Search

Phosphorus (P) scarcity and the environmental hazards posed by P discharges have triggered the development of technologies for P sequestration and removal from waste streams. Agriculture runoff usually has P concentrations high enough to contribute to eutrophication and harmful algal blooms, but they are still too low for successful P removal with conventional technologies commonly applied in wastewater treatment. For this reason, realistic approaches to remove P from agricultural waste streams mainly include natural assimilation and constructed wetlands. Although these technologies have been implemented for some time, P removal is not always achieved to the needed extent and sometimes sufficient surface areas required are unattainable. Phosphorus sorbing materials, especially materials rich in calcium, have emerged to increase the removal potential of runoff treatment wetlands and at the same time sequester P for potential subsequent reuse. This paper analyses the current strategies and technologies for P removal and reuse from agriculture surface runoff streams taking a circular economy approach. It particularly addresses the current state of calcium rich materials commonly used for P removal that have also shown positive results as fertilizers or soil., This work has been possible thanks to the European funding programme “Iniciativa de Empleo Juvenil” and the Spanish Ministry of Science and Innovation (project reference: PEJ2018-005586-A)., Peer Reviewed, Postprint (published version)

Eutrophication is a widespread global scale pollution problem. Agricultural areas are generally the main contributors to eutrophication, whereas sewage and industrial discharges, which usually receive some treatment prior to discharge, are a secondary source. This is mostly the case of the ultra-oligotrophic Florida Everglades, where natural water sources are often enriched by nutrients from large-scale industrial agricultural stormwater runoff. Remediation of these agricultural waters cannot be conducted with the usual environmental engineering solutions, and in this context ecological engineering approaches such as constructed wetlands are much more suitable. Moreover, these wetlands provide other ecosystem services such as carbon sequestration or habitat provisioning. In this paper we have implemented a mechanistic phosphorus model into a time-space-dependent mathematical simulation platform (COMSOL Multiphysics™) which has been calibrated with wetland mesocosm data. Subsequently we have evaluated different characteristics of constructed wetland physical elements such as internal walls and baffles, different types of inlets, parallel and series operation, and increase in hydraulic retention time (HRT) to study total phosphorus (TP) removal performance and to improve efficiency. Simulation results indicate that wetland mesocosm soils released dissolved organic phosphorus which was washed out together with the effluent, making very difficult to attain a concentration lower than a target of 10 µg TP L-1, as required to protect the Everglades. Simulations showed that the design based on combination of the bottom inlet together with parallel operation extensively improves efficiency. Target TP concentrations can be achieved with this design together with an increase on 25% of hydraulic retention time. With this study we demonstrate the usefulness of the model for detailed designs, opening the door for its use in field scale applications., Peer Reviewed, Postprint (author's final draft)

Nitrous oxide (N2O) is a powerful greenhouse gas and the main driver of stratospheric ozone depletion. Since soils are the largest source of N2O, predicting soil response to changes in climate or land use is central to understanding and managing N2O. Here we find that N2O flux can be predicted by models incorporating soil nitrate concentration (NO3 -), water content and temperature using a global field survey of N2O emissions and potential driving factors across a wide range of organic soils. N2O emissions increase with NO3 - and follow a bell-shaped distribution with water content. Combining the two functions explains 72% of N2O emission from all organic soils. Above 5 mg NO3 --N kg-1, either draining wet soils or irrigating well-drained soils increases N2O emission by orders of magnitude. As soil temperature together with NO3 - explains 69% of N2O emission, tropical wetlands should be a priority for N2O management.

Nitrous oxide (N2O) is a powerful greenhouse gas and the main driver of stratospheric ozone depletion. Since soils are the largest source of N2O, predicting soil response to changes in climate or land use is central to understanding and managing N2O. Here we find that N2O flux can be predicted by models incorporating soil nitrate concentration (NO3−), water content and temperature using a global field survey of N2O emissions and potential driving factors across a wide range of organic soils. N2O emissions increase with NO3− and follow a bell-shaped distribution with water content. Combining the two functions explains 72% of N2O emission from all organic soils. Above 5 mg NO3−-N kg−1, either draining wet soils or irrigating well-drained soils increases N2O emission by orders of magnitude. As soil temperature together with NO3− explains 69% of N2O emission, tropical wetlands should be a priority for N2O management.

