewater. Inlet and outlet tracer studies for determination of actual retention times were essential to analyses of treatment performance from an operational subsurface-flow constructed wetland that had been overloaded due to failure to install a pretreatment system for suspended solids removal. Less intensive sampling conducted at a smaller operational winery wastewater constructed wetland that had used pretreatment suspended solids removal and aeration indicated that the constructed wetlands were capable of complete organic load removal from the winery wastewater.

  15. 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.

  16. Phytotoxicity testing of winery wastewater for constructed wetland treatment.

    PubMed

    Arienzo, Michele; Christen, Evan W; Quayle, Wendy C

    2009-09-30

    Rapid and inexpensive phytotoxicity bioassays for winery wastewater (WW) are important when designing winery wastewater treatment systems involving constructed wetlands. Three macrophyte wetland species (Phragmites australis, Schoenoplectus validus and Juncus ingens) were tested using a pot experiment simulating a wetland microcosm. The winery wastewater concentration was varied (0.5%, 5%, 10%, 25%, 50%, 75% and 100%) and pH was corrected for some concentrations using lime as an amendment. The tolerance of the three aquatic macrophytes species to winery wastewater was studied through biomass production, total chlorophyll and nitrogen, phosphorous and potassium tissue concentrations. The results showed that at greater than 25% wastewater concentration all the macrophytes died and that Phragmites was the least hardy species. At less than 25% wastewater concentration the wetland microcosms were effective in reducing chemical oxygen demand, phenols and total soluble solids. We also evaluated the performance of two laboratory phytotoxicity assays; (1) Garden Cress (Lepidium sativum), and (2) Onion (Allium coepa). The results of these tests revealed that the effluent was highly toxic with effective concentration, EC(50), inhibition values, as low as 0.25%. Liming the WW increased the EC(50) by 10 fold. Comparing the cress and onion bioassays with the wetland microcosm results indicated that the thresholds for toxicity were of the same order of magnitude. As such we suggest that the onion and cress bioassays could be effectively used in the wine industry for rapid wastewater toxicity assessment.

  17. 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)

  18. 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)

  19. 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

  20. Constructed wetlands for wastewater treatment: five decades of experience.

    PubMed

    Vymazal, Jan

    2011-01-01

    The first experiments on the use of wetland plants to treat wastewaters were carried out in the early 1950s by Dr. Käthe Seidel in Germany and the first full-scale systems were put into operation during the late 1960s. Since then, the subsurface systems have been commonly used in Europe while free water surface systems have been more popular in North America and Australia. During the 1970s and 1980s, the information on constructed wetland technology spread slowly. But since the 1990 s the technology has become international, facilitated by exchange among scientists and researchers around the world. Because of the need for more effective removal of ammonia and total nitrogen, during the 1990 s and 2000s vertical and horizontal flow constructed wetlands were combined to complement each other to achieve higher treatment efficiency. Today, constructed wetlands are recognized as a reliable wastewater treatment technology and they represent a suitable solution for the treatment of many types of wastewater.

  1. TREATMENT WETLAND HABITAT AND WILDLIFE USE ASSESSMENT AND NORTH AMERICAN TREATMENT WETLAND DATABASE V 2.0

    EPA Science Inventory

    The USEPA sponsored a project to collect and catalog information from wastewater treatment wetlands into a computer database. EPA has also written a user friendly, stand-alone, menu-driven computer program to allow anyone with DOS 3.3 or higher to access the information in the da...

  2. TREATMENT WETLAND HABITAT AND WILDLIFE USE ASSESSMENT AND NORTH AMERICAN TREATMENT WETLAND DATABASE V 2.0

    EPA Science Inventory

    The USEPA sponsored a project to collect and catalog information from wastewater treatment wetlands into a computer database. EPA has also written a user friendly, stand-alone, menu-driven computer program to allow anyone with DOS 3.3 or higher to access the information in the da...

  3. Heterotrophic bacterial activities and treatment performance of surface flow constructed wetlands receiving woodwaste leachate.

    PubMed

    Tao, Wendong; Hall, Ken J; Duff, Sheldon J B

    2006-07-01

    Heterotrophic activities were investigated by measuring 3H-leucine incorporation to bacterial protein and 14C-glucose turnover in surface flow constructed wetlands receiving woodwaste leachate. No significant longitudinal variation was found in heterotrophic activities of bacterioplankton. An open wetland, a vegetated wetland, and a fertilized vegetated wetland were used to examine the effects of vegetation and ammonium nitrate amendment. There was not a significant difference in treatment performance among the three wetlands, except for a significant pH increase and more efficient volatile fatty acids removal in the fertilized wetland. The fertilized wetland had the highest leucine incorporation rate and shortest glucose turnover time accompanied by the lowest glucose mineralization percentage, followed by the open wetland, then the vegetated wetland. Planktonic and sedimentary bacteria contributed to the majority of the total heterotrophic activities; epiphytic bacteria played a minor role. Heterotrophic activities were influenced by the availability of nutrient, electron acceptor, and organic substrate.

  4. Constructed wetland treatment system for upper blackfoot mining complex

    SciTech Connect

    Sanders, F.S.

    1996-12-31

    A combined passive oxidation/sedimentation (pre-treatment) and constructed wetland (polishing) system has been designed and installed to treat mine drainage at the inactive Upper Blackfoot River Mining Complex northeast of Lincoln, MT. The system is designed to treat up to 100 gpm flow with moderate heavy metal concentrations (25 to 95 mg/L Zn; lower concentrations of Pb, Cu, and As), moderate Fe concentrations (< 100 mg/L), and periodic high acidity (pH 2.6 to 3.5). The treatment scheme is flexible to accommodate a wide range of flows, metal concentrations, and acidity in order to gain cost-efficiencies and to meet restrictive discharge standards for the environmentally-sensitive Blackfoot River watershed. The wetland treatment system presently is undergoing start-up testing and initial tuning and will be operational during summer, 1996. Conceptual and engineering designs are presented along with preliminary data.

  5. Constructed wetland treatment system in textile industry and sustainable development.

    PubMed

    Davies, L C; Pedro, I S; Ferreira, R A; Freire, F G; Novais, J M; Martins-Dias, S

    2008-01-01

    This study focuses on the evaluation of the adequacy and sustainability of a constructed wetland (CW), with vertical flow (VF) design to treat a strongly coloured textile wastewater.Secondly an accidental AO7 overloaded discharge (700 mg l(-1)) was studied. A set of three similar VFCW beds (3x1 m2), operating in series, allowed also the efficient treatment of the AO7 heavy loaded wastewaters. The treated effluent quality enables water reuse for irrigation purposes or within the process.

  6. Domestic wastewater treatment by constructed wetlands enhanced with bioremediating rhizobacteria.

    PubMed

    Salgado, Irina; Cárcamo, Herlen; Carballo, María Elena; Cruz, Mario; Del Carmen Durán, María

    2017-06-23

    Constructed wetlands (CWs) offer several advantages for treating waters; however, the successful application of these systems remains a challenge. Practical solutions to pollution through CWs remain incipient because wetlands are still studied as "black boxes"; further studies are required regarding the involvement of rhizosphere bacteria in the removal of pollutants. This research focused on increasing the performance of CWs treatment systems for the removal of inorganic and organic pollutants from domestic wastewater, by the application of native bioremediating rhizobacteria. A bacterial consortium (CAD/1S) was designed with four rhizobacteria strains isolated from Typha domingensis plants of natural wetlands. Each individual strain was identified by 16S ribosomal RNA (rRNA) gene sequencing. This consortium removed organic matter, ammonium, and phosphate with percentages over 70% from model wastewater. The evaluation of abiotic and biotic factors' influence on pollutant removal indicated the best conditions to remove pollutants: a neutral pH, a 72-h contact time, and an inoculum from single growth of each strain. The subsequent bioaugmentation with the consortium of CWs at laboratory scale allowed 100%, greater than 70 and 55% removal of organic matter, ammonium, and phosphate, respectively. The set of results allowed the proposal of a new strategy for the improvement of CWs technology for the treatment of domestic wastewater pollutants.

  7. Evaluation of phosphorus retention in a South Florida treatment wetland.

    PubMed

    Nungesser, M K; Chimney, M J

    2001-01-01

    The Everglades Construction Project of the South Florida Water Management District (District) will employ large constructed wetlands known as Stormwater Treatment Areas (STAs) to reduce phosphorus concentrations in runoff entering the Everglades. The District built and operated a prototype STA, the 1,545 ha Everglades Nutrient Removal Project (ENRP), to determine the efficacy of subtropical wetlands for improving regional water quality with a focus on reducing total phosphorus (TP). In five years of operation, the ENRP has consistently exceeded its performance goals of TP outflow concentrations <50 microg P/L and a 75% TP load reduction. Since August 1994, the ENRP has retained 70.3 metric tons of TP that otherwise would have entered the Everglades. When corrected for surface area and inflow TP load, TP removal efficiency was highest in the inflow buffer cell and decreased generally in a downstream fashion through the wetland. High TP removal efficiency in treatment cell 4 was attributed to superior performance of its submerged aquatic vegetation community relative to the emergent and floating macrophyte community in the other cells. Controlled experiments in the District's STA Optimization Research Program will help clarify what effect vegetation and operational conditions may have on nutrient removal in the STAs.

  8. Escherichia coli control in a surface flow treatment wetland.

    PubMed

    MacIntyre, M E; Warner, B G; Slawson, R M

    2006-06-01

    A field experiment showed that numbers of Escherichia coli declined significantly when floating Lemna spp. plants were removed to create open water areas in a typical newly constructed surface flow treatment wetland in southern Ontario. It is suggested that E. coli declined immediately after Lemna removal because the Lemna was shading the water column from penetration by natural UV radiation, it was providing favourable attachment sites for the E. coli, and it was not allowing effective free exchange of oxygen from surface winds to the water column to maintain high enough dissolved oxygen supplies for predator zooplankton populations. Operators of wetland systems must have the specialized skills required to recognize the cause and the appropriate maintenance requirements to maintain efficient operation of such unconventional systems should E. coli numbers increase during the course of operation.

  9. 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.

  10. Linking hydrology and denitrification kinetics in treatment wetlands

    NASA Astrophysics Data System (ADS)

    Kjellin, J.; Wörman, A.; Hallin, S.

    2007-12-01

    A number of factors control the kinetics of denitrification in natural environments, particularly, in treatment wetlands. In order to understand and, in some sense, optimize nitrogen removal in wetlands we must link hydrological and geochemical processes. Based on a two-dimensional flow model we found that topography and vegetation distribution as well as density of vegetation are crucial reproducing the residence time distribution from a tracer test experiment. The tracer test used simultaneous injection of three labelled isotopes; H2O-3, PO4- 32 and NO3-15. Not only are the reactions constrained by the circulation patterns and water residence time, but there are essential links between vegetation as friction causing objects for the water flow and vegetation as host medium for biofilms in which denitrification can occur. This study has illuminated the importance for the treatment efficiency of the various time-scales involved in the denitrification occurring in wetlands used for treating municipal wastewater. Sampling of bed sediments in Ekeby Wetland, Eskilstuna, Sweden, were used as a basis for laboratory measurements of potential denitrification activity (PDA), evaluation of the Michaelis-Menten kinetics and denaturing gel electrophoreses (DGGE) patterns of nosZ genes, which represent the denitrifying bacterial community structure in various locations. A most essential contribution of the study is to translate such basic microbiological entities into a system response model that considers both water flow and mixing as well as microbiological reactions. The behaviour of this system model was also compared with the tracer test bfreakthrough curves. The structure and placement of vegetation is found to be of utmost importance for the contact between biofilms and nitrate-polluted wastewater and, thus, for the treatment efficiency. Erroneously placed vegetation can cause flow channelling with little utilisation of the entire wetland volume and little availability of

  11. Accumulation of contaminants in fish from wastewater treatment wetlands

    USGS Publications Warehouse

    Barber, L.B.; Keefe, S.H.; Antweiler, R.C.; Taylor, H.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.

  12. Municipal wastewater treatment with pond-constructed wetland system: a case study.

    PubMed

    Wang, X; Bai, X; Qiu, J; Wang, B

    2005-01-01

    The performance of a pond-constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond-constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.

  13. Mosquito production from four constructed treatment wetlands in peninsular Florida.

    PubMed

    Rey, Jorge R; O'Meara, George F; O'Connell, Sheila M; Cutwa-Francis, Michele M

    2006-06-01

    Several techniques were used to sample adult and immature mosquitoes in 4 constructed treatment wetlands in Florida. Adults of 19 species (7 genera) of mosquitoes were collected, and immatures of the most abundant species and of 60% of all species also were collected. Few significant differences between sites and stations in the numbers of mosquitoes collected were discovered. Culex nigripalpus Theobald was the most abundant mosquito found in adult (carbon dioxide-baited suction traps) and ovitrap collections, whereas Mansonia spp. and Uranotaenia spp. were most common in pump-dip-grab samples. The roles of rooted and floating vegetation and of water quality in determining mosquito production from these areas are discussed.

  14. 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.

  15. 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).

  16. Clogging in subsurface-flow treatment wetlands: measurement, modeling and management.

    PubMed

    Nivala, Jaime; Knowles, Paul; Dotro, Gabriela; García, Joan; Wallace, Scott

    2012-04-15

    This paper reviews the state of the art in measuring, modeling, and managing clogging in subsurface-flow treatment wetlands. Methods for measuring in situ hydraulic conductivity in treatment wetlands are now available, which provide valuable insight into assessing and evaluating the extent of clogging. These results, paired with the information from more traditional approaches (e.g., tracer testing and composition of the clog matter) are being incorporated into the latest treatment wetland models. Recent finite element analysis models can now simulate clogging development in subsurface-flow treatment wetlands with reasonable accuracy. Various management strategies have been developed to extend the life of clogged treatment wetlands, including gravel excavation and/or washing, chemical treatment, and application of earthworms. These strategies are compared and available cost information is reported.

  17. Ecological considerations in wetlands treatment of municipal wastewaters

    SciTech Connect

    Godfrey, P.J.; Kaynor, E.R.; Benforado, J.

    1985-01-01

    What are the possible or probable environmental consequences of applying municipal wastewater to wetlands. Here, 31 papers address this question from various perspectives. Coverage includes: state-of-the art engineering for applying wastewater to wetlands; environmental values and perspectives; ecosystem dynamics - particularly hydrology-nutrient interactions; human and wildlife environmental health problems that could result from wastewater applications; case histories of the long term effects on wetlands that received wastewater or simulated wastewater for several years; and wetland management potential.

  18. Stormwater treatment: do constructed wetlands yield improved pollutant management performance over a detention pond system?

    PubMed

    Bavor, H J; Davies, C M; Sakadevan, K

    2001-01-01

    Constructed wetland systems have been proposed as representing an improved ecotechnological option over detention basins, in terms of their abilities to reduce stormwater bacterial and nutrient loads to receiving waters. Concentrations of microbial and pollutants were determined in inflow and outflow samples collected from each type of system. Removal efficiencies for the wetland although higher than for the pond, were lower than some previously reported values for the treatment of municipal wastewater by constructed wetlands. Performance of a number of constructed wetland systems for stormwater treatment is evaluated considering the functional components of the systems.

  19. Treatment efficiency of effluent prawn culture by wetland with floating aquatic macrophytes arranged in series.

    PubMed

    Henares, M N P; Camargo, A F M

    2014-11-01

    The efficiency of a series of wetland colonized with Eichhornia crassipes and Salvinia molesta to treat the effluent of a giant river prawn (Macrobrachium rosenbergii) broodstock pond was evaluated in this study. The experimental design was completely randomized and was performed in 9 rectangular tanks (1.6 m3) with three treatments (constructed wetlands) and three replicates. The treatment types included: a wetland colonized with E. crassipes and S. molesta (EcSm) arranged sequentially, a wetland with E. crassipes only (Ec) and a wetland with S. molesta only (Sm). The means of suspended particulate material (SPM), total inorganic nitrogen (TIN), total Kjeldahl nitrogen (TKN), P-orthophosphate (PO4-P) and total phosphorus (TP) of the treated effluents were compared using ANOVA followed by Tukey's test (P<0.05). The effluent treated in Ec and EcSm wetlands exhibited lower SPM concentrations. The Ec wetland reduced TIN, TKN, PO4-P and TP by 46.0, 43.7, 44.4 and 43.6%, respectively. In the EcSm wetland, the reduction of TIN (23.0%), TKN (33.7%) and PO4-P (26.7%) was similar to the Sm wetland (19.8% TIN, 30.9% TKN and 23.8% PO4-P). The Ec wetland was more efficient in treating pond effluent due likely to the higher root surface of E. crassipes, which forms an extensive area favorable to retention and adsorption of debris and absorption of nutrients.

  20. 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...

  1. 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.

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

    SciTech Connect

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

    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 of 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 constructed

  3. 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

  4. Propagation of Human Enteropathogens in Constructed Horizontal Wetlands Used for Tertiary Wastewater Treatment

    PubMed Central

    Graczyk, Thaddeus K.; Lucy, Frances E.; Tamang, Leena; Mashinski, Yessika; Broaders, Michael A.; Connolly, Michelle; Cheng, Hui-Wen A.

    2009-01-01

    Constructed subsurface flow (SSF) and free-surface flow (FSF) wetlands are being increasingly implemented worldwide into wastewater treatments in response to the growing need for microbiologically safe reclaimed waters, which is driven by an exponential increase in the human population and limited water resources. Wastewater samples from four SSF and FSF wetlands in northwestern Ireland were tested qualitatively and quantitatively for Cryptosporidium spp., Giardia duodenalis, and human-pathogenic microsporidia, with assessment of their viability. Overall, seven species of human enteropathogens were detected in wetland influents, vegetated areas, and effluents: Cryptosporidium parvum, C. hominis, C. meleagridis, C. muris, G. duodenalis, Encephalitozoon hellem, and Enterocytozoon bieneusi. SSF wetland had the highest pathogen removal rate (i.e., Cryptosporidium, 97.4%; G. duodenalis, 95.4%); however, most of these values for FSF were in the negative area (mean, −84.0%), meaning that more pathogens were discharged by FSF wetlands than were delivered to wetlands with incoming wastewater. We demonstrate here that (i) the composition of human enteropathogens in wastewater entering and leaving SSF and FSF wetlands is highly complex and dynamic, (ii) the removal and inactivation of human-pathogenic microorganisms were significantly higher at the SSF wetland, (iii) FSF wetlands may not always provide sufficient remediation for human enteropathogens, (iv) wildlife can contribute a substantial load of human zoonotic pathogens to wetlands, (v) most of the pathogens discharged by wetlands were viable, (vi) large volumes of wetland effluents can contribute to contamination of surface waters used for recreation and drinking water abstraction and therefore represent a serious public health threat, and (vii) even with the best pathogen removal rates achieved by SSF wetland, the reduction of pathogens was not enough for a safety reuse of the reclaimed water. To our knowledge, this

  5. 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...

  6. 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.

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

    SciTech Connect

    Rothenberg, L; Mohan, R; Van Dyk, J; Fraass, B; Bortfeld, T

    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 of 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, structure

  8. 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.

  9. SU-C-17A-01: MRI-Based Radiotherapy Treatment Planning In Pelvis

    SciTech Connect

    Hsu, S; Cao, Y; Jolly, S; Balter, J

    2014-06-15

    Purpose: To support radiotherapy dose calculation, synthetic CT (MRCT) image volumes need to represent the electron density of tissues with sufficient accuracy. This study compares CT and MRCT for pelvic radiotherapy. Methods: CT and multi-contrast MRI acquired using T1- based Dixon, T2 TSE, and PETRA sequences were acquired on an IRBapproved protocol patient. A previously published method was used to create a MRCT image volume by applying fuzzy classification on T1- weighted and calculated water image volumes (air and fluid voxels were excluded using thresholds applied to PETRA and T2-weighted images). The correlation of pelvic bone intensity between CT and MRCT was investigated. Two treatment plans, based on CT and MRCT, were performed to mimic treatment for: (a) pelvic bone metastasis with a 16MV parallel beam arrangement, and (b) gynecological cancer with 6MV volumetric modulated arc therapy (VMAT) using two full arcs. The CT-calculated fluence maps were used to recalculate doses using the MRCT-derived density grid. The dose-volume histograms and dose distributions were compared. Results: Bone intensities in the MRCT volume correlated linearly with CT intensities up to 800 HU (containing 96% of the bone volume), and then decreased with CT intensity increase (4% volume). There was no significant difference in dose distributions between CT- and MRCTbased plans, except for the rectum and bladder, for which the V45 differed by 15% and 9%, respectively. These differences may be attributed to normal and visualized organ movement and volume variations between CT and MR scans. Conclusion: While MRCT had lower bone intensity in highly-dense bone, this did not cause significant dose deviations from CT due to its small percentage of volume. These results indicate that treatment planning using MRCT could generate comparable dose distributions to that using CT, and further demonstrate the feasibility of using MRI-alone to support Radiation Oncology workflow. NIH R01EB016079.

  10. Use of vetiver grass constructed wetland for treatment of leachate.

    PubMed

    Bwire, K M; Njau, K N; Minja, R J A

    2011-01-01

    Performance of Constructed Wetland planted with vetiver grasses for the treatment of leachate was investigated in controlled experiments involving horizontal subsurface flow constructed wetland (HSSFCW). The HSSFCW experimental unit had two cells, one planted with vetiver grasses and another bare. Both units were packed with limestone gravel as substrate and were operated with equal hydraulic loading and hydraulic retention time. Collected samples of influents and effluents were analysed for COD, Cr, Pb, Fe and pH. The results showed that vetiver grasses tolerated leachate with high loading of COD up to 14,000 mg L(-1). The planted cell outperformed the unplanted cell in terms of COD, Cr, Pb and Fe removal. The systems showed optimum points for COD and Pb removal as a function of feed concentrations. The optimum COD removal values of 210 mgm(-2) day(-1) at feed COD concentration of 11,200 mg COD L(-1) and 89 mgm(-2) day(-1) at feed concentration of 7,200 mg COD L(-1) were obtained for planted and unplanted cells respectively. Similarly Pb removal values of 0.0132 mgm(-2) day(-1) at 1.0 mg Pb L(-1) and 0.0052 mgm(-2) day(-1) at 1.04 mgPb L(-1) were obtained for planted and unplanted units respectively. Removal of Fe as a function of feed Fe concentration showed a parabolic behaviour but Cr removal showed linear behaviour with feed Cr concentrations in both units. The system showed very good removal efficiencies with Cr and Fe but poor efficiencies were recorded for Pb.

  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. SU-F-19A-01: APBI Brachytherapy Treatment Planning: The Impact of Heterogeneous Dose Calculations

    SciTech Connect

    Loupot, S; Han, T; Salehpour, M; Gifford, K

    2014-06-15

    Purpose: To quantify the difference in dose to PTV-EVAL and OARs (skin and rib) as calculated by (TG43) and heterogeneous calculations (CCC). Methods: 25 patient plans (5 Contura and 20 SAVI) were selected for analysis. Clinical dose distributions were computed with a commercially available treatment planning algorithm (TG43-D-(w,w)) and then recomputed with a pre-clinical collapsed cone convolution algorithm (CCCD-( m,m)). PTV-EVAL coverage (V90%, V95%), and rib and skin maximum dose were compared via percent difference. Differences in dose to normal tissue (V150cc, V200cc of PTV-EVAL) were also compared. Changes in coverage and maximum dose to organs at risk are reported in percent change, (100*(TG43 − CCC) / TG43)), and changes in maximum dose to normal tissue are absolute change in cc (TG43 − CCC). Results: Mean differences in V90, V95, V150, and V200 for the SAVI cases were −0.2%, −0.4%, −0.03cc, and −0.14cc, respectively, with maximum differences of −0.78%, −1.7%, 1.28cc, and 1.01cc, respectively. Mean differences in the 0.1cc dose to the rib and skin were −1.4% and −0.22%, respectively, with maximum differences of −4.5% and 16%, respectively. Mean differences in V90, V95, V150, and V200 for the Contura cases were −1.2%, −2.1%, −1.8cc, and −0.59cc, respectively, with maximum differences of −2.0%, −3.16%, −2.9cc, and −0.76cc, respectively. Mean differences in the 0.1cc dose to the rib and skin were −2.6% and −3.9%, respectively, with maximum differences of −3.2% and −5.7%, respectively. Conclusion: The effects of translating clinical knowledge based on D-(w,w) to plans reported in D-(m,m) are minimal (2% or less) on average, but vary based on the type and placement of the device, source, and heterogeneity information.

  13. Ceriodaphnia and Chironomus in situ toxicity tests assessing the wastewater treatment efficacy of constructed wetlands

    SciTech Connect

    Barjaktarovic, L.; Nix, P.; Gulley, J.

    1995-12-31

    In situ toxicity tests were designed for Ceriodaphnia dubia and Chironomus tentans as part of a larger study designed to assess the effectiveness of constructed wetlands for the treatment of wastewater produced by oil production at Suncor OSG. The artificial wetlands were 50m long by 3m wide, with three replicates of the control and the treatment. Each wetland had four sample sites equidistant along its length, creating a gradient of treatment from site A being the most toxic to site D being the least toxic. Each test was conducted twice during the summer of 1994. Both the Ceriodaphnia and Chironomus test cages were a flow through design to allow for maximal exposure to the water within the wetlands. Mortality and reproduction were used as endpoints for Ceriodaphnia, whereas mortality and growth were used as endpoints for the Chironomus test. Test durations were fifteen and ten days respectively. Chironomus had very high mortality along the entire wetlands whereas Ceriodaphnia survival and fecundity increased along the length of the treatment wetlands. Both organisms had low mortality and high growth/fecundity in the control wetlands.

  14. Evaluation of wetland and tertiary wastewater treatments for estrogenicity using in vivo and in vitro assays.

    PubMed

    Xie, L; Sapozhnikova, Y; Bawardi, O; Schlenk, D

    2005-01-01

    The effects of wetland wastewater treatment on estrogenic activity and estrogenic activity of water after tertiary treatment were evaluated using in vivo (rainbow trout vitellogenin [VTG] expression) and in vitro (yeast estrogen screening) assays. Juvenile rainbow trout exposed to tertiary-treated wastewater from the Green Acres Treatment Plant in Orange County Water District had increased plasma VTG levels compared with control fish. When trout were exposed to wastewater-dominated water before it entered into Prado Wetland (Riverside County, CA), VTG concentrations were increased above those of controls and were not significantly different from fish exposed to water exiting the wetland. VTG E2-equivalent concentrations (EEQs) of the water samples from the Green Acres Plant were 16.92 +/- 16.49 ng/L. Activity of water entering Prado Wetland was 29.80 +/- 28.41 ng/L EEQ, and water exiting was 24.34 +/- 23.17 ng/L EEQ. In vitro assays estimated that estrogenic activity of water from the Green Acres Plant was <1 ng/L EEQ, whereas water entering and exiting Prado Wetland had yeast estrogen screening EEQs of 2.57 and <1 ng/L, respectively. Our results suggest that environmental estrogens that are not potent estrogen-receptor ligands exist in wastewaters from the Green Acres Plant as well as water entering and exiting Prado Wetland. Wetland treatment did not remove environmental estrogens in the water. Our results also suggest that in vitro assays may underestimate estrogenic activity of sampled water.

  15. Study on treatment of aquaculture wastewater using a hybrid constructed wetland

    NASA Astrophysics Data System (ADS)

    Hu, Jinzhao; Hu, Rui; Qi, Dan; Lu, Xujie

    2017-04-01

    This paper reported the pollutant removal performances of a hybrid wetland system for the treatment of aquaculture wastewater. The system consisted of two treatment stages: a subsurface vertical flow (VF) wetland, followed by a horizontal flow (HF). The aquaculture wastewater with the different concentrations such as eutrophy and mesotrophy was treated using hybrid constructed wetland. The experimental results showed that the removal efficiencies of eutrophy aquaculture wastewater achieved 56%, 71%, 73% for nitrite, phosphate and nitrate, respectively. At the same conditions, it can be found that the removal efficiencies of mesotrophy aquaculture wastewater achieved 39%, 74%, 73% for nitrite, phosphate and nitrate, respectively.

  16. 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.

  17. Multi-stage constructed wetland systems for municipal wastewater treatment.

    PubMed

    Masi, F; Caffaz, S; Ghrabi, A

    2013-01-01

    In the present paper the detailed design and performances of two municipal wastewater treatment plants, a four-stage constructed wetlands (CW) system located in the city of Dicomano (about 3,500 inhabitants) in Italy, and a three-stage CW system for the village of Chorfech (about 500 inhabitants) in Tunisia, are presented. The obtained results demonstrate that multi-stage CWs provide an excellent secondary treatment for wastewaters with variable operative conditions, reaching also an appropriate effluent quality for reuse. Dicomano CWs have shown good performances, on average 86% of removal for the Organic Load, 60% for Total Nitrogen (TN), 43% for Total Phosphorus (TP), 89% for Total Suspended Solids (TSS) and 76% for Ammonium (NH4(+)). Even the disinfection process has performed in a very satisfactory way, reaching up to 4-5 logs of reduction of the inlet pathogens concentration, with an Escherichia coli average concentration in the outlet often below 200 UFC/100 mL. The mean overall removal rates of the Chorfech CWs during the monitored period have been, respectively, equal to 97% for TSS and Biochemical Oxygen Demand (BOD5), 95% for Chemical Oxygen Demand (COD), 71% for TN and 82% for TP. The observed removal of E. coli by the CW system was in this case 2.5 log units.

  18. Efficiency of Constructed Wetland Vegetated with Cyperus alternifolius Applied for Municipal Wastewater Treatment

    PubMed Central

    Ebrahimi, Asghar; Taheri, Ensiyeh; Ehrampoush, Mohammad Hassan; Nasiri, Sara; Jalali, Fatemeh; Soltani, Rahele; Fatehizadeh, Ali

    2013-01-01

    The treatment of municipal wastewater from Yazd city (center of Iran) by constructed wetland vegetated with Cyperus alternifolius was assessed. Two identical wetlands with a total working volume of 60 L and 10 cm sandy layer at the bottom were used. First wetland (W1) was control and had no Cyperus alternifolius plant. Second wetland (W2) had 100 Cyperus alternifolius shrubs with 40 cm height. Influent wastewater was provided from Yazd's septic tanks effluents and after a 4-day retention time in wetlands, reactors effluent was sampled for parameters analysis. Results show that chemical oxygen demand (COD), NO3 −–N, NH4 +–N, and PO4 −3–P in W1 were reduced to 72%, 88%, 32%, and 0.8%, and in W2, these parameters were removed in values of 83%, 81%, 47%, and 10%, respectively. In both wetlands, the highest and lowest removal efficiencies were related to COD and phosphorus, respectively. Also, the removed phosphorus can be released to stream when the soil saturated or influent phosphorus decreased and when the plant died. After a 4-day-retention time, the W2 wetland showed a statistically significantly lower COD and NH4 +–N in comparison with W2 wetland. PMID:24027589

  19. Efficiency of constructed wetland vegetated with Cyperus alternifolius applied for municipal wastewater treatment.

    PubMed

    Ebrahimi, Asghar; Taheri, Ensiyeh; Ehrampoush, Mohammad Hassan; Nasiri, Sara; Jalali, Fatemeh; Soltani, Rahele; Fatehizadeh, Ali

    2013-01-01

    The treatment of municipal wastewater from Yazd city (center of Iran) by constructed wetland vegetated with Cyperus alternifolius was assessed. Two identical wetlands with a total working volume of 60 L and 10 cm sandy layer at the bottom were used. First wetland (W1) was control and had no Cyperus alternifolius plant. Second wetland (W2) had 100 Cyperus alternifolius shrubs with 40 cm height. Influent wastewater was provided from Yazd's septic tanks effluents and after a 4-day retention time in wetlands, reactors effluent was sampled for parameters analysis. Results show that chemical oxygen demand (COD), NO3 (-)-N, NH4 (+)-N, and PO4 (-3)-P in W1 were reduced to 72%, 88%, 32%, and 0.8%, and in W2, these parameters were removed in values of 83%, 81%, 47%, and 10%, respectively. In both wetlands, the highest and lowest removal efficiencies were related to COD and phosphorus, respectively. Also, the removed phosphorus can be released to stream when the soil saturated or influent phosphorus decreased and when the plant died. After a 4-day-retention time, the W2 wetland showed a statistically significantly lower COD and NH4 (+)-N in comparison with W2 wetland.

  20. Stormwater nitrogen removal performance of a floating treatment wetland.

    PubMed

    Borne, Karine E; Tanner, Chris C; Fassman-Beck, Elizabeth A

    2013-01-01

    The nitrogen (N) removal efficiency and effluent quality of two parallel stormwater retention ponds, one retrofitted with a floating treatment wetland (FTW) and one without any vegetation, was compared in a field trial. This study shows that inclusion of FTWs in stormwater retention ponds has potential to moderately improve N removal. Median FTW outlet event mean concentrations (EMCs) were lower than median inlet and control pond outlet EMCs for all species of N, except for NH(4)-N. Performance was statistically better from late spring to end autumn due to higher organic nitrogen (ON) removal and denitrification in presence of the FTW. Low dissolved oxygen (DO), higher temperature and increased organic matter (OM) and microbial activity below the FTW, likely facilitated the higher denitrification rates observed over this period. Greater sediment N accumulation in the FTW pond also contributed to its higher overall N removal. Higher OM availability in the FTW pond due to release of root exudates and supply of detritus from plant die-back may have contributed to floc formation in the water column, increasing particulate ON settlement. Enhanced ON mineralisation may also be responsible but was probably limited in summer due to the low DO induced by the FTW. Direct uptake by the plants appears to be of less importance.

  1. Treatment of atrazine in nursery irrigation runoff by a constructed wetland.

    PubMed

    Runes, Heather B; Jenkins, Jeffrey J; Moore, James A; Bottomley, Peter J; Wilson, Bruce D

    2003-02-01

    To investigate the treatment capability of a surface flow wetland at a container nursery near Portland, Oregon, atrazine was introduced during simulated runoff events. Treatment efficiency was evaluated as the percent atrazine recovered (as percent of applied) in the water column at the wetland's outlet. Atrazine treatment efficiency at the outlet of the constructed wetland during a 7-d period ranged from 18-24% in 1998 (experiments 1-3) and 16-17% in 1999 (experiments 4 and 5). Changes in total flow, or frequency and intensity of runoff events did not affect treatment. For experiment 6 in 1999, where the amount, frequency, and duration of runoff events exceeded all other experiments, treatment was compromised. For all experiments, deethylatrazine (DEA) and deisopropylatrazine (DIA) accounted for 13-21% of the initial application. Hydroxyatrazine (HA) was rarely detected in the water. Organic carbon adsorption coefficients (Koc) were determined from batch equilibrium sorption isotherms with wetland sediment, and they decreased in the order of HA > DIA > atrazine > DEA. Static water-sediment column experiments indicated that sorption is an important mechanism for atrazine loss from water passing through the constructed wetland. The results of the MPN assay indicated the existence in the wetland of a low-density population of microorganisms with the potential to mineralize atrazine's ethyl side chain.

  2. Effluent blending in constructed wetlands: Pollution prevention applications at a coal yard treatment facility

    SciTech Connect

    Carder, J.P.; Hoylman, A.M.; Sparks, B.J.

    1995-12-31

    Effluent blending, in combination with constructed wetland biotechnology, is a promising method for reducing the loading rates of pollution to receiving streams. At Oak Ridge National Laboratory, a project is underway to demonstrate this principle. An 8:2 ratio of sewage treatment plant to coal yard runoff treatment facility (CYRTF) effluent will be polished by 2 constructed wetland cells containing emergent wetland plants in saturated pea gravel at a rate of 3600 gallons per day. The relatively high concentration of nutrients in the STP effluent should stimulate biological processes leading to the reduction of chemical oxygen demand and the conversion of excess sulfate (in the CYRTF effluent) to alkalinity. Chlorine, which is added to the STP effluent to control bacteria, should also be eliminated. Measurements of wastewater toxicity, before and after the effluent blend has passed through the constructed wetlands, will be used to assess the technology`s effectiveness at reducing pollution.

  3. Nitrate removal and denitrification affected by soil characteristics in nitrate treatment wetlands.

    PubMed

    Lin, Ying-Feng; Jing, Shuh-Ren; Lee, Der-Yuan; Chang, Yih-Feng; Shih, Kai-Chung

    2007-03-01

    Several small-scale surface flow constructed wetlands unplanted and planted (monoculture) with various macrophytes (Phragmites australis, Typha orientalis, Pennisetum purpureum, Ipomoea aquatica, and Pistia stratiotes) were established to continuously receive nitrate-contaminated groundwater. Soil characteristics and their effects on nitrate removal and soil denitrification were investigated. The results showed that planted wetland cells exhibited significantly higher (P < 0.05) nitrate removal efficiencies (70-99%) and soil denitrification rates (3.78-15.02 microg N2O-N/g dry soil/h) than an unplanted covered wetland cell (1%, 0.11 microg N2O-N/g/h). However, the unplanted uncovered wetland cell showed a nitrate removal efficiency (55%) lower than but a soil denitrification rate (9.12 microg N2O-N/g/h) comparable to the planted cells. The nitrate removal rate correlated closely and positively with the soil denitrification rate for the planted cells, indicating that soil denitrification is an important process for removing nitrate in constructed wetlands. The results of nitrogen budget revealed that around 68.9-90.7% of the overall nitrogen removal could be attributed to the total denitrification. The soil denitrification rate was found to correlate significantly (P < 0.01) with the extractable organic carbon, organic matter, and in situ-measured redox potential of wetland soil, which accordingly were concluded as suitable indicators of soil denitrification rate and nitrate removal rate in nitrate treatment wetlands.

