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Roland A Muller - One of the best experts on this subject based on the ideXlab platform.
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dynamics of emerging organic contaminant removal in conventional and intensified subsurface flow Treatment Wetlands
Science of The Total Environment, 2019Co-Authors: Jaime Nivala, Johannes Boog, Stefanie Kahl, Manfred Van Afferden, Thorsten Reemtsma, Roland A MullerAbstract:Abstract Six pilot-scale Treatment Wetlands treating municipal wastewater were monitored for classical wastewater parameters and selected Emerging Organic Compounds (EOCs): caffeine (CAF), ibuprofen (IBU), naproxen (NPX), benzotriazole (BTZ), diclofenac (DCL), acesulfame (ACE) and carbamazepine (CBZ) on a weekly basis over the course of one year. Treatment efficacy of the Wetland systems was compared to that of a municipal wastewater Treatment plant adjacent to the research site (activated sludge technology). The aerated Wetlands VAp and HAp, and the two-stage vertical flow system VGp + VSp showed the highest Treatment efficacy (>70% removal on a mass basis) and comparable Treatment efficacy to the conventional WWTP for removal of CAF, IBU, NPX, BTZ, and DCL. Annual mass removal of ACE in the WWTP was 50% and varied in the Wetlands (depending on system design) from zero to 62%. On a mean monthly basis, ACE removal in the Treatment Wetlands VGp + VSp, VAp, HAp, R was high (> 90%) for six months of the year. Monthly mean mass removal of CBZ was negligible for the WWTP and all Treatment Wetland systems except H50p, which showed up to 49% mass removal in June. Monthly mean mass removals of classical wastewater parameters and readily biodegradable EOCs (represented by CAF, IBU, NPX) were most stable in the intensified Wetland designs VAp, HAp, and R. A statistical analysis confirms that system complexity, aerobic conditions, and temperature have the highest correlation to overall pollutant removal in the Treatment Wetland systems, including EOCs of high to moderate biodegradability. First-order removal rate coefficents and temperature correction factors for EOCs are reported for the first time in the Treatment Wetland literature. Limitations on the use of these values in engineering design are discussed.
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Resilience of carbon and nitrogen removal due to aeration interruption in aerated Treatment Wetlands.
The Science of the total environment, 2017Co-Authors: Johannes Boog, Jaime Nivala, Manfred Van Afferden, Thomas Aubron, Sibylle Mothes, Roland A MullerAbstract:Treatment Wetlands have long been used for domestic and industrial wastewater Treatment. In recent decades, Treatment Wetland technology has evolved and now includes intensified designs such as aerated Treatment Wetlands. Aerated Treatment Wetlands are particularly dependent on aeration, which requires reliable air pumps and, in most cases, electricity. Whether aerated Treatment Wetlands are resilient to disturbances such as an aeration interruption is currently not well known. In order to investigate this knowledge gap, we carried out a pilot-scale experiment on one aerated horizontal flow Wetland and one aerated vertical flow Wetland under warm (Twater>17°C) and cold (Twater 17°C (warm weather) and within 6-8d (horizontal flow system) and 4-5d (vertical flow system) at Twater 17°C was twice as high as in the horizontal flow aerated Wetland. The quick recovery of Treatment performance highlights the benefits of aerated Treatment Wetlands as resilient wastewater Treatment technologies.
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hydraulic characterization and optimization of total nitrogen removal in an aerated vertical subsurface flow Treatment Wetland
Bioresource Technology, 2014Co-Authors: Johannes Boog, Jaime Nivala, Manfred Van Afferden, Scott Wallace, Thomas Aubron, Roland A MullerAbstract:Abstract In this study, a side-by-side comparison of two pilot-scale vertical subsurface flow constructed Wetlands (6.2 m2 × 0.85 m, qi = 95 L/m2 d, τn = 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.
