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Information of the physical and ecological state of streams along with an overview of the need for maintenance is traditionally a time-consuming manual field task with subsequent limitations in area coverage. Here we propose a novel approach to stream monitoring and management using a low-cost Unmanned Aerial Vehicle (UAV) platform to collect data comparable to that from traditional monitoring schemes. This technology provides high resolution imagery while being easy to implement at a low cost along with providing data that represent the stream in both fine scale and at landscape scale. The results show a significant correlation between results obtained by the two methods, with the largest difference in DFI-values being ten, but in many cases being < five. The UAV-method is especially strong in supporting geographical measurements of stream width and course along with certain stream parameters such as physical variation, water flow and gravel coverage. The results indicate that UAV mapping of streams is a feasible alternative or support to the traditional mapping of certain open stream types with the possibility of covering more area with the same time-use.
Niels Svane; Mogens R. Flindt; Ronja N. Petersen; Sara Egemose. Physical stream quality measured by drones and image analysis versus the traditional manual method. Environmental Technology 2020, 1 -11.
AMA StyleNiels Svane, Mogens R. Flindt, Ronja N. Petersen, Sara Egemose. Physical stream quality measured by drones and image analysis versus the traditional manual method. Environmental Technology. 2020; ():1-11.
Chicago/Turabian StyleNiels Svane; Mogens R. Flindt; Ronja N. Petersen; Sara Egemose. 2020. "Physical stream quality measured by drones and image analysis versus the traditional manual method." Environmental Technology , no. : 1-11.
Climate changes and urbanization push cities to redesign their drainage systems, which may increase separate stormwater discharges to local recipients. In the EU, regulation of these is governed by the Water Framework Directive (WFD) and the Floods Directive, but national implementation varies and is often supplemented with local non-legislative guidelines. By reviewing trends and discrepancies in the Danish regulation practice for separated stormwater discharges, this article investigates how the directives are put into effect. A legislative gap for separate stormwater discharges introduces uncertainty in the discharge permit conditions, which especially affect conditions targeting water quality. We point to several topics to be addressed, e.g., the level at which the regulation of separate stormwater discharges takes place, opportunities for coordination with flood risk and climate change adaptation initiatives, as well as uncertainties regarding the application of Best Available Techniques. Working with these issues would elevate the regulation practice and aid regulators in reaching a more holistic and consistent approach, thus improving chances of reaching the desired recipient status before or after the WFD deadline in 2027. This could be undertaken at river basin, river basin district or national level, but there is also potential for harvesting mutual benefits by addressing these challenges internationally.
Ditte Jensen; Anja Thomsen; Torben Larsen; Sara Egemose; Peter Mikkelsen. From EU Directives to Local Stormwater Discharge Permits: A Study of Regulatory Uncertainty and Practice Gaps in Denmark. Sustainability 2020, 12, 6317 .
AMA StyleDitte Jensen, Anja Thomsen, Torben Larsen, Sara Egemose, Peter Mikkelsen. From EU Directives to Local Stormwater Discharge Permits: A Study of Regulatory Uncertainty and Practice Gaps in Denmark. Sustainability. 2020; 12 (16):6317.
Chicago/Turabian StyleDitte Jensen; Anja Thomsen; Torben Larsen; Sara Egemose; Peter Mikkelsen. 2020. "From EU Directives to Local Stormwater Discharge Permits: A Study of Regulatory Uncertainty and Practice Gaps in Denmark." Sustainability 12, no. 16: 6317.
The characteristics of stormwater need focus due to climate change. Paved areas and recipients receiving more stormwater have an enhanced need for treatment before discharge to remove suspended solids, nutrients and xenobiotics. To handle and treat stormwater efficiently, knowledge concerning first flush patterns is crucial. Therefore, we have studied 12 entire rain events and correlated water volume, suspended solids, and dissolved and particulate phosphorus to catchment characteristics and precipitation characteristics. We have mainly studied smaller rain events (average 12.6 mm), as nearly 90% of the events in the studied catchment are
Sara Egemose; Anne B. Petersen; Melanie J. Sønderup; Mogens R. Flindt. First Flush Characteristics in Separate Sewer Stormwater and Implications for Treatment. Sustainability 2020, 12, 5063 .