  4. 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

  5. Analysis of chemical reaction kinetics of depredating organic pollutants from secondary effluent of wastewater treatment plant in constructed wetlands.

    PubMed

    Wang, Hao; Jiang, Dengling; Yang, Yong; Cao, Guoping

    2013-01-01

    Four subsurface constructed wetlands were built to treat the secondary effluent of a wastewater treatment plant in Tangshan, China. The chemical pollutant indexes of chemical oxygen demand (COD) were analyzed to evaluate the removal efficiency of organic pollutants from the secondary effluent of the wastewater treatment plant. In all cases, the subsurface constructed wetlands were efficient in treating organic pollutants. Under the same hydraulic loading condition, the horizontal flow wetlands exhibited better efficiency of COD removal than vertical flow wetlands: the removal rates in horizontal flow wetlands could be maintained at 68.4 ± 2.42% to 92.2 ± 1.61%, compared with 63.8 ± 1.19% to 85.0 ± 1.25% in the vertical flow wetlands. Meanwhile, the chemical reaction kinetics of organic pollutants was analyzed, and the results showed that the degradation courses of the four subsurface wetlands all corresponded with the first order reaction kinetics to a large extent.

  6. 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 TiO2) 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 TiO2). Benzotriazole was not found to be susceptible to photodegradation in the absence of TiO2. The integration of the sunlight-induced processes (with TiO2) 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.

  7. Case study: purification efficiency of a treatment wetland used at a peat extraction area

    NASA Astrophysics Data System (ADS)

    Eskelinen, Riku; Ronkanen, Anna-Kaisa; Marttila, Hannu; Kløve, Bjørn

    2014-05-01

    The inflow and outflow of a treatment wetland was intensively monitored between March 2012 and October 2012. Sampling was done with automated sampling equipment bidaily during the snowmelt period and daily for the rest of the study period. The treatment wetland is located downstream of a peat extraction area with a surface area of 208 ha. Drainage network at the peat extraction area has been fitted with peak flow control structures and a sedimentation basin from which the water is pumped to the treatment wetland. The treatment wetland has a surface area of 11 ha of peatland soil and is covered by grassy vegetation during the summer season. After flowing through the wetland water is discharging to a small stream through a v-notch weir. All samples were analysed for electric conductivity (EC), suspended solids (SS), Colour, Turbidity and pH. Additional analyses for various elements and nutrients were done for samples selected on the basis of hydrology. Results of the additional analyses represent the dissolved fraction of analysed elements as the samples were first filtrated with 0.45 µm filter for SS. Our results show that the purification efficiency varies during the measurement period. For example, to SS the overall purification efficiency was 62 %. However during the spring flood the purification efficiency is negative which can be caused by snowmelt water flushing previous year's dead vegetation or particulate matter accumulated during the winter period. After midsummer we can observe drastic increase in the retention of SS. Similar pattern can be seen in the retention of phosphorous with overall retention of 11 % of the total phosphorous. In the case of nitrogen the overall performance for the wetland is poor. Some of this can be explained by poor retention of NO2-3-N due to cold weather during spring melt season. However during the summer time denitrification process seems to be working as the retention of N improves. Retention of dissolved organic carbon

  8. Wetland treatment of oil and gas well wastewaters. Quarterly technical report, August 25--November 24, 1992

    SciTech Connect

    Kadlec, R.H.; Srinivasan, K.R.

    1992-12-24

    In this quarterly report, results of efforts on Tasks 2 and 3 are presented and discussed. Construction of a laboratory-type wetland (green house) has been begun and this undertaking is described in this report. The literature search has shown that clay amendments to wetlands are beginning to be used in Europe for P removal in agricultural drainage systems. The authors have undertaken similar studies on the use of inexpensive amendments to wetlands such as modified-clays and algae to enhance the performance of a constructed wetland for the treatment of oil and gas well wastewaters. The results from these studies are presented and analyzed in this report. Further, the literature search (nominally completed under Task 1) unearthed more recent studies (some unpublished) and a summary is included in this quarterly report.

  9. Sewage and industrial waste treatment: Wetlands. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-03-01

    The bibliography contains citations concerning developments, operations, and evaluations of the treatment of wastewaters and sludges in natural and artificial wetlands. The citations also examine aquaculture treatments of industrial, municipal, and domestic wastewaters. Topics include nutrient removal, heavy metal recovery, and case studies of wetlands being used for wastewater treatment. (Contains 250 citations and includes a subject term index and title list.)

  10. Sewage and industrial waste treatment: Wetlands. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-12-01

    The bibliography contains citations concerning developments, operations, and evaluations of the treatment of wastewaters and sludges in natural and artificial wetlands. The citations also examine aquaculture treatments of industrial, municipal, and domestic wastewaters. Topics include nutrient removal, heavy metal recovery, and case studies of wetlands being used for wastewater treatment. (Contains 250 citations and includes a subject term index and title list.)

  11. 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.

  12. 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.

  13. 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.

  14. Ciliate communities in a constructed mangrove wetland for wastewater treatment.

    PubMed

    Chen, Qing-Hua; Tam, Nora Fung-Yee; Shin, Paul K S; Cheung, Siu-Giu; Xu, Run-Lin

    2009-05-01

    In wetlands constructed for treating municipal and industrial wastewater, including mangroves, the effect of wastewater discharged on the substrate has often been neglected. Ciliates, an important group of protozoa, are sensitive to pollutants and any changes in ciliate diversity and community structure reflects the habitat quality. The ciliate communities at six sections along a constructed mangrove belt (33 m in length) planted with Aegicerascorniculatum were investigated in Shenzhen, South China. In all samples collected in both rainy and dry seasons, 183 ciliate species were observed. Most species (56%) were free-swimming forms, while only 10.8% were sessile ciliates. The abundance and species number of ciliates were both found to decrease from the anterior (the wastewater inlet) to the posterior (the outlet) parts of the wetland belt, indicating that organic matter and bacteria in wastewater, which served as food for most ciliates, were gradually removed by the constructed wetland. The r/K (number of r- and K-selected species) ratios at the six sections were relatively small, between 0.2 and 0.4, whereas the C/P (abundance of colpodids and polyhymenophorans) quotient at some sections was higher than 1. These results indicate that although most of the environments along the constructed wetland belt were not stressful for ciliate communities, there were habitats that favored colpodids in high abundances.

  15. Nitrate removal in shallow, open-water treatment wetlands.

    PubMed

    Jasper, Justin T; Jones, Zackary L; Sharp, Jonathan O; Sedlak, David L

    2014-10-07

    The diffuse biomat formed on the bottom of shallow, open-water unit process wetland cells contains suboxic zones that provide conditions conducive to NO3(-) removal via microbial denitrification, as well as anaerobic ammonium oxidation (anammox). To assess these processes, nitrogen cycling was evaluated over a 3-year period in a pilot-scale wetland cell receiving nitrified municipal wastewater effluent. NO3(-) removal varied seasonally, with approximately two-thirds of the NO3(-) entering the cell removed on an annual basis. Microcosm studies indicated that NO3(-) removal was mainly attributable to denitrification within the diffuse biomat (i.e., 80 ± 20%), with accretion of assimilated nitrogen accounting for less than 3% of the NO3(-) removed. The importance of denitrification to NO3(-) removal was supported by the presence of denitrifying genes (nirS and nirK) within the biomat. While modest when compared to the presence of denitrifying genes, a higher abundance of the anammox-specific gene hydrazine synthase (hzs) at the biomat bottom than at the biomat surface, the simultaneous presence of NH4(+) and NO3(-) within the biomat, and NH4(+) removal coupled to NO2(-) and NO3(-) removal in microcosm studies, suggested that anammox may have been responsible for some NO3(-) removal, following reduction of NO3(-) to NO2(-) within the biomat. The annual temperature-corrected areal first-order NO3(-) removal rate (k20 = 59.4 ± 6.2 m yr(-1)) was higher than values reported for more than 75% of vegetated wetlands that treated water in which NO3(-) was the primary nitrogen species (e.g., nitrified secondary wastewater effluent and agricultural runoff). The inclusion of open-water cells, originally designed for the removal of trace organic contaminants and pathogens, in unit-process wetlands may enhance NO3(-) removal as compared to existing vegetated wetland systems.

  16. 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.

  17. H02 WETLAND TREATMENT SYSTEM WATER CHEMISTRY SAMPLING AND RESULTS REPORT

    SciTech Connect

    Bach, M; Michael Serrato, M; Eric Nelson, E

    2008-02-15

    The H-02 Wetland Treatment System (Figure 1) is used to remove heavy metals (e.g., copper and zinc) from the H-Area process and storm water discharge. Routine flow enters an equalization basin by inlets on either the east (Location 1) or west end (Location 2). The west end influent constitutes 75% of the average flow into the basin which has an average residence time of approximately 3 days at low pool (i.e., 120 gal/min. through a volume of 0.5 million gallons). The water then exits via the basin outlet on the east end. Next, the water flows to a splitter box (Location 3) which evenly separates the flow between two wetland cells for a design flow of 60 gal/min. per wetland cell with a residence time in the cell of approximately 2 days. The wetland effluent is then combined (Location 4) and flows through a spillway before reaching the National Pollution Discharge Elimination System (NPDES) measurement point near Road 4. During initial operation, it was observed that the pH of the water leaving the equalization basin was elevated compared to the influent pH. Furthermore, the elevated pH remained through the wetland cells so that there was an average pH of 10 leaving the wetland cells during the daytime which exceeds the upper NPDES limit of 8.5. The purpose of the current study was to evaluate the cause of the increase in pH within the equalization basin of the H-02 Wetland Treatment System. Possible mechanisms included algal activity and inorganic chemistry interactions (e.g., interactions with the clay and/or bentonite liner). Water quality parameters were evaluated throughout the H-02 Wetland Treatment system and over time in order to determine the cause of high pH values measured in the basin and wetland. Fluctuations in dissolved oxygen (DO) and accompanying changes in pH would be expected in systems where algae are an influencing factor. An unexpected increase or decrease in the concentration of inorganic substances may indicate operational changes or an

  18. 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.

  19. Comparison of Constructed Wetland Mesocosms Designed for Treatment of Copper-Contaminated Wastewater

    SciTech Connect

    Gladden, J.B.

    2001-02-15

    This study compared the performance of two constructed wetland mesocosms used to model a full-scale wetland system designed for treatment of copper-contaminated wastewater. One mesocosm (designated site-specific) was built near the construction site of the full-scale wetland using on-site soil, commercially available vegetation [Scirpus californicus (C.A. Meyer) Steud.], and water from the targeted wastestream. A second mesocosm (designated generic) was constructed at Clemson University using local soil, cultured S. californicus, and local municipal water amended with CuSO{sub 4}. Performance objectives were to achieve 22 m g/L total copper and no toxicity (Ceriodaphnia dubia Richard, 7-d/static/ renewal) in wetland outflows. Total inflow copper to the site-specific and generic mesocosms ranged from non-detect to 87 {micro} g/L and from 27 to 68 {micro} g/L, respectively. Overall total copper removal was 40% ({+-}33) for the site-specific mesocosm and 73% ({+-}14) for the generic mesocosm. In seven of nine monthly toxicity tests, C. dubia reproduction was significantly decreased ({alpha} = 0.05) in outflow of the site-specific mesocosm. No outflow toxicity was observed for the generic mesocosm. Although performance of the two mesocosms differed, both studies contributed to full-scale design by highlighting critical aspects of wetland function and augmenting operation and maintenance plans, enhancing overall constructed wetland design.

  20. 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.

  1. Reducing phosphorus flux from organic soils in surface flow treatment wetlands.

    PubMed

    Lindstrom, Susan M; White, John R

    2011-10-01

    Treatment wetlands have a finite period of effective nutrient removal after which treatment efficiency declines. This is due to the accumulation of organic matter which decreases the capacity and hydraulic retention time of the wetland. We investigated four potential solutions to improve the soluble reactive P (SRP) removal of a municipal wastewater treatment wetland soil including; dry down, surface additions of alum or calcium carbonate and physical removal of the accreted organic soil under both aerobic and anaerobic water column conditions. The flux of SRP from the soil to the water column under aerobic conditions was higher for the continuously flooded controls (1.1±0.4 mg P m(-2) d(-1)), dry down (1.5±0.9 mg P m(-2) d(-1)) and CaCO3 (0.8±0.7 mg P m(-2) d(-1)) treatments while the soil removal and alum treatments were significantly lower at 0.02±0.10 and -0.07±0.02 mg P m(-2) d(-1), respectively. These results demonstrate that the two most effective management strategies at sequestering SRP were organic soil removal and alum additions. There are difficulties and costs associated with removal and disposal of soils from a treatment wetland. Therefore our findings suggest that alum addition may be the most cost effective and efficient means of increasing the sequestering of P in aging treatment wetlands experiencing reduced P removal rates. However, more research is needed to determine the longer term effects of alum buildup in the organic soil on the wetland biota, in particular, on the macrophytes and invertebrates. Since alum effectiveness is time limited, a longer term solution to P flux may favor the organic soil removal.

  2. 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, toxic 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.

  3. 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...

  4. Effect of plant species on water quality at the outlet of a sludge treatment wetland.

    PubMed

    Gagnon, Vincent; Chazarenc, Florent; Kõiv, Margit; Brisson, Jacques

    2012-10-15

    Sludge treatment wetlands are mainly used to reduce the volume of activated sludge, and the pollutants at the outlet are generally returned to the wastewater treatment plant. However, in cases where sludges are produced far from treatment plants not only must the sludge be treated, but the discharge of pollutants into the surrounding environment must also be limited. The aim of this study was to evaluate the efficiency of different plant species in optimising pollutant removal in a decentralised sludge treatment wetland. In addition, a new system design was assessed, in which the wetland was not completely drained, and a saturated layer was created using an overflow. The experimental setup consisted of 16 mesocosms in total, planted with monocultures of Phragmites australis, Typha angustifolia and Scirpus fluviatilis, and unplanted controls, each in four replicates. The experiment was conducted during the third summer of operation after setup. The system was fed with highly concentrated fish farm sludge at a load of 30 kg of total solids m(-2) yr(-1). Results showed that such wetlands were highly efficient, with removal rates between 94% and 99% for most pollutants. Planted systems generally outperformed the unplanted control, with a significantly lower mass of pollutants at the outlet of the sludge treatment wetland planted with Phragmites, followed by those with Typha and then Scirpus. The distinct influence of plant species on pollution removal was explained by the sequestration of nitrogen and phosphorus in plant tissues and by the rhizosphere effect, which enhance the biodegradation of organic matter, allowed the nitrification process and created redox conditions favourable to the sorption of phosphorus. Filtration and evapotranspiration rates played a major role in limiting the discharge of pollutants, and the impact was enhanced by the fact that the sludge treatment wetland was not completely drained.

  5. The design of vegetative constructed wetlands for the treatment of highway runoff.

    PubMed

    Shutes, R B; Revitt, D M; Lagerberg, I M; Barraud, V C

    1999-09-01

    The Environment Agency for England and Wales are responsible for assessing the effects of highway runoff and for monitoring the treatment systems/procedures which have been introduced for the reduction of deleterious effects. The Agency is looking into the improvement of surface water management in terms of best management practices and plans to work in partnership with the Highways Agency to achieve this aim. Among the treatment options being considered are constructed wetlands. Draft Guidelines have been developed to provide information on their design. This paper describes procedures for carrying out an Environmental Sensitivity Analysis to determine whether treatment by a constructed wetland is appropriate. Information on water quality and quantity is required as well as the sensitivity of the receiving environment. The legislative position, particularly in relation to the discharge quality of the water and the conservation status of the receiving environment, needs also to be considered. The factors that will determine the most appropriate wetland design criteria include traffic loadings, road drainage area, land availability, cost and the size/extent and type of the receiving water body. The following structures are recommended for incorporation in the overall design; oil separator and silt trap, spillage containment, settlement pond, vegetative wetland and final settlement tank. The operation and maintenance procedures and the monitoring requirements for a functioning wetland are described.

  6. 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.

  7. Treatment of dairy wastewater using constructed wetlands and intermittent sand filters.

    PubMed

    Healy, M G; Rodgers, M; Mulqueen, J

    2007-09-01

    In Ireland, the most common method of disposal of dairy parlour washings is by land spreading. This treatment method has numerous problems, namely high-labour requirements and the potential for eutrophication of surface and ground waters. Constructed wetlands are commonly used for treatment of secondary municipal wastewaters and they have been gaining popularity for treatment of agricultural wastewaters in Ireland. Intermittent sand filtration may offer an alternative to traditional treatment methods. As well as providing comparable treatment performance, they also have a smaller footprint, due to the substantially higher organic loading rates that may be applied to their surfaces. This paper discusses the performance and design criteria of constructed wetlands for the treatment of domestic and agricultural wastewater, and sand filters for the treatment of domestic wastewater. It also proposes sand filtration as an alternative treatment mechanism for agricultural wastewater and suggests design guidelines.

  8. 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.

  9. 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.

  10. Seeking a way to promote the use of constructed wetlands for domestic wastewater treatment in developing countries.

    PubMed

    Zurita, F; Belmont, M A; De Anda, J; White, J R

    2011-01-01

    The aim of this study was to evaluate the domestic wastewater treatment efficiency as well as the survivability of commercially valuable ornamental plants in subsurface flow wetlands (SSFW) for domestic wastewater (DWW) treatment in laboratory and pilot wetland studies. The laboratory scale study included five different species (Zantedeschia aethiopica, Strelitzia reginae, Anthurium andreanum, Canna hybrids and Hemmerocallis dumortieri) that were evaluated in horizontal flow subsurface treatment cells. All the plants survived during the 6-month experimental period demonstrating high wetland nutrient treatment efficiency. In order to validate and expand these preliminary results, a pilot-scale wetland study was carried out in SSFWs under two different flow regimes (horizontal and vertical flow). Four ornamental species were tested during a 1-year period: Zantedeschia aethiopica, Strelitzia reginae, Anthurium andreanum and Agapanthus africanus. The removal efficiencies were significantly higher in the vertical subsurface-flow constructed wetlands (VFCW) for all pollutants, except for nitrate (NO(3)-N), total nitrogen (TN) and total suspended solids (TSS). These results show that it is feasible to use select non-wetland plants with high market value in SSFWs without reducing the efficiency of the wastewater treatment system, although future work should continue in order to apply this technology in a large scale. The added value of floriculture in treatment wetlands can help to promote the use of constructed wetlands (CW) for domestic wastewater treatment in developing countries where economical resources are scarce and water pollution with DWW is common.

  11. Treatment of domestic wastewater by subsurface flow constructed wetlands filled with gravel and tire chip media.

    PubMed

    Richter, A Y; Weaver, R W

    2003-12-01

    Subsurface flow constructed wetlands (SFCWs) are becoming increasingly common in on-site treatment of wastewater. Gravel is the most popular form of wetland fill medium, but tire chips provide more porosity, are less dense, and less expensive. This study determines the treatment efficiency of SFCWs filled with gravel or tire chip media to treat domestic wastewater. The influent and effluent of six SFCWs filled with tire chip medium and six SFCWs filled with gravel were monitored for 5 to 16 consecutive months. Parameters measured included pH, biochemical oxygen demand (BOD5), total and volatile suspended solids, NH4, P, and fecal and total coliforms. The only clear difference between medium types in wetland performance was for P. Soluble P in the effluent averaged 1.6 +/- 1.0 mg l(-1) in the tire chip-filled wetlands and 4.8 +/- 3.2 mg l(-1) in the gravel-filled wetlands. Most likely, Fe from exposed wires in shredded steel-belted tires complexed with P to create an insoluble compound. Tire chips may be a better fill medium for SFCWs than gravel because of higher porosity, lower cost, and greater reduction of P in effluent.

  12. 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.

  13. 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

  14. Passive treatment using coal combustion products: An innovative vertical flow constructed wetland field study

    SciTech Connect

    Nairn, R.W.; Mercer, M.N.; Everett, J.W.

    1999-07-01

    Designs of constructed wetlands for acid mine drainage (AMD) treatment have evolved substantially during the past decade. Current research focuses on the study of vertical-flow treatment systems containing labile organic substrates. Also known as successive alkalinity producing systems (SAPS), these systems emphasize contact of acidic waters with the substrate, thus maximizing biological alkalinity generation, via bacterial sulfate reduction, and abiotic alkalinity generation via carbonate dissolution processes. in this study, a coal combustion product (CCP) was utilized to generate supplementary alkalinity in addition to that provided by traditional substrate materials of spent mushroom substrate (SMS) and high CaCO{sub 3} content limestone. Although limestone is commonly utilized for abiotic alkalinity generation in AMC treatment wetlands, CCPs are not. The preliminary effectiveness of this innovative vertical flow passive treatment system was evaluated during the initial year of operation. The wetlands are successfully retaining iron, aluminum and manganese and are increasing pH, alkalinity, dissolved oxygen (from ,1.0 to >13 mg/L, due to biological productivity), and calcium (from 31 to 385 mg/L, presumably due to limestone and hydrated fly ash dissolution). No hydraulic conductivity problems have been encountered in the initial year of operation. CCPs may offer an attractive alternative, or supplementary, alkalinity generating source for AMD treatment wetlands.

  15. Evaluation of a constructed wetland treatment system specifically designed to decrease bioavailable copper in a wastestream.

    PubMed

    Murray-Gulde, Cynthia L; Bearr, Jonathan; Rodgers, John H

    2005-05-01

    A specifically designed constructed wetland decreased copper concentrations in a wastestream to 22 microg Cu/L and eliminated associated toxicity. Metal toxicity is a function of both concentration and form. This research measured copper partitioning to ligands within the wetland and observed changes in copper form with regard to bioavailability. Average monthly copper concentrations in the constructed wetland treatment system ranged from 10 to 47 microg/L in the upstream (i.e., inflow to the constructed wetland prior to the retention basin) and from non-detection to 11 microg/L in the downstream (i.e., outflow to the receiving stream). On average, 78% total-recoverable, 85% acid-soluble, and 83% soluble copper were removed from inflow to outflow of this constructed wetland; however, total recoverable and acid-soluble copper measurements were not useful indicators of bioavailable copper. Survival of Ceriodaphnia dubia increased from an average of 2% survival in the inflow to 96% in the outflow and reproduction increased from an average of 8 to 24 neonates/female, respectively. Soluble copper is a more accurate predictor of the concentration at which effects were observed. Average ratio of acid volatile sulfides to simultaneously extractable metals was 1.4: 0.06 micromol/g indicating sufficient sulfides to sequester available metals in the system.

  16. 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.

  17. 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)...

  18. 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...

  19. 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...

  20. Nitrogen removal by the enhanced floating treatment wetlands from the secondary effluent.

    PubMed

    Gao, Lei; Zhou, Weili; Huang, Jungchen; He, Shengbing; Yan, Yijia; Zhu, Wenying; Wu, Suqing; Zhang, Xu

    2017-06-01

    Three novel floating treatment wetlands, including autotrophic enhanced floating treatment wetland (AEFTW), heterotrophic enhanced floating treatment wetland (HEFTW) and enhanced floating treatment wetland (EFTW) were developed to remove nitrogen from the secondary effluent. Results showed that the analogously excellent nitrogen removal performance was achieved in AEFTW and HEFTW. About 89.4% of the total nitrogen (TN) was removed from AEFTW at a low S/N of 0.9 and 88.5% from HEFTW at a low C/N of 3.5 when the hydraulic retention time (HRT) was 1d in summer. Higher nitrification and denitrification performance were achieved in AEFTW. Addition of electron donors effectively reduced the N2O emission, especially in summer and autumn. High-throughput sequencing analysis revealed that the electron donors distinctly induced the microbial shifts. Dechloromonas, Thiobacillus and Nitrospira became the most predominant genus in HEFTW, AEFTW and EFTW. And autotrophic and heterotrophic denitrification could simultaneously occur in HEFTW and AEFTW. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. 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...

  2. Habitat quality assessment of two wetland treatment systems in the arid west: A pilot study

    SciTech Connect

    McAllister, L.S.

    1993-08-01

    The use of wetland treatment systems (WTS) for treating municipal wastewater is increasing in the United States, but little is known about the ability of these systems to duplicate or sustain wetland functions. The pilot study was designed to examine methods and the usefulness of various wetland indicators for assessing the wildlife habitat quality in six WTS sites throughout the United States and to identify any major differences in indicator values between WTS and non-WTS. The report focusses on two of the sites, one located in east-central Arizona and one in the Carson Valley in Nevada. Habitat indicator data collected in the field, as well as existing data, were summarized and compared with ranges of values for the same indicators from non-WTS. Of the indicators measured, vegetation, invertebrates, site morphology, and birds appear to be the most promising for assessing and monitoring habitat quality in terms of reliability of data.

  3. 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

  4. Wastewater treatment in a compact intensified wetland system at the Badboot: a floating swimming pool in Belgium.

    PubMed

    Van Oirschot, D; Wallace, S; Van Deun, R

    2015-09-01

    The Badboot (Dutch for swimming pool boat) is a floating swimming pool located in the city center of Antwerp in Belgium. The overall design consists of a recycled ferry boat that serves as a restaurant and next to that a newly built ship that harbours an Olympic size swimming pool, sun decks, locker rooms with showers, and a party space. A major design goal of the project was to make the ship as environmentally friendly as possible. To avoid discharge of contaminated waste water in the Antwerp docks, the ship includes onsite treatment of wastewater in a compact constructed wetland. The treatment wetland system was designed to treat wastewater from visitor locker rooms, showers, toilets, two bars, and the wastewater from the restaurant kitchen. Due to the limited space on board the ship, only 188 m(2) could be allocated to a wetland treatment system. As a result, part of the design included intensification of the wetland treatment process through the use of Forced Bed Aeration, which injects small quantities of air in a very uniform grid pattern throughout the wetland with a mechanical air compressor. The system was monitored between August 2012 and March 2013 (with additional sampling in the autumn of 2014). Flows and loads to the wetland were highly variable, but removal efficiency was extremely high; 99.5 % for chemical oxygen demand (COD), 88.6 % for total nitrogen and 97.2 % for ammonia. The treatment performance was assessed using a first-order, tanks-in-series model (the P-k-C* model) and found to be roughly equivalent to similar intensified wetlands operating in Germany. However, treatment performance was substantially better than data reported on passive wetlands, likely as a result of intensification. Even with mechanically assisted aeration, the total oxygen delivered to the treatment wetlands was insufficient to support conventional nitrification and denitrification, so it is likely that alternate nitrogen removal pathways, such as anammox, are

  5. Tracer experiment and flow modelling applied to Ekeby treatment wetland, Sweden.

    NASA Astrophysics Data System (ADS)

    Kjellin, J. P.; Worman, A.

    2005-05-01

    The use of treatment wetlands have come to play an important role in reducing nutrient content in wastewater and in run-off water from agricultural areas. It is of interest to optimize the nutrient removal efficiency. In order to do so hydrological and geochemical processes, and the coupling between them, must be known in greater detail than is currently the case. One way of investigating this matter is to perform tracer experiments and evaluate the results using computer simulations. In November 2002 a simultaneous tracer experiment was performed in a treatment wetland, using tritiated water, P-32 and N-15. The wetland is situated 120 km west of Stockholm in Sweden, and the basin where the experiment was performed has an area of 2,6 ha. The simultaneous use of conservative tracer and reactive tracers enables a fair evaluation of both hydraulic processes and biochemical reactions. In this presentation evaluation of the hydraulic matters will be in focus, the geochemical issues will be described in companion presentations. In order to evaluate the hydraulic behaviour and the fate of tritium through the wetland, a two-dimensional flow model was developed in a MATLAB environment. The model is able to deal with variations in shape, bottom topography and friction factors. It was used to simulate flow of inert particles through the wetland. Breakthrough curves of tritium and simulation results were studied and compared for different setups of friction parameters. The simulations show that bottom topography and shape of basin alone are not enough to explain the spreading of water residence times in the wetland. Distribution and density of vegetation, simulated as friction factors, are shown to be crucial when it comes to reproducing the residence time distribution from the experiment.

  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.

  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. 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.

  9. A review on numerous modeling approaches for effective, economical and ecological treatment wetlands.

    PubMed

    Kumar, J L G; Zhao, Y Q

    2011-03-01

    Constructed wetlands (CWs) for wastewater treatment have evolved substantially over the last decades and have been recognized as an effective means of "green technology" for wastewater treatment. This paper reviews the numerous modeling approaches ranging from simple first-order models to more complex dynamic models of treatment behaviour in CWs. The main objective of the modeling work is to better understand the process in CWs and optimize design criteria. A brief study in this review discusses the efforts taken to describe the process-based model for the efficient removal of pollutants in CWs. Obtaining better insights is essential to understand the hydraulic and biochemical processes in CWs. Currently, employed modeling approaches can be seen in two categories, i.e. "black-box models" and "process-based models". It is evident that future development in wetland technology will depend on improved scientific knowledge of internal treatment mechanisms.

  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 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.

  12. Contaminant removal in septage treatment with vertical flow constructed wetlands operated under batch flow conditions.

    PubMed

    Jong, Valerie Siaw Wee; Tang, Fu Ee

    2016-01-01

    Individual septic tanks are the most common means of on-site sanitation in Malaysia, but they result in a significant volume of septage. A two-staged vertical flow constructed wetlands (VFCWs) system for the treatment of septage was constructed and studied in Sarawak, Malaysia. Raw septage was treated in the first stage wetlands, and the resulting percolate was fed onto the second stage wetlands for further treatment. Here, the effects of a batch loading regime on the contaminant removal efficiency at the second stage wetlands, which included palm kernel shell within their filter substrate, are presented. The batch loading regime with pond:rest (P:R) period of 1:1, 2:2 and 3:3 (day:day) was studied. The improvement of the effluent redox condition was evident with P:R = 3:3, resulting in excellent organic matters (chemical oxygen demand and biochemical oxygen demand) and nitrogen reduction. The bed operated with P:R = 1:1 experienced constant clogging, with a water layer observed on the bed surface. For the P:R = 3:3 regime, the dissolved oxygen profile was not found to decay drastically after 24 hours of ponding, suggesting that the biodegradation mainly occurred during the first day. The study results indicate that a suitable application regime with an adequate rest period is important in VFCWs to ensure efficient operation.

  13. Treatment of metal-chloride-enriched wastewater by simulated constructed wetlands.

    PubMed

    Mitchell, L K; Karathanasis, A D

    1995-09-01

    The ability of surface flow and subsurface flow simulated wetlands to remove heavy metals from a NaCI-enriched wastewater was examined, employing bulrush (Scirpus validus) and cattail (Typha angustifolia) plants, and two organically amended substrates (mixtures of mushroom compost and leaf litter,with topsoil) with a limestone liner. A simulated wastewater solution containing Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn as chloride salts was added to the wetlands at a rate of 0.3 l h(-1). During 12 weeks of surface flow, Fe was retained most efficiently (74%), and Mn the least (24%). Most metal retention occurred in residual forms, primarily in the upper 5 cm of the substrate. A subsequent 10 week subsurface flow treatment exhibited greater removal efficiencies for all metals, probably due to increased contact with the highly buffered lower substrate. During both treatments, bioaccumulation occurred in plants, but accounted for a very small portion of the total metal removal. Plant species did not significantly influence wetland performance with respect to metal retention. Substrate type did not affect removal efficiency for most metals, but did influence the forms of the metals retained in the wetland.

  14. Wetland areas: Natural water treatment systems. January 1970-May 1989 (Citations from Pollution Abstracts). Report for January 1970-May 1989

    SciTech Connect

    Not Available

    1989-06-01

    This bibliography contains citations concerning the ability of salt marshes, tidal flats, marshlands, bogs, and other wetland areas to degrade, absorb, filter, consume, or mitigate natural and man-made pollution and wastes, while still providing refuge and breeding grounds for wildlife. The ecology, biochemistry, and viability of naturally occuring and artificially established wetlands as water-treatment systems and wildlife areas is considered. The effects of individual pollutants, environmental factors, species diversity, and cleansing ability of wetland areas on the potential for wildlife refuge, sewage treatment, treatment of industrial and municipal wastes, handling agricultural runoff, mitigating accidental spills, and flooding are discussed. (Contains 271 citations fully indexed and including a title list.)

  15. Wastewater treatment in tsunami affected areas of Thailand by constructed wetlands.

    PubMed

    Brix, H; Koottatep, T; Laugesen, C H

    2007-01-01

    The tsunami of December 2004 destroyed infrastructure in many coastal areas in South-East Asia. In January 2005, the Danish Government gave a tsunami relief grant to Thailand to re-establish the wastewater management services in some of the areas affected by the tsunami. This paper describes the systems which have been built at three locations: (a) Baan Pru Teau: A newly-built township for tsunami victims which was constructed with the contribution of the Thai Red Cross. Conventional septic tanks were installed for the treatment of blackwater from each household and its effluent and grey water (40 m3/day) are collected and treated at a 220 m2 subsurface flow constructed wetland. (b) Koh Phi Phi Don island: A wastewater collection system for the main business and hotel area of the island, a pumping station and a pressure pipe to the treatment facility, a multi-stage constructed wetland system and a system for reuse of treated wastewater. The constructed wetland system (capacity 400 m3/day) consists of vertical flow, horizontal subsurface flow, free water surface flow and pond units. Because the treatment plant is surrounded by resorts, restaurants and shops, the constructed wetland systems are designed with terrains as scenic landscaping. (c) Patong: A 5,000 m2 constructed wetland system has been established to treat polluted water from drainage canals which collect overflow from septic tanks and grey water from residential areas. It is envisaged that these three systems will serve as prototype demonstration systems for appropriate wastewater management in Thailand and other tropical countries.

  16. 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

  17. Effects of inorganic nitrogen enrichment on mosquitoes (Diptera: Culicidae) and the associated aquatic community in constructed treatment wetlands.

    PubMed

    Sanford, Michelle R; Chan, Karrie; Walton, William E

    2005-09-01

    Ammonium nitrogen (NH4-N) is a significant component of municipal and agricultural wastewaters, and nitrogen reduction is an important use of constructed treatment wetlands. The effects of ammonium nitrogen enrichment on resources of larval mosquitoes, larval mosquito abundance, adult mosquito production, and the abundance of related wetland organisms were examined in 0.1-ha replicate treatment wetlands. The hypothesis of a bottom-up effect induced by ammonium addition was not supported by bacterial abundance, mean bacterial cell size, or algal biomass in the water column. There was, however, a significant negative correlation between bacterial cell length and Culex tarsalis Coquillett (Diptera: Culicidae) larval abundance 1 wk later in wetlands enriched with ammonium nitrogen. Larval mosquito (Culex spp.) abundance in southern California wetlands enriched with NH4-N (mean approximately equal to 3 mg/liter) was significantly greater than in control wetlands at ambient nitrogen levels (8.3 mg NO3-N/liter, 0.1 mg NH4-N/liter). Adult mosquito production was nine-fold greater and chironomid larvae were significantly more abundant in wetlands enriched with NH4-N than in controls but other censused taxa exhibited no significant trends. Mosquitofish, Gambusia affinis (Baird & Girard), abundance was significantly reduced in enriched wetlands, but other potential mosquito predators were not significantly affected by ammonium enrichment.

  18. 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.

  19. Performance of pilot-scale constructed wetlands for secondary treatment of chromium-bearing tannery wastewaters.

    PubMed

    Dotro, Gabriela; Castro, Silvana; Tujchneider, Ofelia; Piovano, Nancy; Paris, Marta; Faggi, Ana; Palazolo, Paul; Larsen, Daniel; Fitch, Mark

    2012-11-15

    Tannery operations consist of converting raw animal skins into leather through a series of complex water- and chemically-intensive batch processes. Even when conventional primary treatment is supplemented with chemicals, the wastewater requires some form of biological treatment to enable the safe disposal to the natural environment. Thus, there is a need for the adoption of low cost, reliable, and easy-to-operate alternative secondary treatment processes. This paper reports the findings of two pilot-scale wetlands for the secondary treatment of primary effluents from a full tannery operation in terms of resilience (i.e., ability to produce consistent effluent quality in spite of variable influent loads) and reliability (i.e., ability to cope with sporadic shock loads) when treating this hazardous effluent. Areal mass removal rates of 77.1 g COD/m2/d, 11 g TSS/m2/d, and 53 mg Cr/m2/d were achieved with a simple gravity-flow horizontal subsurface flow unit operating at hydraulic loading rates of as much as 10 cm/d. Based on the findings, a full-scale wetland was sized to treat all the effluent from the tannery requiring 68% more land than would have been assumed based on literature values. Constructed wetlands can offer treatment plant resilience for minimum operational input and reliable effluent quality when biologically treating primary effluents from tannery operations.

  20. The integration of constructed wetlands into a treatment system for airport runoff.

    PubMed

    Revitt, D M; Worral, P; Brewer, D

    2001-01-01

    A new surface runoff treatment system has been designed for London Heathrow Airport, which incorporates separate floating constructed wetlands or reedbeds and sub-surface flow constructed wetlands as major pollutant removal systems. The primary requirement of the newly developed treatment system is to control the concentrations of glycols following their use as de-icers and anti-icers within the airport. The ability of reedbeds to contribute to this treatment role was fully tested through pilot scale, on-site experiments over a 2 year period. The average reductions in runoff BOD concentrations achieved by pilot scale surface flow and sub-surface flow reedbeds were 30.9% and 32.9%, respectively. The corresponding average glycol removal efficiencies were 54.2% and 78.3%, following shock dosing inputs. These treatment performances are used to predict the required full scale constructed wetland surface areas needed to attain the desired effluent water quality. The treatment system also incorporates aeration, storage and, combined with reedbed technology, has been designed to reduce a mixed inlet BOD concentration of 240 mg/l to less than 40 mg/l for water temperatures varying between 6 degrees C and 20 degrees C.