Nitrous oxide (N2O) is a powerful greenhouse gas and the main driver of stratospheric ozone depletion. Since soils are the largest source of N2O, predicting soil response to changes in climate or land use is central to understanding and managing N2O. Here we find that N2O flux can be predicted by models incorporating soil nitrate concentration (NO3−), water content and temperature using a global field survey of N2O emissions and potential driving factors across a wide range of organic soils. N2O emissions increase with NO3− and follow a bell-shaped distribution with water content. Combining the two functions explains 72% of N2O emission from all organic soils. Above 5 mg NO3−-N kg−1, either draining wet soils or irrigating well-drained soils increases N2O emission by orders of magnitude. As soil temperature together with NO3− explains 69% of N2O emission, tropical wetlands should be a priority for N2O management.

In a great number of scientific articles on water quality improvement using constructed wetlands (CW) and riparian buffers zones (RBZ) at catchment scale, contradictory results are found. In most cases this is due to underestimating or even ignoring the role of the hydrological factor for water quality improvement. It has often resulted in biased estimates of buffering systems’ efficiency at catchment scale and, consequently, has caused planning and establishment failures, mistakes and inconsistencies in legislative acts and finally, it has influenced stakeholder's willingness to support these eco-technological measures. In this paper we present a short but critical overview of the potential of CWs and RBZs in water quality improvement at catchment scale and highlight the most important aspects to be considered when planning, establishing and managing these systems.

In a great number of scientific articles on water quality improvement using constructed wetlands (CW) and riparian buffers zones (RBZ) at catchment scale, contradictory results are found. In most cases this is due to underestimating or even ignoring the role of the hydrological factor for water quality improvement. It has often resulted in biased estimates of buffering systems efficiency at catchment scale and, consequently, has caused planning and establishment failures, mistakes and inconsistencies in legislative acts and finally, it has influenced stakeholders willingness to support these eco-technological measures. In this paper we present a short but critical overview of the potential of CWs and RBZs in water quality improvement at catchment scale and highlight the most important aspects to be considered when planning, establishing and managing these systems. (C) 2016 Elsevier B.V. All rights reserved., Funding Agencies|AESN; LifeARTWet [ENV/F/000133]; PIREN Seine; Estonian Research Council [IUT2-16]; EU through the European Regional Development Fund (Centre of Excellence ENVIRON); EU through the European Regional Development Fund (Centre of Excellence EcolChange)

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world. In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive), international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reduce the input of nutrients to freshwater and marine environments. A widely used method to achieve this is to allow water to pass through a created or restored wetland. However, the large variation in measured nutrient removal rates in such wetlands calls for a systematic review. Methods: Searches for primary studies were performed in electronic databases and on the internet. One author performed the screening of all retrieved articles at the title and abstract level. To check that the screening was consistent and complied with the agreed inclusion/exclusion criteria, subsets of 100 articles were screened by the other authors. When screening at full-text level the articles were evenly distributed among the authors. Kappa tests were used to evaluate screening consistency. Relevant articles remaining after screening were critically appraised and assigned to three quality categories, from two of which data were extracted. Quantitative synthesis consists of meta-analyses and response surface analyses. Regressions were performed using generalized additive models that can handle nonlinear relationships and interaction effects. Results: Searches generated 5853 unique records. After screening on relevance and critical appraisal, 93 articles including 203 wetlands were used for data extraction. Most of the wetlands were situated in Europe and North America. The removal rate of both total nitrogen (TN) and total phosphorus (TP) is highly dependent on the loading rate. Significant relationships were also found for annual average air temperature (T) and wetland area (A). Median removal rates of TN and TP were 93 and 1.2 g m(-2) year(-1.), respectively. Removal eff, Funding Agencies|Mistra Council for Evidence-based Environmental Management (Mistra EviEM); Swedish Foundation for Strategic Environmental Research (Mistra)Swedish Foundation for Strategic Research

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world. In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive), international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reduce the input of nutrients to freshwater and marine environments. A widely used method to achieve this is to allow water to pass through a created or restored wetland. However, the large variation in measured nutrient removal rates in such wetlands calls for a systematic review. Methods: Searches for primary studies were performed in electronic databases and on the internet. One author performed the screening of all retrieved articles at the title and abstract level. To check that the screening was consistent and complied with the agreed inclusion/exclusion criteria, subsets of 100 articles were screened by the other authors. When screening at full-text level the articles were evenly distributed among the authors. Kappa tests were used to evaluate screening consistency. Relevant articles remaining after screening were critically appraised and assigned to three quality categories, from two of which data were extracted. Quantitative synthesis consists of meta-analyses and response surface analyses. Regressions were performed using generalized additive models that can handle nonlinear relationships and interaction effects. Results: Searches generated 5853 unique records. After screening on relevance and critical appraisal, 93 articles including 203 wetlands were used for data extraction. Most of the wetlands were situated in Europe and North America. The removal rate of both total nitrogen (TN) and total phosphorus (TP) is highly dependent on the loading rate. Significant relationships were also found for annual average air temperature (T) and wetland area (A). Median removal rates of TN and TP were 93 and 1.2 g m(-2) year(-1.), respectively. Removal eff, Funding Agencies|Mistra Council for Evidence-based Environmental Management (Mistra EviEM); Swedish Foundation for Strategic Environmental Research (Mistra)Swedish Foundation for Strategic Research