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oxygen transfer and consumption in subsurface flow Treatment Wetlands
Ecological Engineering, 2013Co-Authors: Jaime Nivala, Kinfe Kassa, Manfred Van Afferden, Tom Headley, Hans Brix, Scott Wallace, Roland A MullerAbstract:Abstract Subsurface oxygen availability tends to be one of the main rate-limiting factors for removal of carbonaceous and nitrogenous compounds in subsurface flow (SSF) Wetlands used for domestic wastewater Treatment. This paper reviews the pertinent literature regarding oxygen transfer and consumption in subsurface flow Treatment Wetlands, and discusses the factors that influence oxygen availability. We also provide first results from a pilot-scale research facility in Langenreichenbach, Germany (15 individual systems of various designs, both with and without plants). Based on the approach given in Kadlec and Wallace (2009) , areal-based oxygen consumption rates for horizontal flow systems were estimated to be between 0.5 and 12.9 g/m2-d; for vertical flow systems between 7.9 and 58.6 g/m2-d; and for intensified systems between 10.9 and 87.5 g/m2-d. In general, as the level of intensification increases, so does subsurface oxygen availability. The use of water or air pumps can result in systems with smaller area requirements (and better Treatment performance), but it comes at the cost of increased electricity inputs. As the Treatment Wetland technology envelope expands, so must methods to compare oxygen consumption rates of traditional and intensified SSF Treatment Wetland designs.
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comparative analysis of constructed Wetlands the design and construction of the ecotechnology research facility in langenreichenbach germany
Ecological Engineering, 2013Co-Authors: Jaime Nivala, Manfred Van Afferden, Tom Headley, Hans Brix, Scott Wallace, Katy Bernhard, Roland A MullerAbstract:The Langenreichenbach ecotechnology research facility contains 15 individual pilot-scale Treatment systems of eight different designs or operational variants. The designs differ in terms of flow direction, degree of media saturation, media type, loading regime, and aeration mechanism. Seven systems were constructed as planted and unplanted pairs, in order to elucidate the role of common reed (Phragmites australis) in these technologies. The facility is unique in the fact that it is located adjacent to the wastewater Treatment plant for the nearby village, enabling all of the pilot-scale systems to receive the same wastewater. The construction of the Langenreichenbach research facility is placed within the overarching discipline of ecological engineering. An overview of the Treatment Wetland design spectrum (ranging from passive to highly intensified designs) is discussed and the specific designs implemented at Langenreichenbach are presented in detail, along with the internal sampling methods for both saturated and unsaturated systems.
John R. White - One of the best experts on this subject based on the ideXlab platform.
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Reducing phosphorus flux from organic soils in surface flow Treatment Wetlands.
Chemosphere, 2011Co-Authors: Susan M. Lindstrom, John R. WhiteAbstract: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.
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competitive sorption and desorption behavior for three fluoroquinolone antibiotics in a wastewater Treatment Wetland soil
Chemosphere, 2010Co-Authors: Jeremy L Conkle, Charisma Lattao, John R. White, Robert L CookAbstract:Abstract 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. Log K F values for all three compounds were between 4.09 and 3.90 for sorption and 4.24 and 4.05 μg 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 20 h, 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.
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Alum application to improve water quality in a municipal wastewater Treatment Wetland: Effects on macrophyte growth and nutrient uptake
Chemosphere, 2010Co-Authors: Lynette M. Malecki-brown, John R. White, Hans BrixAbstract: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 (
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Alum application to improve water quality in a municipal wastewater Treatment Wetland.
Journal of environmental quality, 2009Co-Authors: Lynette M. Malecki-brown, John R. White, Mark D. SeesAbstract:Nutrient removal in Treatment Wetlands declines during winter months due to temperature. A 3-mo (wintertime) mesocosm study was conducted to determine the effectiveness of alum in immobilizing P as well as other nutrients during this period of reduced Treatment efficiency. Eighteen mesocosms, triplicate alum, and three controls or no alum were established with either Typha spp., Schoenoflectus californicus, or SAV (Najas guadalupensis-dominated). Alum was delivered by timer at a rate of 0.81 g Al m -2 d -1 and parameters measured included: pH, soluble reactive phosphorus (SRP), total phosphorus (TP), dissolved organic carbon (DOC), dissolved inorganic nitrogen (DIN), total kjeldahl nitrogen (TKN), and soluble aluminum (Al). Alum-treated mesocosms had significantly lower pH values (8.1) than controls (8.8), but well within the elevated pH range for aluminum toxicity. Alum significantly reduced all measured water column nutrients with the exception of ammonium N, which remained unaffected, and particulate P, which increased. This study demonstrated that seasonal low! dosage alum application to different vegetation communities in a Treatment Wetland can significantly improve Treatment efficiencies for SRP (87 vs. 58%) and TP (62 vs. 44%) but also increase DOC (19 vs. 0%) and TKN (12 vs. -3%) removal capacity to a lesser degree. Alum applications within close proximity of the Treatment Wetland effluent points should be implemented with caution due to the production of alum floc-bound P which could potentially affect discharge permit compliance for total suspended solids or total P.