  1. 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.

  2. Soil biogeochemical characteristics influenced by alum application in a municipal wastewater treatment wetland.

    PubMed

    Malecki-Brown, Lynette M; White, John R; Reddy, K R

    2007-01-01

    Constructed treatment wetlands are a relatively low-cost alternative used for tertiary treatment of wastewater. Phosphorus (P) removal capacity of these wetlands may decline, however, as P is released from the accrued organic soils. Little research has been done on methods to restore the treatment capacity of aging constructed wetlands. One possibility is the seasonal addition of alum during periods of low productivity and nutrient removal. Our 3-mo mesocosm study investigated the effectiveness of alum in immobilizing P during periods of reduced treatment efficiency, as well as the effects on soil biogeochemistry. Eighteen mesocosms were established, triplicate experimental and control units for Typha sp., Schoenoplectus californicus, and submerged aquatic vegetation (SAV) (Najas guadalupensis dominated). Alum was slowly dripped to the water column of the experimental units at a rate of 0.91 g Al m(-2) d(-1) and water quality parameters were monitored. Soil cores were collected at experiment initiation and completion and sectioned into 0- to 5- and 5- to 10-cm intervals for characterization. The alum floc remained in the 0- to 5-cm surface soil, however, soil pH and microbial parameters were impacted throughout the upper 10 cm with the lowest pH found in the Typha treatment. Plant type did not impact most biogeochemical parameters; however, data were more variable in the SAV mesocosms. Amorphous Al was greater in the surface soil of alum-treated mesocosms, inversely correlated with soil pH and microbial biomass P in both soil layers. Microbial activity was also suppressed in the surface soil of alum-treated mesocosms. This research suggests alum may significantly affect the biogeochemistry of treatment wetlands and needs further investigation.

  3. 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.

  4. Model evaluation of simultaneous injection of inert and reactive tracers in treatment wetlands

    NASA Astrophysics Data System (ADS)

    Worman, A.; Kjellin, J. P.

    2005-05-01

    Treatment wetlands have shown to play an important role in reducing the nutrient content of recipient waters. The overall objective of this study is to evaluate simultaneous tracer experiment in Ekeby treatment wetland in Eskilstuna, Sweden, with tritiated water, nitrogen (N-15) and phosphorus (P-32). Particular modelling tools are essential to be able to understand the complexity of the wetland processes and to reveal the role underlying mechanisms. The model evaluation is based on a 2D physical description of stationary water flow and an uncoupled 1D formulation of the transport and transformation of nitrogen (N) and phosphorus (P). The overall N- and P- response of the wetland is obtained from averaging responses over the distribution of flow pathways. The flow modelling, described in a companion presentation, is thus a prerequisite for the interpretation of the P- and N-processes. Both P and N are affected by retention in the wetland, which is clear from comparing the slope of the tails of the breakthrough of P-32 and N-15 with tritium. The lower slopes of the reactive tracers compared to tritium indicate a slow wash-out for N and P. Nitrogen was also partly removed due to denitrification, which is evident from a larger degree of removal than phosphorus. A first-order loss rate coefficient, k, for N averaged for the entire wetland is about k = 0.12 1/days. The rate coefficient was defined from the expression Meff/Min=Exp(-k ), where is the mean residence time, the effluent N-mass is Meff and the influent N-mass is Min. However, laboratory experiments indicate that the micro-biological activity in the bed sediment is generally much higher than the average for the wetland. Therefore, a consistent model interpretation of the denitrification process required that we accounted for both a rate-limited exchange with the hyporheic zone (sediments) and the first-order loss of N-2 from the hyporheic zone to the atmosphere.

  5. 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

  6. [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.

  7. Quality assurance field operations report for the pilot study evaluating the habitat value of wetland treatment systems

    SciTech Connect

    McAllister, L.S.

    1992-12-01

    The use of wetland treatment systems (WTS), or constructed wetlands, for treating municipal wastewater is increasing in the United States, but little is known about the ability of these systems to duplicate or sustain wetland functions. The purpose of the field operations report is to document field methods and activities as they were conducted during the 1991 field season. The report includes details of sampling procedures, criteria used for making sampling decisions, data that were collected at each site, and analysis of quality control data, and a discussion of difficulties encountered. The field operations report will cover only the field work pertaining to compiling data on selected indicators of wetland condition by taking measurements at sites and utilizing the Wetland Evaluation Technique (WET), to evaluate habitat quality and other values of WTS and to assess the technique's utility for WTS evaluation.

  8. Winery wastewater treatment by constructed wetlands and the use of treated wastewater for cash crop production.

    PubMed

    Mulidzi, A R

    2007-01-01

    A 45 m long, 4 m wide and 1 m deep wetland was constructed at Goudini in 2002 to treat distillery and winery effluent. After the plants were fully established, the wastewater with an average chemical oxygen demand (COD) of 14,000 mg/l was introduced to the wetland system at a rate of 4,050 litres per day. After treatment, wastewater at the outlet had an average COD of 500 mg/l, indicating more than 90% COD removal. After treatment, the wastewater was used to irrigate cash crops as part of poverty alleviation for farm workers. The experiment consisted of four treatment: clean irrigation water with fertilizer applied (B1); clean irrigation water without fertilizer applied (B2); wastewater irrigation with fertilizer applied (B3); and wastewater irrigation without fertilizer applied (B4). These were replicated seven times. Cabbage was cultivated as a cash crop. The results indicated that cabbage could be irrigated with winery wastewater treated by wetlands. The study found that there was significant difference between treatments that were fertilized compared with those that were not fertilized. The results indicated that wastewater irrigation improved the nutritional status of the soil.

  9. Plankton composition, distribution and significance in a tropical integrated pilot constructed treatment wetland in Uganda.

    PubMed

    Luyiga, S; Kiwanuka, S

    2003-01-01

    The importance of the plankton community in wastewater treatment has been under-estimated for a long time, simply because of its biomass accumulation resulting in final release of organic matter back into the system after decomposition. In a two-year 3-month periodical study on a tropical integrated wastewater treatment constructed wetland, the phytoplankton role was tested and it has been shown that, through harvesting, the phytoplankton community plays a significant role in municipal wastewater treatment. The high phytobiomass, which was dominated by green algae (Chlorophyta), enhanced high levels of dissolved oxygen and high pH within the open ponds, and because of this, the system was found to be highly efficient in BOD5 (81%) and NH4+-N (93%) removal. The high pH enhanced ammonia volatilization within the open ponds. Regression statistics between the plankton community composition and some of the physicochemical parameters (BOD, NH4+-N, DO, pH) within the wetland system show a significant relationship. In conclusion, open treatment wetlands provide a wide variety of planktonic organisms as water quality improvement systems through the provision of oxygen and alteration of the pH for BOD5 and ammonium reduction respectively.

  10. The Renewal of Fresh Water Through Treatment Wetlands: A Global Model

    NASA Astrophysics Data System (ADS)

    Bradford, M.; Fraser, L.; Steer, D.

    2001-05-01

    We present a global model that incorporates population growth, freshwater supply, dam construction, and, most importantly, an estimate of the returns of freshwater by the treatment of wastewater through wetlands. By including treatment wetlands within the global hydrological cycle, we estimate that humans can reduce the annual appropriation of freshwater in 2025 to 52%, even with the assumption that per capita rate of water use is increasing. The diminishing world supply and availability of freshwater is forcing a general re-assessment of freshwater use and the treatment of wastewater. Even with an increase in the construction of dams, the rate of population growth and the projected amount of future water use far surpasses the rate of supply. An earlier global model estimated that humans appropriated 52% of the annual accessible freshwater in 1990, and would appropriate at least 72% in 2025. This alarming figure is actually a very conservative estimate considering that the per capita rate of increase of water use is increasing. If per capita rate of increase was accounted for in the model, 99% of accessible freshwater will be appropriated in 2025. The use of constructed and natural wetlands for the treatment of wastewater may be an effective worldwide tool to help address the problem of fresh water availability.

  11. Model-based design of horizontal subsurface flow constructed treatment wetlands: a review.

    PubMed

    Rousseau, Diederik P L; Vanrolleghem, Peter A; De Pauw, Niels

    2004-03-01

    The increasing application of constructed wetlands for wastewater treatment coupled with increasingly strict water quality standards is an ever growing incentive for the development of better process design tools. This paper reviews design models for horizontal subsurface flow constructed treatment wetlands, ranging from simple rules of thumb and regression equations, to the well-known first-order k-C* models, Monod-type equations and more complex dynamic, compartmental models. Especially highlighted in this review are the model constraints and parameter uncertainty. A case study has been used to demonstrate the model output variability and to unravel whether or not more complex but also less manageable models offer a significant advantage to the designer.

  12. Microbial community response during the treatment of pharmaceutically active compounds (PhACs) in constructed wetland mesocosms.

    PubMed

    Yan, Qing; Min, Jie; Yu, Yonghong; Zhu, Zhiwei; Feng, Guozhong

    2017-11-01

    The presence of pharmaceutically active compounds (PhACs) in wastewater treatment plant effluent poses a potential risk to aquatic ecosystems. Constructed wetlands have recently been used to control PhACs. However, the microbial communities that are involved in these processes have not been comprehensively investigated. This study aimed to evaluate the removal of PhACs and microbial response in constructed wetlands during the treatment of PhACs. The effects of PhACs on bacterial communities in constructed wetland mesocosms were analyzed by Illumina MiSeq sequencing technology. Results indicated that removal efficiencies of PhACs were enhanced over time, and constructed wetlands offer higher removal efficiencies for the PhACs studied compared to conventional wastewater treatment plants. Plants improved microbial richness and diversity while both indices were negatively correlated with PhAC concentrations ranging from 30 to 500 μg/L in constructed wetland mesocosms. The microbial communities of the constructed wetland mesocosms were dominated by Proteobacteria, Acidobacteria, and Bacteroidetes under PhAC exposure, while Desulfobulbus and Treponema were the dominant genera. In particular, Proteobacteria were correlated with PhAC concentrations. Overall, this study provides valuable microbial community ecology data to understand how microbial populations respond to PhAC stress in constructed wetlands. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. 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: BOD5 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-NH4(+) 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.

  14. Modeling E.coli fate and transport in treatment wetlands using the water quality analysis and simulation program.

    PubMed

    Boutilier, Leah; Jamieson, Rob; Gordon, Robert; Lake, Craig

    2011-01-01

    Treatment wetlands can be a viable wastewater treatment option, especially in rural and remote regions where centralized wastewater treatment is not feasible. Bacteria fate and transport modeling within wetlands requires further development if they are to become a more reliable and predictable form of wastewater treatment. The goal of this paper was to calibrate and test an unsteady state numerical model for the simulation of E. coli fate and transport within full-scale surface flow (SF) wetlands treating domestic wastewater. The Water Quality Analysis and Simulation Program (WASP) was used to develop the model. Accurately predicting E. coli effluent concentrations using WASP was difficult due to the dynamic nature of the wetland environment including hydraulics, seasonal variability, and wetland maturity. WASP was successful in predicting average E. coli effluent concentrations but did not accurately forecast maximum and minimum values. The model produced better fits with observed E. coli effluent concentrations during the summer months, when observed effluent concentrations were less variable. Hydraulic tracer studies and model results suggest that preferential flow pathways may be affecting E. coli removal due to reduced retention times. Flow channelling or short circuiting may have been caused by high flow conditions and/or dense cattail growth. A more detailed understanding of treatment wetland hydraulics is required before we can accurately predict treatment performance.

  15. Iron and manganese removal in wetland treatment systems: rates, processes and implications for management.

    PubMed

    Batty, Lesley; Lesley, Batty; Hooley, Daniel; Daniel, Hooley; Younger, Paul; Paul, Younger

    2008-05-01

    Mine water drainage is a significant environmental problem throughout the world and constructed wetlands are being increasingly used to treat such contaminating discharges. Iron and manganese removal within a wetland treatment system at Whittle Colliery, UK which receives alkaline waters, was monitored to determine rates and processes within the different components of the system. In addition hourly samples were taken for a period of 24 h to determine the effect of photosynthetic organisms on metal removal. Significant iron removal occurred, with removal rates of 98% at Whittle. Oxidation of iron to form iron hydroxide precipitates was the dominant removal process in the proximal sections of the treatment system (i.e. oxidation ponds and initial reaches of the wetland), whereas biotic removal processes appeared to become more important in distal parts of the systems, where iron concentrations were much lower. Significant manganese removal was also observed, although this did not become substantial until iron concentrations had fallen below 5 mg/L. The process by which manganese was removed is not clear, but bacterially-mediated oxidation may be involved. Further elucidation of the relative importance of abiotic and biotic removal processes within treatment systems is important in the design and long-term management of constructed systems.

  16. Comparison of microfauna communities in full scale subsurface flow constructed wetlands used as secondary and tertiary treatment.

    PubMed

    Puigagut, Jaume; Salvadó, Humbert; García, David; Granes, Francesc; García, Joan

    2007-04-01

    In order to evaluate the microfauna composition and distribution in two horizontal subsurface flow constructed wetlands used as secondary and tertiary treatment a full-scale wastewater treatment plant was monitored during five months. Results indicate that total microfauna abundance in the wetland treating primary influents is around five times higher than that found in the wetland treating secondary influents. Ciliated protozoa and microflagellates are the most important microfauna groups in both wetlands; microflagellates in terms of abundance and ciliates in terms of biomass. The most abundant ciliate species in the wetland treating primary influents are polysaprobic organisms as Dexiostoma campylum, Trimyema compressum, and to a lesser extend Metopus spp. On the other hand, the most important ciliate species found in the wetland treating secondary influents are mainly aerobic ciliates as Vorticella comvallaria-complex, Aspidisca cicada, Litonotus lamella and some ciliates belonging to the group of the scuticociliates and Hypotrichidae. The sort of the organic matter treated (particulated or dissolved) is at least as important as the amount of it in order to explain microfauna dynamics in constructed wetlands.

  17. Substrata effects on bacterial biofilm development in a subsurface flow dairy waste treatment wetland.

    PubMed

    Silyn-Roberts, G; Lewis, G

    2003-01-01

    Biofilm development on two distinct rock substrata was investigated both in vitro and in a subsurface flow wastewater treatment wetland in order to determine the effect of hydrophobicity on initial bacterial adsorption, tertiary biofilm development and microbial population structure. Two commonly used wetland rock types, slag (a hydrophobic by-product of the steel smelter industry) and greywacke (a more hydrophilic sedimentary rock) were evaluated. In vitro investigations of initial microbial adsorption trends showed that the more hydrophobic slag displayed rapid bacterial adsorption rates compared to greywacke. Mean microbial adsorption rates of a mixed wetland bacterial population over 5 hours, described using a first order kinetics model, were 1.3 x 10(-12) m/sec for slag and consistently lower at 8.7 x 10(-13) m/sec for greywacke. Pristine rock studs of the two substrata were also exposed to wetland microbial communities during a six week field trial using confocal scanning laser microscopy to determine tertiary biofilm structure and fluorescent in situ hybridisation to investigate bacterial populations. During the first five weeks of growth CSLM analysis revealed that 75% of biofilms on slag were thicker and had greater coverage compared with those grown on greywacke. After six weeks of growth over 50% of the tertiary biofilms were structurally very similar on both rock types and only 25% of those grown on slag were larger than those on greywacke. In situ hybridisation analysis of bacterial populations revealed very little difference in population structure between biofilms grown on slag and those grown on greywacke. Eubacteria were present as a very high proportion of total bacteria throughout biofilm development (74.3%). The beta subgroup was the most populous of the Proteobacteria (31.4%) followed by the gamma subgroup (13.4%) and the alpha subgroup (1.3%). The results of this study suggest that slag, as a more hydrophobic substratum, promotes the initial

  18. 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.

  19. 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.

  20. Applying solubilization treatment to reverse clogging in laboratory-scale vertical flow constructed wetlands.

    PubMed

    Guofen, Hua; Wei, Zhu; Lianfang, Zhao; Yunhui, Zhang

    2010-01-01

    Substrate clogging is characterized as a frequently occurring operational problem for subsurface-flow constructed wetlands. The application of solubilization treatment to reduce clogging was tested in lab-scaled setups to provide a promising solution. The performance of solubilization treatment on reducing clogging and the related effects on plants and biofilms in the wetland system were investigated in this paper. The results showed that the infiltration rate and available porosity of wetland substrate increased as a function of increased dosage of NaOH, HCl, NaClO, and detergent, respectively. Among the four solvents, it appeared that NaClO had the most obvious effects on reducing clogging and the infiltration rate and effective porosity recovered to 69% of the original condition. The two possible reasons for solubilization were the flocculents' structure of the clogs was broken up or parts of the organic clogs were dissolved. The function of adding NaOH and NaClO was to dissolve the protein and polysaccharides of the organic clogs; the function of adding HCl was to release the anaerobic gas wrapped in the organic clogs. Furthermore, experiments results also showed that the solubilized solvents did not demonstrate a long-term negative effect on plants and biofilms.

  1. Subsurface-flow constructed wetlands treatment in the plains: five years of experience.

    PubMed

    Dahab, M F; Surampalli, R Y

    2001-01-01

    This paper documents the performance of a subsurface-flow constructed wetlands system during its initial five years of operation under variable loading and operating conditions associated with a northern midwestern US climate. The results indicate that effective and sufficient CW seasonal removals of TSS, VSS, CBOD5, COD, and fecal coliform were achieved. Wastewater temperatures seemed to affect CBOD5 and COD removal rates. Nitrogen and phosphorus reductions were not as effective and varied seasonally, as well as with wastewater temperature. The addition of a sand filter, to aid in further nitrification and disinfection following CW treatment, markedly improved the performance of the wetlands system. After a few years of operation, the remarkable performance of the CW system was dampened by apparent clogging and subsequent eruption of wastewater at the head-end of the treatment cells. While clogging was partially caused by biomass build-up in the wetlands substrate, visual observations suggest that excessive vegetation coupled with relaxed maintenance may also be responsible for clogging.

  2. 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.

  3. 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.

  4. Seasonal influence on sulfate reduction and zinc sequestration in subsurface treatment wetlands.

    PubMed

    Stein, Otto R; Borden-Stewart, Deborah J; Hook, Paul B; Jones, Warren L

    2007-08-01

    To characterize the effects of season, temperature, plant species, and chemical oxygen demand (COD) loading on sulfate reduction and metals removal in treatment wetlands we measured pore water redox potentials and concentrations of sulfate, sulfide, zinc and COD in subsurface wetland microcosms. Two batch incubations of 20 day duration were conducted in each of four seasons defined by temperature and daylight duration. Four treatments were compared: unplanted controls, Typha latifolia (broadleaf cattail), and Schoenoplectus acutus (hardstem bulrush), all at low COD loading (267 mg/L), plus bulrush at high COD loading (534 mg/L). Initial SO4-S and zinc concentrations were 67 and 24 mg/L, respectively. For all treatments, sulfate removal was least in winter (4 degrees C, plant dormancy) greatest in summer (24 degrees C, active plant growth) and intermediate in spring and fall (14 degrees C), but seasonal variation was greater in cattail, and especially, bulrush treatments. Redox measurements indicated that, in winter, plant-mediated oxygen transfer inhibited activity of sulfate reducing bacteria, exacerbating the reduction in sulfate removal due to temperature. Doubling the COD load in bulrush treatments increased sulfate removal by only 20-30% when averaged over all seasons and did not alter the basic pattern of seasonal variation, despite tempering the wintertime increase in redox potential. Seasonal and treatment effects on zinc removal were broadly consistent with sulfate removal and presumably reflected zinc-sulfide precipitation. Results strongly suggest that interactive effects of COD loading rate, temperature, season, and plant species control not only sulfate reduction and zinc sequestration, but also the balance of competition between various microbial consortia responsible for water treatment in constructed wetlands.

  5. 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.

  6. Macrophyte growth in a pilot-scale constructed wetland for industrial wastewater treatment.

    PubMed

    Hadad, H R; Maine, M A; Bonetto, C A

    2006-06-01

    A pilot-scale wetland was constructed to assess the feasibility of treating the wastewater from a tool industry in Santo Tomé, Santa Fe, Argentina. The wastewater had high conductivity and pH, and contained Cr, Ni and Zn. This paper describes the growth of vegetation in the experimental wetland and the nutrient and metal removal. The wetland was 6 x 3 x 0.4 m. Water discharge was 1000 l d(-1) and residence time was 7d. After the wetland was rendered impermeable, macrophytes from Middle Paraná River floodplain were transplanted. Influent and effluent quality was analyzed every 15 d. TP, Cr, Ni and Zn concentrations in leaves, roots and sediment (inlet and outlet) were measured monthly. Cover and biomass of predominant species were estimated. Also, greenhouse experiments were carried out to measure the effects of conductivity and pH on floating species. The variables measured in the influent were significantly higher than those in the effluent, except for HCO(3)(-) and NH(4)(+). TP and metal concentrations in sediment at the inlet were significantly higher than those at the outlet. Conductivity and pH of the incoming wastewater were toxic for the floating species. Typha domingensis displaced the other species and reached positive relative cover rate and biomass greater than those at the undisturbed natural environment. T. domingensis proved to be highly efficient for the treatment of wastewater. For that reason, it is the advisable species for the treatment of wastewater of high conductivity and pH enriched with metals, characteristic of many industrial processes.

  7. 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.

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

    SciTech Connect

    Sikora, F.J.; Behrends, L.L.; Coonrod, H.S.; Phillips, W.D.; Bader, D.F.

    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 (L 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.

  9. 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; Loo, B; Maxim, P; Hynning, E; Hardemark, 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 and 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 RaySearch Laboratories.

  10. Wetland areas: Natural water treatment systems. (Latest citations from Pollution Abstracts). Published Search. [Dual use wildlife refuges

    SciTech Connect

    Not Available

    1992-12-01

    The bibliography contains citations concerning the dual use of wetland areas as both water treatment systems and wildlife refuges. The ability of salt marshes, tidal flats, marshlands, and bogs to absorb and filter natural and synthetic wastes is examined. Topics include the effects of individual pollutants; environmental factors; species diversity; the cleansing ability of wetland areas; and the handling of sewage, industrial and municipal wastes, agricultural runoff, accidental spills, and flooding. (Contains 250 citations and includes a subject term index and title list.)

  11. Dairy farm wastewater treatment using horizontal subsurface flow wetlands with Typha domingensis and different substrates.

    PubMed

    Schierano, María Celeste; Maine, María Alejandra; Panigatti, María Cecilia

    2017-01-01

    The aim of this work was to evaluate the influence of different substrates in the performance of a horizontal flow constructed wetland employed in dairy farm wastewater treatment. Typha domingensis was chosen for this study due to its high productivity and efficiency in nutrient removal. Fifteen microcosm-scale reactors simulating horizontal flow constructed wetlands were disposed in a greenhouse in triplicate. Five substrates (river gravel, gravel, LECA, river gravel + zeolite and gravel + zeolite) were evaluated. Real effluent with previous treatment was used. Dairy farm effluents favoured T. domingensis growth, probably due to their high nutrient concentrations. The treatments with the different substrates studied were efficient in the treatment of the dairy farm effluent obtaining ammonium ([Formula: see text]) and total phosphorus (TP) removals between 88-99% and 86-99%, respectively. Removal efficiencies were significantly higher in treatments using LECA and combined substrate (gravel + zeolite). After treatment, the quality of the final effluent was significantly improved. Outlet effluent complied with regulations and could be discharged into the environment.

  12. Comparing the efficiency of Cyperus alternifolius and Phragmites australis in municipal wastewater treatment by subsurface constructed wetland.

    PubMed

    Shahi, Davod Hossein; Eslami, Hadi; Ehrampoosh, Mohamad Hasan; Ebrahimi, Asghar; Ghaneian, Mohamad Taghy; Ayatollah, Shirin; Mozayan, Mohamad Reza

    2013-04-15

    Nowadays, application of natural wastewater treatment systems such as wetland not only reduces economic costs and energy consumption, but also decreases environmental pollution. This study aimed to compare efficiency of Cyperus alternifolius and Phragmites australis in Municipal wastewater treatment by Subsurface Constructed Wetland Method. This is an applied-interventionnal study in which three reactors (control pilot, Cyperus alternifolius (umbrella palm) plant pilot and Phragmites australis (reed) plant pilot were designed by subsurface constructed wetland method. Then 90 samples were taken from input and output of reactors with four-day retention time. These samples were tested and finally the data were analyzed by Paired Sample Test statistical analysis. The results showed that removal efficiency of the parameters such as COD, BOD5, TSS, NO3-N, NH3-N, PO4-P, total coliform and fecal coliform was 74, 73, 84, 40, 36, 70, 33 and 38% in Cyperus alternifolius plant wetland, 44, 34, 77, 15, 0.3, 1, 17 and 26% in control wetland and 59, 54, 73, 6, 3, 10, 93 and 50 in Phragmites australis plant wetland, respectively. This reduction rate in all parameters- except fecal coliform- was statistically significant (p = 0.05). The results of this study showed that Cyperus alternifolius plant had higher efficiency in the removal of chemical parameters, whereas Phragmites australis plant had appropriate efficiency in the removal of microbiological parameters. Therefore, it can be concluded that application of these two plants can be effective in wastewater treatment.

  13. 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...

  14. Biotransformation of trace organic contaminants in open-water unit process treatment wetlands.

    PubMed

    Jasper, Justin T; Jones, Zackary L; Sharp, Jonathan O; Sedlak, David L

    2014-05-06

    The bottoms of shallow, open-water wetland cells are rapidly colonized by a biomat consisting of an assemblage of photosynthetic and heterotrophic microorganisms. To assess the contribution of biotransformation in this biomat to the overall attenuation of trace organic contaminants, transformation rates of test compounds measured in microcosms were compared with attenuation rates measured in a pilot-scale system. The biomat in the pilot-scale system was composed of diatoms (Staurosira construens) and a bacterial community dominated by β- and γ-Proteobacteria. Biotransformation was the dominant removal mechanism in the pilot-scale system for atenolol, metoprolol, and trimethoprim, while sulfamethoxazole and propranolol were attenuated mainly via photolysis. In microcosm experiments, biotransformation rates increased for metoprolol and propranolol when algal photosynthesis was supported by irradiation with visible light. Biotransformation rates increased for trimethoprim and sulfamethoxazole in the dark, when microbial respiration depleted dissolved oxygen concentrations within the biomat. During summer, atenolol, metoprolol, and propranolol were rapidly attenuated in the pilot-scale system (t1/2 < 0.5 d), trimethoprim and sulfamethoxazole were transformed more slowly (t1/2 ≈ 1.5-2 d), and carbamazepine was recalcitrant. The combination of biotransformation and photolysis resulted in overall transformation rates that were 10 to 100 times faster than those previously measured in vegetated wetlands, allowing for over 90% attenuation of all compounds studied except carbamazepine within an area similar to that typical of existing full-scale vegetated treatment wetlands.

  15. Emissions of NO and N2O in wetland microcosms for swine wastewater treatment.

    PubMed

    Zhang, Shunan; Liu, Feng; Xiao, Runlin; Li, Yong; Zhou, Juan; Wu, Jinshui

    2015-12-01

    Nitric oxide (NO) and nitrous oxide (N2O) emitted from wetland systems contribute an important proportion to the global warming effect. In this study, four wetland microcosms vegetated with Myriophyllum elatinoides (WM), Alternanthera philoxeroides (WA), Eichhornia crassipes (WE), or without vegetation (NW) were compared to investigate the emissions of NO and N2O during nitrogen (N) removal process when treating swine wastewater. After 30-day incubation, TN removal rates of 96.4, 74.2, 97.2, and 47.3 % were observed for the WM, WA, WE, and NW microcosms, respectively. Yet, no significant difference was observed in WM and WE (p > 0.05). The average NO and N2O emissions in WE was significantly higher than those in WM, WA, and NW (p < 0.05). In addition, the emission of N2O in WE accounted for 2.10 % of initial TN load and 2.17 % of the total amount of TN removal, compared with less than 1 % in the other microcosms. These findings indicate that wetland vegetated with M. elatinoides may be an optimal system for swine wastewater treatment, based on its higher removal of N and lower emissions of NO and N2O.

  16. Improving Urban Stormwater Runoff Quality by Nutrient Removal through Floating Treatment Wetlands and Vegetation Harvest.

    PubMed

    Xu, Bing; Wang, Xue; Liu, Jia; Wu, Jiaqiang; Zhao, Yongjun; Cao, Weixing

    2017-08-01

    Two floating treatment wetlands (FTWs) in experimental tanks were compared in terms of their effectiveness on removing nutrients. The results showed that the FTWs were dominated by emergent wetland plants and were constructed to remove nutrients from simulated urban stormwater. Iris pseudacorus and Thalia dealbata wetland systems were effective in reducing the nutrient. T. dealbata FTWs showed higher nutrient removal performance than I. pseudacorus FTWs. Nitrogen (N) and phosphorous (P) removal rates in water by T. dealbata FTWs were 3.95 ± 0.19 and 0.15 ± 0.01 g/m(2)/day, respectively. For I. pseudacorus FTWs, the TN and TP removal rates were 3.07 ± 0.15 and 0.14 ± 0.01 g/m(2)/day, respectively. The maximum absolute growth rate for T. dealbata corresponded directly with the maximum mean nutrient removal efficiency during the 5th stage. At harvest, N and P uptak of T. dealbata was 23.354 ± 1.366 g and 1.489 ± 0.077 g per plant, respectively, approximate twice as high as by I. pseudacorus.

  17. 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.

  18. Wetland treatment of oil and gas well wastewaters. Quarterly technical report, November 25, 1992--February 24, 1993

    SciTech Connect

    Kadlec, R.H.; Srinivasan, K.R.

    1993-04-02

    During the first quarter of the above contract, all the elements of Task 1 were completed. The first quarterly report presented an overview of a wetland and its increasing use in industrial wastewater treatment. An idealized, reaction engineering description of wetlands was presented to demonstrate how the various processes that occur in a wetland can be modeled. Previous work on the use of wetlands to remove BOD, TSS, Phosphorus and Nitrogen was reviewed. Recent literature on the application of wetland technology to the treatment of petroleum-related wastewater was critically evaluated and an outline of the research plans for the first year was delineated. Further, our literature search (nominally completed under Task 1) unearthed more recent studies (some unpublished) and a summary was included in the second quarterly report. In the second quarterly report, results of our efforts on the construction of a laboratory-type wetland were also reported. Initial studies on the use of wetland amendments such as modified-clays and algae cells were presented and discussed. Adsorption of heavy metal ions, Cu{sup 2+} and Cr(VI) onto soils drawn from the laboratory-type wetland built as a part of this contract has been undertaken and these results are presented and discussed in this quarterly report. A number of studies on the design and preparation of modified-clays for the adsorption of Cr(VI) and {beta}-naphthoic acid (NA) has been carried out during this quarter and these are also described and discussed in this report. The choice of {beta}-naphthoic acid (NA) as an ionogenic organic compound was made on the basis of a recent personal communication to the Project Director that NA is a major contaminant in many oil and gas well wastewaters.

  19. Pollutant removal from municipal wastewater employing baffled subsurface flow and integrated surface flow-floating treatment wetlands.

    PubMed

    Saeed, Tanveer; Al-Muyeed, Abdullah; Afrin, Rumana; Rahman, Habibur; Sun, Guangzhi

    2014-04-01

    This article reports pollutant removal performances of baffled subsurface flow, and integrated surface flow-floating treatment wetland units, when arranged in series for the treatment of municipal wastewater in Bangladesh. The wetland units (of the hybrid system) included organic, inorganic media, and were planted with nineteen types of macrophytes. The wetland train was operated under hydraulic loading fluctuation and seasonal variation. The performance analyses (across the wetland units) illustrated simultaneous denitrification and organics removal rates in the first stage vertical flow wetland, due to organic carbon leaching from the employed organic media. Higher mean organics removal rates (656.0 g COD/(m(2)·day)) did not completely inhibit nitrification in the first stage vertical flow system; such pattern could be linked to effective utilization of the trapped oxygen, as the flow was directed throughout the media by the baffle walls. Second stage horizontal flow wetland showed enhanced biodegradable organics removal, which depleted organic carbon availability for denitrification. The final stage integrated wetland system allowed further nitrogen removal from wastewater, via nutrient uptake by plant roots (along with nitrification), and generation of organic carbon (by the dead macrophytes) to support denitrification. The system achieved higher E. coli mortality through protozoa predation, E. coli oxidation, and destruction by UV radiation. In general, enhanced pollutant removal efficiencies as demonstrated by the structurally modified hybrid wetland system signify the necessity of such modification, when operated under adverse conditions such as: substantial input organics loading, hydraulic loading fluctuation, and seasonal variation. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  20. Importance of denitrification to the efficiency of waste-water treatment in forested wetlands. Project completion report

    SciTech Connect

    Twilley, R.R.; Boustany, R.G.

    1990-09-01

    Wastewater, even after secondary treatment, typically contains high concentrations of nutrients that can cause eutrophication of receiving waters and deterioration of water quality. Therefore, there has been much interest in the use of natural wetlands as a simple and energy-efficient means of removing nutrients from wastewater and improving water quality. The utilization of a wetland for tertiary treatment of wastewater is based on the ability of the wetland to act as a nutrient sink. One of the most important processes in wetland ecosystems that influences their capacity as a nitrogen sink is the gaseous exchange of nitrogen with the atmosphere known as denitrification. Since denitrification represents a loss of nitrogen to the atmosphere, the mechanism tends to be most favorable for the removal of nitrogen. The objectives of the research project were to (1) determine the temporal and spatial ambient rates of denitrification and compare these rates to those of sediments amended with increased concentrations of nitrate comparable to concentrations of total nitrogen in the sewage effluent to be discharged; and (2) determine the proportion of total denitrification that can be attributed to direct utilization of nitrate loaded into the wetland, as compared to nitrate produced via nitrification within the wetland. Although nitrate is readily denitrified, short-term incubation rates are relatively low which is attributed to the presently low nitrate concentrations and subsequent reduced denitrifying microbial population in the wetland sediments. Nitrate concentrations varied seasonally associated with increased flooding during spring. Rates of nitrification coupled with denitrification were investigated with nitrogen-15 isotopes. Nitrification is limited in the wetland sedments; therefore, controls the rate of total nitrogen loss from the system.

  1. [Water treatment efficiency of constructed wetland plant-bed/ditch systems].

    PubMed

    Wang, Zhong-Qiong; Zhang, Rong-Bin; Chen, Qing-Hua; Wei, Hong-Bin; Wang, Wei-Dong

    2012-11-01

    Shijiuyang constructed wetland (SJY-CW) in Jiaxing City adopted plant-bed/ditch systems originated from the natural landscape as its major functioning unit. The constructed root channel technology (CRCT) is the core technique applied within the plant-bed/ditch systems. Monitoring results demonstrated that the wetland had the capability of improving water quality indexes by one rank grade according to the national environmental quality standards for surface water (GB 3838-2002). In order to optimize the water quality improvement function of plant-bed/ditch systems and CRCT, a pilot project in SJY-CW was constructed from May to October, 2010. The project contained 16 independent experimental cells. Orthogonal test design was applied to probe into the effects of constructed root channel layers, plant species combination, and reinforced physical substrates on promoting the water quality amelioration efficiency of the plant-bed/ditch systems. Comprehensively considering water treatment effects, construction difficulty, and construction and maintenance cost, the recommended optimal ways are as follows. Plant straws were preferably paved under subsurface zones by two layers with a gap of 20-30 cm. The preferable plant combination was reed (Phragmites australis) plus wild rice (Zizania caduciflora). Calcite might be applied as alternative reinforced media in some suitable sites of plant-bed/ditch systems. Water treatment effects were compared between pilot project and the whole wetland area of SJY-CW. The results showed that the reinforced pilot project exhibited higher treatment efficiency for nutrients than SJY-CW itself. The removal rates of total nitrogen, total phosphorus, and ammonia nitrogen were increased by about 20% - 40% in the pilot project. This suggested that SJY-CW could release its vast water treatment potential by means of increasing water flux through the subsurface root channel zones of plant beds. Therefore, some adjustment and control measures could be

  2. Sewage and industrial waste treatment: wetlands. January 1977-July 1988 (Citations from the Selected Water Resources Abstracts data base). Report for January 1977-July 1988

    SciTech Connect

    Not Available

    1988-08-01

    This bibliography contains citations concerning developments, operations, and evaluations of natural and artificial wetlands treatment of waste water and sludge. Aquaculture treatments of industrial, municipal, and domestic waste water are examined. Topics include nutrient removal, heavy-metal recovery, and case studies of wetlands being used for wastewater treatment. (Contains 93 citations fully indexed and including a title list.)