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world. In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive), international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reduce the input of nutrients to freshwater and marine environments. A widely used method to achieve this is to allow water to pass through a created or restored wetland. However, the large variation in measured nutrient removal rates in such wetlands calls for a systematic review. Methods: Searches for primary studies were performed in electronic databases and on the internet. One author performed the screening of all retrieved articles at the title and abstract level. To check that the screening was consistent and complied with the agreed inclusion/exclusion criteria, subsets of 100 articles were screened by the other authors. When screening at full-text level the articles were evenly distributed among the authors. Kappa tests were used to evaluate screening consistency. Relevant articles remaining after screening were critically appraised and assigned to three quality categories, from two of which data were extracted. Quantitative synthesis consists of meta-analyses and response surface analyses. Regressions were performed using generalized additive models that can handle nonlinear relationships and interaction effects. Results: Searches generated 5853 unique records. After screening on relevance and critical appraisal, 93 articles including 203 wetlands were used for data extraction. Most of the wetlands were situated in Europe and North America. The removal rate of both total nitrogen (TN) and total phosphorus (TP) is highly dependent on the loading rate. Significant relationships were also found for annual average air temperature (T) and wetland area (A). Median removal rates of TN and TP were 93 and 1.2 g m(-2) year(-1.), respectively. Removal eff, Funding Agencies|Mistra Council for Evidence-based Environmental Management (Mistra EviEM); Swedish Foundation for Strategic Environmental Research (Mistra)Swedish Foundation for Strategic Research

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world. In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive), international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reduce the input of nutrients to freshwater and marine environments. A widely used method to achieve this is to allow water to pass through a created or restored wetland. However, the large variation in measured nutrient removal rates in such wetlands calls for a systematic review. Methods: Searches for primary studies were performed in electronic databases and on the internet. One author performed the screening of all retrieved articles at the title and abstract level. To check that the screening was consistent and complied with the agreed inclusion/exclusion criteria, subsets of 100 articles were screened by the other authors. When screening at full-text level the articles were evenly distributed among the authors. Kappa tests were used to evaluate screening consistency. Relevant articles remaining after screening were critically appraised and assigned to three quality categories, from two of which data were extracted. Quantitative synthesis consists of meta-analyses and response surface analyses. Regressions were performed using generalized additive models that can handle nonlinear relationships and interaction effects. Results: Searches generated 5853 unique records. After screening on relevance and critical appraisal, 93 articles including 203 wetlands were used for data extraction. Most of the wetlands were situated in Europe and North America. The removal rate of both total nitrogen (TN) and total phosphorus (TP) is highly dependent on the loading rate. Significant relationships were also found for annual average air temperature (T) and wetland area (A). Median removal rates of TN and TP were 93 and 1.2 g m(-2) year(-1.), respectively. Removal eff, Funding Agencies|Mistra Council for Evidence-based Environmental Management (Mistra EviEM); Swedish Foundation for Strategic Environmental Research (Mistra)Swedish Foundation for Strategic Research

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world. In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive), international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reduce the input of nutrients to freshwater and marine environments. A widely used method to achieve this is to allow water to pass through a created or restored wetland. However, the large variation in measured nutrient removal rates in such wetlands calls for a systematic review. Methods: Searches for primary studies were performed in electronic databases and on the internet. One author performed the screening of all retrieved articles at the title and abstract level. To check that the screening was consistent and complied with the agreed inclusion/exclusion criteria, subsets of 100 articles were screened by the other authors. When screening at full-text level the articles were evenly distributed among the authors. Kappa tests were used to evaluate screening consistency. Relevant articles remaining after screening were critically appraised and assigned to three quality categories, from two of which data were extracted. Quantitative synthesis consists of meta-analyses and response surface analyses. Regressions were performed using generalized additive models that can handle nonlinear relationships and interaction effects. Results: Searches generated 5853 unique records. After screening on relevance and critical appraisal, 93 articles including 203 wetlands were used for data extraction. Most of the wetlands were situated in Europe and North America. The removal rate of both total nitrogen (TN) and total phosphorus (TP) is highly dependent on the loading rate. Significant relationships were also found for annual average air temperature (T) and wetland area (A). Median removal rates of TN and TP were 93 and 1.2 g m(-2) year(-1.), respectively. Removal eff, Funding Agencies|Mistra Council for Evidence-based Environmental Management (Mistra EviEM); Swedish Foundation for Strategic Environmental Research (Mistra)Swedish Foundation for Strategic Research