Jaime Nivala - One of the best experts on this subject based on the ideXlab platform.
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Recent Advances in the Application, Design, and Operations & Maintenance of Aerated Treatment Wetlands
Water, 2020Co-Authors: Jaime Nivala, Clodagh Murphy, Andrew FreemanAbstract:This paper outlines recent advances in the design, application, and operations and maintenance (O&M) of aerated Treatment Wetland systems as well as current research trends. We provide the first-ever comprehensive estimate of the number and geographical distribution of aerated Treatment Wetlands worldwide and review new developments in aerated Wetland design and application. This paper also presents and discusses first-hand experiences and challenges with the O&M of full-scale aerated Treatment Wetland systems, which is an important aspect that is currently not well reported in the literature. Knowledge gaps and suggestions for future research on aerated Treatment Wetlands are provided.
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dynamics of emerging organic contaminant removal in conventional and intensified subsurface flow Treatment Wetlands
Science of The Total Environment, 2019Co-Authors: Jaime Nivala, Johannes Boog, Stefanie Kahl, Manfred Van Afferden, Thorsten Reemtsma, Roland A MullerAbstract:Abstract Six pilot-scale Treatment Wetlands treating municipal wastewater were monitored for classical wastewater parameters and selected Emerging Organic Compounds (EOCs): caffeine (CAF), ibuprofen (IBU), naproxen (NPX), benzotriazole (BTZ), diclofenac (DCL), acesulfame (ACE) and carbamazepine (CBZ) on a weekly basis over the course of one year. Treatment efficacy of the Wetland systems was compared to that of a municipal wastewater Treatment plant adjacent to the research site (activated sludge technology). The aerated Wetlands VAp and HAp, and the two-stage vertical flow system VGp + VSp showed the highest Treatment efficacy (>70% removal on a mass basis) and comparable Treatment efficacy to the conventional WWTP for removal of CAF, IBU, NPX, BTZ, and DCL. Annual mass removal of ACE in the WWTP was 50% and varied in the Wetlands (depending on system design) from zero to 62%. On a mean monthly basis, ACE removal in the Treatment Wetlands VGp + VSp, VAp, HAp, R was high (> 90%) for six months of the year. Monthly mean mass removal of CBZ was negligible for the WWTP and all Treatment Wetland systems except H50p, which showed up to 49% mass removal in June. Monthly mean mass removals of classical wastewater parameters and readily biodegradable EOCs (represented by CAF, IBU, NPX) were most stable in the intensified Wetland designs VAp, HAp, and R. A statistical analysis confirms that system complexity, aerobic conditions, and temperature have the highest correlation to overall pollutant removal in the Treatment Wetland systems, including EOCs of high to moderate biodegradability. First-order removal rate coefficents and temperature correction factors for EOCs are reported for the first time in the Treatment Wetland literature. Limitations on the use of these values in engineering design are discussed.
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Resilience of carbon and nitrogen removal due to aeration interruption in aerated Treatment Wetlands.
The Science of the total environment, 2017Co-Authors: Johannes Boog, Jaime Nivala, Manfred Van Afferden, Thomas Aubron, Sibylle Mothes, Roland A MullerAbstract:Treatment Wetlands have long been used for domestic and industrial wastewater Treatment. In recent decades, Treatment Wetland technology has evolved and now includes intensified designs such as aerated Treatment Wetlands. Aerated Treatment Wetlands are particularly dependent on aeration, which requires reliable air pumps and, in most cases, electricity. Whether aerated Treatment Wetlands are resilient to disturbances such as an aeration interruption is currently not well known. In order to investigate this knowledge gap, we carried out a pilot-scale experiment on one aerated horizontal flow Wetland and one aerated vertical flow Wetland under warm (Twater>17°C) and cold (Twater 17°C (warm weather) and within 6-8d (horizontal flow system) and 4-5d (vertical flow system) at Twater 17°C was twice as high as in the horizontal flow aerated Wetland. The quick recovery of Treatment performance highlights the benefits of aerated Treatment Wetlands as resilient wastewater Treatment technologies.
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hydraulic characterization and optimization of total nitrogen removal in an aerated vertical subsurface flow Treatment Wetland
Bioresource Technology, 2014Co-Authors: Johannes Boog, Jaime Nivala, Manfred Van Afferden, Scott Wallace, Thomas Aubron, Roland A MullerAbstract:Abstract In this study, a side-by-side comparison of two pilot-scale vertical subsurface flow constructed Wetlands (6.2 m2 × 0.85 m, qi = 95 L/m2 d, τn = 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.