  3. TH-A-19A-01: An Open Source Software for Proton Treatment Planning in Heterogeneous Medium

    SciTech Connect

    Desplanques, M; Baroni, G; Wang, K; Phillips, J; Gueorguiev, G; Sharp, G

    2014-06-15

    Purpose: Due to its success in Radiation Oncology during the last decade, interest in proton therapy is on the rise. Unfortunately, despite the global enthusiasm in the field, there is presently no free, multiplatform and customizable Treatment Planning System (TPS) providing proton dose distributions in heterogenous medium. This restricts substantially the progress of clinical research for groups without access to a commercial Proton TPS. The latest implementation of our pencil beam dose calculation algorithm for proton beams within the 3D Slicer open-source environment fulfills all the conditions described above. Methods: The core dose calculation algorithm is based on the Hong algorithm (1), which was upgraded with the Kanematsu theory describing the evolution of the lateral scattering of proton beamlets in heterogeneous medium. This algorithm deals with both mono-energetic beams and Spread Out Bragg Peak (SOBP). In order to be user-friendly, we provide a graphical user interface implemented with the Qt libraries, and visualization with the 3D Slicer medical image analysis software. Two different pencil beam algorithms were developed, and the clinical proton beam line at our facility was modeled. Results: The dose distributions provided by our algorithms were compared to dose distributions coming from both commercialized XiO TPS and literature (dose measurements, GEANT4 and MCNPx) and turned out to be in a good agreement, with maximum dose discrepancies of 5% in homogeneous phantoms and 10% in heterogeneous phantoms. The algorithm of SOBP creation from an optimized weigthing of mono-energetic beams results in flat SOBP. Conclusion: We hope that our efforts in implementing this new, open-source proton TPS will help the research groups to have a free access to a useful, reliable proton dose calculation software.(1) L. Hong et al., A pencil beam algorithm for proton dose calculations, Phys. Med. Biol. 41 (1996) 1305–1330. This project is paid for by NCI

  4. Potential use of mangroves as constructed wetland for municipal sewage treatment in Futian, Shenzhen, China.

    PubMed

    Yang, Q; Tam, N F Y; Wong, Y S; Luan, T G; Su, W S; Lan, C Y; Shin, P K S; Cheung, S G

    2008-01-01

    A pilot-scale mangrove wetland was constructed in Futian, Shenzhen for municipal sewage treatment. Three identical belts (length: 33m, width: 3m, depth: 0.5m) were filled with stone (bottom), gravel and mangrove sand (surface). Seedlings of two native mangrove species (Kandelia candel, Aegiceras corniculatum) and one exotic species (Sonneratia caseolaris) were transplanted to the belts with one species for each belt. The hydraulic loading was 5m(3)d(-1) and hydraulic retention time 3d. High levels of removal of COD, BOD(5), TN, TP and NH(3)-N were obtained. The treatment efficiency of S. caseolaris and A. corniculatum was higher than that of K. candel. Faster plant growth was obtained for S. caseolaris. The substrate in the S. caseolaris belt also showed higher enzyme activities including dehydrogenase, cellulase, phosphatase, urease and beta-glucosidase. The removal rates of organic matter and nutrients were positively correlated with plant growth. The results indicated that mangroves could be used in a constructed wetland for municipal sewage treatment, providing post-treatment to remove coliforms was also included.

  5. Strategies and techniques to enhance constructed wetland performance for sustainable wastewater treatment.

    PubMed

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

    2015-10-01

    Constructed wetlands (CWs) have been used as an alternative to conventional technologies for wastewater treatment for more than five decades. Recently, the use of various modified CWs to improve treatment performance has also been reported in the literature. However, the available knowledge on various CW technologies considering the intensified and reliable removal of pollutants is still limited. Hence, this paper aims to provide an overview of the current development of CW strategies and techniques for enhanced wastewater treatment. Basic information on configurations and characteristics of different innovations was summarized. Then, overall treatment performance of those systems and their shortcomings were further discussed. Lastly, future perspectives were also identified for specialists to design more effective and sustainable CWs. This information is used to inspire some novel intensifying methodologies, and benefit the successful applications of potential CW technologies.

  6. 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.

  7. Development of a constructed wetland water treatment system for selenium removal: incorporation of an algal treatment component.

    PubMed

    Huang, Jung-Chen; Suárez, María C; Yang, Soo In; Lin, Zhi-Qing; Terry, Norman

    2013-09-17

    On the basis of the fact that algae have the ability to volatilize substantial quantities of selenium (Se), we investigated the concept of including an algal pretreatment unit into a constructed wetland system for the removal of Se from river water entering the Salton Sea. Of six different algal strains tested, the most effective in terms of Se volatilization and Se removal from the water column was a Chlorella vulgaris strain (designated Cv). Cv removed 96% of Se (supplied as selenate) from the microcosm water column within 72 h, with up to 61% being removed by volatilization to the atmosphere. X-ray absorption spectroscopy revealed that the major forms of Se likely to be accumulated in an algal-wetland system are selenomethionine, a precursor of volatile Se formation, and elemental Se. Our results suggest that the inclusion of an algal pretreatment unit within a constructed wetland water treatment system should not only enhance the efficiency of Se removal but also significantly reduce the risk of the buildup of ecotoxic forms of Se by promoting the biological volatilization of Se.

  8. Palm tree mulch as substrate for primary treatment wetlands processing high strength urban wastewater.

    PubMed

    Herrera-Melián, J A; González-Bordón, A; Martín-González, M A; García-Jiménez, P; Carrasco, M; Araña, J

    2014-06-15

    The life span of subsurface flow treatment wetlands is determined by the clogging of the substrate. Thus, the influent should undergo primary treatment to reduce loadings of suspended solids and dissolved organic matter. An-organic based substrate should be less prone to clogging because of its remarkably higher porosity and plasticity. Mulch obtained from branches of the Canarian palm tree (Phoenix canariensis) has been tested as substrate for mixed flow, intermittently fed treatment wetland mesocosms processing high strength urban wastewater. The effect of the presence of plants (Phragmites and Cyperus), influent pressure and hydraulic loading rate was studied. The best removals (SS: 89%, COD: 77%, turbidity: 82%) have been obtained with planted reactors treating highly concentrated influents at the lower hydraulic loading rates tested. The palm tree mulch units achieved similar removals of SS, COD and turbidity to one having gravel as substrate and planted with common reed. Mulch obtained from stems of giant reed (Arundo donax) provided similar removals of SS and turbidity but that of COD was lower. The combination of organic-based TWs with gravel-based ones provided high removals (SS: 95%, COD: 78%, turbidity: 95%) while the risk of clogging was strongly reduced. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Treatment of laboratory wastewater in a tropical constructed wetland comparing surface and subsurface flow.

    PubMed

    Meutia, A A

    2001-01-01

    Wastewater treatment by constructed wetland is an appropriate technology for tropical developing countries like Indonesia because it is inexpensive, easily maintained, and has environmentally friendly and sustainable characteristics. The aim of the research is to examine the capability of constructed wetlands for treating laboratory wastewater at our Center, to investigate the suitable flow for treatment, namely vertical subsurface or horizontal surface flow, and to study the effect of the seasons. The constructed wetland is composed of three chambered unplanted sedimentation tanks followed by the first and second beds, containing gravel and sand, planted with Typha sp.; the third bed planted with floating plant Lemna sp.; and a clarifier with two chambers. The results showed that the subsurface flow in the dry season removed 95% organic carbon (COD) and total phosphorus (T-P) respectively, and 82% total nitrogen (T-N). In the transition period from the dry season to the rainy season, COD removal efficiency decreased to 73%, T-N increased to 89%, and T-P was almost the same as that in the dry season. In the rainy season COD and T-N removal efficiencies increased again to 95% respectively, while T-P remained unchanged. In the dry season, COD and T-P concentrations in the surface flow showed that the removal efficiencies were a bit lower than those in the subsurface flow. Moreover, T-N removal efficiency was only half as much as that in the subsurface flow. However, in the transition period, COD removal efficiency decreased to 29%, while T-N increased to 74% and T-P was still constant, around 93%. In the rainy season, COD and T-N removal efficiencies increased again to almost 95%. On the other hand, T-P decreased to 76%. The results show that the constructed wetland is capable of treating the laboratory wastewater. The subsurface flow is more suitable for treatment than the surface flow, and the seasonal changes have effects on the removal efficiency.

  10. An application of baseflow isolation and passive wetland treatment to watershed restoration

    SciTech Connect

    Hoover, K.L.; Rightnour, T.A.; Zug, F.R. III

    1999-07-01

    The project site, located in West Virginia, is a reclaimed wood waste disposal area situated on Pennsylvanian coal strata. Following reclamation of the disposal area, flow in the adjacent stream was observed to have elevated iron and manganese concentrations. The source of the groundwater baseflow entering this portion of the stream appeared to be hydrologically related to the landfill by its close proximity. The source of the metals contamination was not determined, but may be related to percolation from the disposal area into the underlying coal strata. The observable contamination was typical of alkaline coal mine drainage and met the criteria for passive wetland treatment. However, the contaminated baseflow entered the stream along the sides and bottom of the channel at several locations over a 100-meter section and could not be collected for accurate characterization of pollutant loading. Treatment of the entire contaminated stream flow to comply with NPDES permit requirements would have been prohibitively expensive, and insufficient space was available for a treatment facility of adequate size within the narrow stream valley. Given these constraints, it was decided to isolate the contaminated baseflow from the surface flow by construction of a lined stream relocation on top of a gravity-drained collection zone in the existing stream channel. The collection zone consists of a bed of coarse aggregate with a central collection pipe discharging to a submerged outlet, which prevents air from entering the collection zone and minimizes the formation of iron precipitates. The relocated stream channel was formed in place on top of the collection zone with compacted earth, and lined with one layer of polypropylene geomembrane covered by two layers of geotextile. Gabion baskets were then placed on top of the liner for stream stabilization and shaping of the final channel. Accurate discharge characterization at the end of the collection pipe allowed the design of a

  11. Constructed wetlands for municipal solid waste landfill leachate treatment. Final report

    SciTech Connect

    Peverly, J.; Sanford, W.E.; Steenhuis, T.S.

    1993-11-01

    In 1989, the US Geological Survey and Cornell University, in cooperation with the New York State Energy Research and Development Authority and the Tompkins County Solid Waste Department, began a three-year study at a municipal solid-waste landfill near Ithaca, New York, to test the effectiveness of leachate treatment with constructed wetlands and to examine the associated treatment processes. Specific objectives of the study were to examine: treatment efficiency as function of substrate composition and grain size, degree of plant growth, and seasonal changes in evapotranspiration rates and microbial activity; effects of leachate and plant growth on the hydraulic characteristics of the substrate; and chemical, biological, and physical processes by which nutrients, metals, and organic compounds are removed from leachate as it flows through the substrate. A parallel study at a municipal solid-waste landfill near Fenton, New York was conducted by researchers at Cornell University, Ithaca College, and Hawk Engineering (Trautmann and others, 1989). Results are described.

  12. Treatment of domestic wastewater by vertical flow constructed wetland planted with umbrella sedge and Vetiver grass.

    PubMed

    Kantawanichkul, Suwasa; Sattayapanich, Somsiri; van Dien, Frank

    2013-01-01

    The aim of this study was to investigate the efficiency of wastewater treatment by vertical flow constructed wetland systems under different hydraulic loading rates (HLR). The comparison of two types of plants, Cyperus alternifolius (Umbrella sedge) and Vetiveria zizanioides (Vetiver grass), was also conducted. In this study, six circular concrete tanks (diameter 0.8 m) were filled with fine sand and gravel to the depth of 1.23 m. Three tanks were planted with Umbrella sedge and the other three tanks were planted with Vetiver grass. Settled domestic wastewater from Chiang Mai University (chemical oxygen demand (COD), NH4(+)-N and suspended solids (SS) of 127.1, 27.4 and 29.5 mg/L on average, respectively) was intermittently applied for 45 min and rested for 3 h 15 min. The HLR of each tank was controlled at 20, 29 and 40 cm/d. It was found that the removal efficiency of the Umbrella sedge systems was higher than the Vetiver grass systems for every parameter, and the lowest HLR provided the maximum treatment efficiency. The removal efficiency of COD and nitrogen in terms of total Kjeldahl nitrogen (TKN) was 76 and 65% at 20 cm/d HLR for Umbrella sedge compared to only 67 and 56% for Vetiver grass. Nitrogen accumulation in plant biomass was also higher in Umbrella sedge than in Vetiver grass in every HLR. Umbrella sedge was thus proved to be a suitable constructed wetland plant in tropical climates.

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

    PubMed

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

    2016-11-01

    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.

  14. Treatment performances of French constructed wetlands: results from a database collected over the last 30 years.

    PubMed

    Morvannou, A; Forquet, N; Michel, S; Troesch, S; Molle, P

    2015-01-01

    Approximately 3,500 constructed wetlands (CWs) provide raw wastewater treatment in France for small communities (<5,000 people equivalent). Built during the past 30 years, most consist of two vertical flow constructed wetlands (VFCWs) in series (stages). Many configurations exist, with systems associated with horizontal flow filters or waste stabilization ponds, vertical flow with recirculation, partially saturated systems, etc. A database analyzed 10 years earlier on the classical French system summarized the global performances data. This paper provides a similar analysis of performance data from 415 full-scale two-stage VFCWs from an improved database expanded by monitoring data available from Irstea and the French technical department. Trends presented in the first study are confirmed, exhibiting high chemical oxygen demand (COD), total suspended solids (TSS) and total Kjeldahl nitrogen (TKN) removal rates (87%, 93% and 84%, respectively). Typical concentrations at the second-stage outlet are 74 mgCOD L(-1), 17 mgTSS L(-1) and 11 mgTKN L(-1). Pollutant removal performances are summarized in relation to the loads applied at the first treatment stage. While COD and TSS removal rates remain stable over the range of applied loads, the spreading of TKN removal rates increases as applied loads increase.

  15. Treatment of swine wastewater in marsh-pond-marsh constructed wetlands.

    PubMed

    Reddy, G B; Hunt, P G; Phillips, R; Stone, K; Grubbs, A

    2001-01-01

    Swine waste is commonly treated in the USA by flushing into an anaerobic lagoon and subsequently applying to land. This natural system type of application has been part of agricultural practice for many years. However, it is currently under scrutiny by regulators. An alternate natural system technology to treat swine wastewater may be constructed wetland. For this study we used four wetland cells (11 m width x 40 m length) with a marsh-pond-marsh design. The marsh sections were planted to cattail (Typha latifolia, L.) and bulrushes (Scirpus americanus). Two cells were loaded with 16 kg N ha(-1) day(-1) with a detention of 21 days. They removed 51% of the added N. Two additional cells were loaded with 32 kg ha(-1) day(-1) with 10.5 days detention. These cells removed only 37% of the added N. However, treatment operations included cold months in which treatment was much less efficient. Removal of N was moderately correlated with the temperature. During the warmer periods removal efficiencies were more consistent with the high removal rates reported for continuous marsh systems--often > than 70%. Phosphorus removal ranged from 30 to 45%. Aquatic macrophytes (plants and floating) assimilated about 320 and 35 kg ha(-1), respectively of N and P.

  16. 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 mgO2.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.

  17. Treatment of landfill leachate-impacted groundwater using cascade aeration and constructed wetlands

    SciTech Connect

    Loer, J.; O`Flanagan, B.; Fellows, W.

    1995-12-31

    At an unlined municipal solid waste landfill, heavy metal and toxic organic compounds present in leachate have impacted groundwater, necessitating extraction and treatment of the contaminated groundwater. A remedial design relying on a natural systems engineering approach will take advantage of existing contours (gravity flow) and surroundings (wetlands), and will limit energy inputs and eliminate chemical inputs. Impacted groundwater will be extracted, and aerated via a cascade constructed of polypropylene sheets fabricated into {open_quotes}step{close_quotes} sections and set into a side slope of the landfill. Volatilization of organics and oxidation of iron and heavy metals to insoluble compounds will occur during cascading and will continue within a sedimentation basin where settling of iron precipitates will induce co-settling of heavy metal precipitates. Following the sedimentation basin, a constructed wetland containing both aerobic zones and anaerobic zones will provide additional treatment of remaining solids and heavy metals, before surface discharge. Use of a natural systems approach significantly reduces operating costs compared to a mechanical-aeration, chemical-precipitation system, and is more aesthetically pleasing and suited to the remote locale. The system is under construction and seasonal operation will begin in spring 1996.

  18. 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.

  19. Comparison of operational design criteria for subsurface flow constructed wetlands for wastewater treatment.

    PubMed

    Leonard, K M; Swanson, G W

    2001-01-01

    Many communities are investigating the use of constructed wetlands as a simple, viable alternative to poorly operating on-site wastewater treatment. Currently, the most popular design models in the U.S.A. for subsurface flow units are the US Environmental Protection Agency (EPA) and the Tennessee Valley Authority (TVA) methods. However, there has been limited data verifying if the operating performance is up to design standards. In order to address this problem, this paper documents the performance of such treatment systems over a broad range of conditions in North Alabama. The operational data is used to determine a best-fit value of reaction rate constant and proposes improved input parameters for both design models. According to this data, the average plug-flow reaction rate constant was calculated to be 0.70 d-1 for the EPA method, while the recommended organic loading criterion is 11.4 m2/kg BOD5 per day into the wetland for the TVA method.

  20. 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.

  1. Wetland treatment of oil and gas well wastewaters. Quarterly technical report, May 25, 1992---August 24, 1992

    SciTech Connect

    Kadlec, R.H.; Srinivasan, K.R.

    1995-11-01

    The purpose of this study is to extend the knowledge base for wetland treatment to include processes and substances of particular importance to small, on-site systems receiving oil and gas well waste water. Collection of data on the sorption of heavy metals and the degradation of toxic organics is one of the key tasks. The toxic organics phenolics and anthracene, and chromium and copper have been selected as target adsorbates. An information search was performed on oil refinery waste treatment wetland systems.

  2. 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

  3. Energy and water balance response of a vegetated wetland to herbicide treatment of invasive Phragmites australis

    NASA Astrophysics Data System (ADS)

    Mykleby, Phillip M.; Lenters, John D.; Cutrell, Gregory J.; Herrman, Kyle S.; Istanbulluoglu, Erkan; Scott, Durelle T.; Twine, Tracy E.; Kucharik, Christopher J.; Awada, Tala; Soylu, Mehmet E.; Dong, Bo

    2016-08-01

    The energy and water balance of a Phragmites australis dominated wetland in south central Nebraska was analyzed to assess consumptive water use and the potential for ;water savings; as a result of vegetation eradication via herbicide treatment. Energy balance measurements were made at the field site for two growing seasons (treated and untreated), including observations of net radiation, heat storage, and sensible heat flux, which was measured using a large-aperture scintillometer. Latent heat flux was calculated as a residual of the energy balance, and comparisons were made between the two growing seasons and with model simulations to examine the relative impacts of vegetation removal and climate variability. Observed ET rates dropped by roughly 32% between the two growing seasons, from a mean of 4.4 ± 0.7 mm day-1 in 2009 (with live vegetation) to 3.0 ± 0.8 mm day-1 in 2010 (with dead P. australis). These results are corroborated by the Agro-IBIS model simulations, and the reduction in ET implies a total ;water savings; of 245 mm over the course of the growing season. The significant decreases in ET were accompanied by a more-than-doubling of sensible heat flux, as well as a ∼60% increase in heat storage due to decreased LAI. Removal of P. australis was also found to cause measurable changes in the local micrometeorology at the wetland. Consistent with the observed increase in sensible heat flux during 2010, warmer, drier, windier conditions were observed in the dead, P. australis section of the wetland, compared to an undisturbed section of live, native vegetation. Modeling results suggest that the elimination of transpiration in 2010 was partially offset by an increase in surface evaporation, thereby reducing the subsequent water savings by roughly 60%. Thus, the impact of vegetation removal depends on the local climate, depth to groundwater, and management decisions related to regrowth of vegetation.

  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. 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 TiO2 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 NO3(-). 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.

  6. Effects of hydraulic resistance by vegetation on stage dynamics of a stormwater treatment wetland

    NASA Astrophysics Data System (ADS)

    Paudel, Rajendra; Grace, Kevin A.; Galloway, Stacey; Zamorano, Manuel; Jawitz, James W.

    2013-03-01

    SummaryThis work examined the potential effects of large-scale thinning of emergent vegetation on the stage dynamics in a very large (33.3 km2) constructed treatment wetland in South Florida. Dense vegetative biomass in treatment wetlands may restrict water flow and increase water levels, which may in turn have adverse effects on vegetative community structure. Here, we developed a physically-based, spatially-distributed hydrodynamic model of Stormwater Treatment Area 2, Cell 2 (STA2C2) to investigate the spatio-temporal variability of water level (stage) in response to management for thinning of emergent macrophytes (e.g., burning and/or herbicide treatments). The model was calibrated against stage measured at six monitoring stations for 1 year, and subsequently validated against 2 years of stage data from eight stations. Finally, the validated model was extended to simulate various vegetation management scenarios. The model provided an excellent fit to observed stage data in both calibration and validation periods (median model efficiency indices of 0.82 and 0.83, respectively). Higher stages in the treatment cell were dominantly associated with peak inflow magnitude and the timing of event intervals. Prolonged periods of sustained deep water conditions were observed when one flow peak was followed by consecutive peaks. A gradual stage gradient from the inlet to outlet was observed during peak flow periods, with a shift to a sharp gradient at approximately two-thirds distance from the inlet. Stages in the wetland were found to be controlled less by the hydraulic resistance, as indicated by a low sensitivity of simulated water levels for a ±50% perturbation in flow resistance parameter. Water depths were reduced by a maximum of 12 cm at the inlet region by thoroughly thinning the remaining emergent vegetation in STA2C2. Similarly, a maximum of only 2% of the total STA2C2 area was prevented from exceeding a water depth believed to be detrimental to Typha sp. (1

  7. 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.

  8. Treatment performance of a constructed wetland during storm and non-storm events in Korea.

    PubMed

    Maniquiz, M C; Lee, S Y; Choi, J Y; Jeong, S M; Kim, L H

    2012-01-01

    The efficiency of a free water surface flow constructed wetland (CW) in treating agricultural discharges from stream was investigated during storm and non-storm events between April and December, 2009. Physico-chemical and water quality constituents were monitored at five sampling locations along the flow path of the CW. The greatest reduction in pollutant concentration was observed after passing the sedimentation zone at approximately 4% fractional distance from the inflow. The inflow hydraulic loading, flow rates and pollutant concentrations were significantly higher and variable during storm events than non-storm (baseflow) condition (p <0.001) that resulted to an increase in the average pollutant removal efficiencies by 10 to 35%. The highest removal percentages were attained for phosphate (51 ± 22%), ammonium (44 ± 21%) and phosphorus (38 ± 19%) while nitrate was least effectively retained by the system with only 25 ± 17% removal during non-storm events. The efficiency of the system was most favorable when the temperature was above 15 °C (i.e., almost year-round except the winter months) and during storm events. Overall, the outflow water quality was better than the inflow water quality signifying the potential of the constructed wetland as a treatment system and capability of improving the stream water quality.

  9. 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.

  10. Halophytes as vertical-flow constructed wetland vegetation for domestic wastewater treatment.

    PubMed

    Fountoulakis, M S; Sabathianakis, G; Kritsotakis, I; Kabourakis, E M; Manios, T

    2017-04-01

    Recent findings show that halophytes have the ability to accumulate salts in their tissues, making them a very interesting group of plants for domestic wastewater treatment in constructed wetlands (CWs). In that case, it might be possible to reduce the salinity of the final effluent, which is a crucial parameter for wastewater reuse in agriculture. During this study three halophytes, Atriplex halimus, Juncus acutus and Sarcocornia perennis, were tested for phyto-desalination of domestic wastewater in a vertical flow constructed wetland (VFCW) and compared with common reeds (Phragmites australis). In addition, the effect of this alternative vegetation on the overall performance of the system regarding organic matter, nutrients, boron and pathogen removal was monitored. The organic loading rate (OLR) was about 21gCOD/m(2)/d and the hydraulic loading rate (HLR) was 95mm/d in both cases. Promising results were obtained for A. halimus, which shows high biomass productivity and significant capability to accumulate salts, mainly Na, in its tissues. A positive effect on pathogen removal efficiency was also recorded. However, nitrogen concentration in the effluent of the VFCW planted with halophytes was found to be higher than in the effluent of the VFCW planted with reeds. Finally, no significant effect on organic matter and phosphorus removal efficiency was observed from the use of halophytes in place of reeds.

  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. Advantages of using subsurface flow constructed wetlands for wastewater treatment in space applications: Ground-based mars base prototype

    NASA Astrophysics Data System (ADS)

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

    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 ™" 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.

  14. 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.

  15. 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

  16. Treatment of Chlorinated Aliphatic Contamination of Groundwater by Horizontal Recirculation Wells and by Constructed Vertical Flow Wetlands

    DTIC Science & Technology

    2002-03-01

    term remediation at hundreds of sites across the Air Force. Complementary modeling and column studies examined the potential for controlling and...the treatment phase after pumping. Complementary modeling and column studies examined the potential for controlling and treating groundwater...possible by the highly chemically reducing environment created in the organic-rich wetland sediment. This dynamic and productive region

  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

    2017-09-05

    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. 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.

  19. Constructed treatment wetland: a study of eight plant species under saline conditions.

    PubMed

    Klomjek, Pantip; Nitisoravut, Suwanchai

    2005-02-01

    A series of investigations was conducted to evaluate the feasibility of using constructed treatment wetlands to remove pollutants from saline wastewater. Eight emergent plants; cattail, sedge, water grass, Asia crabgrass, salt meadow cordgrass, kallar grass, vetiver grass and Amazon, were planted in experimental plots and fed with municipal wastewater that was spiked with sodium chloride (NaCl) to simulate a saline concentration of approximately 14-16 mScm-1. All macrophytes were found tolerant under the tested conditions except Amazon and vetiver grass. Nutrient assimilation of salt tolerant species was in the range of 0.006-0.061 and 0.0002-0.0024 gm-2d-1 for nitrogen and phosphorus, respectively. Treatment performances of planted units were found to be 72.4-78.9% for BOD5, 43.2-56.0% for SS, 67.4-76.5% for NH3-N and 28.9-44.9% for TP. The most satisfactory plant growth and nitrogen assimilation were found for cattail (Typha angustifolia) though the plant growth was limited, whereas Asia crabgrass (Digitaria bicornis) was superior for BOD5 removal. Both were evaluated again in a continuous flow constructed wetland system receiving saline feed processing wastewater. A high removal rate regularly occurred in long-term operating conditions. The reduction in BOD5, SS, NH3-N and TP was in the range of 44.4-67.9%, 41.4-70.4%, 18.0-65.3% and 12.2-40.5%, respectively. Asia crabgrass often provided higher removal especially for BOD5 and SS removal. Nutrient enriched wastewater promoted flourishing growth of algae and plankton in the surface flow system, which tended to reduce treatment performance.

  20. Wetland treatment (HSSP) of wastewater from a milk-processing unit using Bambusa vulgaris, Typha latifolia and Cyperus rotundus.

    PubMed

    Tandon, Shalini; Inarkar, Mangesh; Kumar, Rakesh

    2010-01-01

    Studies were conducted in soil-less horizontal sub-surface flow wetland (HSSF) embedded with graded gravels using Golden bamboo, Bambusa vulgaris (a non-wetland species), Typha latifolia and Cyperus rotundus (wetland species) for the treatment of wastewater from a milk processing unit. The wastewater was treated with a dilution ratio of 3:1. Removal efficiencies of BOD and COD were studied at one, two and three days hydraulic retention time (HRT). At one day HRT, the removal efficiency (%) of these parameters was lower in comparison to when the wastewater was subjected to two and three days HRT. The increase in removal efficiency with increase in HRT was marginal when it was increased from 2 days to 3 days. The percentage removal of COD and BOD at two days retention time followed the order: Golden bamboo (93, 88) > Cyperus rotundus (91, 90) > Typha latifolia (85, 87).

  1. Cold climate phosphorus uptake by submerged aquatic plants in a sewage treatment free water surface wetland.

    PubMed

    Ulén, Barbro; Tonderski, Karin S

    2005-01-01

    In November 2002, biomass phosphorus (P) of submerged aquatic plants with associated epiphyton was measured using P-32 tracer addition in a treatment wetland receiving tertiary treated municipal sewage. The wetland is situated 120 km west of Stockholm, Sweden receiving tertiary treated municipal sewage. During the experiment, inflow water had a total P concentration of 0.3 and an iron concentration of 0.7 mg 1(-1) with a residence time of 3-3.5 days. Samples of submerged plants mainly slender waterweed (Elodea nuttallii, L.) and sago pondweed (Potamogeton pectinatus, L.) were taken in two shallow areas (0.21 and 0.51 ha respectively) adjacent to the inlet of one of the wetland subbasins. The sampled area represented 27% of the total 2.6 ha area of the basin. The young phytomass contained 0.02 kg P and the older vegetation parts and epiphyton 0.04 kg P. The sampling took place 90-96 hours after exposure of a pulse of P-32 (18 GBq), i.e. when 75% had passed. Total phytomass was low, only 2 g m(-2) as dry weight. The young phytomass close to the site of injection had higher average beta activity in disintegrations per minute and milligram dry weight (140 DPM mg dw(-1)) than the older parts of the submerged plants (70 DPM mg dw(-1)) indicating an active plant uptake in the former. The latter was interpreted as epiphyton uptake, but since the biomass of old shoots was higher than of young, more P-32 was removed by processes associated with epiphyton as was removed by the young phytomass. In two shallow central zones, the former was equal to 0.006 per thousand of exposed radioactivity in water, while 0.003 per thousand was found in the young phytomass in the same zones of the basin. Close to the inlet a fast P assimilation by the plant biomass was demonstrated. The role of submerged aquatic plants in phosphorus turnover in sewage treatment basins under winter conditions is discussed.

  2. 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

  3. Microcosm wetlands for wastewater treatment with different hydraulic loading rates and macrophytes.

    PubMed

    Jing, Shuh-Ren; Lin, Ying-Feng; Wang, Tze-Wen; Lee, Der-Yuan

    2002-01-01

    Constructed wetlands (CW) usually require large land areas for treating wastewater. This study evaluated the feasibility of applying CW with less land requirement by operating a group of microcosm wetlands at a hydraulic retention time (HRT) of less than 4 d in southern Taiwan. An artificial wastewater, simulating municipal wastewater containing 200 mg L(-1) of chemical oxygen demand (COD), 20 mg L(-1) of NH4+-N (AN), and 20 mg L(-1) of PO4(3-)-P (OP), was the inflow source. Three emergent plants [reed, Phragmites australis (Cav.) Trin. ex Steud.; water primrose, Ludwigia octovalvis (Jacq.) P.H. Raven; and dayflower, Commelina communis L.] and two floating plants [water spinach, Ipomoea aquatica Forssk.; and water lettuce, Pistia stratiotes L.] plants were tested. The planted systems showed more nutrient removal than unplanted systems; however, the type of macrophytes in CW did not make a major difference in treatment. At the HRTs of 2 to 4 d, the planted system maintained greater than 72,80, and 46% removal for COD, AN, and OP, respectively. For AN and OP removal, the highest efficiencies occurred at the HRT of 3 d, whereas maximum removal rates for AN and OP occurred at the HRT of 2 d. Both removal rates and efficiencies were reduced drastically at the HRT of 1 d. Removals of COD, OP, and AN followed first-order reactions within the HRTs of 1 to 4 d. The efficient removals of these constituents obtained with HRT between 2 and 4 d indicated the possibility of using a CW system for wastewater treatment with less land requirement.

  4. Methodologies for pre-validation of biofilters and wetlands for stormwater treatment.

    PubMed

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

    2015-01-01

    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. 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. 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. 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. 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.

  5. 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 (NH3-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); NH3-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.

  6. 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.

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

    PubMed

    Bakhshoodeh, Reza; Alavi, Nadali; Paydary, Pooya

    2017-09-02

    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 BOD5 (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.

  8. 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.

  9. 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

  10. Phototransformation of wastewater-derived trace organic contaminants in open-water unit process treatment wetlands.

    PubMed

    Jasper, Justin T; Sedlak, David L

    2013-10-01

    Open-water cells in unit process treatment wetlands can be used to exploit sunlight photolysis to remove trace organic contaminants from municipal wastewater effluent. To assess the performance of these novel systems, a photochemical model was calibrated using measured photolysis rates for atenolol, carbamazepine, propranolol, and sulfamethoxazole in wetland water under representative conditions. Contaminant transformation by hydroxyl radical ((•)OH) and carbonate radical ((•)CO3(-)) were predicted from steady-state radical concentrations measured at pH values between 8 and 10. Direct photolysis rates and the effects of light screening by dissolved organic matter on photolysis rates were estimated using solar irradiance data, contaminant quantum yields, and light screening factors. The model was applied to predict the land area required for 90% removal of a suite of wastewater-derived organic contaminants by sunlight-induced reactions under a variety of conditions. Results suggest that during summer, open-water cells that receive a million gallons of water per day (i.e., about 4.4 × 10(-2) m(3) s(-1)) of nitrified wastewater effluent can achieve 90% removal of most compounds in an area of about 15 ha. Transformation rates were strongly affected by pH, with some compounds exhibiting faster transformation rates under the high pH conditions associated with photosynthetic algae at the sediment-water interface and other contaminants exhibiting faster transformation rates at the circumneutral pH values characteristic of algae-free cells. Lower dissolved organic carbon concentrations typically resulted in increased transformation rates.

  11. Sewage and industrial waste treatment: Wetlands. January 1977-December 1989 (Citations from the Selected Water Resources Abstracts data base). Report for January 1977-December 1989

    SciTech Connect

    Not Available

    1989-12-01

    This bibliography contains citations concerning developments, operations, and evaluations of natural and artificial wetlands treatment of waste water and sludge. Aquaculture treatments of industrial, municipal, and domestic waste water are examined. Topics include nutrient removal, heavy-metal recovery, and case studies of wetlands being used for waste water treatment. (This updated bibliography contains 135 citations, 23 of which are new entries to the previous edition.)

  12. 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.

  13. Effect of season, substrate composition, and plant growth on landfill leachate treatment in a constructed wetland

    SciTech Connect

    Surface, J.M.; Peverly, J.H.; Steenhuis, T.S.; Sanford, W.E.

    1991-12-31

    In 1989 the US, Geological Survey (USGS), in cooperation with Tompkins County, New York Departments of Planning and Solid Waste, began a 3-year study at a municipal solid-waste landfill near Ithaca, N.Y., to test the efficiency of leachate treatment by constructed wetlands and to examine the associated treatment processes. Specific objectives of the study were to examine: (1) Treatment efficiency as function of substrate composition and grain size, degree of plant growth, and seasonal changes in evapotranspiration rates and microbial activity; (2) effects of leachate and plant growth on the hydraulic characteristics of the substrate; and (3) chemical, biological, and physical processes by which nutrients, metals, and organic compounds are removed from leachate as it flows through the substrate. This report addresses the first two of these objectives and briefly discusses the third. It (1) describes the substrate plots, leachate-distribution system, sampling methods, and analytical procedures; and (2) presents results in terms of (a) percent removal rates of selected constituents between inflow- and outflow-sampling points, (b) seasonal effects on constituent-removal rates, and (c) effect of substrate composition on constituent removal and plant growth.

  14. 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.

  15. Constructed wetlands with light expanded clay aggregates for agricultural wastewater treatment.

    PubMed

    Dordio, A; Carvalho, A J P

    2013-10-01

    Constructed wetlands (CWs) are receiving a renewed attention as a viable phytotechnology for treating agricultural wastewaters and for the removal of more specific pollutants, in particular recalcitrant ones. In this work, the performance of CW mesocosms using light expanded clay aggregates (LECA) as the bed's substrate and planted with Phragmites australis was investigated for treatment of olive mill wastewater (OMW), swine wastewater (SW) contaminated with oxytetracycline and water contaminated with herbicide MCPA (2-methyl-4-chlorophenoxyacetic acid). Both wastewaters (OMW and SW) initially presented high organic matter content and total suspended solids which were removed by the system with efficiencies higher than 80%. Removal of polyphenols in OMW and nitrogen compounds in SW also showed similar or higher efficiencies in comparison with other treatment systems reported in the literature. The antibiotic oxytetracycline was completely removed from SW within the assay period in unplanted LECA beds, but planted beds allowed a significantly faster removal. In regard to water contaminated with MCPA, the results showed that LECA has a large sorption capacity for this herbicide (removal efficiencies of 56-97%). In general, considerably higher pollutant removal efficiencies were obtained when plants were used (up to 28% higher). The results obtained are indicative that CWs with LECA as substrate may be an adequate option for agricultural wastewater treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. 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.

  17. 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.

  18. Environmental factors influencing survival of threespine stickleback (Gasterosteus aculeatus) in a multipurpose constructed treatment wetland in southern California.

    PubMed

    Walton, William E; Wirth, Margaret C; Workman, Parker D

    2007-06-01

    Survival of the threespine stickleback, Gasterosteus aculeatus, differed among marshes in a demonstration 9.9-ha multipurpose constructed treatment wetland designed to improve the quality of secondary-treated municipal wastewater in southern California. At a mean loading rate of 3.3 kg NH4-N ha(-1) d(-1) (6 kg total N ha(-1) d(-1)), the suitability of the wetland to support a population of sticklebacks was estimated to be low. The development of potentially toxic levels of un-ionized ammonia, particularly during periods when pH increased concomitantly with oxygen generation by phytoplankton biomass > 300 mg chlorophyll a liter(-1), and disinfection by-products were associated with lowered survivorship of sentinel fish. Moreover, the high oxygen demand from nitrification of NH4-N created daily periods of low dissolved oxygen concentration (6-16 h at < 2 mg liter(-1)) in the open water areas of the shallow marshes. Low dissolved oxygen concentration in open water zones of the seven marshes during a part of each day and persistent anaerobic conditions in the emergent vegetation rendered the majority of the wetland's substrate surface unavailable for successful reproduction by sticklebacks. The potential sites for Gasterosteus to replace mosquitofish, Gambusia affinis and G. holbrooki, as a biological control agent against mosquitoes are probably limited to comparatively cool-water habitats with high water quality, such as riverine wetlands.