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world. In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive), international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reduce the input of nutrients to freshwater and marine environments. A widely used method to achieve this is to allow water to pass through a created or restored wetland. However, the large variation in measured nutrient removal rates in such wetlands calls for a systematic review. Methods: Searches for primary studies were performed in electronic databases and on the internet. One author performed the screening of all retrieved articles at the title and abstract level. To check that the screening was consistent and complied with the agreed inclusion/exclusion criteria, subsets of 100 articles were screened by the other authors. When screening at full-text level the articles were evenly distributed among the authors. Kappa tests were used to evaluate screening consistency. Relevant articles remaining after screening were critically appraised and assigned to three quality categories, from two of which data were extracted. Quantitative synthesis consists of meta-analyses and response surface analyses. Regressions were performed using generalized additive models that can handle nonlinear relationships and interaction effects. Results: Searches generated 5853 unique records. After screening on relevance and critical appraisal, 93 articles including 203 wetlands were used for data extraction. Most of the wetlands were situated in Europe and North America. The removal rate of both total nitrogen (TN) and total phosphorus (TP) is highly dependent on the loading rate. Significant relationships were also found for annual average air temperature (T) and wetland area (A). Median removal rates of TN and TP were 93 and 1.2 g m(-2) year(-1.), respectively. Removal eff, Funding Agencies|Mistra Council for Evidence-based Environmental Management (Mistra EviEM); Swedish Foundation for Strategic Environmental Research (Mistra)Swedish Foundation for Strategic Research

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world.In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive),international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reducethe input of plant nutrients to freshwater and marine environments. A widely used method to achieve this is to letwater pass through a constructed or restored wetland (CW). However, the large variation in measured nutrientremoval rates in such wetlands calls for a systematic review. The objective of this review is to quantify nitrogen andphosphorus removal rates in constructed or restored wetlands and relate them to wetland characteristics, loading characteristics, and climate factors. Wetlands are created to treat water from a number of different sources. Sources that will be considered in this review include agricultural runoff and urban storm water run-off, as well as aquaculture wastewater and outlets from domestic wastewater treatment plants, with particular attention to thesituation in Sweden. Although the performance of wetlands in temperate and boreal regions is most relevant tothe Swedish stakeholders a wider range of climatic conditions will be considered in order to make a thorough evaluation of climatic factors. Methods: Searches for primary studies will be performed in electronic databases as well as on the internet. Oneauthor will perform the screening of all retrieved articles at the title and abstract level. To check that the screeningis consistent and complies with the agreed inclusion/exclusion criteria, subsets of 100 articles will be screened by the other authors. When screening at full-text level the articles will be evenly distributed among the authors. Kappatests will be used to evaluate screening consistency. Data synthesis will be based on meta-regression. The nutrient removal rates will be taken as response variables and the

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world.In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive),international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reducethe input of plant nutrients to freshwater and marine environments. A widely used method to achieve this is to letwater pass through a constructed or restored wetland (CW). However, the large variation in measured nutrientremoval rates in such wetlands calls for a systematic review. The objective of this review is to quantify nitrogen andphosphorus removal rates in constructed or restored wetlands and relate them to wetland characteristics, loading characteristics, and climate factors. Wetlands are created to treat water from a number of different sources. Sources that will be considered in this review include agricultural runoff and urban storm water run-off, as well as aquaculture wastewater and outlets from domestic wastewater treatment plants, with particular attention to thesituation in Sweden. Although the performance of wetlands in temperate and boreal regions is most relevant tothe Swedish stakeholders a wider range of climatic conditions will be considered in order to make a thorough evaluation of climatic factors. Methods: Searches for primary studies will be performed in electronic databases as well as on the internet. Oneauthor will perform the screening of all retrieved articles at the title and abstract level. To check that the screeningis consistent and complies with the agreed inclusion/exclusion criteria, subsets of 100 articles will be screened by the other authors. When screening at full-text level the articles will be evenly distributed among the authors. Kappatests will be used to evaluate screening consistency. Data synthesis will be based on meta-regression. The nutrient removal rates will be taken as response variables and the