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oxygen transfer and consumption in subsurface flow Treatment Wetlands
Ecological Engineering, 2013Co-Authors: Jaime Nivala, Kinfe Kassa, Manfred Van Afferden, Tom Headley, Hans Brix, Scott Wallace, Roland A MullerAbstract:Abstract Subsurface oxygen availability tends to be one of the main rate-limiting factors for removal of carbonaceous and nitrogenous compounds in subsurface flow (SSF) Wetlands used for domestic wastewater Treatment. This paper reviews the pertinent literature regarding oxygen transfer and consumption in subsurface flow Treatment Wetlands, and discusses the factors that influence oxygen availability. We also provide first results from a pilot-scale research facility in Langenreichenbach, Germany (15 individual systems of various designs, both with and without plants). Based on the approach given in Kadlec and Wallace (2009) , areal-based oxygen consumption rates for horizontal flow systems were estimated to be between 0.5 and 12.9 g/m2-d; for vertical flow systems between 7.9 and 58.6 g/m2-d; and for intensified systems between 10.9 and 87.5 g/m2-d. In general, as the level of intensification increases, so does subsurface oxygen availability. The use of water or air pumps can result in systems with smaller area requirements (and better Treatment performance), but it comes at the cost of increased electricity inputs. As the Treatment Wetland technology envelope expands, so must methods to compare oxygen consumption rates of traditional and intensified SSF Treatment Wetland designs.
Karine E Borne - One of the best experts on this subject based on the ideXlab platform.
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floating Treatment Wetland influences on the fate and removal performance of phosphorus in stormwater retention ponds
Ecological Engineering, 2014Co-Authors: Karine E BorneAbstract:Abstract A field trial comparing the fate and removal performance of phosphorus (P) in two parallel stormwater retention ponds, one retrofitted with a Floating Treatment Wetland (FTW) and one without any vegetation (a control), was carried out near Auckland, New Zealand. Results suggest that inclusion of a FTW would significantly improve P removal efficiency exhibiting 27% lower TP outlet event mean concentrations (EMCs) than a conventional retention pond. The low SRP inlet EMC did not allow the performance of either pond to be differentiated. Inlet particulate bound P (PP) is thought to have been associated with particulate copper on fine particles like colloidal organic matter and/or clay and trapped into the sticky biofilm of the roots to subsequently settle on the bottom of the pond. The FTW pond induced a more neutral water column pH and higher organic release into the water column, likely promoting dissolved phosphorus sorption onto particles. Surprisingly, the reduced (low redox potential) sediment observed below the FTW did not induce P release probably due to the more neutral pH conditions allowing re-adsorption onto organics and/or clay minerals (e.g. Al-OH). This resulted in higher P sediment accumulation in the FTW pond. P uptake by plants is not thought to be a significant removal pathway. Sorption of dissolved P, physical entrapment of PP in roots and settlement are thought to be the main P removal pathways for ponds equipped with FTWs.
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floating Treatment Wetland influences on the fate of metals in road runoff retention ponds
Water Research, 2014Co-Authors: Karine E Borne, Elizabeth Fassmanbeck, Chris C TannerAbstract: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.
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floating Treatment Wetland retrofit to improve stormwater pond performance for suspended solids copper and zinc
Ecological Engineering, 2013Co-Authors: Karine E Borne, Elizabeth A Fassman, Chris C TannerAbstract:Abstract A field trial study with side-by-side monitoring of two parallel stormwater Treatment ponds, one of which contained a floating Treatment Wetland (FTW), has been carried out to assess the benefit of retrofitting a conventional retention pond with a FTW. Inflow and outflow event mean concentrations (EMCs) were quantified and used to assess the overall pollutant removal efficiency of each system. Findings show that a FTW can significantly improve the runoff water quality and thus reduce the impact on the receiving environment. The present study reveals that a pond retrofit with a FTW would be more efficient than a conventional retention pond, exhibiting a 41% (for total suspended solids – TSS), 40% (for particulate zinc – PZn), 39% (for particulate copper – PCu) and 16% (for dissolved copper – DCu) lower effluent EMC. Physical entrapment of the particulate pollutants into the roots’ biofilm seems be a significant removal pathway, which could be impacted by the inflow volume. Due to higher humic content, lower dissolved oxygen and more neutral water column pH induced by the FTW, there was increased potential for adsorption processes and/or precipitation as insoluble copper sulphides, in addition to the direct Cu uptake by the plants. The dissolved zinc (DZn) inlet EMCs, which already met the Australian and New Zealand Environment Conservation Council (ANZECC) water quality guidelines and could correspond to an irreducible concentration of the system, were too low to differentiate the performance of either pond.