  19. Bayesian Analysis Of Stormwater Quality Treatment: Application To A Surface Sand Filter And A Subsurface Gravel Wetland

    NASA Astrophysics Data System (ADS)

    Avellaneda, P.; Ballestero, T. P.; Roseen, R.; Houle, J.; Linder, E.

    2010-12-01

    In a previous study of the same research project, Avellaneda et al. (2010) reported the application of a transport model for simulating contaminant removal by a sand filter. The model was based on the one-dimensional advection-dispersion equation. The unknown parameters of the model were the contaminant deposition rate and the hydrodynamic dispersion. The model was calibrated on a storm by storm basis and optimized parameter values were provided for 15 rainfall-runoff events. Although a statistical summary of optimized parameter values was provided, they recommended these results as input information for the implementation of a more rigorous statistical approach towards the description of parameter uncertainty. In this study, a Bayesian statistical approach is used to determine parameter uncertainty for the stormwater treatment model and monitoring data reported by Avellaneda et al. (2010). The objectives of this study are: (1) to develop a Bayesian stormwater quality approach for two stormwater treatment systems: a subsurface gravel wetland and a sand filter; (2) to determine the posterior probability distribution (PPD) of the deposition rate and the hydrodynamic dispersion; and (3) to perform Monte Carlo simulations to estimate effluent pollutant concentrations from the stormwater systems using the calculated PPDs. Two stormwater treatment systems were selected for this study: a sand filter and a subsurface gravel wetland. Both systems are located at the University of New Hampshire Stormwater Center in Durham, New Hampshire (USA). Influent and effluent for these two stormwater treatment systems were monitored between August 2004 and September 2006. A total of 15 storms were collected for the subsurface gravel wetland and 16 storms for the sand filter. Runoff constituent analysis included: TSS, TPH-D, and Zn. Results indicate that the mean particle deposition rate of the sand filter is higher than that of the subsurface gravel wetland. The deposition rate

  20. 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

  1. 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.

  2. 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.

  3. Comparison of the treatment performance of hybrid constructed wetlands treating stormwater runoff.

    PubMed

    Choi, J Y; Maniquiz-Redillas, M C; Hong, J S; Lee, S Y; Kim, L H

    2015-01-01

    This study was conducted to compare the treatment performance of two hybrid constructed wetlands (CWs) in treating stormwater runoff. The hybrid CWs were composed of a combination of free water surface (FWS) and horizontal subsurface flow (HSSF) CWs. Based on the results, strong correlation exists between potential runoff impacts and stormwater characteristics; however, the low correlations also suggest that not only the monitored parameters contribute to stormwater event mean concentrations (EMC) of pollutants, but other factors should also be considered as well. In the hydraulic and treatment performance of the hybrid CWs, a small surface area to catchment area (SA/CA) ratio, receiving a high concentration of influent EMC, will find it hard to achieve great removal efficiency; also a large SA/CA ratio, receiving low concentration of influent EMC, will find it hard to achieve great removal efficiency. With this, SA/CA ratio and influent characteristics such as EMC or load should be considered among the design factors of CWs. The performance data of the two CWs were used to consider the most cost-effective design of a hybrid CW. The optimum facility capacity (ratio of total runoff volume to storage volume) that is applicable for a target volume reduction and removal efficiency was provided in this study.

  4. Enhancing the water purification efficiency of a floating treatment wetland using a biofilm carrier.

    PubMed

    Zhang, Lingling; Zhao, Jing; Cui, Naxin; Dai, Yanran; Kong, Lingwei; Wu, Juan; Cheng, Shuiping

    2016-04-01

    Floating treatment wetlands (FTWs) and biofilm carriers are widely used in water purification. The objective of the present work was to explore whether and to what extent an FTW integrated with plants and biofilm carriers (FTW-I) could enhance the nutrient removal efficiency. Significantly higher removal rates of ammonia nitrogen (85.2 %), total phosphorus (82.7 %), and orthophosphate (82.5 %) were observed in the FTW-I treatment relative to the FTW with plants (FTW-P; 80.0, 78.5, and 77.6 %, respectively) and the FTW with biofilm carriers (FTW-B; 56.7, 12.9, and 13.4 %, respectively) (p < 0.05). The mass balance results indicated that plant uptake was the main pathway for N and P removal (accounting for 58.1 and 91.4 %, respectively) in FTW-I, in which only 1.2 % of the N and 5.7 % of the P was deposited on the bottom of the tank. In addition, the plants translocated 43.9 and 80.2 % of the N and P in the water and 83.5 and 88.3 % of the absorbed N and P, respectively, into their aboveground tissues. The combination of an FTW and biofilm carriers can improve the efficiency of water purification, and nutrients can be rapidly removed from the system by harvesting the aboveground plant tissues.

  5. Treatment of freshwater fish farm effluent using constructed wetlands: the role of plants and substrate.

    PubMed

    Naylor, S; Brlsson, J; Labelle, M A; Drizo, A; Comeau, Y

    2003-01-01

    Freshwater fish farm effluents have low nutrient concentrations but high flow rates, resulting in pollutant load, especially phosphorus (P), causing eutrophication. The feasibility was tested of a treatment combining, within a single constructed wetland, the contribution of macrophytes for reducing organic matter and nitrogen (N), with the high efficiency of steel slag and limestone for P removal. Twenty subsurface flow (SSF) basins of 280 L with different combinations of plants (Phragmites communis or Typha latifolia) and substrates (steel slag, limestone, gravel, peat) were fed with a reconstituted fish farm effluent in a greenhouse experiment. Pollutant removal was generally very good under all treatments. N and organic matter removal were correlated with plant biomass while P removal was better in substrates with steel slag and limestone. However, the high pH of the P-adsorbing substrate was detrimental to plant growth so that no combination of plants and substrates could maximise in one step the simultaneous removal of all evaluated pollutants. Therefore, the use of two sequential units is recommended, a first one consisting of a macrophyte planted basin using a neutral substrate to remove organic matter and N, followed by a second unplanted basin containing only a P-adsorbing substrate.

  6. 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.

  7. 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

    2017-04-24

    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. Three 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 were 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.

  8. 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.

  9. General design, construction, and operation guidelines: Constructed wetlands wastewater treatment systems for small users including individual residences. Second edition

    SciTech Connect

    Steiner, G.R.; Watson, J.T.

    1993-05-01

    One of the Tennessee Valley Authority`s (TVA`s) major goals is cleanup and protection of the waters of the Tennessee River system. Although great strides have been made, point source and nonpoint source pollution still affect the surface water and groundwater quality in the Tennessee Valley and nationally. Causes of this pollution are poorly operating wastewater treatment systems or the lack of them. Practical solutions are needed, and there is great interest and desire to abate water pollution with effective, simple, reliable and affordable wastewater treatment processes. In recognition of this need, TVA began demonstration of the constructed wetlands technology in 1986 as an alternative to conventional, mechanical processes, especially for small communities. Constructed wetlands can be downsized from municipal systems to small systems, such as for schools, camps and even individual homes.

  10. 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

  11. A comparative study of five horizontal subsurface flow constructed wetlands using different plant species for domestic wastewater treatment.

    PubMed

    Villaseñor Camacho, J; De Lucas Martínez, A; Gómez Gómez, R; Mena Sanz, J

    2007-12-01

    This project studied domestic wastewater treatment by horizontal subsurface flow (HSSF) constructed wetlands (CW) and compared the effect of four different plant species on the operating conditions, dissolved oxygen (DO), and redox potential (ORP), and their efficiency on pollutants removal. Five HSSF CWs were fed for 10 months with low loaded synthetic domestic wastewater, using theoretical hydraulic residence time of 7.6 days. The plant species under study were the following: Phragmites australis (CW1), Lythrum salicaria (CW3), Cladium mariscus (CW4) and Iris pseudacorus (CW5). CW2 was not planted and this was used as control. Qualitative measurements determined a greater growth of Lythrum salicaria and Iris pseudacorus than the others. Dissolved oxygen concentrations were very low in the entire bulk liquid of all the CWs. Also ORP values were very similar in all wetlands, dealing with facultative anaerobic environments. All planted wetlands improved pollutants removal compared with the unplanted control wetland. The performances in terms of COD, TN, TP and SO4(2-) removal obtained by the different CWs were in the ranges 80-90%, 35-55%, 15-40% and 45-60% respectively. Lythrum salicaria and Iris pseudacorus, which exhibited greater growth, were always the most efficient species that improved not only nutrients plant uptake but also other microbial removal processes probably due to a higher aeration potential, such as nitrification or aerobic respiration. Sulphate reduction was the most important mechanism for COD removal. Cladium mariscus, an autochthonous plant that grows in the south-central Iberian Peninsula, was less efficient than Lythrum salicaria and Iris pseudacorus, but improved the unplanted wetland wastewater efficiency.

  12. 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.

  13. Removal of endocrine disruptors by tertiary treatments and constructed wetlands in subtropical Australia.

    PubMed

    Chapman, H

    2003-01-01

    The controversial topic of endocrine disrupting chemicals (EDC) in aquatic environments is of international and Australian significance with the need for sustainable management of water resources increasing. The issues have been highlighted on the major continents of Europe and North America but so far have received less attention in Australia. A major source of these compounds has been identified as sewage effluent, which is treated prior to release to the environment with a primary focus on pathogen and nutrient removal. Sewage effluent is a complex mixture, which can contain many organic and inorganic compounds some of which may remain after treatment processes. More recently, technologies such as ozonation, UV treatment and advanced filtration have improved the quality of effluent discharged to the environment but there are still unresolved issues relating to poorly understood chemistries relating to EDCs in effluent discharges and the possible impacts in aquatic environments and to human health. This paper reports on an investigation of the removal from sewage effluent of selected chemicals that are known or suspected environmental endocrine disruptors (EEDs) by sand filtration, ozonation and UV treatment at the Landeborough Water Reclamation Plant in Queensland, Australia. Compounds detected in the raw effluent included pesticides, herbicides, some heavy metals and the human hormones 17beta estradiol and estrone. Most of these ware removed by the advanced treatments at the water reclamation plant, with only trace concentrations of some compounds present in the final effluent. Removal of toxicants by a free water surface wetland is also reported on. Some of the constraints of direct chemical measurements are discussed and some solutions proposed.

  14. The effect of primary treatment and flow regime on clogging development in horizontal subsurface flow constructed wetlands: An experimental evaluation.

    PubMed

    Pedescoll, Anna; Corzo, Angélica; Alvarez, Eduardo; García, Joan; Puigagut, Jaume

    2011-06-01

    The effect of both the type of primary treatment (hydrolitic up-flow sludge blanket (HUSB) reactor and conventional settling) and the flow regime (batch and continuous) on clogging development in subsurface flow constructed wetlands (SSF CWs) was studied. Clogging indicators (such as accumulated solids, hydraulic conductivity and drainable porosity) were determined in an experimental plant with three treatment lines. Correlations were encountered between the solids accumulated and both saturated hydraulic conductivity and drainable porosity reduction over time (74.5% and 89.2% of correlation, respectively). SSF CW implemented with a HUSB reactor accumulated ca. 30% lower sludge (1.9 kg DM/m(2)) than a system with a settler (2.5-2.8 kg DM/m(2)). However, no significant differences were recorded among treatment lines concerning hydraulic parameters (such as hydraulic conductivity or porosity). Root system development contributed to clogging. Accordingly, planted wetlands showed between 30% and 40% and 10% lower hydraulic conductivity and porosity reduction, respectively, than non-planted wetlands.

  15. 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.

  16. 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

  17. Temperature, plant species and residence time effects on nitrogen removal in model treatment wetlands.

    PubMed

    Allen, C R; Stein, O R; Hook, P B; Burr, M D; Parker, A E; Hafla, E C

    2013-01-01

    Total nitrogen (TN) removal in treatment wetlands (TWs) is challenging due to nitrogen cycle complexity and the variation of influent nitrogen species. Plant species, season, temperature and hydraulic loading most likely influence root zone oxygenation and appurtenant nitrogen removal, especially for ammonium-rich wastewater. Nitrogen data were collected from two experiments utilizing batch-loaded (3-, 6-, 9- and 20-day residence times), sub-surface TWs monitored for at least one year during which temperature was varied between 4 and 24 °C. Synthetic wastewater containing 17 mg/l N as NH4 and 27 mg/l amino-N, 450 mg/l chemical oxygen demand (COD), and 13 mg/l SO4-S was applied to four replicates of Carex utriculata, Schoenoplectus acutus and Typha latifolia and unplanted controls. Plant presence and species had a greater effect on TN removal than temperature or residence time. Planted columns achieved approximately twice the nitrogen removal of unplanted controls (40-95% versus 20-50% removal) regardless of season and temperature. TWs planted with Carex outperformed both Typha and Schoenoplectus and demonstrated less temperature dependency. TN removal with Carex was excellent at all temperatures and residence times; Schoenoplectus and Typha TN removal improved at longer residence times. Reductions in TN were not accompanied by increases in NO3, which was consistently below 1 mg/l N.

  18. 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 (BOD5) 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 SO4(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.

  19. TREATMENT PERFORMANCE OF A COMBINED CONSTRUCTED WETLAND SYSTEM AND ITS GREENHOUSE GASES EMISSION

    NASA Astrophysics Data System (ADS)

    Xu, K. Q.; Liu, C.; Ebie, Y.; Inamori, Y.

    2009-12-01

    Constructed wetlands (CWs) can be classified into three typical types: Vertical flow (VF), Free-water Surface (FWS) and Subsurface Flow (SF) CWs according to their structures and directions of water flow. A combined FWS-VF-SFS CW system was designed and built to promote its treatment performance for actual domestic wastewater and reduce greenhouse gas emissions. The results from the pilot-scale combined system indicated that comparatively good performance for pollutant removal, which was 98.5%, 95.9%, 93.2% and 90.7% for BOD5, SS, NH4-N and TP under 6-day HRT, respectively. It was also found that the N2O emission was mainly from the VF unit of the system, which accounted for more than 80% of the total emission, whereas N2O emission from the FWS unit was nearly zero. On the other hand, the CH4 emission was not so high as N2O in the combined CW system, which mainly emitted from the FWS and SF units.

  20. Partitioning of heavy metals in sub-surface flow treatment wetlands receiving high-strength wastewater.

    PubMed

    Wojciechowska, Ewa; Gajewska, Magdalena

    2013-01-01

    The retention of heavy metals at two pilot-scale treatment wetlands (TWs), consisting of two vertical flow beds (VSSF) followed by a horizontal flow bed (HSSF) was studied. The TWs received high-strength wastewater: reject waters from sewage sludge centrifugation (RW) and landfill leachate (LL). The concentrations of the metals Fe, Mn, Zn, Al, Pb, Cu, Cd, Co, and Ni were measured in treated wastewater, substrate of the beds and in plant material harvested from the beds (separately in above ground (ABG) parts and below ground (BG) parts). The TWs differed in metals retention. In the RW treating TW the metal removal efficiencies varied from 27% for Pb to over 97% for Fe and Al. In the LL treating system the concentrations of most metals decreased after VSSF-1 and VSSF-2 beds; however, in the outflow from the last (HSSF) bed, the concentrations of metals (apart from Al) increased again, probably due to the anaerobic conditions at the bed. A major removal pathway was sedimentation and adsorption onto soil substrate as well as precipitation and co-precipitation. In the LL treating facility the plants contained substantially higher metal concentrations in BG parts, while the upward movement of metals was restricted. In the RW treating facility the BG/ABG ratios were lower, indicating that metals were transported to shoots.

  1. [Treatment studies of industrial rainoff with a new type of constructed wetland].

    PubMed

    He, Li-Jun; Ma, Yong-Wen; Wan, Jin-Quan; Li, Dong-Ya; Wang, Yan

    2012-03-01

    According to water characteristics of industrial rain runoff in a catchment of Tongsha reservoir, Dongguan city, an improved baffled constructed wetland (BCW) was used for purification experiment study of simulated and on-the-spot rain runoff. The purification effects of simulated rain runoff were compared in different operated phases of BCW. Meanwhile, the variation of the pollutants (COD, SS, TN, TP, NH4(+) -N, Pb, Zn, Cu) along the BCW and their removal mechanism were analyzed and discussed, respectively. In the simulated experiment, the effluent water quality of BCW system met the needs of Environmental Quality Standard for Surface Water( GB 3838-2002) III, besides TN met IV, and most of the pollutants were removed in the front of the BCW. In the purification study of on-the-spot rain runoff, removal rate of COD, SS, TN, TP and NH4(+) -N were 90.9%, 97.0%, 83.4%, 92.2% and 90.0%, respectively; removal rate of Pb, Zn and Cu were 98.4%, 94.1% and 93.6%, respectively. The effluent met the grade III. Results showed that there was remarkable treatment performance of industrial catchment rain runoff when BCW system was used, which also can withstand strong shock load. Moreover, a modest variation of temperature affected the removal of pollutants in the BCW insignificantly.

  2. 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.

  3. 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.

  4. 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

  5. Hydraulics and flow modelling of water treatment wetlands constructed on peatlands in Northern Finland.

    PubMed

    Ronkanen, Anna-Kaisa; Kløve, Bjørn

    2008-08-01

    In this study, we evaluated flow structure, effective flow area (A(eff)) and effective porosity (theta(eff)) in three peatlands using the stable isotope (18)O/(16)O ratio and tracer tests. We also applied the readily available groundwater modelling MODFLOW code for wetland flow modelling and simulated in one study site how the hydraulic performance of the wetland will be improved by changing the design of the distribution ditch. Preferential flow paths occurred in all three studied wetlands and A(eff) varied from 40% to 90% of total wetland area while theta(eff) was 0.75-0.99. Constructed flow models accurately simulated the hydraulic head across wetlands (r(2)=0.95-0.99). Similarities between the flow models and the stable isotope distributions observed in this study suggest possibilities in using MODFLOW to design peatlands. The improvement of the inlet ditch configuration (ditch length/wetland width>0.45) can prevent or reduce short-circuiting and dead zones in peatlands treating wastewater.

  6. 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.

  7. 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 NH4(+) which can be attributed to the volatilization of NH4(+) 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 NH4(+)-N concentration in the soil was very low and it increased gradually during purification due to increasing soil cation exchange capacity. Thus by trapping NH4(+) 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.

  8. Development of constructed wetlands in performance intensifications for wastewater treatment: a nitrogen and organic matter targeted review.

    PubMed

    Wu, Shubiao; Kuschk, Peter; Brix, Hans; Vymazal, Jan; Dong, Renjie

    2014-06-15

    The knowledge on the performance enhancement of nitrogen and organic matter in the expanded constructed wetlands (CWs) with various new designs, configurations, and technology combinations are still not sufficiently summarized. A comprehensive review is accordingly necessary for better understanding of this state-of-the-art-technology for optimum design and new ideas. Considering that the prevailing redox conditions in CWs have a strong effect on removal mechanisms and highly depend on wetland designs and operations, this paper reviews different operation strategies (recirculation, aeration, tidal operation, flow direction reciprocation, and earthworm integration), innovative designs, and configurations (circular-flow corridor wetlands, towery hybrid CWs, baffled subsurface CWs) for the intensifications of the performance. Some new combinations of CWs with technologies in other field for wastewater treatment, such as microbial fuel cell, are also discussed. To improve biofilm development, the selection and utilization of some specific substrates are summarized. Finally, we review the advances in electron donor supply to enhance low C/N wastewater treatment and in thermal insulation against low temperature to maintain CWs running in the cold areas. This paper aims to provide and inspire some new ideas in the development of intensified CWs mainly for the removal of nitrogen and organic matter. The stability and sustainability of these technologies should be further qualified. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. 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.

  10. Vegetation effects on floating treatment wetland nutrient removal and harvesting strategies in urban stormwater ponds.

    PubMed

    Wang, Chih-Yu; Sample, David J; Bell, Cameron

    2014-11-15

    Floating treatment wetlands (FTWs) consist of emergent macrophytes that are placed on a floating mat in a pond for water treatment and aesthetic purposes. FTWs may have unique advantages with respect to treating urban runoff within existing retention ponds for excess nutrients. However, research is lacking in providing guidance on performance of specific species for treating urban runoff, and on timing of harvest. Harvesting is needed to remove nutrients permanently from the retention pond. We investigated vegetation effects on FTWs on nitrogen (N) and phosphorus (P) removal performance and storage in above-ground FTW macrophyte tissues. The study evaluated pickerelweed (PW, Pontederia cordata L.) and softstem bulrush (SB, Schoenoplectus tabernaemontani) over time in microcosms flushed with water obtained from a nearby urban retention pond in northern Virginia near Washington, DC. While the literature exhibits a wide range of experimental sizes, using the term mesocosm, we have chosen the term microcosm to reflect the small size of our vessel; and do not include effects of sediment. The experiment demonstrated PW outperformed SB for P and N removal. Based upon analysis of the accumulated nutrient removal over time, a harvest of the whole PW and SB plants in September or October is recommended. However, when harvesting only the aerial parts, we recommend harvesting above-ground PW tissues in July or August to maximize nutrient removal. This is because PW translocates most of its nutrients to below-ground storage organs in the fall, resulting in less nutrient mass in the above-ground tissue compared to the case in the summer (vegetative stage). Further research is suggested to investigate whether vegetation can be overly damaged from multiple harvests on an annual basis in temperate regions.

  11. Suitability of constructed wetlands and waste stabilisation ponds in wastewater treatment: nitrogen transformation and removal

    NASA Astrophysics Data System (ADS)

    Senzia, M. A.; Mashauri, D. A.; Mayo, A. W.

    It is estimated that 90% of sewage in cities in developing countries are today discharged untreated into water bodies. In Tanzania, pollution of rivers such as Karanga, Njoro and Rao in Moshi; Mirongo in Mwanza and Themi in Arusha is the cause of frequent disease outbreaks in communities downstreams. Solutions to effluent crisis can be found by its proper treatment and disposal. The principal objective of wastewater treatment is to allow effluents to be disposed without danger to human health or unacceptable damage to the ecology of receiving water bodies. Field investigations were made on pilot scale horizontal subsurface flow constructed wetlands (CW) units located downstream of waste stabilisation ponds (WSP). Six units filled with gravel of 6-25 mm diameters in equal proportion, which gave an initial hydraulic conductivity of 86 m/d were used. While four units covering surface area of 40.7 m 2 each, were located downstream of primary facultative pond, the other two units with surface area 15.9 m 2 each were located downstream of maturation pond. An attempt was made to compare the output of mathematical models for Phragmites and Typha macrophytes located downstream of primary facultative pond. Based on total inflow nitrogen of 1.457 gN/m 2 d, while Phragmites has shown a removal of 54%, Typha had a removal of 44.2%. Furthermore, while the system downstream of primary facultative pond has accretion as a major pathway, accounting for 19.1% of inflow nitrogen, the system downstream of maturation pond has denitrification as its major removal mechanism accounting for 20.5%. In this paper, a comparison of land required by CW and WSP based on the amount of water to be treated is made.

  12. 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.

  13. [Performance of constructed wetland for municipal wastewater tertiary treatment: winter and summer comparison].

    PubMed

    Xiang, Xue-Min; Yang, Hong-Tao; Zhou, Ji-Ti; Yang, Feng-Lin; Wang, Zhong-Hua

    2009-03-15

    An improved three-stage vertical flow constructed wetland (CW) was used for tertiary treatment of effluent from two typical Dalian municipal wastewater treatment plants. The experiments were carried out under ambient condition in Dalian for the whole year. Performances of the CW for COD, TN, NH4(+) -N and TP removal in summer (Jun.-Aug.), winter (Nov.-Jan. the second year) and spring (Feb.-Apr.) were compared. In summer, the removal rates of COD, TN, NH4(+) -N and TP reached 88.5%, 76%, 100% and 98%, respectively. While in winter they reached 88%, 85.3%, 86.4% and 97%, respectively. In spring, the removal rates reached 87.7%, 76.7%, 70.3% and 95.5%, respectively. The effluent water quality for summer, winter and spring were: COD 2.8, 3.8 and 3.9 mg x L(-1), respectively; TP 0.02, 0.05, and 0.07 mg x L(-1), respectively; TN 6.8, 2.9, and 9.2 mg x L(-1), respectively; NH4(+)-N 0.01, 0.3, and 8.1 mg x L(-1), respectively. Results showed good performance of CW for Dalian municipal wastewater tertiary treatment, especially for COD and TP removal. The effluent COD and TP meet the needs of Environmental Quality Standard for Surface Water (GB 3838-2002) III, whereas the effluent TN and NH4(+)- N meet the needs of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002) class I A and B, separately. The pollutant removal loads in summer, winter and spring were as flow: COD 4.9, 5.1, and 5.0 g x (m2 x d)(-1); TN 3.4, 3.0, and 5.5 g x (m2 x d)(-1); NH4(+) -N 0.2, 0.6, and 3.7 g x (m2 x d)(-1); TP 0.15, 0.30, and 0.28 g(m2 x d)(-1). It is indicated that no significant influence of seasons on pollutant removal is found by comparing the removal rates as well as pollutant removal loads in different seasons, however, the removal of NH4(+) -N and TN in CW is mainly influenced by influent pollutant loads.

  14. 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.

  15. 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.

  16. Presence and persistence of wastewater pathogen Escherichia coli O157:H7 in hydroponic reactors of treatment wetland species.

    PubMed

    VanKempen-Fryling, R J; Stein, O R; Camper, A K

    2015-01-01

    Treatment wetlands (TWs) efficiently remove many pollutants including a several log order reduction of pathogens from influent to effluent; however, there is evidence to suggest that pathogen cells are sequestered in a subsurface wetland and may remain viable months after inoculation. Escherichia coli is a common pathogen in domestic and agricultural wastewater and the O157:H7 strain causes most environmental outbreaks in the United States. To assess attachment of E. coli to the TW rhizosphere, direct measurements of E. coli levels were taken. Experiments were performed in chemostats containing either Teflon nylon as an abiotic control or roots of Carex utriculata or Schoenoplectus acutus. Flow of simulated wastewater through the chemostat was set to maintain a 2 hour residence time. The influent was inoculated with E. coli O157:H7 containing DsRed fluorescent protein. Root samples were excised and analyzed via epifluorescent microscopy. E. coli O157:H7 was detected on the root surface at 2 hours after inoculation, and were visible as single cells. Microcolonies began forming at 24 hours post-inoculation and were detected for up to 1 week post-inoculation. Image analysis determined that the number of microcolonies with >100 cells increased 1 week post-inoculation, confirming that E. coli O157:H7 is capable of growth within biofilms surrounding wetland plant roots.

  17. Sunlight inactivation of viruses in open-water unit process treatment wetlands: modeling endogenous and exogenous inactivation rates.

    PubMed

    Silverman, Andrea I; Nguyen, Mi T; Schilling, Iris E; Wenk, Jannis; Nelson, Kara L

    2015-03-03

    Sunlight inactivation is an important mode of disinfection for viruses in surface waters. In constructed wetlands, for example, open-water cells can be used to promote sunlight disinfection and remove pathogenic viruses from wastewater. To aid in the design of these systems, we developed predictive models of virus attenuation that account for endogenous and exogenous sunlight-mediated inactivation mechanisms. Inactivation rate models were developed for two viruses, MS2 and poliovirus type 3; laboratory- and field-scale experiments were conducted to evaluate the models' ability to estimate inactivation rates in a pilot-scale, open-water, unit-process wetland cell. Endogenous inactivation rates were modeled using either photoaction spectra or total, incident UVB irradiance. Exogenous inactivation rates were modeled on the basis of virus susceptibilities to singlet oxygen. Results from both laboratory- and field-scale experiments showed good agreement between measured and modeled inactivation rates. The modeling approach presented here can be applied to any sunlit surface water and utilizes easily measured inputs such as depth, solar irradiance, water matrix absorbance, singlet oxygen concentration, and the virus-specific apparent second-order rate constant with singlet oxygen (k2). Interestingly, the MS2 k2 in the open-water wetland was found to be significantly larger than k2 observed in other waters in previous studies. Examples of how the model can be used to design and optimize natural treatment systems for virus inactivation are provided.

  18. [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.

  19. Nitrogen transformations and balance in constructed wetlands for slightly polluted river water treatment using different macrophytes.

    PubMed

    Wu, Haiming; Zhang, Jian; Wei, Rong; Liang, Shuang; Li, Cong; Xie, Huijun

    2013-01-01

    Nitrogen removal processing in different constructed wetlands treating different kinds of wastewater often varies, and the contribution to nitrogen removal by various pathways remains unclear. In this study, the seasonal nitrogen removal and transformations as well as nitrogen balance in wetland microcosms treating slightly polluted river water was investigated. The results showed that the average total nitrogen removal rates varied in different seasons. According to the mass balance approach, plant uptake removed 8.4-34.3 % of the total nitrogen input, while sediment storage and N(2)O emission contributed 20.5-34.4 % and 0.6-1.9 % of nitrogen removal, respectively. However, the percentage of other nitrogen loss such as N(2) emission due to nitrification and denitrification was estimated to be 2.0-23.5 %. The results indicated that plant uptake and sediment storage were the key factors limiting nitrogen removal besides microbial processes in surface constructed wetland for treating slightly polluted river water.

  20. Advanced treatment of refractory organic pollutants in petrochemical industrial wastewater by bioactive enhanced ponds and wetland system.

    PubMed

    Liu, Shuo; Ma, Qiusha; Wang, Baozhen; Wang, Jifu; Zhang, Ying

    2014-05-01

    A large-scale combined ponds-wetland system was applied for advanced treatment of refractory pollutants in petrochemical industrial wastewater. The system was designed to enhance bioactivity and biological diversity, which consisted of anaerobic ponds (APs), facultative ponds (FPs), aerobic pond and wetland. The refractory pollutants in the petrochemical wastewater to be treated were identified as alkanes, chloroalkanes, aromatic hydrocarbons, and olefins, which were significantly degraded and transformed along with the influent flowing through the enhanced bioactive ponds-wetland system. 8 years of recent operational data revealed that the average removal rate of stable chemical oxygen demand (COD) was 42.7 % and that influent COD varied from 92.3 to 195.6 mg/L. Final effluent COD could reach 65.8 mg/L (average). COD removal rates were high in the APs and FPs and accounted for 75 % of the total amount removed. This result indicated that the APs and FPs degraded refractory pollutants through the facilitation of bacteria growth. The changes in the community structures of major microbes were assessed by 16SrDNA-denaturing gradient gel electrophoresis. The same analysis was used to identify the main bacterial function for the removal of refractory pollutants in the APs and FPs. The APs and FPs displayed similar microbial diversities, and some of the identified bacteria degraded and removed refractory pollutants. The overall results proved the applicability, stability, and high efficiency of the ponds-wetland system with enhanced bioactivity in the advanced removal of refractory pollutants from petrochemical industrial wastewater.

  1. Upflow anaerobic sludge blanket and aerated constructed wetlands for swine wastewater treatment: a pilot study.

    PubMed

    Masi, F; Rizzo, A; Martinuzzi, N; Wallace, S D; Van Oirschot, D; Salazzari, P; Meers, E; Bresciani, R

    2017-07-01

    Swine wastewater management is often affected by two main issues: a too high volume for optimal reuse as a fertilizer and a too high strength for an economically sustainable treatment by classical solutions. Hence, an innovative scheme has been tested to treat swine wastewater, combining a low cost anaerobic reactor, upflow anaerobic sludge blanket (UASB), with intensified constructed wetlands (aerated CWs) in a pilot scale experimental study. The swine wastewater described in this paper is produced by a swine production facility situated in North Italy. The scheme of the pilot plant consisted of: (i) canvas-based thickener; (ii) UASB; (iii) two intensified aerated vertical subsurface flow CWs in series; (iv) a horizontal flow subsurface CW. The influent wastewater quality has been defined for total suspended solids (TSS 25,025 ± 9,323 mg/l), organic carbon (chemical oxygen demand (COD) 29,350 ± 16,983 mg/l), total reduced nitrogen and ammonium (total Kjeldahl nitrogen (TKN) 1,783 ± 498 mg/l and N-NH4(+) 735 ± 251 mg/l) and total phosphorus (1,285 ± 270 mg/l), with nitrates almost absent. The overall system has shown excellent performances in terms of TSS, COD, N-NH4(+) and TKN removal efficiencies (99.9%, 99.6%, 99.5%, and 99.0%, respectively). Denitrification (N-NO3(-) effluent concentration equal to 614 ± 268 mg/l) did not meet the Italian quality standards for discharging in water bodies, mainly because the organic carbon was almost completely removed in the intensified CW beds.

  2. Floating Treatment Wetland influences on the fate of metals in road runoff retention ponds.

    PubMed

    Borne, Karine E; Fassman-Beck, Elizabeth A; Tanner, Chris C

    2014-01-01

    A field trial comparing the fate of metals in two parallel stormwater retention ponds, one of which was retrofitted with a Floating Treatment Wetland (FTW), was carried out near Auckland, New Zealand. Results suggest that the FTW increased metal accumulation in the pond sediment especially in summer due to lower sediment Eh, more anoxic water column, neutral pH and greater source of organic matter (OM) induced by the FTW. These factors combined with higher temperature enhanced metal sorption onto OM, flocculation of particulate pollutants, metal sulphide formation and reduced OM degradation and thus limited release of metals. Unlike Zn, Cu speciation in the pond sediment was relatively unchanged under various sediment Eh conditions due to its strong binding property with sulphide and OM. Occasional moderate metal release was detected from the FTW pond sediment likely due to aerobic OM degradation at the beginning of spring and/or hydroxides reduction when sediments became reduced later in the season. No release was noticed from the conventional pond sediment likely due to biosorption and/or uptake by algae which developed in the conventional pond and settled on the bottom sediment. Direct uptake by the plants of the FTW and sorption onto root plaques are not thought to be significant removal pathways. Nevertheless roots play a major role in trapping particulate pollutants, eventually sloughing off to settle on the bottom of the pond, and provide an adequate substrate for bacterial development due to release of organic compounds which are both essential for dissolved metal sorption and metal sulphide formation.

  3. Estimation of landscape potential for construction of surface-flow wetlands for wastewater treatment in Estonia.

    PubMed

    Lesta, Merje; Mauring, Tõnu; Mander, Ulo

    2007-08-01

    The main aim of this article is to demonstrate a method of complex landscape analysis in order to estimate the landscape suitability for the construction of surface-flow wetlands (SFW) for wastewater treatment. This is a multilevel suitability analysis from a more general regional (landscape) assessment based on a map of landscape types (1:100,000) toward a detailed analysis based on aerial orthophotos and detailed soil maps (1:10,000). The assessment scheme consists of landscape classification according to the physical-chemical properties of landscape factors (soil conditions, landforms, hydrogeology, expert decisions concerning landscape values, and suitability analysis). The partial suitability values of SFWs are derived by summarizing expert values for landscape factors (each ranging from -1 to +1). By multiplying the summarized partial suitability values with nature protection values (ranging from 0 to 1), we obtain the final suitability value for each landscape type. Any kind of nature protection area has been considered nonsuitable and excluded at regional-level analysis. The results of the regional analysis demonstrate that suitability is distributed relatively equally over the study area. The high suitability potential (classified as "very suitable") is relatively evenly distributed in lowland regions throughout the country. The share of "very suitable" and "suitable" areas in different counties varies from 5 to 23% and 7 to 49%, respectively. The detailed analysis based on aerial orthophotos showed that areas suitable for SFWs can also be found within the areas determined to be unsuitable based on the less detailed map of landscape types, whereas differences are much greater between settlements chosen for the detailed suitability analysis.

  4. 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.

  5. Wetlands stewardship

    SciTech Connect

    Whelan, J.M.

    1992-04-01

    Wetlands have important ecological values and functions. It is estimated that 80 percent of the Nation's coastal fisheries are dependent on wetlands for spawning, nursery areas, and food sources. Both coastal and inland wetlands provide essential breeding, nesting, feeding, and predator escape habitats for millions of waterfowl, other birds, mammals, and reptiles. Well over one-third of the 564 plant and animal species listed as threatened or endangered in the United States utilize wetland habitats during some portion of their life cycle. Wetlands Stewardship is intended as a resource for everyone interested in wetlands protection.

  6. 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.

  7. Comparison between polishing (maturation) ponds and subsurface flow constructed wetlands (planted and unplanted) for the post-treatment of the effluent from UASB reactors.

    PubMed

    von Sperling, M; Dornelas, F L; Assunção, F A L; de Paoli, A C; Mabub, M O A

    2010-01-01

    This paper presents the results of a comparison of the performance of two treatment systems operating in parallel, with the same influent wastewater. The investigated systems are (i) UASB + three polishing ponds in series + coarse filter (200 population equivalents) and (ii) UASB + subsurface flow constructed wetlands (50 population equivalents). Two wetland units, operating in parallel, were analysed, being one planted (Typha latifolia) and the other unplanted. The systems were located in Belo Horizonte, Brazil. The wetland systems showed to be more efficient in the removal of organic matter and suspended solids, leading to good effluent BOD and COD concentrations and excellent SS concentrations. The planted wetland performed better than the unplanted unit, but the latter was also able to provide a good effluent quality. The polishing pond system was more efficient in the removal of nitrogen (ammonia) and coliforms (E. coli). Land requirements and cost considerations are presented.

  8. A promising approach of reject water treatment using a tidal flow constructed wetland system employing alum sludge as main substrate.