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world.In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive),international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reducethe input of plant nutrients to freshwater and marine environments. A widely used method to achieve this is to letwater pass through a constructed or restored wetland (CW). However, the large variation in measured nutrientremoval rates in such wetlands calls for a systematic review. The objective of this review is to quantify nitrogen andphosphorus removal rates in constructed or restored wetlands and relate them to wetland characteristics, loading characteristics, and climate factors. Wetlands are created to treat water from a number of different sources. Sources that will be considered in this review include agricultural runoff and urban storm water run-off, as well as aquaculture wastewater and outlets from domestic wastewater treatment plants, with particular attention to thesituation in Sweden. Although the performance of wetlands in temperate and boreal regions is most relevant tothe Swedish stakeholders a wider range of climatic conditions will be considered in order to make a thorough evaluation of climatic factors. Methods: Searches for primary studies will be performed in electronic databases as well as on the internet. Oneauthor will perform the screening of all retrieved articles at the title and abstract level. To check that the screeningis consistent and complies with the agreed inclusion/exclusion criteria, subsets of 100 articles will be screened by the other authors. When screening at full-text level the articles will be evenly distributed among the authors. Kappatests will be used to evaluate screening consistency. Data synthesis will be based on meta-regression. The nutrient removal rates will be taken as response variables and the

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world.In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive),international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reducethe input of plant nutrients to freshwater and marine environments. A widely used method to achieve this is to letwater pass through a constructed or restored wetland (CW). However, the large variation in measured nutrientremoval rates in such wetlands calls for a systematic review. The objective of this review is to quantify nitrogen andphosphorus removal rates in constructed or restored wetlands and relate them to wetland characteristics, loading characteristics, and climate factors. Wetlands are created to treat water from a number of different sources. Sources that will be considered in this review include agricultural runoff and urban storm water run-off, as well as aquaculture wastewater and outlets from domestic wastewater treatment plants, with particular attention to thesituation in Sweden. Although the performance of wetlands in temperate and boreal regions is most relevant tothe Swedish stakeholders a wider range of climatic conditions will be considered in order to make a thorough evaluation of climatic factors. Methods: Searches for primary studies will be performed in electronic databases as well as on the internet. Oneauthor will perform the screening of all retrieved articles at the title and abstract level. To check that the screeningis consistent and complies with the agreed inclusion/exclusion criteria, subsets of 100 articles will be screened by the other authors. When screening at full-text level the articles will be evenly distributed among the authors. Kappatests will be used to evaluate screening consistency. Data synthesis will be based on meta-regression. The nutrient removal rates will be taken as response variables and the

Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world.In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive),international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reducethe input of plant nutrients to freshwater and marine environments. A widely used method to achieve this is to letwater pass through a constructed or restored wetland (CW). However, the large variation in measured nutrientremoval rates in such wetlands calls for a systematic review. The objective of this review is to quantify nitrogen andphosphorus removal rates in constructed or restored wetlands and relate them to wetland characteristics, loading characteristics, and climate factors. Wetlands are created to treat water from a number of different sources. Sources that will be considered in this review include agricultural runoff and urban storm water run-off, as well as aquaculture wastewater and outlets from domestic wastewater treatment plants, with particular attention to thesituation in Sweden. Although the performance of wetlands in temperate and boreal regions is most relevant tothe Swedish stakeholders a wider range of climatic conditions will be considered in order to make a thorough evaluation of climatic factors. Methods: Searches for primary studies will be performed in electronic databases as well as on the internet. Oneauthor will perform the screening of all retrieved articles at the title and abstract level. To check that the screeningis consistent and complies with the agreed inclusion/exclusion criteria, subsets of 100 articles will be screened by the other authors. When screening at full-text level the articles will be evenly distributed among the authors. Kappatests will be used to evaluate screening consistency. Data synthesis will be based on meta-regression. The nutrient removal rates will be taken as response variables and the

Four 2- to 3-ha constructed freshwater riparian wetlands in Lake County, Illinois, were subjected to two hydrologic regimes of pumped river water to simulate nonpoint source pollution. The experimental wetlands at the Des Plaines River Wetland Demonstration Project were designed to develop and test wetland design principles, construction methods, and management programs needed to create and maintain wetlands for the purposes of water quality management, flood control, and fish and wildlife habitat. High-flow wetlands (HFW) with short retention times received 34 to 38 cm of river water per week, and low-flow wetlands (LFW) with high retention times received 10 to 15 cm per week. This report summarizes research results for phosphorus dynamics and retention, macrophyte development, periphyton productivity, and overall water column metabolism through 1992. All of these functions were hypothesized to be related to hydrologic conditions.