Johannes Boog - One of the best experts on this subject based on the ideXlab platform.
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dynamics of emerging organic contaminant removal in conventional and intensified subsurface flow Treatment Wetlands
Science of The Total Environment, 2019Co-Authors: Jaime Nivala, Johannes Boog, Stefanie Kahl, Manfred Van Afferden, Thorsten Reemtsma, Roland A MullerAbstract:Abstract Six pilot-scale Treatment Wetlands treating municipal wastewater were monitored for classical wastewater parameters and selected Emerging Organic Compounds (EOCs): caffeine (CAF), ibuprofen (IBU), naproxen (NPX), benzotriazole (BTZ), diclofenac (DCL), acesulfame (ACE) and carbamazepine (CBZ) on a weekly basis over the course of one year. Treatment efficacy of the Wetland systems was compared to that of a municipal wastewater Treatment plant adjacent to the research site (activated sludge technology). The aerated Wetlands VAp and HAp, and the two-stage vertical flow system VGp + VSp showed the highest Treatment efficacy (>70% removal on a mass basis) and comparable Treatment efficacy to the conventional WWTP for removal of CAF, IBU, NPX, BTZ, and DCL. Annual mass removal of ACE in the WWTP was 50% and varied in the Wetlands (depending on system design) from zero to 62%. On a mean monthly basis, ACE removal in the Treatment Wetlands VGp + VSp, VAp, HAp, R was high (> 90%) for six months of the year. Monthly mean mass removal of CBZ was negligible for the WWTP and all Treatment Wetland systems except H50p, which showed up to 49% mass removal in June. Monthly mean mass removals of classical wastewater parameters and readily biodegradable EOCs (represented by CAF, IBU, NPX) were most stable in the intensified Wetland designs VAp, HAp, and R. A statistical analysis confirms that system complexity, aerobic conditions, and temperature have the highest correlation to overall pollutant removal in the Treatment Wetland systems, including EOCs of high to moderate biodegradability. First-order removal rate coefficents and temperature correction factors for EOCs are reported for the first time in the Treatment Wetland literature. Limitations on the use of these values in engineering design are discussed.
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Application: Treatment Wetlands
OpenGeoSys Tutorial, 2018Co-Authors: Johannes BoogAbstract:This chapter describes the implementation of a 2D steady-state reactive transport model (RTM) of a Treatment Wetland. Treatment Wetlands are technologies used for handling wastewater and other contaminated types of water.
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Resilience of carbon and nitrogen removal due to aeration interruption in aerated Treatment Wetlands.
The Science of the total environment, 2017Co-Authors: Johannes Boog, Jaime Nivala, Manfred Van Afferden, Thomas Aubron, Sibylle Mothes, Roland A MullerAbstract:Treatment Wetlands have long been used for domestic and industrial wastewater Treatment. In recent decades, Treatment Wetland technology has evolved and now includes intensified designs such as aerated Treatment Wetlands. Aerated Treatment Wetlands are particularly dependent on aeration, which requires reliable air pumps and, in most cases, electricity. Whether aerated Treatment Wetlands are resilient to disturbances such as an aeration interruption is currently not well known. In order to investigate this knowledge gap, we carried out a pilot-scale experiment on one aerated horizontal flow Wetland and one aerated vertical flow Wetland under warm (Twater>17°C) and cold (Twater 17°C (warm weather) and within 6-8d (horizontal flow system) and 4-5d (vertical flow system) at Twater 17°C was twice as high as in the horizontal flow aerated Wetland. The quick recovery of Treatment performance highlights the benefits of aerated Treatment Wetlands as resilient wastewater Treatment technologies.
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hydraulic characterization and optimization of total nitrogen removal in an aerated vertical subsurface flow Treatment Wetland
Bioresource Technology, 2014Co-Authors: Johannes Boog, Jaime Nivala, Manfred Van Afferden, Scott Wallace, Thomas Aubron, Roland A MullerAbstract:Abstract In this study, a side-by-side comparison of two pilot-scale vertical subsurface flow constructed Wetlands (6.2 m2 × 0.85 m, qi = 95 L/m2 d, τn = 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.