    PubMed

    Yang, Y; Zhao, Y Q; Wang, S P; Guo, X C; Ren, Y X; Wang, L; Wang, X C

    2011-01-01

    This study examined a novel reuse of alum sludge, an inescapable by-product of drinking water treatment process when aluminium salt is added as a coagulant, as the main medium in a laboratory-scale multi-stage constructed wetland (CW) system for reject water treatment. Such reject water is a main concern in municipal wastewater treatment plant (MWWTP) for increasing the organic and nutrient loading. A 'tidal flow' strategy was employed to enhance the wetland aeration to stimulate organic matters (OM) and ammoniacal-nitrogen (N) oxidation while the 'step feed' operation was adopted to supply the necessary amount of carbon source for denitrification. The results reveal that alum sludge acting as P adsorbent can secure the P removal. Meanwhile, high removals of N and OM can also be obtained due to the active bacteria growth on the alum sludge surface. The results show that average removal efficiencies of 65.4 +/- 12.3% for chemical oxygen demand (COD), 67.8 +/- 9.2% for five-day biochemical oxygen demand (BOD5), 33.6 +/- 17.0% for N and 99.5 +/- 0.49% for P can be achieved over a period of 190 days. This indicates that novel reuse of alum sludge as medium in CW system can provide a promising approach for reject water treatment. Therefore, it will significantly reduce the amount of pollutant feedback through reject water recycling in a MWWTP.

  9. FGD liner experiments with wetlands

    SciTech Connect

    Mitsch, W.J.; Ahn, C.; Wolfe, W.E.

    1999-07-01

    The construction of artificial wetlands for wastewater treatment often requires impermeable liners not only to protect groundwater resources but also to ensure that there is adequate water in the wetland to support appropriate aquatic life, particularly wetland vegetation. Liners or relatively impervious site soils are very important to the success of constructed treatment wetlands in areas where ground water levels are typically close to the ground surface. This study, carried out at the Olentangy River Wetland Research Park, investigated the use of FGD material from sulfur scrubbers as a possible liner material for constructed wetlands. While several studies have investigated the use of FGD material to line ponds, no studies have investigated the use of this material as a liner for constructed wetlands. They used experimental mesocosms to see the effect of FGD liner materials in constructed wetlands on water quality and on wetland plant growth. This paper presents the results of nutrient analyses and physicochemical investigation of leachate and surface outflow water samples collected from the mesocosms. Plant growth and biomass of wetland vegetation are also included in this paper. First two year results are reported by Ahn et al. (1998, 1999). The overall goal of this study is the identification of advantages and disadvantages of using FGD by-product as an artificial liner in constructed wetlands.

  10. 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...

  11. Zambia Wetland

    Atmospheric Science Data Center

    2013-04-16

    ... article title:  Floodwaters Renew Zambia's Kafue Wetland     View Larger Image ... roundish shape of the Lukanga Swamp, another important wetland. The images along the left are natural color views from MISR's ...

  12. 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.

  13. 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.

  14. Comparative evaluation of three attached growth systems and a constructed wetland for in situ treatment of raw municipal wastewater.

    PubMed

    Loupasaki, E; Diamadopoulos, E

    2013-01-01

    The necessity to treat municipal wastewaters in situ, with a low cost, yet effective system, led to the research of alternative methods for wastewater treatment. Attached growth systems can be an alternative option. Three attached growth systems with different media substrate, a rockwool cubes unit, a Kaldnes rings unit and a plastic bottle caps unit were studied in comparison with a constructed wetland in order to evaluate their ability to treat raw municipal wastewater. The selection of the three different media was based on their high porosity and surface area, as well as their availability and price. Three different operating periods were carried out with variations in the organic loading rate and the feeding frequency. The units were fed intermittently with short resting periods, less than 32 h, and relative high mean organic loading rates of 70, 50 and 30 g chemical oxygen demand (COD)/(m2d), respectively for each operating period. The constructed wetland and the rockwool cubes unit were the most effective, with mean COD reduction as mass rate (mg/d) 88% and 88%, biological oxygen demand 78% and 76%, dissolved organic carbon 73% and 67%, and total suspended solids 91% and 92%, respectively. Total nitrogen reduction was significantly higher at the constructed wetland with mean reduction as mass rate 51%, 60% and 83% for each period, compared to 41%, 43% and 60%, respectively, of the rockwool cubes unit. This study showed that it is possible to design, build and operate in situ small and decentralized treatment systems by using readily available packing materials and with minimum wastewater pretreatment.

  15. Wetland areas: Natural water treatment systems. January 1978-August 1989 (a Bibliography from Pollution Abstracts). Report for January 1978-August 1989

    SciTech Connect

    Not Available

    1990-03-01

    This bibliography contains citations concerning the ability of salt marshes, tidal flats, marshlands, bogs, and other wetland areas to degrade, absorb, filter, consume, or mitigate natural and man-made pollution and wastes, while maintaining their ability to provide refuge and breeding grounds for wildlife. The ecology, biochemistry, and viability of naturally occurring and artificially established wetlands as water-treatment systems and wildlife areas are considered. The effects of individual pollutants, environmental factors, species diversity, and cleansing ability of wetland areas on the potential for wildlife refuge, sewage treatment, treatment of industrial and municipal wastes, handling agricultural runoff, mitigating accidental spills, and flooding are discussed. (This updated bibliography contains 243 citations, 21 of which are new entries to the previous edition.)

  16. 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

  17. 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...

  18. 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...

  19. 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.

  20. Simulation of the treatment performance of outdoor subsurface flow constructed wetlands in temperate climates.

    PubMed

    Langergraber, Günter

    2007-07-15

    Numerical models are a means to increase the understanding of the processes occurring in the "black box" constructed wetland. Once reliable models for constructed wetlands are available they can be also used for evaluating and improving existing design criteria. The paper shows simulation results for outdoor experimental subsurface vertical flow constructed wetlands using CW2D, a multi-component reactive transport module developed to simulate transport and reactions of the organic matter, nitrogen and phosphorus in subsurface flow constructed wetlands. The surface area of the experimental vertical flow bed was 20 m(2). The organic load applied was 27 g COD m(-2) d(-1) (corresponding to a specific surface area of 3 m(2) per person). The aim of the work is to calibrate the model for temperature dependency that has been implemented in CW2D. Water temperature during the investigation period varied between 4 degrees C and 18 degrees C. The measured effluent concentrations during summer could be simulated using the standard CW2D parameter set when the flow model was calibrated well. However, the increasing effluent concentrations at low temperatures could not be simulated with the standard CW2D parameter set where temperature dependencies are considered only for maximum growth, decay, and hydrolysis rates. By introducing temperature dependencies for half-saturation constants for the hydrolysis and nitrification processes it was possible to simulate the observed behaviour. The work presented is a step on the way to validate the CW2D module. Model validation is a necessary step before numerical simulation can be finally used in practice, e.g. for checking existing design guidelines.

  1. Quantification of oxygen release by bulrush (Scirpus validus) roots in a constructed treatment wetland.

    PubMed

    Bezbaruah, Achintya N; Zhang, Tian C

    2005-02-05

    Amount of oxygen released by bulrush (Scirpus validus) roots has been quantified based on the radial oxygen loss (ROL) exhibited by the roots, the number and the length of active lateral roots, and the field plant density. It was found that wetland bulrush contains two types of active lateral roots (showing ROL), viz., laterals of brown and white main roots. The two laterals have distinct oxygen release characteristics. Based on the dissolved oxygen (DO) microprofiles of brown and white laterals, the ROLs were found to be approximately 61 ng O2 cm(-2) root surface min(-1) and approximately 68 ng O2 cm(-2) root surface min(-1), respectively, at bulk 5-day biochemical oxygen demand (BOD5) of 76 mg L(-1). The respective average active root lengths of the brown and the white laterals were approximately 40 and approximately 1676 microm. Based on field and laboratory measurements, the average amount of oxygen released by bulrush was found to be 2.30 mg O2 m(-2) wetland surface d(-1); of this approximately 71% is from the white roots. The results of this study indicate that plants do not release enough oxygen to meet the total oxygen demand of bulk wastewater, and therefore, constructed wetlands should be designed as an anaerobic or an aerobic-anaerobic hybrid system rather than as an aerobic system. However, the results of this study should be viewed in the background of possible errors (including a reactor design flaw), which might have made the measured oxygen release significantly lower than what plant roots actually release. Further studies are needed to quantify wetland plant oxygen release based on micro-scale measurements. 2004 Wiley Periodicals, Inc.

  2. Landfill leachate treatment by an experimental subsurface flow constructed wetland in tropical climate countries.

    PubMed

    Ujang, Z; Soedjono, E; Salim, M R; Shutes, R B

    2005-01-01

    Municipal leachate was treated in an experimental unit of constructed wetlands of subsurface flow type. The parameters studied were organics (BOD and COD), solids and heavy metals (Zn, Ni, Cu, Cr and Pb). Using two types of emergent plants of Scirpus globulosus and Eriocaulon sexangulare, more than 80% removal was achieved for all the parameters. E. sexangulare removed organics and heavy metals better than Scirpus globulosus. A higher concentration of heavy metals in the influent did not change the removal efficiency.

  3. Landfill leachate treatment using sub-surface flow constructed wetland by Cyperus haspan.

    PubMed

    Akinbile, Christopher O; Yusoff, Mohd Suffian; Ahmad Zuki, A Z

    2012-07-01

    Performance evaluation of pilot scale sub-surface constructed wetlands was carried out in treating leachate from Pulau Burung Sanitary Landfill (PBSL). The constructed wetland was planted with Cyperus haspan with sand and gravel used as substrate media. The experiment was operated for three weeks retention time and during the experimentation, the influent and effluent samples were tested for its pH, turbidity, color, total suspended solid (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD(5)), ammonia nitrogen (NH(3)-N), Total phosphorus (TP), total nitrogen (TN) and also for heavy metals such as iron (Fe), magnesium (Mg), manganese (Mn) and zinc (Zn) concentrations. The results showed that the constructed wetlands with C. haspan were capable of removing 7.2-12.4% of pH, 39.3-86.6% of turbidity, 63.5-86.6% of color, 59.7-98.8% of TSS, 39.2-91.8% of COD, 60.8-78.7% of BOD(5), 29.8-53.8% of NH(3)-N, 59.8-99.7% of TP, 33.8-67.0% of TN, 34.9-59.0% of Fe, 29.0-75.0% of Mg, 51.2-70.5% of Mn, and 75.9-89.4% of Zn. The significance of removal was manifested in the quality of the effluent obtained at the end of the study. High removal efficiencies in the study proved that leachate could be treated effectively using subsurface constructed wetlands with C. haspan plant. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. 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. The 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.

  5. 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

  6. 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 NH4(+)-N, TN, NO2(-)-N, NO3(-)-N, SO4(2-), and PO4(3-) removal efficiency in the ISs-CWs were 83.60%, 82.43%, 15.61%, 48.93%, 80.45%, and 78.94% respectively. The average NO2(-)-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.

  7. Treatment of reactive azo dye from textile wastewater by burhead (Echinodorus cordifolius L.) in constructed wetland: Effect of molecular size.

    PubMed

    Noonpui, Sirikan; Thiravetyan, Paitip

    2011-01-01

    The potential of burhead (Echinodorus cordifolius L.) for the treatment of textile wastewater has been investigated. Reactive red 2; RR2 [MW=615], reactive red 120; RR120 [MW=1469] and reactive red 141; RR141 [MW=1775] were studied in order to determine the effect of molecular size on the efficiency of dye removal by plants in batch systems of constructed wetlands under soil and soil-free conditions. Dye concentrations, total dissolve solids (TDS), conductivity and pH in the effluents, and the relative growth rates (RGR) of plants were measured. The highest efficiency of dye removal during 7 days under soil-free conditions was RR2 (33.09 μmol(RR2)kg(-1)(FW)), followed by RR120 (13.35 μmol(RR120)kg(-1)(FW)) and RR141 (10.57 μmol(RR141)kg(-1)(FW)), respectively. This suggests that the structure and size of dye molecule strongly affects the efficiency of dye removal by plant. The results from a synthetic wetland experiment found that dye removal was 96 % at 4 days and 6 days under soil and soil-free conditions, respectively. Furthermore, plants were able to decrease TDS (42 %), conductivity (50 %) and pH (from 9.5 to 7.4) within 2 days in the synthetic reactive red(141) dye wastewater (SRRW141) under soil-free conditions, thus demonstrating the potential of burhead for textile wastewater treatment.

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

    PubMed

    Sadaria, Akash M; Supowit, Samuel D; Halden, Rolf U

    2016-06-21

    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.

  9. [Treatment of 1, 2-dichlorobenzene in wastewater by using horizontal subsurface flow constructed wetlands].

    PubMed

    Ding, Cheng; Yang, Tang-Yi; Yu, Qian; Li, Zhao-Xia; Yang, Chun-Sheng

    2011-09-01

    Pilot-scale horizontal subsurface flow constructed wetlands (SFCW) planted with Phragmites australis were constructed to treat in 1,2-dichlorobenzene (o-DCB) wastewater. Different soil substrates of loam (W-L), fine sand (W-F) and coarse sand (W-C) were used in the three SFCW and a loam wetland with no reeds W-Z was taken as control. Results showed that the optimal hydraulic retention time (HRT) and pollutants surface loading rate(ALR)were 5 d and 150 mg x (m2 x d)(-1). Removal efficiencies for o-DCB of W-L, W-F, W-C and W-Z were 81.2%, 71.1%, 72.4% and 65.2%, respectively. The performance of systems achieved in mid-August and declined from October, with order of W-L > W-C > W-Z > W-F. Spatial concentration dynamics of o-DCB and dissolved oxygen (DO) were also investigated in W-L and W-Z, which indicated that DO was an important role to removal of o-DCB. The residual quantity of o-DCB in wetland substrate decreased along the flow direction and increased with the depth of substrate layers, the mean residual in the root, stem and leaf of reeds were 30.28, 14.85 and 6.18 microg x g(-1).

  10. Multi-stage ponds-wetlands ecosystem for effective wastewater treatment*

    PubMed Central

    Peng, Jian-feng; Wang, Bao-zhen; Wang, Lin

    2005-01-01

    The performance of the Dongying multi-stage ponds-wetlands ecosystem was investigated in this work. Study of the removal of different pollutants (BOD5, COD, SS, TP, TN, NH3-N, etc.) in different temperature seasons and different units in this system indicated that effluent BOD5 and SS were constant to less than 11 mg/L and 14 mg/L throughout the experimental processes; but that the removal efficiencies of pollutants such as TP, TN, NH3-N, COD varied greatly with season. The higher the temperature was, the higher was the observed removal in this system. Additionally, each unit of the system functioned differently in removing pollutants. BOD5 and SS were mainly removed in the first three units (hybrid facultative ponds, aeration ponds and aerated fish ponds), whereas nitrogen and phosphates were mainly removed in hydrophyte ponds and constructed reed wetlands. The multi-stage ponds-wetlands ecosystem exhibits good potential of removing different pollutants, and the effluent quality meet several standards for wastewater reuse. PMID:15822145

  11. Effect of natural dissolved organic carbon on phosphate removal by ferric chloride and aluminum sulfate treatment of wetland waters

    NASA Astrophysics Data System (ADS)

    Qualls, Robert G.; Sherwood, Lindsay J.; Richardson, Curtis J.

    2009-09-01

    The use of wetlands for the removal of excess N and P has become widespread. Some sensitive P-limited ecosystems, however, may require additional reductions in the concentration of P entering the system. It has been proposed that the treatment of wetlands through addition of ferric chloride or aluminum sulfate can augment the natural P removal mechanisms. However, high concentrations of natural dissolved organic matter may interfere with the removal of P by metal addition. We evaluated the doses of ferric chloride and aluminum sulfate necessary to reduce total P concentrations below 0.32 μM (10 μg/L) in water from the Northern Everglades, and we determined the effect of various concentrations (21, 38, and 60 mg/L) of natural dissolved organic carbon (DOC) on the removal of PO4 and total P. High concentrations of natural DOC inhibited both the short-term removal of PO4 and the longer-term removal of total P from the water column. Similar results were observed using 15 μM citric acid in an experiment to determine whether citric acid could effectively mimic the inhibition of phosphorus removal associated with natural DOC. Stoichiometry of these experiments indicates that the mechanism of natural DOC interference was not complexation of the metal ions by the DOC; we hypothesize that it could be adsorption to the terminal hydroxyl groups on a polynuclear Fe or Al colloid, effectively blocking the adsorption sites from a phosphate molecule. Also, the ability of citric acid to mimic the inhibitory effects also suggests that the results of the study are broadly applicable to wetland and other waters with high natural organic acid concentrations.

  12. A constructed wetland model for synthetic reactive dye wastewater treatment by narrow-leaved cattails (Typha angustifolia Linn.).

    PubMed

    Nilratnisakorn, S; Thiravetyan, P; Nakbanpote, W

    2009-01-01

    Textile wastewater is contaminated by reactive dye causing unattractive levels of wastewater color, high pH and high salt content when discharged into public water systems. Decolorization of textile wastewater by plant, phytoremediation, is an alternative, sustainable method which is suitable for long term operation. Narrow-leaved cattails are one species of wetland plant with efficiency for decolorizing and remediating textile wastewater. In addition, chemical oxygen demand (COD) can be lowered and dye residue can be removed. The plant also showed a good salt tolerance even after being exposed to a salt solution for 15 days. The narrow-leaved cattails were set up in a constructed wetland model with a vertical flow system operating from bottom to top for synthetic reactive dye wastewater (SRDW) removal. Narrow-leaved cattails could achieve the removal of SRDW at approximately 0.8 g(SRDW) m(-2) day(-1). Decolorization of SRDW by this plant was approximately 60%. The advantage of this method is that it is suitable for textile wastewater management and improvement of wetland. These plants could lower COD, remove dye, sodium and total dissolved solids (TDS) whereas other biological and chemical methods could not remove TDS and dye in the same time. These results suggested that the spongy cell structure of this plant has the ability to absorb large amounts of water and nutrients. Physico-chemical analysis revealed increasing amounts of sulfur, silicon, iron and calcium in the plant leafs and roots after exposure to wastewater. Proteins or amide groups in the plant might help in textile dye removal. Regarding decolorization, this plant accumulates dye in the intercellular space and still grows in this SRDW condition. Hence, it can be noted here that narrow-leaved cattails are efficient for textile dye wastewater treatment.

  13. Nitrification cessation and recovery in an aerated saturated vertical subsurface flow treatment wetland: Field studies and microscale biofilm modeling.

    PubMed

    Murphy, Clodagh; Rajabzadeh, Amin R; Weber, Kela P; Nivala, Jaime; Wallace, Scott D; Cooper, David J

    2016-06-01

    In aerated treatment wetlands, oxygen availability is not a limiting factor in sustaining a high level of nitrification in wastewater treatment. In the case of an air blower failure, nitrification would cease, potentially causing adverse effects to the nitrifying bacteria. A field trial was completed investigating nitrification loss when aeration is switched off, and the system recovery rate after the aeration is switched back on. Loss of dissolved oxygen was observed to be more rapid than loss of nitrification. Nitrate was observed in the effluent long after the aeration was switched off (48h+). A complementary modeling study predicted nitrate diffusion out of biofilm over a 48h period. After two weeks of no aeration in the established system, nitrification recovered within two days, whereas nitrification establishment in a new system was previously observed to require 20-45days. These results suggest that once established resident nitrifying microbial communities are quite robust. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. 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.

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

    PubMed

    Supowit, Samuel D; Sadaria, Akash M; Reyes, Edward J; Halden, Rolf U

    2016-02-02

    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.

  16. 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

  17. 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.

  18. Removal efficiency of a constructed wetland for wastewater treatment according to vegetation dominance.

    PubMed

    Maine, M A; Suñe, N; Hadad, H; Sánchez, G; Bonetto, C

    2007-06-01

    A free water surface wetland was built to treat wastewater containing metals (Cr, Ni and Zn) and nutrients from a tool factory in Santo Tomé, Santa Fe, Argentina. Eichhornia crassipes became dominant and covered about 80% of the surface throughout the first year, and decreased progressively until its disappearance. When water depth was lowered Typha domingensis steadily increased plant cover and attained 30% of the surface by the end of the study. While E. crassipes was dominant, the wetland retained 62% of the incoming Cr and 48% of the Ni. NO3- and NO2-, were also removed (65% and 78%, respectively), while dissolved inorganic phosphate (i-P(diss)) and NH4+ were not removed. Zn was below 50 microg l(-1) in both the influent and effluent. Metal concentration in the sediments did not increase and retention was mediated through macrophytes uptake. During the period of E. crassipes decline the wetland retained 49% of the incoming Cr, 45% of Ni, 58% NO3-, 94% NO2-, 58% NH4+ and 47% i-P(diss). Cr, Ni and Zn in the bottom sediment increased in the inlet but not in the outlet. Since T. domingensis became dominant, retention was 58% Cr, 48% Ni and 64% i-P(diss), while 79% NO3-, 84% NO2- and 13% NH4+ were removed. Metals in the bottom sediment increased in the inlet. In spite of the significant growth of E. crassipes at the beginning, T. domingensis remained after most of the transplanted macrophytes had disappeared. Macrophyte disappearance could be related to the overall toxicity of several environmental constrains as high pH and conductivity, metal concentration, and sulphide presence.

  19. 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.

  20. 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.

  1. The Cartridge Theory: a description of the functioning of horizontal subsurface flow constructed wetlands for wastewater treatment, based on modelling results.

    PubMed

    Samsó, Roger; García, Joan

    2014-03-01

    Despite the fact that horizontal subsurface flow constructed wetlands have been in operation for several decades now, there is still no clear understanding of some of their most basic internal functioning patterns. To fill this knowledge gap, on this paper we present what we call "The Cartridge Theory". This theory was derived from simulation results obtained with the BIO_PORE model and explains the functioning of urban wastewater treatment wetlands based on the interaction between bacterial communities and the accumulated solids leading to clogging. In this paper we start by discussing some changes applied to the biokinetic model implemented in BIO_PORE (CWM1) so that the growth of bacterial communities is consistent with a well-known population dynamics models. This discussion, combined with simulation results for a pilot wetland system, led to the introduction of "The Cartridge Theory", which states that the granular media of horizontal subsurface flow wetlands can be assimilated to a generic cartridge which is progressively consumed (clogged) with inert solids from inlet to outlet. Simulations also revealed that bacterial communities are poorly distributed within the system and that their location is not static but changes over time, moving towards the outlet as a consequence of the progressive clogging of the granular media. According to these findings, the life-span of constructed wetlands corresponds to the time when bacterial communities are pushed as much towards the outlet that their biomass is not anymore sufficient to remove the desirable proportion of the influent pollutants.

  2. The use of palm kernel shell (PKS) as substrate material in vertical-flow engineered wetlands for septage treatment in Malaysia.

    PubMed

    Jong, Valerie Siaw Wee; Tang, Fu Ee

    2015-01-01

    In this study, the treatment of septage (originating from septic tanks) was carried out in a pilot-scale, two-staged, vertical-flow engineered wetland (VFEW). Palm kernel shells (PKS) were incorporated as part of the VFEW's substrate (B-PKS), to compare its organic matter (OM) and nitrogen (N) removal efficiency against wetlands with only sand substrates (B-SD). The results revealed satisfactory OM removal with >90% reduction efficiencies at both wetlands B-PKS and B-SD. No increment of chemical oxygen demand (COD) concentration was observed in the effluent of B-PKS. Ammonia load removal efficiencies were comparable (>91% and 95% in wetland B-PKS and B-SD, respectively). However, nitrate accumulation was observed in the effluent of B-SD where PKS was absent. This was due to the limited denitrification in B-SD, as sand is free of carbon. A lower nitrate concentration was associated with higher COD concentration in the effluent at B-PKS. This study has shown that the use of PKS was effective in improving the N removal efficiency in engineered wetlands.

  3. Coastal wetlands

    SciTech Connect

    Prince, H.H.; d'Itri, F.M.

    1986-01-01

    This book presents an overview of coastal wetlands, mainly focusing on the Great Lakes ecosystem. Topics covered include the following: the effects of water level fluctuations on Great Lakes coastal marshes; environmental influences on the distribution and composition of wetlands in the Great Lakes Basin; vegetation dynamics, buried seeds, and water level fluctuations on the shorelines of the Great Lakes; preliminary observations on the flux of carbon, nitrogen, and phosphorous in a Great Lakes coastal marsh; nutrient cycling by wetlands and possible effects of water levels; and Avain wetland habitat functions affected by water level fluctuations.

  4. System design and treatment efficiency of a surface flow constructed wetland receiving runoff impacted stream water.

    PubMed

    Maniquiz, M C; Choi, J Y; Lee, S Y; Kang, C G; Yi, G S; Kim, L H

    2012-01-01

    This study reported the efficiency of a free water surface flow constructed wetland (CW) system that receives runoff impacted stream water from a forested and agricultural watershed. Investigations were conducted to examine the potential effect of hydraulic fluctuations on the CW as a result of storm events and the changes in water quality along the flow path of the CW. Based on the results, the incoming pollutant concentrations were increased during storm events and greater at the near end of the storm than at the initial time of storm. A similar trend was observed to the concentrations exiting the CW due to the wetland being a relatively small percentage of the watershed (<0.1%) that allowed delays in runoff time during storm events. The concentrations of most pollutants were significantly reduced (p < 0.05) except for nitrate (p = 0.5). Overall, this study suggests that the design of the system could feasibly function for the retention of most pollutants during storm events as the actual water quality of the outflow was significantly better by 21-71% than the inflow and the levels of pollutants were reduced to appreciable levels.

  5. Evaluation of Ageratum conyzoides in field scale constructed wetlands (CWs) for domestic wastewater treatment.

    PubMed

    Tilak, A S; Wani, Suhas P; Datta, A; Patil, M D; Kaushal, M; Reddy, K R

    2017-05-01

    Ageratum conyzoides were evaluated in field scale subsurface flow constructed wetlands (CWs) to quantify its nitrogen (N) and phosphorus (P) uptake and compare with wetland plants (Pistia stratiotes, Typha latifolia and Canna indica). The two-field scale subsurface flow CWs, located in the International Crops Research Institute for Semi-Arid Tropics, received wastewater from an urban colony. The CW1 and CW2 had the same dimensions (length:10 m, width:3 m, total depth:1.5 m and sand and gravel:1 m), similar flow rates (3 m(3)/d), hydraulic loading rates (HLRs-10 cm/d) and hydraulic retention time (HRT-5 days) from July 2014-August 2015. The vegetation in both CWs consisted of Pistia stratiotes, Typha latifolia, Canna indica, and Ageratum conyzoides, respectively. The CW1 (% reduction with respect to concentrations) reduced total suspended solids (TSS) (68%), NH4-N (26%), NO3-N (30%), soluble reactive P (SRP) (20%), chemical oxygen demand (COD) (45%) and fecal coliforms (71%), while the CW2 (%-reduction with respect to concentrations) reduced TSS (63%), NH4-N (32%), NO3-N (26%), SRP (35%), COD (39%) and fecal coliforms (70%). Ageratum conyzoides can be used in combination with Pistia stratiotes, Typha latifolia and Canna indica to enhance removal of excessive N, P and fecal coliforms from domestic wastewater.

  6. Comparison of horizontal and vertical constructed wetland systems for landfill leachate treatment.

    PubMed

    Yalcuk, Arda; Ugurlu, Aysenur

    2009-05-01

    The main purpose of this study was to treat organic pollution, ammonia and heavy metals present in landfill leachate by the use of constructed wetland systems and to quantify the effect of feeding mode. The effect of different bedding material (gravel and zeolite surface) was also investigated. A pilot-scale study was conducted on subsurface flow constructed wetland systems operated in vertical and horizontal mode. Two vertical systems differed from each other with their bedding material. The systems were planted with cattail (Typha latifolia) and operated identically at a flow rate of 10 l/day and hydraulic retention times of 11.8 and 12.5 day in vertical 1, vertical 2 and horizontal systems, respectively. Concentration based average removal efficiencies for VF1, VF2 and HF were NH(4)-N, 62.3%, 48.9% and 38.3%; COD, 27.3%, 30.6% and 35.7%; PO(4)-P, 52.6%, 51.9% and 46.7%; Fe(III), 21%, 40% and 17%, respectively. Better NH(4)-N removal performance was observed in the vertical system with zeolite layer than that of the vertical 2 and horizontal system. In contrast, horizontal system was more effective in COD removal.

  7. Transformation of chloroform in model treatment wetlands: from mass balance to microbial analysis.

    PubMed

    Chen, Yi; Wen, Yue; Zhou, Junwei; Zhou, Qi; Vymazal, Jan; Kuschk, Peter

    2015-05-19

    Chloroform is one of the common disinfection byproducts, which is not susceptible to degradation and poses great health concern. In this study, the chloroform removal efficiencies and contributions of sorption, microbial degradation, plant uptake, and volatilization were evaluated in six model constructed wetlands (CWs). The highest chloroform removal efficiency was achieved in litter-added CWs (99%), followed by planted (46-54%) and unplanted CWs (39%). Mass balance study revealed that sorption (73.5-81.2%) and microbial degradation (17.6-26.2%) were the main chloroform removal processes in litter-added CWs, and that sorption (53.6-66.1%) and plant uptake (25.3-36.2%) were the primary contributors to chloroform removal in planted CWs. Around 60% of chloroform got accumulated in the roots after plant uptake, and both transpiration and gas-phase transport were expected to be the drivers for the plant uptake. Sulfate-reducing bacteria and methanogens were found to be the key microorganisms for chloroform biodegradation through cometabolic dechlorination, and positive correlations were observed between functional genes (dsrA, mcrA) and biodegradation rates. Overall, this study suggests that wetland is an efficient ecosystem for sustainable chloroform removal, and that plant and litter can enhance the removal performance through root uptake and microbial degradation stimulation, respectively.

  8. 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 (...

  9. 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; Sheu, R; Rosenzweig, K

    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 carried 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.

  10. 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; Liu, X; Stingo, F; Followill, D; Mirkovic, D; Howell, R; Kry, S

    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. CT 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 dental

  11. 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 (NH4(+) -N) was added to evaluate the dominant NH4(+) -N removal pathway. The results showed that 98.8% of NH4(+) -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 NH4(+) -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 N2 O flux constituted only 7.5% of total gas losses. The dynamics of NO3(-) -N and N2 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.

  12. 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; Pogue, B; Jarvis, L; Gladstone, D

    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 to 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 skin

  13. Feasibility of Typha latifolia for high salinity effluent treatment in constructed wetlands for integration in resource management systems.

    PubMed

    Jesus, J M; Calheiros, C S C; Castro, P M L; Borges, M T

    2014-01-01

    High salinity wastewaters have limited treatment options due to the occurrence of salt inhibition in conventional biological treatments. Using recirculating marine aquaculture effluents as a case study, this work explored the use of Constructed Wetlands as a treatment option for nutrient and salt loads reduction. Three different substrates were tested for nutrient adsorption, of which expanded clay performed better. This substrate adsorbed 0.31 mg kg(-1) of NH4(+)-N and 5.60 mg kg(-1) of PO4(3-)-P and 6.9 mg kg(-1) dissolved salts after 7 days of contact. Microcosms with Typha latifolia planted in expanded clay and irrigated with aquaculture wastewater (salinity 2.4%, 7 days hydraulic retention time, for 4 weeks), were able to remove 94% NH(4+)-N (inlet 0.25 +/- 0.13 mg L(-1)), 78% NO2(-)-N (inlet 0.78 +/- 0.62 mg L(-1)), 46% NO3(-)-N (inlet 18.83 +/- 8.93 mg L(-1)) whereas PO4(3-)-P was not detected (inlet 1.41 +/- 0.21 mg L(-1)). Maximum salinity reductions of 52% were observed. Despite some growth inhibition, plants remained viable, with 94% survival rate. Daily treatment dynamics studies revealed rapid PO4(3-)-P adsorption, unbalancing the N:P ratio and possibly affecting plant development. An integrated treatment approach, coupled with biomass valorization, is suggested to provide optimal resource management possibilities.

  14. Wetland Loss.

    ERIC Educational Resources Information Center

    Barrett, Marilyn

    1994-01-01

    Examines what wetland conservation means to different groups of Louisiana's coastal residents. Describes coastal resources, reasons for their deterioration, conservation efforts, and the impact of a public perception that conservation of wetlands is closely tied to conservation of the existing lifestyle. (LZ)

  15. Exploring Wetlands.

    ERIC Educational Resources Information Center

    Kerr, Elizabeth; Harrison, Gordon

    1996-01-01

    Presents a wetlands education model for secondary education students. Students monitor a wetland, participate in decision-making, and take actions to protect it. In a series of six steps, the model guides students through the process of defining a problem; envisioning solutions; evaluating appropriate solutions based on environmental, economic and…

  16. 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)

  17. Wetland Loss.

    ERIC Educational Resources Information Center

    Barrett, Marilyn

    1994-01-01

    Examines what wetland conservation means to different groups of Louisiana's coastal residents. Describes coastal resources, reasons for their deterioration, conservation efforts, and the impact of a public perception that conservation of wetlands is closely tied to conservation of the existing lifestyle. (LZ)

  18. Exploring Wetlands.

    ERIC Educational Resources Information Center

    Kerr, Elizabeth; Harrison, Gordon

    1996-01-01

    Presents a wetlands education model for secondary education students. Students monitor a wetland, participate in decision-making, and take actions to protect it. In a series of six steps, the model guides students through the process of defining a problem; envisioning solutions; evaluating appropriate solutions based on environmental, economic and…

  19. 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)

  20. 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...

  1. The effect of vegetation on pesticide dissipation from ponded treatment wetlands: quantification using a simple model.

    PubMed

    Rose, Michael T; Crossan, Angus N; Kennedy, Ivan R

    2008-07-01

    Field data shows that plants accelerate pesticide dissipation from aquatic systems by increasing sedimentation, biofilm contact and photolysis. In this study, a graphical model was constructed and calibrated with site-specific and supplementary data to describe the loss of two pesticides, endosulfan and fluometuron, from a vegetated and a non-vegetated pond. In the model, the major processes responsible for endosulfan dissipation were alkaline hydrolysis and sedimentation, with the former process being reduced by vegetation and the latter enhanced. Fluometuron dissipation resulted primarily from biofilm reaction and photolysis, both of which were increased by vegetation. Here, greater photolysis under vegetation arose from faster sedimentation and increased light penetration, despite shading. Management options for employing constructed wetlands to polish pesticide-contaminated agricultural runoff are discussed. The lack of easily fulfilled sub-models and data describing the effect of aquatic vegetation on water chemistry and sedimentation is also highlighted.

  2. [Analysis of microorganism species diversity in plant intercropping models in a wetland system constructed for treatment of municipal sewage].

    PubMed

    Chen, Yong-Hua; Wu, Xiao-Fu; Chen, Ming-Li; Zhang, Zhen-Ni; Li, Ke-Lin; Wang, Zhong-Cheng; Lei, Dian

    2011-08-01

    The selective culture method and PCR-DGGE technology were applied to analyze the number and the biodiversity of microorganism species in cells with plant intercropping models and without plants in different seasons in a wetland system constructed for treatment of municipal sewage. The results showed that the numbers of microorganisms were considerably larger in the cells with plant intercropping models than those without plants, while the number of microorganisms was apparently larger in summer than that in winter in all treatments. Along the three-sequenced treatment cells with plant intercropping models a "low-high-low" changing trend in the numbers of microorganisms in summer. The UPGMA cluster analysis showed that the treatments in the same season were clustered in the same branch except for a few samples in winter and the biodiversity index was consistently higher in summer than that in winter. Five different sequences (DF1-DF5) were obtained through BLAST analysis and retrieval. The closest known origin groups were located as Escherichia coli, Citrobacter sp., Proteus sp., Klebsiella oxytoca, and Burkholderia sp. respectively. The BLASTX comparison test showed that DF1 closely related to the activities of the Mycobacterium bacillus and the Bacillus amyloliquefaciens, DF2 functioned as a conservative potential ATP binding protein, DF3 related to the activities of the Bacillus cereus spore, DF4 was involved in catabolism metabolism of microorganism and DF5 played an important role in decomposition of organic matters.

  3. Performance evaluation of wastewater treatment using horizontal subsurface flow constructed wetlands optimized by micro-aeration and substrate selection.

    PubMed

    Zhong, Fei; Wu, Juan; Dai, Yanran; Xiang, Dongfang; Cheng, Shuiping; Ji, Hongjiu

    2015-01-01

    The effects of micro-aeration and substrate selection on domestic sewage treatment performance were explored using three pairs (with or without micro-aeration) of horizontal subsurface flow (HSSF) constructed wetlands (CWs) filled with zeolite, ceramsite or quartz granules. The individual and combined effects of micro-aeration and substrate selection on the purification performance of the experimental-scale HSSF CWs were evaluated. The results showed that micro-aeration significantly increased the treatment efficiencies for chemical oxygen demand, total nitrogen, total phosphorus (TP), ortho-phosphate (PO4(3-)-P) and ammonium nitrogen (NH4+-N) using HSSF CWs, while the substrate selection significantly affected the TP, PO4(3-)-P and NH4+-N removal efficiencies (p<0.05). A two-way analysis of variance (ANOVA) indicated that there was a significant interaction term (i.e. micro-aeration×substrate selection) for NH4+-N removal (p<0.05). Among the three substrates, ceramsite was the best substrate for the treatment of domestic sewage using HSSF CWs. Therefore, the results of this study suggest that a ceramsite-filled HSSF CW with micro-aeration could be the optimal configuration for decentralized domestic sewage treatment.

  4. A pilot-scale study of domestic wastewater treatment by different type constructed wetland systems and its potential green house gases emissions

    NASA Astrophysics Data System (ADS)

    Xu, K.; Liu, C.; Gui, P.; Ebie, Y.; Inamori, Y.

    2007-12-01

    Constructed wetland (CV) systems are reliable, flexible in design, and can be built, operated, and maintained at lower costs compared to conventional methods of chemical treatment. There for CW systems are widely used for controlling water-body eutrophication as an ease-operation and cost-effective ecological technology in developing countriens. However, growing attention has been directed to its greenhouse side-effect and global-warming potential in recent years. In this study, three typical constructed wetlands: Vertical Flow (VF), Free Water Surface (FWS) and Subsurface Flow (SF), and combined VF-SF-FWS constructed wetlands were used not only to compare the nutrients removal performance for treatment of low C/N ratio loading domestic wastewater, but also to investigate and compare their CH4 and N2O greenhouse gas emissions characteristics. The results indicated that the four types of CWs had high removal efficiencies for organic matter and SS. Moreover, the combined wetland also showed a comparatively good performance for nitrogen and phosphorus removal, which was 93.6%, 92.8%, 81.3% and 84.5% for BOD5, SS, TN and TP, respectively. It was found that the combined CW and VF CW has a comparative lower global warming potential. The FWS CW had the highest tendency to emit CH4 and led to a higher global warming potential among four types of CWs, which was about the same as 425mgCO2/m2/h.

  5. A comparative study of vertical flow and free-water surface constructed wetlands for low C/N ratio domestic wastewater treatment and its greenhouse gases emission

    NASA Astrophysics Data System (ADS)

    Xu, K.; Liu, C.; Ebie, Y.; Inamori, Y.

    2008-12-01

    Constructed wetland (CW) systems are reliable, flexible in design, and can be built, operated, and maintained at lower costs compared to conventional methods of chemical treatment. Therefore, CW systems are widely used for controlling water-body eutrophication as an ease-operation and cost-effective ecological technology in developing countries. However, growing attention has been directed to its greenhouse side-effect and global-warming potential in recent years. In this study, two typical constructed wetlands: Vertical flow (VF) and Free-water surface (FWS) constructed wetlands were used not only to compare the nutrients removal performance for treatment of low C/N ratio loading domestic wastewater, but also to investigate and compare their CH4 and N2O greenhouse gases emission characteristics. The results indicated that the VF CW showed a comparatively good performance for nitrogen and phosphorus removal than FWS constructed wetland, which was 98.5, 95.9, 93.2 and 90.7 percent for BOD5, SS, NH4-N and TP under 6 days HRT, respectively. It was found that the FWS CW had the higher tendency to emit CH4 than the VF CW during four seasons of one year.

  6. 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.

  7. 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...

  8. 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...

  9. Emission of greenhouse gases from constructed wetlands for wastewater treatment and from riparian buffer zones.

    PubMed

    Mander, U; Teiter, S; Augustin, J

    2005-01-01

    We measured N2O, CH4 and CO2 fluxes in horizontal and vertical flow constructed wetlands (CW) and in a riparian alder stand in southern Estonia using the closed chamber method in the period from October 2001 to November 2003. The average rates of N20, CH4 and CO2 emission from the riparian gray alder stand were from -0.4 to 58 microg N2O-N m(-2) h(-1) and 0.1-265 microg CH4-C m(-2) h(-1), 55-61 mg CO2-C m(-2) h(-1), respectively. The average N2O-N emission from the microsites above the inflow pipes of horizontal subsurface flow (HSSF) CWs was 6.4-31 microg N2O-N m(-2) h(-1), whereas the outflow microsites emitted 2.4-8 microg N2O-N m(-2) h(-1). In vertical subsurface flow (VSSF) beds the same value was 35.6-44.7 microg N2O-N m(-2) h(-1). The average CH4 emission from the inflow and outflow microsites in the HSSF CWs differed significantly ranging from 640 to 9715 and from 30 to 770 microg CH4-C m(-2) h(-1), respectively. The average CO2 emission was somewhat higher in VSSF beds (140-291 mg CO2-C m(-2) h(-1)) and at inflow microsites of HSSF beds (61-140 mg CO2-C m(-2) h(-1)). The global warming potential (GWP) from N2O and CH4 was comparatively high in both types of CWs (4.8 +/- 9.8 and 6.8 +/- 16.2 t CO2 eq ha(-1) a(-1) in the HSSF CW 6.5 +/- 13.0 and 5.3 +/- 24.7 t CO2 eq ha(-1) a(-1) in the hybrid CW, respectively). The GWP of riparian alder forest from both N2O and CH4 was relatively low (0.4 +/- 1.0 and 0.1 +/- 0.30 t CO2 eq ha(-1) a(-1), respectively), whereas the CO2-C flux was remarkable (3.5 +/- 3.7 t ha(-1) a(-1). The global influence of CWs is not significant. Even if all the global domestic wastewater were treated by wetlands, their share in the trace gas emission budget would be less than 1%.

  10. 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%), NH4(+)-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 NH4(+)-N for biochar-packed VFCWs. The phosphorus removal was dependent on the media adsorption capacities through the whole experiment. However, the NH4(+)-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.

  11. 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 (BOD5) 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.

  12. Management of arsenic-accumulated waste from constructed wetland treatment of mountain tap-water.

    PubMed

    Nakwanit, Sannop; Visoottiviseth, Pornsawan; Khokiattiwong, Somkiat; Sangchoom, Wantana

    2011-01-30

    Arsenic-contaminated mountain tap water supply in Ron Phibun District, Nakorn Si Thammarat Province, Thailand poses a health hazard. Arsenic was removed using a constructed wetland (CW) system, in which the treated contaminated tap water was sedimented in 3 consecutive ponds before entering into the CW ponds, containing either Cyperus spp. or Colocasia esculenta. Following 1 year of operation both plants had similar ability to remove arsenic from mountain tap water. Arsenic was mostly concentrated at the roots of both plants. Arsenic in C. esculenta leaves was allowed to leach out in freshwater for 149 days, but the level (0.05 mg L(-1)) was much lower than standard guidelines for industrial discharge. For Cyperus spp., young shoots were utilized as ornamental plants. As the sediments contained high arsenic levels, they were converted by a solidification/stabilization (S/S) system into cement-containing blocks, which after curing for 21 days produced arsenic leaching at levels that did not require a secure landfill for storage. The success of this study demonstrated that CW combined with appropriate S/S system is a suitable approach for Thailand in removing arsenic from contaminated water.

  13. Assessment of uncertainty in constructed wetland treatment performance and load estimation methods.

    PubMed

    Eskelinen, Riku; Ronkanen, Anna-Kaisa; Marttila, Hannu; Kløve, Bjørn

    2016-06-01

    Constructed wetlands (CWs) are commonly established to reduce pollution load from different sources. In environmental permits, the load remaining after CW purification is typically estimated through concentration and flow measurements. This load monitoring is often carried out using long water quality sampling intervals, which causes uncertainty in load estimation. In this study, a large suspended solids (SSs) and dissolved organic carbon (DOC) dataset was used to quantify the uncertainty in load estimation at the inlet and outlet of a CW with different sampling frequencies (sampling every 1, 2, 3 or 4 weeks). A method to reduce the uncertainty by dividing the CW flow duration curve (FDC) into four equal categories and assigning mean/median concentration for each category according to the measured concentrations was also tested. The results showed that estimated SS load was associated with considerable uncertainty and that this uncertainty increased with lower sampling frequency. The FDC method was able to decrease the uncertainty, but much still remained, especially when concentrations of the measured variable showed great variation. In such cases, sensor technology might be a feasible option for further reducing the uncertainty.

  14. 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.

  15. Treatment of industrial wastewater with two-stage constructed wetlands planted with Typha latifolia and Phragmites australis.

    PubMed

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

    2009-07-01

    Industrial wastewater treatment comprises several processes to fulfill the discharge permits or to enable the reuse of wastewater. For tannery wastewater, constructed wetlands (CWs) may be an interesting treatment option. Two-stage series of horizontal subsurface flow CWs with Phragmites australis (UP series) and Typha latifolia (UT series) provided high removal of organics from tannery wastewater, up to 88% of biochemical oxygen demand (BOD(5)) (from an inlet of 420 to 1000 mg L(-1)) and 92% of chemical oxygen demand (COD) (from an inlet of 808 to 2449 mg L(-1)), and of other contaminants, such as nitrogen, operating at hydraulic retention times of 2, 5 and 7 days. No significant (P<0.05) differences in performance were found between both the series. Overall mass removals of up to 1294 kg COD ha(-1)d(-1) and 529 kg BOD(5)ha(-1)d(-1) were achieved for a loading ranging from 242 to 1925 kg COD ha(-1)d(-1) and from 126 to 900 kg BOD(5)ha(-1)d(-1). Plants were resilient to the conditions imposed, however P. australis exceeded T. latifolia in terms of propagation.

  16. Evidence and implications of the background phosphorus concentration of submerged aquatic vegetation wetlands in Stormwater Treatment Areas for Everglades restoration

    NASA Astrophysics Data System (ADS)

    Juston, John M.; Debusk, Thomas A.

    2011-01-01

    The limits of phosphorus (P) removal from the 18,120 ha Stormwater Treatment Areas (STAs) for Everglades restoration depend largely on the performance of submerged aquatic vegetation (SAV) wetlands, as SAV treatment cells now provide final stage treatment for 85% of the STA project. A long-term internal P profile in STA-2 cell 3 (STA2C3), one of the longest-running and best performing SAV cells, demonstrated no further net removal in the back quarter of the cell once total P (TP) levels approached 15 μg L-1. Inflow-outflow performance data from STA2C3 were analyzed at monthly and annual scales and were pooled with data from an additional eight STA SAV treatment cells. The pooled data allowed inference of background TP concentrations in SAV treatment cells using existing Bayesian methods. Results showed a central tendency of 16 μg L-1 (13-17, 90% bounds), insensitivity to P loads less than ˜1.7 g m-2 yr-1, and interannual variability outside these bounds. Internal data from the STA2C3 profile provided validation. Background P concentrations of 7 and 6 μg L-1 were identified for dissolved organic and particulate P fractions in the data pool, respectively, again similar to values in the STA2C3 gradient. Existing simulation modeling approaches for STA evaluations were identified as ineffective at or near background TP concentrations. Instead, we use an empirical and probabilistic approach based on full-scale data from STAs that produces annual risk of exceedance statistics and is easy to update. The current analysis suggests tangible risks for exceeding proposed annual discharge criteria from the STAs in the range of 16-20 μg L-1.

  17. 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)

  18. 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)

  19. 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 BOD5/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.

  20. Internal loading of phosphorus in a sedimentation pond of a treatment wetland: effect of a phytoplankton crash.

    PubMed

    Palmer-Felgate, Elizabeth J; Mortimer, Robert J G; Krom, Michael D; Jarvie, Helen P; Williams, Richard J; Spraggs, Rachael E; Stratford, Charlie J

    2011-05-01

    Sedimentation ponds are widely believed to act as a primary removal process for phosphorus (P) in nutrient treatment wetlands. High frequency in-situ P, ammonium (NH(4)(+)) and dissolved oxygen measurements, alongside occasional water quality measurements, assessed changes in nutrient concentrations and productivity in the sedimentation pond of a treatment wetland between March and June. Diffusive equilibrium in thin films (DET) probes were used to measure in-situ nutrient and chemistry pore-water profiles. Diffusive fluxes across the sediment-water interface were calculated from the pore-water profiles, and dissolved oxygen was used to calculate rates of primary productivity and respiration. The sedimentation pond was a net sink for total P (TP), soluble reactive P (SRP) and NH(4)(+) in March, but became subject to a net internal loading of TP, SRP and NH(4)(+) in May, with SRP concentrations increasing by up to 41μM (1300μl(-1)). Reductions in chlorophyll a and dissolved oxygen concentrations also occurred at this time. The sediment changed from a small net sink of SRP in March (average diffusive flux: -8.2μmolm(-2)day(-1)) to a net source of SRP in June (average diffusive flux: +1324μmolm(-2)day(-1)). A diurnal pattern in water column P concentrations, with maxima in the early hours of the morning, and minima in the afternoon, occurred during May. The diurnal pattern and release of SRP from the sediment were attributed to microbial degradation of diatom biomass, causing reduction of the dissolved oxygen concentration and leading to redox-dependent release of P from the sediment. In June, 2.7mol-Pday(-1) were removed by photosynthesis and 23mol-Pday(-1) were supplied by respiration in the lake volume. SRP was also released through microbial respiration within the water column, including the decomposition of algal matter. It is imperative that consideration to internal recycling is given when maintaining sedimentation ponds, and before the installation of new

  1. 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...

  2. 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...

  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. Project 15: McIntosh enhanced stormwater treatment wetland best management practice

    USDA-ARS?s Scientific Manuscript database

    This study will quantify the effectiveness of best management practice (BMP) in enhancing the treatment of stormwater runoff. By combining treatment mechanisms in series rather than using a single method of treatment for stormwater, the overall levels and reliability of pollutant removal can be impr...

  5. 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.

  6. Physical-chemical characterization of sludge and granular materials from a vertical flow constructed wetland for municipal wastewater treatment.

    PubMed

    Kim, B; Gautier, M; Michel, P; Gourdon, R

    2013-01-01

    The use of vertical flow constructed wetlands (VFCWs) is well developed in France and other countries for the treatment of wastewaters from small communities. The patented Azoé® process has been developed by a French company, SCIRPE, in order to improve denitrification and phosphorus removal as compared to classical VFCWs. It includes a biological trickling filter pretreatment followed by two stages of partially flooded VFCW. The performances of partially flooded VFCW are well demonstrated for the removal of organic matter and nitrogen. The system is now being considered for phosphorus removal as well. In this article, sludge and granular materials sampled from the filters of a municipal plant where the Azoé® system has been operated for 8 years were analyzed in order to provide data that may contribute to a better understanding of the dynamics of phosphorus retention. Elemental analyses showed that phosphorus was predominantly captured in the sludge layer accumulated at the surface of the first stage. The progressive mineralization of the sludge over time was also clearly highlighted. The phosphate phases were mainly associated with iron and calcium. The transport of phosphorus via the migration of fine particles through the porous medium in the first stage was also observed.

  7. A lab-scale study of constructed wetlands with sugarcane bagasse and sand media for the treatment of textile wastewater.

    PubMed

    Saeed, Tanveer; Sun, Guangzhi

    2013-01-01

    This paper reports the pollutant removal efficiencies of two lab-scale hybrid wetland systems treating a textile wastewater. The two systems had identical configurations, each consisting of a vertical flow (VF) and a horizontal flow (HF) wetland that were filled with organic sugarcane bagasse and sylhet sand as the main media. The systems were operated under high hydraulic loading (HL) (566-5660 mm/d), and inorganic nitrogen (254-508 gN/m(2) d) and organics loadings (9840-19680 g COD/m(2) d and 2154-4307 g BOD(5)/m(2) d). Simultaneous removals of BOD(5) (74-79%) and ammonia (59-66%) were obtained in the first stage VF wetlands, demonstrating the efficiency of the media for oxygen transfer to cope with the high pollutant loads. The organic carbon (C) content of sugarcane bagasse facilitated denitrification in the VF wetlands. Second stage HF wetlands provided efficient color removal under predominantly anaerobic condition. Overall, the wetland systems showed stable removal performances under high, and unsteady, pollutant loadings.

  8. A practical method for the restoration of clogged rural vertical subsurface flow constructed wetlands for domestic wastewater treatment using earthworm.

    PubMed

    Li, Huaizheng Z; Wang, Sheng; Ye, Jianfeng F; Xu, Zuxin X; Jin, Wei

    2011-01-01

    This paper presents a simple method for the restoration of clogged vertical subsurface flow constructed wetland by earthworm. Since clogging always takes place at the top layer, epigeic earthworm is suitable for restoration of the clogged wetland. Earthworm can not only loosen the substrate, but also transform 80∼90% of undissolved organic particles into dissolved matters. Accordingly, the accumulated solids in substrate with earthworm are 50% less than the one without earthworm. The wetland with earthworm removed 2∼5 percentage points more nitrogen and 12 percentage points more phosphorous for its better ventilation conditions, while 2 percentage points less COD because the generation of dissolved organic matter from undissolved organic particles by earthworm. In general, the influence of earthworm on the effluent quality of the wetland could be ignored. Hydrology of six full-scale clogged wetlands was restored by Eisenia foetida. The optimal strength of earthworm addition is 0.5 kg/m2, which spend RMB six yuan/m2, less than € 0.75/m2. No specific training is required for the staffs on this method; it takes 10 days to restore the clogged wetland.

  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. Performance of a wetland/anoxic limestone drain treatment system at the Douglas abandoned mine land project

    SciTech Connect

    Sterner, P.L.; Cliff, J.B.; Skousen, J.G.; Sexstone, A.J.

    1996-12-31

    Acid Mine Drainage (AMD) exiting West Virginia`s Abandoned Mine Land (AML) sites often is remediated using passive treatment systems. A new passive treatment technology which employs a combination wetland/anoxic limestone drain (WALD) is currently being evaluated at one AML site near Thomas, WV. The WALD utilizes a three cell design to complete treatment. Cell 1 (dimensions 365.8m x 2.5m x 1.8m- L x W x D) employs a 0.6m base of limestone overlain by 1.2m of organic material. Cell 2 (dimensions 457.2m x 9.1m x 2.4m) employs a 1.5m limestone base overlain by 0.9m of organic material. Cell 3 (dimensions 25m x 9.1 in x 1.2m) is a sedimentation basin which allows deposition of precipitating metals. Thirteen polyvinyl chloride (PVC) cylinders with multiple ports were installed throughout the system so that water sampling at various locations and depths can be conducted. The working hypotheses to be tested is whether microbial iron reduction in organic sediments is sufficient to prevent limestone coating by iron oxyhydroxides, thus allowing continuous limestone dissolution and subsequent pH increase of the treated AMD. Influent water enters the system via surface flow at a rate of approximately 240 gpm from pipes draining an underground coal mine. Average influent AMD parameters over the study period were: pH = 3.0, total acidity = 426 mg/L, total alkalinity = 0 mg/L, total iron = 20 mg/L, total manganese = 6 mg/L and aluminum = 31 mg/L. Results based on effluent water quality indicate that AMD is being treated by the WALD.

  11. Metals Retention in Constructed Wetland Sediments

    SciTech Connect

    KNOX, ANNA

    2004-10-27

    The A-01 wetland treatment system (WTS) was designed to remove metals from the effluent at the A-01 NPDES outfall at the Savannah River Site, Aiken, SC. Sequential extraction data was used to evaluate remobilization and retention of Cu, Pb, Zn, Mn, and Fe in the wetland sediment. Remobilization of metals was determined by the Potentially Mobile Fraction (PMF) and metal retention by the Recalcitrant Factor (RF). The PMF, which includes water soluble, exchangeable, and oxides fractions, is the contaminant fraction that has the potential to enter into the mobile aqueous phase under changeable environmental conditions. PMF values were low for Cu, Zn and Pb (about 20 percent) and high for Fe and Mn (about 60 to 70 percent). The RF, which includes crystalline oxides, sulfides or silicates and aluminosilicates, is the ratio of strongly bound fractions to the total concentration of elements in sediment. RF values were about 80 percent for Cu, Zn and Pb, indicating high retention in the sediment and 30 percent to above 40 percent for Fe and Mn indication low retention.

  12. Behavior of Typha angustifolia L. in a free water surface constructed wetlands for the treatment of swine wastewater.

    PubMed

    De Los Reyes, Catalina Plaza; Villamar, Cristina A; Neubauer, María Elisa; Pozo, Guillermo; Vidal, Gladys

    2013-01-01

    The objective of this study was to evaluate the behavior of Typha angustifolia L. in nitrogen retention in a Free Water Surface Constructed Wetland (FWS) for the swine wastewater treatment over a three-year operating period. Results show that the behavior of Typha angustifolia L. in a FWS for treatment of swine wastewater is affected by nitrogen concentration, seasonal variation and plant establishment in the system. Indeed, the application of Nitrogen Loading Rates (NLR) between 7.1-14.3 kg TN/ha·d removes 40% of Total Nitrogen (TN), where the maximum removal (20-40%) takes place in the spring-summer seasons. However, concentrations higher than 120.3 mg NH4 (+)-N/L significantly decrease (P = 0.004) diametrical growth by 55%. However, it was possible to estimate that NLR >14.3 kg TN/ha·d increased biomass production and plant uptake in Typha angustifolia L. during the period analyzed. Additionally, aboveground biomass values were between 1.509.6-2.874.0 g/m(2) and nitrogen uptake 27.4-40.8 g/m(2), where this last value represents 29% of the TN applied during the study. Finally, the TN accumulation in sediments represents less than 2% of the TN incorporated during this period. These results show that an increase of 50% of the TN in sediments increases plant abundance in 73%, which is related to the mineralization processes favored in the system during the last year of operation.

  13. 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...

  14. 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...

  15. 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 NO3(-)-N·m(-2) d(-1) and 2.74 g SO4(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 NO2(-)-N and NH4(+)-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 sulfate

  16. Vertical flow constructed wetlands for municipal wastewater and septage treatment in French rural area.

    PubMed

    Paing, J; Voisin, J

    2005-01-01

    This paper presents the purification performance of 20 wastewater treatment plants with vertical reed bed filters (Macrophyltres), built between 1998 and 2003 by SAS Voisin, for communities of between 150 and 1400 PE. The first stage vertical reed bed (directly fed with raw wastewater by intermittent feeding) achieved high removal of SS, BOD and COD (mean respectively 96%, 98%, 92%). The second stage permitted compliance easily with effluent standards (SS < 15 mg/l, BOD < 15 mg/l, COD < 90 mg/l and mean TKN < 10 mg/l). Performance was not significantly influenced by variations of organic and hydraulic load, nor by seasonal variations. Rigorous operation and maintenance were required to obtain optimal performances. Another application of vertical reed beds is the treatment of septage (sludge from individual septic tanks). The results obtained on two sites operating for 2 and 3 years are presented. The first site achieved complete treatment of septage (solid and liquid fraction), the second permitted a pre-treatment for co-treatment of percolate with wastewater.

  17. 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...

  18. Atrazine remediation in wetland microcosms.

    PubMed

    Runes, H B; Bottomley, P J; Lerch, R N; Jenkins, J J

    2001-05-01

    Laboratory wetland microcosms were used to study treatment of atrazine in irrigation runoff by a field-scale-constructed wetland under controlled conditions. Three experiments, in which 1 ppm atrazine was added to the water column of three wetland, one soil control, and one water control microcosm, were conducted. Atrazine dissipation from the water column and degradate formation (deethylatrazine [DEA]; deisopropylatrazine [DIA]; and hydroxyatrazine [HA]) were monitored. Atrazine dissipation from the water column of wetland microcosms was biphasic. Less than 12% of the atrazine applied to wetland microcosms remained in the water column on day 56. Atrazine degradates were observed in water and sediment, with HA the predominant degradate. Analysis of day 56 sediment samples indicated that a significant portion of the initial application was detected as the parent compound and HA. Most probable number (MPN) assays demonstrated that atrazine degrader populations were small in wetland sediment. Wetland microcosms were able to reduce atrazine concentration in the water column via sorption and degradation. Based on results from this study, it is hypothesized that plant uptake contributed to atrazine dissipation from the water column.

  19. 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 ...

  20. 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 ...

  1. 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)

  2. Coastal 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 materials. The material is designed for use with Connecticut schools, but it can be adapted to other localities. The unit materials emphasize the structure,…

  3. 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)

  4. 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…

  5. [Treatment of marine-aquaculture effluent by the multi-soil-layer (MSL) system and subsurface flow constructed wetland].

    PubMed

    Song, Ying; Huang, Yu-ting; Ge, Chuan; Zhang, Hao; Chen, Xin; Zhang, Zhi-jianz; Luo, An-cheng

    2014-09-01

    To evaluate the feasibility of using multi-soil-layer (MSL) system and subsurface flow constructed wetland to treat the wastewater of marine cultured Penaeus vannamei and to determine the suitable process for the local aquaculture wastewater pollution characteristics. In this study, MSL system and four constructed wetland systems with Spartina anglica, Phragmites australis, Typha latifolia and unplanted system were evaluated for their potentials of pollutants removal capacity. The results showed the average removal rates of chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH(4)+ -N) and nitrate (NO-(3) -N) by MSL system were 80. 38% ± 2. 14% , 68. 14% ± 3.51% , 40.79% ± 3. 10% , 42. 68% ± 2.90% and 54. 19% ± 5. 15% , respectively. Additionally, the ability of pollutants removal of other four wetland systems decreased in the order: Spartina anglica, Phragmites australis, Typha latifolia and unplanted system.

  6. 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 BOD5; 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.

  7. 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)

  8. 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)

  9. 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...

  10. 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...

  11. 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...

  12. 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.

  13. Evaluation of the treatment performance of lab-scaled vertical flow constructed wetlands in removal of organic compounds, color and nutrients in azo dye-containing wastewater.

    PubMed

    Dogdu, Gamze; Yalcuk, Arda

    2016-01-01

    The objective of this study is to examine the treatment performance of vertical flow intermittent feeding constructed wetland (VFCW) in removal of organic pollution, nutrients and color in azo-dye containing wastewater. The systems consisted of PVC reactors, some filling materials such as gravel, sand and zeolite and wetland plants including Typha angustifolia and Canna indica. The average treatment efficiency of the systems for COD, color, sulphate, NH4-N, and PO4-P were in the range of 57-63%, 94-99%, 44-48%, 39-44%, and 84-88%, respectively among the VFCW reactors. It is concluded that VFCW reactor system can effectively be used in the treatment of dye-rich wastewater, especially for the removal of color and in the reduction of COD. Biofilm formation and cleavage of azo bonds could be observed by SEM and FTIR results, respectively. Almost similar NH4-N and PO4-P removal were obtained in all reactors by using same amount of zeolite media.

  14. 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

  15. 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

  16. 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.

  17. Effect of hydraulic loading rate on the efficiency of effluent treatment in a recirculating puffer aquaculture system coupled with constructed wetlands

    NASA Astrophysics Data System (ADS)

    Xu, Jiabo; Shi, Yonghai; Zhang, Genyu; Liu, Jianzhong; Zhu, Yazhu

    2013-11-01

    Constructed wetlands (CWs) were integrated into an indoor recirculating aquaculture system of obscure puffer (Takifugu obscurus) for effluent treatment. The effect of hydraulic loading rate (HLR) on the efficiency of effluent treatment by CWs was examined for over a month. The CWs were operated under brackish conditions (salinity 7.4-7.6) at 3 different HLRs (0.762, 0.633, and 0.458 m d-1) 3 times, 10 days each. Overall, the CWs exhibited high efficiency in removal of total ammonium nitrogen (by 81.03-92.81%) and nitrite nitrogen (by 99.40%-99.68%). The efficiency of CWs in removal of total ammonium nitrogen, nitrate nitrogen, total Kjeldahl nitrogen, total phosphorous, and total suspended solids (TSS) increased with the decrease of HLR. The CWs operated at the 3 HLRs in a decreasing trend proves to be effective, providing a useful method for effluent treatment in commercial puffer aquaculture systems.

  18. Sunlight inactivation of fecal indicator bacteria in open-water unit process treatment wetlands: Modeling endogenous and exogenous inactivation rates.

    PubMed

    Nguyen, Mi T; Jasper, Justin T; Boehm, Alexandria B; Nelson, Kara L

    2015-10-15

    A pilot-scale open-water unit process wetland was monitored for one year and found to be effective in enhancing sunlight inactivation of fecal indicator bacteria (FIB). The removal of Escherichia coli and enterococci in the open-water wetland receiving non-disinfected secondary municipal wastewater reached 3 logs and 2 logs in summer time, respectively. Pigmented enterococci were shown to be significantly more resistant to sunlight inactivation than non-pigmented enterococci. A model was developed to predict the inactivation of E. coli, and pigmented and non-pigmented enterococci that accounts for endogenous and exogenous sunlight inactivation mechanisms and dark processes. Endogenous inactivation rates were modeled using the sum of UVA and UVB irradiance. Exogenous inactivation was only significant for enterococci, and was modeled as a function of steady-state singlet oxygen concentration. The rate constants were determined from lab experiments and an empirical correction factor was used to account for differences between lab and field conditions. The model was used to predict removal rate constants for FIB in the pilot-scale wetland; considering the variability of the monitoring data, there was general agreement between the modeled values and those determined from measurements. Using the model, we estimate that open-water wetlands at 40° latitude with practical sizes can achieve 3-log (99.9%) removal of E. coli and non-pigmented enterococci throughout the year [5.5 ha and 7.0 ha per million gallons of wastewater effluent per day (MGD), respectively]. Differences in sunlight inactivation rates observed between pigmented and non-pigmented enterococci, as well as between lab-cultured and indigenous wastewater bacteria highlight the challenges of using FIB as model organisms for actual pathogens in natural sunlit environments.

  19. Nutrient removal through autumn harvest of Phragmites australis and Thypha latifolia shoots in relation to nutrient loading in a wetland system used for polishing sewage treatment plant effluent.

    PubMed

    Toet, Sylvia; Bouwman, Meike; Cevaal, Annechien; Verhoeven, Jos T A

    2005-01-01

    The efficacy and feasibility of annual harvesting of Phragmites australis and Typha latifolia shoots in autumn for nutrient removal was evaluated in a wetland system used for polishing sewage treatment plant (STP) effluent. Aboveground biomass and nutrient dynamics nutrient removal through harvest were studied in parallel ditches with stands of Phragmites or Typha that were mown in October during two successive years. The inflow rate of STP effluent to the ditches was experimentally varied, resulting in pairs of ditches with mean hydraulic retention times (HRT) of 0.3, 0.8, 2.3, and 9.3 days, corresponding to N and P mass loading rates of 122-4190 g N m(-2) yr(-1) and 28.3-994 g P m(-2) yr(-1). Nitrogen and P removal efficiency by harvest of Phragmites and Typha shoots in October increased with increasing HRT, despite the opposite HRT effect on N and P standing stocks. This removal through harvest appeared to be useful in treatment wetlands with N and P mass loading rates lower than approximately 120 g N m(-2) yr(-1) and 30 g P m(-2) yr(-1), corresponding to a HRT of roughly 9 days in the ditches of this wetland system. At the HRT of 9.3 days, the annual mass input to the ditches was reduced through the harvest by 7.0-11% and 4.5 -9.2% for N and P, respectively. At the higher nutrient mass loading rates, the nutrient removal through harvest was insignificant compared to the mass inputs. The vitality of Phragmites and Typha, measured as maximum aboveground biomass, was not affected by the annual cutting of the shoots in autumn over two years. The Typha stands yielded higher N and P removal efficiencies through shoot harvest than the Phragmites stands, which was largely the result of lower decreases in N and P standing stocks between August and October. This difference in nutrient standing stocks between the two species was caused by a combined effect of greater decreases in nutrient concentrations largely due to higher nutrient retranslocation efficiencies of

  20. Performance of a pilot-scale constructed wetland for stormwater runoff and domestic sewage treatment on the banks of a polluted urban river.

    PubMed

    Guo, Weijie; Li, Zhu; Cheng, Shuiping; Liang, Wei; He, Feng; Wu, Zhenbin

    2014-01-01

    To examine the performance of a constructed wetland system on stormwater runoff and domestic sewage (SRS) treatment in central east China, two parallel pilot-scale integrated constructed wetland (ICW) systems were operated for one year. Each ICW consisted of a down-flow bed, an up-flow bed and a horizontal subsurface flow bed. The average removal rates of chemical oxygen demand (CODCr), total suspended solids (TSS), ammonia (NH4(+)-N), total nitrogen (TN) and total phosphorus (TP) were 63.6, 91.9, 38.7, 43.0 and 70.0%, respectively, and the corresponding amounts of pollutant retention were approximately 368.3, 284.9, 23.2, 44.6 and 5.9 g m(-2) yr(-1), respectively. High hydraulic loading rate (HLR) of 200 mm/d and low water temperatures (<15 °C) resulted in significant decrease in removals for TP and NH4(+)-N, but had no significant effects on removals of COD and TSS. These results indicated that the operation of this ICW at higher HLR (200 mm/d) might be effective and feasible for TSS and COD removal, but for acceptable removal efficiencies of nitrogen and phosphorus it should be operated at lower HLR (100 mm/d). This kind of ICW could be employed as an effective technique for SRS treatment.

  1. Pilot-scale comparison of constructed wetlands operated under high hydraulic loading rates and attached biofilm reactors for domestic wastewater treatment.

    PubMed

    Fountoulakis, M S; Terzakis, S; Chatzinotas, A; Brix, H; Kalogerakis, N; Manios, T

    2009-04-01

    Four different pilot-scale treatment units were constructed to compare the feasibility of treating domestic wastewater in the City of Heraklio, Crete, Greece: (a) a free water surface (FWS) wetland system, (b) a horizontal subsurface flow (HSF) wetland system, (c) a rotating biological contactor (RBC), and (d) a packed bed filter (PBF). All units operated in parallel at various hydraulic loading rates (HLR) ranging from 50% to 175% of designed operating HLR. The study was conducted during an 8 month period and showed that COD removal efficiency of HSF was comparable (>75%) to that of RBC and PBF, whereas that of the FWS system was only 57%. Average nutrient removal efficiencies for FWS, HSF, RBC and PBF were 6%, 21%, 40% and 43%, respectively for total nitrogen and 21%, 39%, 41% and 42%, respectively for total phosphorus. Removals of total coliforms were lowest in FWS and PBF (1.3 log units) and higher in HSF and RBC (2.3 to 2.6 log units). HSF showed slightly lower but comparable effluent quality to that of RBC and PBF systems, but the construction cost and energy requirements for this system are significantly lower. Overall the final decision for the best non-conventional wastewater treatment system depends on the construction and operation cost, the area demand and the required quality of effluent.

  2. Demonstration of constructed wetlands for treatment of municipal wastewaters, monitoring report for the period, March 1988--October 1989

    SciTech Connect

    Choate, K.D.; Watson, J.T.; Steiner, G.R.

    1990-08-01

    To evaluate the constructed wetland technology, the Tennessee Valley Authority (TVA) implemented a municipal wastewater demonstration project in western Kentucky. Using combined city, State, and TVA appropriated funds, three constructed wetland systems were built at Benton, Hardin, and Pembroke, Kentucky. Demonstration objectives include evaluating relative advantages and disadvantages of these types of systems; determining permit compliance ability; developing, evaluating, and improving basic design and operation criteria; evaluating cost effectiveness; and transferring technology to users and regulators. A demonstration monitoring project was implemented with a partnership of funds from the Environmental Protection Agency (EPA) Region IV, other EPA funds through the National Small Flows Clearinghouse (NSFC), and TVA appropriations. TVA is managing the project in cooperation with an interagency team consisting of EPA, Kentucky Division of Water and NSFC. This report, which supersedes the first monitoring report (Choate, et. al., 1989) of these demonstration projects, describes each constructed wetland system, its status, and summarizes monitoring data and plans for each system. 5 refs., 30 figs., 26 tabs.

  3. 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.

  4. 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.

  5. Acidic mine drainage abatement in an anaerobic sub-surface flow wetland environment - case history of the treatment system at Corsica, PA

    SciTech Connect

    Dietz, J.M.; Stidinger, D.M.

    1996-12-31

    Wetland Treatment Systems (WTS) have been constructed over the past decade for the treatment of Acidic Mine Drainage (AMD). Potential benefits of anaerobic sub-surface flow treatment were initially identified from attempts to improve effectiveness of a surface flow wetland at the Jennings Environmental Education Center in western Pennsylvania which, although not completely successful, resulted in acidity removal rates two to four times greater than pre-modification rates. This study was conducted to investigate the potential benefits of sub-surface flow design, which utilizes a sub-surface collection system, in comparison to conventional surface flow design. Two field-scale WTS, each containing anaerobic surface flow and sub-surface flow treatment cells (approximately 100 m{sup 2} each), were constructed along an existing AMD discharge, near Corsica, Pennsylvania, with a 3-4 pH, 250-400 mg/L (as CaCO{sub 3}) acidity, 20-40 mg/L iron, 15-40 mg/L manganese and 10-30 mg/L aluminum. Sampling of the WTS included two elements: a weekly monitoring program from March 1992 through November 1992 to collect discharge water quality data; and a post-flow design was found to provide statistically greater acidity removal with an average rate of 61.8 grams per day per square meter (GDM), in comparison to surface flow which had an average rate of 4.78 GDM, and provided effluent alkalinities greater than 100 mg/L (as CaCO{sub 3}) and pH greater than 6.5 at the flows and loading evaluated. Removal rates for iron and aluminum removal of 3.02 and 2.48 GDM in the sub-surface flow design were also significantly greater than surface flow design which had removal rates of 1.89 and 0.20 GDM, respectively. Manganese removal was ineffective in both surface and sub-surface flow designs.

  6. 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.

  7. Comparative study of microbial community structure in integrated vertical-flow constructed wetlands for treatment of domestic and nitrified wastewaters.

    PubMed

    Chang, Jun-Jun; Wu, Su-Qing; Liang, Kang; Wu, Zhenbin; Liang, Wei

    2015-03-01

    Microbial processes play a vital important role in the removal of contaminants in constructed wetland (CW). However, the microbial physiology and community structure can be influenced by environmental conditions. In this study, four pilot-scale integrated vertical-flow constructed wetlands (IVCWs) were employed to treat domestic and nitrified wastewaters. The microbial properties, along with their response to wastewater quality characteristics and seasonal variation, were determined. The results showed higher Shannon-Weiner diversity (H) and evenness (E) index of fatty acids (FAs), and relative abundances of signature FAs in down-flow cells and in the systems fed with domestic wastewater (DW). The relative abundances of fungi and gram-negative and aerobic bacteria were greater in up-flow cells. The dominant anaerobic bacteria found in most cells might be accounted for the prevailing anaerobic environment within the wetland beds, which could mean that the system fed with nitrified wastewater (NW) should perform better in nitrogen removal. The redundancy analysis (RDA) showed that pollutant concentrations, especially organic matter, influence the FA compositions greatly, and the most significant difference of microbial community structures was detected in down-flow cells fed with DW and up-flow ones with NW. The branched FAs, which could be used to represent anaerobic bacteria, were observed in down-flow cells treating DW and had a significant positive correlation with chemical oxygen demand (COD) concentration, probably suggesting the important role of anaerobic bacteria in organic matter degradation in the IVCWs. Seasonal variation, however, did not greatly influence the microbial community structure in the IVCWs.

  8. 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,…

  9. Constructed Wetlands for Removal of Heavy Metals from NPDES Outfall Effluent

    SciTech Connect

    Nelson, E.A.

    2002-08-29

    The A-01 NPDES outfall at the Savannah River Site receives process wastewater discharges and stormwater runoff from the Savannah River Technology Center. Routine monitoring indicated that copper concentrations were regularly higher than discharge permit limit, necessitating treatment of nearly one million gallons of water each day plus storm runoff to meet compliance standards. A conceptual design for a constructed treatment wetland was developed as the most cost-effective alternative. A pilot study was conducted using mesocosms to confirm that the design concept would reduce copper to acceptable levels. After treatment in the mesocosms, effluent copper concentrations were routinely below permit limits, even though the influent concentrations varied widely.

  10. 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.

  11. Occurrence, removal and environmental risk assessment of pharmaceuticals and personal care products in rural wastewater treatment wetlands.

    PubMed

    Chen, Yi; Vymazal, Jan; Březinová, Tereza; Koželuh, Milan; Kule, Lumír; Huang, Jingang; Chen, Zhongbing

    2016-10-01

    Rural communities in central and eastern Europe usually use constructed wetlands (CWs) to treat domestic wastewater. Effluents from these systems are regularly discharged to receiving water, resulting in a potential transfer of pharmaceuticals and personal care products (PPCPs) from sewage to the aquatic environment. In this study, the seasonal occurrence, removal and risk assessment of 32 multi-class PPCPs were investigated in three CWs from the village of south Bohemia, Czech Republic. Among the PPCPs considered, 25 compounds were detected in sewage influent, and ibuprofen, caffeine and paracetamol were the most commonly detected PPCPs. The removal efficiencies of PPCPs in the rural CWs exhibited large variability with 11-100% for anti-inflammatories, 37-99% for β-blockers and 18-95% for diuretics. The statistical results revealed significant correlations between removal efficiencies of six PPCPs and conventional water quality parameters. The ecotoxicological assessment study revealed that most of the PPCPs (except ibuprofen) in the effluent yielded low aquatic risk. This study suggested that constructed wetlands could be effective for removing PPCPs and reducing environmental risk of PPCPs discharged from rural communities into surface water systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Characteristics of nitrogen and phosphorus removal by a surface-flow constructed wetland for polluted river water treatment.

    PubMed

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

    2015-01-01

    The characteristics of nitrogen (N) and phosphorus (P) removal were studied during the 2-year operation of a free water surface flow wetland of 900 m² with hydraulic loading of 0.1 m/d to evaluate its potential to treat water from an urban stream polluted with municipal and industrial wastewater. Attention was focused on the removal of dissolved N and P by harvesting plants (local Phragmites australis and Typha orientalis) at the end of each growing season. According to findings, the removals of N and P increased from 47.1% and 17.6%, respectively, in the 1st year to 52.3% and 32.4%, respectively, in the 2nd year. Increments of N and P removal were largely attributable to plant biomass, which increased from an average dry weight of 1.77 kg/m² in the 1st year to 3.41 kg/m² in the 2nd year. The amount of nutrients assimilated by plants in the 2nd year was almost double that of the 1st year. Increasing biomass in the 2nd year also improved redox conditions in the substrate layer, which contributed to increasing the efficiency of N removal. Compared with T. orientalis, P. australis was more competitive and adapted to conditions in the wetland better; it regenerated more vigorously and contributed more to nutrient removal.

  13. 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

  14. 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

  15. 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...

  16. 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.

  17. Evaluation of the giant reed (Arundo donax) in horizontal subsurface flow wetlands for the treatment of dairy processing factory wastewater.

    PubMed

    Idris, Shaharah Mohd; Jones, Paul L; Salzman, Scott A; Croatto, George; Allinson, Graeme

    2012-09-01

    Two emergent macrophytes, Arundo donax and Phragmites australis, were established in experimental horizontal subsurface flow (HSSF), gravel-based constructed wetlands (CWs) and challenged by treated dairy processing factory wastewater with a median electrical conductivity of 8.9 mS cm(-1). The hydraulic loading rate was tested at 3.75 cm day(-1). In general, the plants grew well during the 7-month study period, with no obvious signs of salt stress. The major water quality parameters monitored (biological oxygen demand (BOD), suspended solids (SS) and total nitrogen (TN) but not total phosphorus) were generally improved after the effluent had passed through the CWs. There was no significance different in removal efficiencies between the planted beds and unplanted gravel beds (p > 0.007), nor was there any significant difference in removal efficiencies between the A. donax and P. australis beds for most parameters. BOD, SS and TN removal in the A. donax and P. australis CWs was 69, 95 and 26 % and 62, 97 and 26 %, respectively. Bacterial removal was observed but only to levels that would allow reuse of the effluent for use on non-food crops under Victorian state regulations. As expected, the A. donax CWs produced considerably more biomass (37 ± 7.2 kg wet weight) than the P. australis CWs (11 ± 1.4 kg wet weight). This standing crop equates to approximately 179 and 68 tonnes ha(-1) year(-1) biomass (dry weight) for A. donax and P. australis, respectively (assuming a 250-day growing season and single-cut harvest). The performance similarity of the A. donax and P. australis planted CWs indicates that either may be used in HSSF wetlands treating dairy factory wastewater, although the planting of A. donax provides additional opportunities for secondary income streams through utilisation of the biomass produced.

  18. 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.

  19. Experiences with constructed wetland systems in Korea

    NASA Astrophysics Data System (ADS)

    Youngchul, Kim; Gilson, Hwang; Jin-Woo, Lee; Je-Chul, Park; Dong-Sup, Kim; Min-Gi, Kang; in-Soung, Chang

    2006-10-01

    In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation and maintenance. Many different types of wetland treatment systems have been built during the last 10 years, among which the free water surface wetland has been predominant. Most of the large-scale systems are government projects for improving the water quality of the streams flowing into the estuary dikes and reservoirs. The covering plants used in this system are different in different areas but cattails and reeds or their combinations are common. Constructed wetlands in Korea can be characterized by their shallow depths and short hydraulic residence times. There is no established flow pattern and configuration rules for constructing wetlands, but many efforts have been made with a view to improving their ecological function. Flow control is the most difficult problem in designing a riverbed or riparian wetland. There have been scores of flow rate control devices developed for wetlands, but none of them guarantee wetlands’ safety against flooding. In earlier wetland construction, the building materials were mainly soil. Recently, strong and durable building materials such as rocks, gravel beds, concrete and steel are used at vulnerable places to protect them from erosion. Our investigation indicated that the wetland system would be an appropriate technology because it is not only cheaper to construct, but also requires less maintenance work. However, we suffer from the reduced effectiveness in performance during the winter. We need to evaluate the partial treatment accomplished during 6 to 7 months per year.

  20. 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.

  1. 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.

  2. 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…

  3. Gulf Coast Wetlands

    Atmospheric Science Data Center

    2014-05-15

    article title:  Wetlands of the Gulf Coast     ... web of estuarine channels and extensive coastal wetlands that provide important habitat for fisheries. The city of New Orleans ... or below sea level. The city is protected by levees, but the wetlands which also function as a buffer from storm surges have been ...

  4. 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)

  5. 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)

  6. 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…

  7. 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.

  8. 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 363gdmm(-2)d(-1) in the FTW1 and 536gdmm(-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.

  9. 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), NH4-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. NH4-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.

  10. The use of hydrologically altered wetlands to treat wastewater in coastal Louisiana

    SciTech Connect

    Breaux, A.M.

    1992-01-01

    Two major environmental problems currently affecting Louisiana are a high rate of coastal wetland loss and high levels of surface water pollution. The application of secondarily treated wastewater to wetlands is proposed to dealing with these problems. The benefits of wetland wastewater treatment include improved surface water quality, increased accretion rates to balance subsidence, improved plant productivity, and decreased capital outlays for conventional engineering treatment systems. Wetland treatment systems can be designed and operated to restore deteriorating wetlands to previous levels of productivity. Hydrologically altered wetlands in the Louisiana coastal zone are appropriate for receiving municipal and some industrial effluent. While the US EPA has determined that wetland wastewater treatment is effective in treating municipal effluent, it has discouraged the use of natural wetlands for this purpose. As a result, hydrologically altered wetlands in the Louisiana coastal zone are being neglected and ultimately lost, while scarce funds are used to construct artificial wetlands to treat municipal effluent. Effluent discharge to existing wetlands can be incorporated into a comprehensive management plan designed to increase sediment and nutrient input into subsiding wetlands in the Louisiana coastal zone. Secondarily treated effluent discharged from industrial and municipal facilities in the Louisiana coastal zone were reviewed for suitability for wetland wastewater treatment. Selection criteria for wetland treatment systems were developed for both dischargers and receiving wetlands. Designs for two potential case studies based on established selection criteria for wetland wastewater treatment systems are presented. An economic analysis of the four case studies indicates a high potential for financial savings when wetlands replace conventional engineering methods for tertiary treatment.

  11. Functions of slags and gravels as substrates in large-scale demonstration constructed wetland systems for polluted river water treatment.

    PubMed

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

    2015-09-01

    The choice of substrates with high adsorption capacity, yet readily available and economical is vital for sustainable pollutants removal in constructed wetlands (CWs). Two identical large-scale demonstration horizontal subsurface flow (HSSF) CWs (surface area, 340 m(2); depth, 0.6 m; HLR, 0.2 m/day) with gravel or slag substrates were evaluated for their potential use in remediating polluted urban river water in the prevailing climate of northwest China. Batch experiments to elucidate phosphorus adsorption mechanisms indicated a higher adsorption capacity of slag (3.15 g/kg) than gravel (0.81 g/kg), whereby circa 20 % more total phosphorus (TP) removal was recorded in HSSF-slag than HSSF-gravel. TP removal occurred predominantly via CaO-slag dissolution followed by Ca phosphate precipitation. Moreover, average removals of chemical oxygen demand and biochemical oxygen demand were approximately 10 % higher in HSSF-slag than HSSF-gravel. Nevertheless, TP adsorption by slag seemed to get quickly saturated over the monitoring period, and the removal efficiency of the HSSF-slag approached that of the HSSF-gravel after 1-year continuous operation. In contrast, the two CWs achieved similar nitrogen removal during the 2-year monitoring period. Findings also indicated that gravel provided better support for the development of other wetland components such as biomass, whereby the biomass production and the amount of total nitrogen (TN; 43.1-59.0 g/m(2)) and TP (4.15-5.75 g/m(2)) assimilated by local Phragmites australis in HSSF-gravel were higher than that in HSSF-slag (41.2-52.0 g/m(2) and 3.96-4.07 g/m(2), respectively). Overall, comparable pollutant removal rates could be achieved in large-scale HSSF CWs with either gravel or slag as substrate and provide a possible solution for polluted urban river remediation in northern China.

  12. Seasonality distribution of the abundance and activity of nitrification and denitrification microorganisms in sediments of surface flow constructed wetlands planted with Myriophyllum elatinoides during swine wastewater treatment.

    PubMed

    Li, Xi; Zhang, Miaomiao; Liu, Feng; Chen, Liang; Li, Yuyuan; Li, Yong; Xiao, Rulin; Wu, Jinshui

    2017-06-20

    Surface flow constructed wetlands (SFCWs) planted with Myriophyllum elatinoides for treatment of swine wastewater were examined to evaluate the effect of season, segment (site S1, S2, and S3), and treatment (100mgL(-1) TN, T1; 300mgL(-1) TN, T2; 500mgL(-1) TN, T3) on the activity, and abundances of nitrifying and, denitrifying microorganisms, and on the abundance of sediment bacteria. The activity and abundances of nitrifiers, denitrifiers, and the abundance of bacteria were the highest in T3 samples, especially in S1 (P<0.05). The potential nitrification rate (PNR) was highest in the summer and potential denitrification rate (PDR) showed an increasing trend over seasons. The abundance of ammonia-oxidizing bacteria (AOB) was strongly correlated with PNR, while abundance of denitrifying gene (nirK) was strongly correlated with PDR. These results indicate that M. elatinoides SFCWs for swine wastewater treatment stimulate the growth of nitrifiers, denitrifiers and bacteria in sediments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. [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.

  14. 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.

  15. Changes in the bacterial community structure in two-stage constructed wetlands with different plants for industrial wastewater treatment.

    PubMed

    Calheiros, Cristina S C; Duque, Anouk F; Moura, Alexandra; Henriques, Isabel S; Correia, António; Rangel, António O S S; Castro, Paula M L

    2009-07-01

    This study focused on the diversity of bacterial communities from two series of two-stage constructed wetlands (CWs) treating tannery wastewater, under different hydraulic conditions. Series were separately planted with Typha latifolia and Phragmites australis in expanded clay aggregates and operated for 31 months. The effect of plant species, hydraulic loading and unit stage on bacterial communities was addressed through bacterial enumeration and denaturating gradient gel electrophoresis (DGGE). Diverse and distinct bacterial communities were found in each system unit, which was related in part to the type of plant and stage position (first or second unit in the series). Numerical analysis of DGGE profiles showed high diversity in each unit with an even distribution of species. No clear relation was established between the sample collection time, hydraulic loading applied and the bacterial diversity. Isolates retrieved from plant roots and substrates of CWs were affiliated with gamma-Proteobacteria, Firmicutes, alpha-Proteobacteria, Sphingobacteria, Actinobacteria and Bacteroidetes. Both series were effective in removing organic matter from the inlet wastewater, however, based on batch degradation experiments it seems that biodegradation was limited by the recalcitrant properties of the wastewater.

  16. 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.

  17. Co-treatment of landfill leachate and municipal wastewater using the ZELIAC/zeolite constructed wetland system.

    PubMed

    Mojiri, Amin; Ziyang, Lou; Tajuddin, Ramlah Mohd; Farraji, Hossein; Alifar, Nafiseh

    2016-01-15

    Constructed wetland (CW) is a low-cost alternative technology to treat wastewater. This study was conducted to co-treat landfill leachate and municipal wastewater by using a CW system. Typha domingensis was transplanted to CW, which contains two substrate layers of adsorbents, namely, ZELIAC and zeolite. Response surface methodology and central composite design have been utilized to analyze experimental data. Contact time (h) and leachate-to-wastewater mixing ratio (%; v/v) were considered as independent variables. Colour, COD, ammonia, nickel, and cadmium contents were used as dependent variables. At optimum contact time (50.2 h) and leachate-to-wastewater mixing ratio (20.0%), removal efficiencies of colour, COD, ammonia, nickel, and cadmium contents were 90.3%, 86.7%, 99.2%, 86.0%, and 87.1%, respectively. The accumulation of Ni and Cd in the roots and shoots of T. domingensis was also monitored. Translocation factor (TF) was >1 in several runs; thus, Typha is classified as a hyper-accumulator plant. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Modeling heavy metal removal in wetlands

    SciTech Connect

    Lung, W.S.; Light, R.N.

    1994-12-31

    Although the use of wetland ecosystems to purify water has gained increased attention only recently, it has been recognized as a wastewater treatment technique for centuries. While considerable research has occurred to quantify the nutrient (nitrogen and phosphorus) removal mechanisms of wetlands, relatively few investigators have focused on the mechanisms of heavy metal removal and uptake by wetland sediments and plants. The quantification of the assimilative capacity of heavy metals by wetland ecosystems is a critical component in the design and use of wetlands for this purpose. A computer model has been developed to simulate the fate and transport of heavy metals introduced to a wetland ecosystem. Modeled water quality variables include phytoplankton biomass and productivity; macrophyte (Nulumbo lutea) biomass; total phosphorus in the water column; dissolved copper in the water column and sediments; particulate copper in the water column and sediments; and suspended solids. These variables directly affect the calculated rate of copper uptake by macrophytes, and the rate of copper recycling as a function of the decomposition of copper-laden biomass litter. The model was calibrated using total phosphorus and chlorophyll a data from the Old Woman Creek Wetland in Ohio. Verification of the model was achieved using data on the copper content of the macrophyte Nelumbo lutea.

  19. 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, ...

  20. 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...

  1. 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…

  2. 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…

  3. Fate of viruses in artificial wetlands

    SciTech Connect

    Gersberg, R.M.; Lyon, S.R.; Brenner, R.; Elkins, B.V.

    1987-04-01

    Little is known about the ability of wetlands to remove disease-causing viruses from municipal wastewater. In this study the authors examined the survival of several indicators of viral pollution applied in primary municipal wastewater to artificial wetland ecosystems. Only about 1% of the indigenous F-specific RNA bacteriophages survived flow through the vegetated wetland beds at a 5-cm-day/sup -1/ hydraulic application rate during the period from June through December 1985. The total number of indigenous F-specific bacteriophages was also reduced by about 99% by wetland treatment, with the mean inflow concentration over the period of an entire year reduced from 3129 to 33 PFU ml/sup -1/ in the outflow of an vegetated bed and to 174 PFU ml/sup -1/ in the outflow of an unvegetated bed. Such superior treatment by the vegetated bed demonstrates the significant role of higher aquatic plants in the removal process. Seeded MS2 bacteriophage and seeded poliovirus were removed more efficiently than were the indigenous bacteriophages, with less than 0.2% and MS2 and 0.1% of the poliovirus surviving flow at the same hydraulic application rate. The decay rate (k) of MS2 in a stagnant wetlands was lower than that for flowing systems, reflecting the enhanced capacity for filtration or adsorption of viruses by the root-substrate complex. Artificial wetlands may offer an attractive alternative to conventional land treatment systems for reducing the load disease-causing viruses to the aquatic environment.

  4. 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 (NH3-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.

  5. Distribution and mobilization of pollutants in the sediment of a constructed floating wetland used for treatment of combined sewer overflow events.

    PubMed

    Van de Moortel, Annelies M K; Du Laing, Gijs; De Pauw, Niels; Tack, Filip M G

    2011-05-01

    Sediments in combined sewer overflow treatment systems may exhibit elevated pollutant concentrations. Concentrations measured in the sediment of a floating treatment wetland ranged from 0.17 to 1.6 (cadmium), 28 to 142 (copper), 10 to 33 (chromium), 50 to 141 (manganese), 5 to 20 (nickel), 50 to 203 (lead), and 185 to 804 (zinc) mg/kg dry matter and 7.4 to 17 (iron), 2 to 8 (total nitrogen), and 1.3 to 4.4 (total phosphorus) g/kg dry matter. During overflow events, the entering water volumes can disturb the sediments. A greenhouse experiment was set up to evaluate the possible mobilization of pollutants through disturbation. The disturbation did not result in an increased mobilization of cadmium, copper, chromium, nickel, lead, zinc, nitrogen, phosphorus, and organic carbon towards the pore and surface water. Calcium concentrations in the surface water increased for all sediments, as a result of release from the exchangeable sediment pool and dissolution of carbonates. Geochemical speciation modeling indicated that, in the pore water, the free ion form was the most abundant for calcium, iron, manganese, cadmium, and nickel, with its fraction increasing with time.

  6. 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 (BOD5) 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 PO4-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.

  7. 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 NO3(-) and NH4(+) 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 NO3(-) and NH4(+) removal, respectively. E. nuttallii enhanced nitrification by 17% and significantly contributed to bioelectricity generation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. 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.

  9. Effects of a saturated layer and recirculation on nitrogen treatment performances of a single stage Vertical Flow Constructed Wetland (VFCW).

    PubMed

    Prigent, S; Paing, J; Andres, Y; Chazarenc, F

    2013-01-01

    Upgrades to enhance nitrogen removal were tested in a 2 year old pilot vertical flow constructed wetland in spring and summer periods. The effects of a saturated layer and of recirculation were tested in particular. Two pilots (L = 2 m, W = 1.25 m, H = 1.2 m), filled with expanded schist (Mayennite(®)), were designed with hydraulic saturated layers of 20 and 40 cm at the bottom. Each pilot was fed with raw domestic wastewater under field conditions according to a hydraulic load of 15-38 cm d(-1) (i.e. 158-401 g COD (chemical oxygen demand) m(-2) d(-1)) and to recirculation rates ranging from 0% up to 150%. The initial load during the first 2 years of operation resulted in an incomplete mineralized accumulated sludge leading to total suspended solids (TSS), COD and biochemical oxygen demand (BOD5) release. A 40 cm hydraulic saturated layer enabled an increase of 5-10% total nitrogen (TN) removal compared to a 20 cm saturated layer. Recirculation allowed the dilution of raw wastewater and enhanced nitrification in a single stage. A design of 1.8 m² pe(-1) (48 cm d(-1), 191 g COD m(-2) d(-1)) with a 40 cm saturated layer and 100% recirculation enabled the French standard D4 (35 mg TSS L(-1), 125 mg COD L(-1), 25 mg BOD5 L(-1)), nitrogen concentrations below 20 mg TKN (total Kjeldahl nitrogen) L(-1) and 50 mg TN L(-1), to be met.

  10. Wastewater treatment using integrated anaerobic baffled reactor and Bio-rack wetland planted with Phragmites sp. and Typha sp.

    PubMed

    Jamshidi, Shervin; Akbarzadeh, Abbas; Woo, Kwang-Sung; Valipour, Alireza

    2014-01-01

    The purpose of this study is to examine the potential use of anaerobic baffled reactor (ABR) followed by Bio-rack wetland planted with Phragmites sp. and Typha sp. for treating domestic wastewater generated by small communities (751 mg COD/L, 500 SCOD mg/L, 348 mg BOD5/L). Two parallel laboratory-scale models showed that the process planted with Phragmites sp. and Typha sp. are capable of removing COD by 87% & 86%, SCOD by 90% & 88%, BOD5 by 93% & 92%, TSS by 88% & 86%, TN by 79% & 77%, PO4-P by 21% & 14% at an overall HRT of 21 (843 g COD/m(3)/day & 392 g BOD5/m(3)/day) and 27 (622 g COD/m(3)/day & 302 g BOD5/m(3)/day) hours, respectively. Microbial analysis indicated a high reduction in the MPN of total coliform and TVC as high as 99% at the outlet end of the processes. The vegetated system using Phragmites sp. showed significantly greater (p <0.05) pollutant removal efficiencies due to its extensive root and mass growth rate (p <0.05) of the plant compared to Typha sp. The Phragmites sp. indicated a higher relative growth rate (3.92%) than Typha sp. (0.90%). Microorganisms immobilized on the surface of the Bio-rack media (mean TVC: 2.33 × 10(7) cfu/cm(2)) were isolated, identified and observed using scanning electron microscopy (SEM). This study illustrated that the present integrated processes could be an ideal approach for promoting a sustainable decentralization, however, Phragmites sp. would be more efficient rather than Typha sp.

  11. Use of headspace solid-phase microextraction to characterize odour compounds in subsurface flow constructed wetland for wastewater treatment.

    PubMed

    Huang, Y; Ortiz, L; García, J; Aguirre, P; Mujeriego, R; Bayona, J M

    2004-01-01

    A headspace solid-phase microextraction (HS-SPME) preconcentration method was applied to the analysis of some of the major odorous compounds occurring in wastewater using GC/MS or GC/NPD detection. The detection limit for volatile amines, volatile fatty acids, and volatile alkylsulphides ranged from 3 to 100, 2 to 150, and 0.0006 to 0.035 microg/L, respectively. The SPME method was used to examine the fate of odorous compounds in the subsurface flow constructed wetlands (SFCW) operated under different hydraulic loading rate (HLR), bed aspect ratio, and granular medium size. Among the experimental conditions evaluated in the SFCW beds, HLR was found to be the most important factor influencing the evolution of the studied compounds. There were also significant differences among bed types in the behaviour of ammonia (NH3), acetic acid (Ac), isovaleric acid (IsoA), propionic acid (PrA), and dimethylsulphide. Aspect ratio and medium granular size were minor factors influencing SFCW performance. The major odour compounds by mass in the effluent of SFCW with different operational conditions were NH3 and Ac. Further removal of these two compounds is considered as very important from the viewpoint of chemical composition. On the other hand, Relative Odour Intensity (ROI: ratio between the absolute concentration to the odour threshold concentration) suggested that PrA and IsoA were the two major compounds responsible for odour intensity. Thus, further removal of these two compounds is viewed as very important for the effluent deodorization, especially for PrA. From our results, this compound appears to be produced by processes occurring in the SFCW.

  12. Hybrid constructed wetlands for highly polluted river water treatment and comparison of surface- and subsurface-flow cells.

    PubMed

    Zheng, Yucong; Wang, Xiaochang; Xiong, Jiaqing; Liu, Yongjun; Zhao, Yaqian

    2014-04-01

    A series of large pilot constructed wetland (CW) systems were constructed near the confluence of an urban stream to a larger river in Xi'an, a northwestern megacity in China, for treating polluted stream water before it entered the receiving water body. Each CW system is a combination of surface-and subsurface-flow cells with local gravel, sand or slag as substrates and Phragmites australis and Typha orientalis as plants. During a one-year operation with an average surface loading of 0.053 m(3)/(m(2)·day), the overall COD, BOD, NH3-N, total nitrogen (TN) and total phosphorus (TP) removals were 72.7% ± 4.5%, 93.4% ± 2.1%, 54.0% ± 6.3%, 53.9% ± 6.0% and 69.4% ± 4.6%, respectively, which brought about an effective improvement of the river water quality. Surface-flow cells showed better NH3-N removal than their TN removal while subsurface-flow cells showed better TN removal than their NH3-N removal. Using local slag as the substrate, the organic and phosphorus removal could be much improved. Seasonal variation was also found in the removal of all the pollutants and autumn seemed to be the best season for pollutant removal due to the moderate water temperature and well grown plants in the CWs. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  13. Wetlands -- our natural partners in wastewater management

    SciTech Connect

    Not Available

    1994-01-01

    This video documents research in Michigan and Florida, where swamps, peatlands, marshes, and bogs (wetlands) are being used for advanced (third and final stage) wastewater treatment. Through interviews with biologists, researchers, users, city officials, and engineering firms involved with these experimental projects, one begins to discover the financial and environmental advantages of this type of treatment over dry land treatment.

  14. Wetlands -- our natural partners in wastewater management

    SciTech Connect

    1994-12-31

    This video documents research in Michigan and Florida, where swamps, peatlands, marshes, and bogs (wetlands) are being used for advanced (third and final stage) wastewater treatment. Through interviews with biologists, researchers, users, city officials, and engineering firms involved with these experimental projects, one begins to discover the financial and environmental advantages of this type of treatment over dry land treatment.

  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. 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) no nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity.

  17. 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) no nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity.

  18. Draft Wetlands Rule Released

    NASA Astrophysics Data System (ADS)

    Zielinski, Sarah

    2006-04-01

    The U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers released on 28 March a draft of a new rule to guide compensatory mitigation for when wetlands are unavoidably lost due to development. However, whether the rule is successful in preventing a net loss in wetlands will depend largely on its implementation, according to two wetlands scientists who evaluated the issue for the U.S. National Research Council (NRC) in 2001. Under the federal Clean Water Act, developers who seek to build on wetlands must compensate for any wetlands loss if they are unable to avoid or minimize the loss. Such compensation is covered under the newly proposed compensatory mitigation rule. Benjamin Grumbles, EPA assistant administrator for water, called the rule an ``innovative new standard that will accelerate the pace of wetlands conservation and restoration.''

  19. Treatment of anaerobic digestate supernatant in microbial fuel cell coupled constructed wetlands: Evaluation of nitrogen removal, electricity generation, and bacterial community response.

    PubMed

    Wu, Shubiao; Lv, Tao; Lu, Qimin; Ajmal, Zeeshan; Dong, Renjie

    2017-02-15

    The objective of this study was to assess whether the improved configuration of vertical upflow constructed wetlands (CWs) coupled with aeration in the centre part and effluent recirculation can strengthen the treatment performance of high strength anaerobic digestate supernatant. Moreover, electricity generation and bacterial community characteristics were also examined. The results indicated that intermittent aeration in vertical upflow CWs significantly enhanced organic matter (>69%, 214-401g/m(2)d) and ammonium (>92%, 62-138g/m(2)d) removal, regardless of aeration position. However, the removal efficiency of total nitrogen (TN) was limited to 24%-40%. Effluent recirculation was examined to enhance TN removal up to 69% in the central aerated CW, as compared to 44% observed in the bottom aerated CW. Accordingly, significantly higher abundances of denitrifiers (nirK and nirS) and anaerobic ammonium oxidation bacteria (anammox) were found in the bottom layer of the central aerated CW. In addition, the central aerated CW coupled with effluent recirculation generated significantly higher electricity (maximum power density of 112mW/m(2)) than traditional bottom aerated CWs when integrated with a microbial fuel cell (MFC). Results confirmed the application potential of this new configuration of upflow CW integrated with central aeration and effluent recirculation.

  20. Comparative evaluations of organic matters and nitrogen removal capacities of integrated vertical-flow constructed wetlands: Domestic and nitrified wastewater treatment.

    PubMed

    Chang, Jun J; Liang, Kang; Wu, Su Q; Zhang, Sheng H; Liang, Wei

    2015-01-01

    Two groups of integrated vertical-flow constructed wetland (IVCW) microcosms were established for treating two types of representative wastewater: domestic and nitrified wastewater under two loading rates (LRs) over about two years. Their removal capacities of organic substance and nitrogen as well as the effects of loading rate (LR), outflow temperature and dissolved oxygen (DO) concentration were investigated and compared. Efficient chemical oxygen demand (COD) eliminations were achieved by the IVCWs, with the mass removal rates increasing linearly with the increasing LRs strongly, achieving average value of 56.07 g m(-2) d(-1) at the highest loading rate. Nevertheless, the effluent COD concentrations also increased, with the average value exceeding Class I A discharge standard (< 50 mg L(-1)) for municipal wastewater treatment plants in China at the highest loading rate. Greater total nitrogen (TN) mass removal rates but lower efficiencies were obtained at the high LR for both types of wastewater, and better removal was achieved for nitrified wastewater (NW) in comparison to domestic wastewater (DW), probably due to the prevailing anoxic conditions inside the IVCW beds restricted nitrification process of DW. The influences of LR, temperature and DO on COD removal were slight, but all remarkable on TN reduction. As compared to DO, temperature was more crucial for nitrogen removal, and the temperature dependence coefficient for TN removal of low LR of NW was significantly greater than others.

  1. 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.

  2. 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.

  3. 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.

  4. Purification processes involved in sludge treatment by a vertical flow wetland system: focus on the role of the substrate and plants on N and P removal.

    PubMed

    Korboulewsky, Nathalie; Wang, Runying; Baldy, Virginie

    2012-02-01

    Vertical-flow wetland systems were tested for treatment of liquid waste activated sludge with high content of organic compounds from a soft drink factory. A mesocosm experiment was carried out on planted and unplanted systems to understand the relative importance of substrate and plants in purification processes and to compare three species: Phragmites australis Cav., Typha latifolia L., or Iris pseudacorus L. All planted mesocosms performed better than unplanted mesocosms and Phragmites showed the highest efficiencies, both in volumes and loads, closely followed by Typha. Removal efficiencies were very high in all cases, and physical filtration by the organic substrate was identified as the main processes for nutrient removal (>50%). We showed that plants played direct and indirect roles such as nutrients uptake (up to 23% of the N for Phragmites), evapotranspiration reducing outflow volumes; or improvement of filtration by the root systems and stimulation of microbial activities (respiration rate was double compared to unplanted mesocosms). Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. 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

    2017-03-20

    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 integrated into CWs. In this study, constructed wetlands (CWs) integrated with Fe/C-M/E material were developed. During the experiment of vegetation influence, percentages of NH4(+)-N, NO3(-)-N, TN, and 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, temperature substantially influenced the performance of CWs. For example, NO3(-)-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 NO3(-)-N removal percentage was observed in all CWs. Temperature also influenced the COD removal and soil microbial activity and biomass. Overall, the polyculture showed the best performance during most of the operating time, 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.

  6. Application of patent bio-rack wetland system using Phragmites sp. for domestic wastewater treatment in the presence of high total dissolved solids (TDS) and heavy metal salts.

    PubMed

    Valipour, Alireza; Raman, V Kalyan; Ghole, V S

    2011-07-01

    The quality of water recourses is degrading due to improper wastewater management. The aim of this study is to examine the potential of bio-rack system for treatment of domestic wastewater in the presence of high total dissolved solids (TDS) and heavy metal salts. The bio-rack is a modified wetland system incorporated with the advantages of phytoremediation and attached growth microbial process. The bio-rack is void of the soil strata based root zone system and in lieu a support matrix is provided to enrich the micro flora. The studies indicate that, Phragmites sp. can tolerate TDS up to 9000 mg/L in the bio-rack. The heavy metal removal is a function of phytoaccumulation or phytoextraction, which can lead to morphological deformity if heavy metals exceed the saturation limit of 786 and 5760 mg/kg Cd, 854 and 9280 mg/kg Cu, 639 and 4720 mg/kg Ni, 1187 and 7516 mg/kg Zn, in shoots and roots respectively. The reduction in TDS is marginal (14%) at the highest tolerable limit whereas the heavy metal reduction is 68%, 69%, 67%, 71% for Cd, Cu, Ni and Zn respectively at the outlet of the treatment system. The sewage treatment performance of the bio-rack system for all other parameters is estimated as 75 % Chemical Oxygen Demand (COD), 86 % Biological Oxygen Demand (BOD5), 27% Total Dissolved Solids (TDS), 73% Total Suspended Solids (TSS), 9% chlorides, 70% ammonia nitrogen (NH3-N), 32% phosphate (PO4-P), 92% most probable number (MPN) and 93% total viable count (TVC) reduction.

  7. 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.

  8. 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.

  9. 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...

  10. Percent Wetland Cover

    EPA Pesticide Factsheets

    Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be indicate cleaner surface water. More information about these resources, including the variables used in this study, may be found here: https://edg.epa.gov/data/Public/ORD/NERL/ReVA/ReVA_Data.zip.

  11. 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)

  12. 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...

  13. 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)

  14. 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.

  15. 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.

  16. 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...

  17. 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...

  18. Comparative analysis of the composition of bacterial communities from two constructed wetlands for municipal and swine wastewater treatment.

    PubMed

    Arroyo, Paula; Ansola, Gemma; Blanco, Ivan; Molleda, Patricia; de Luis Calabuig, Estanislao; Sáenz de Miera, Luis E

    2010-03-01

    This work provides information about bacterial community structure in natural wastewater treatment systems treating different types of wastewater. The diversity and composition of bacterial communities associated with the rhizosphere of Typha latifolia and Salix atrocinerea were studied and compared among two different natural wastewater treatment systems, using the direct sequencing of the 16S ribosomal RNA codifying genes. Phylogenetic affiliations of the bacteria detected allowed us to define the main groups present in these particular ecosystems. Moreover, bacterial community structure was studied through two diversity indices. Ten identified and five non-identified phyla were found in the samples; the phylum Proteobacteria was the predominant group in the four ecosystems. The results showed a bacterial community dominated by beta-proteobacteria and a lower diversity value in the swine wastewater treatment system. The municipal wastewater treatment system presented a high diverse community in both macrophytes (Typha latifolia and Salix atrocinerea), with gamma-proteobacteria and alpha-proteobacteria, respectively, as the most abundant groups.

  19. Lead and zinc removal by laboratory-scale constructed wetlands.

    PubMed

    Song, Y; Fitch, M; Burken, J; Nass, L; Chilukiri, S; Gale, N; Ross, C

    2001-01-01

    Constructed wetlands have the potential to trap and remove metals in mine wastewater. To determine the effectiveness of constructed wetlands for treating selected heavy metals in neutral mine effluent typical of lead mines, eight laboratory-scale constructed wetlands were set up to treat a synthetic, slightly alkaline, mine water containing 34.2 mg/L sulfate (SO4(2-)), 50 micrograms/L lead (Pb), and 300 micrograms/L zinc (Zn). After 45 days, one of the wetlands was switched to treat a synthetic smelter effluent with a much greater load of SO4(2-), sodium (Na+), and Pb. Temperature, hydraulic loading, and substrate composition typically did not affect treatment efficiency. The pH of the effluent was reduced from 8.0 to 8.5 to near neutral. The average removal in the eight wetlands was 90% for Pb and 72% for Zn. In wetlands operating on synthetic mine water, SO4(2-) was completely removed, likely by conversion to sulfide by sulfate-reducing bacteria. In the wetland operating on synthetic smelter effluent, only approximately 25% of 6 g/L influent sulfate was removed, and a breakthrough period of 4 days for Na+ was observed. Whole effluent toxicity assays on undiluted wetland effluent from wetlands treating mine and smelter water had 100% survival of fathead minnows and Daphnia magnia. Survival of Ceriodaphnia dubia was zero in undiluted effluent, but 75 to 100% survival was observed when the effluent was diluted to one-half strength.

  20. 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

  1. 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 and 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.

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