AMA StyleSara Egemose, Anne B. Petersen, Melanie J. Sønderup, Mogens R. Flindt. First Flush Characteristics in Separate Sewer Stormwater and Implications for Treatment. Sustainability. 2020; 12 (12):5063.
Chicago/Turabian StyleSara Egemose; Anne B. Petersen; Melanie J. Sønderup; Mogens R. Flindt. 2020. "First Flush Characteristics in Separate Sewer Stormwater and Implications for Treatment." Sustainability 12, no. 12: 5063.
New lakes are established or reestablished to provide ecosystem services such as limiting floods and nutrient discharge and to improve biodiversity. New lakes are often established on fertilized land formerly used for agricultural purposes, thereby posing a risk of issues such as phosphorus (P) release when inundated. Release of P from agricultural soil affects both the developing ecosystem of the new lake and may increase downstream eutrophication. To decrease P release following inundation, three simple and cost-effective soil pretreatments were tested through laboratory soil–water fluxes from the test sites in the new Lake Roennebaek and the fluxes of P, nitrogen (N), and iron (Fe) were compared. The pretreatments compared were sand-capping, depth-plowing, and addition of the commercial iron product CFH-12® (Kemira). Untreated agricultural soil incubated under laboratory conditions released 687 ± 88 mg P·m−2 over 207 days and 85% was released within 60 days from inundation followed by low soil–water P exchange during the remaining incubation period. However, P was still released from the untreated soil 180 days after inundation within the lake. The cumulated P flux of the three pretreatment methods was in comparison negative, between −12 ± 3 and −17 ± 4 mg P·m−2 over 207 days incubation and showed negative P fluxes from cores collected within the lake 180 days after inundation. This study showed that the release of P when establishing new lakes on former agricultural land could be minimized using these simple and cost-effective methods, which may improve the ecological status of future lakes and enable the establishment of new lakes without threatening vulnerable downstream ecosystems.
Thor Kolath; Lotte Reuss; Sara Egemose; Kasper Reitzel. Reduction of Internal Phosphorus Load in New Lakes by Pretreatment of the Former Agricultural Soil—Methods, Ecological Results and Costs. Sustainability 2020, 12, 3575 .
AMA StyleThor Kolath, Lotte Reuss, Sara Egemose, Kasper Reitzel. Reduction of Internal Phosphorus Load in New Lakes by Pretreatment of the Former Agricultural Soil—Methods, Ecological Results and Costs. Sustainability. 2020; 12 (9):3575.
Chicago/Turabian StyleThor Kolath; Lotte Reuss; Sara Egemose; Kasper Reitzel. 2020. "Reduction of Internal Phosphorus Load in New Lakes by Pretreatment of the Former Agricultural Soil—Methods, Ecological Results and Costs." Sustainability 12, no. 9: 3575.
Climate changes, intensive agricultural production, and expanding urban areas make the study of runoff and its possible impact on stream quality increasingly important. In this study, we examined large datasets concerning catchment type, stream quality, and invertebrate composition in a comprehensive geographic information system study. The aim was to examine correlations between land use type and quality of the receiving waters to detect possible differences in anthropogenic impacts. The studied area covered 937 km2, and the dataset included 1672 stretches of streams and data from 468 fauna sampling stations. Runoff from agricultural areas more negatively influenced the stream quality than runoff from urban areas. Considering urban catchments, the areas with separate sewer systems generally influenced the stream quality less than catchments with combined sewer systems. In conclusion, the catchment of any specific stream must contain an area with a minimum of 20–30% without agriculture or urban areas to obtain good ecological status; when focusing only on the riparian zone (10 m on each side of the stream), a minimum of 40–55% is needed to create a good ecological status. Therefore, management focus on the entire catchment is important and separate sewers should be preferred rather than combined sewers.
Claudia S. Karlsen; Mogens R. Flindt; Melanie J. Sønderup; Martin H. Madsen; Sara Egemose. Impact of Land Use and Runoff on Stream Quality. Sustainability 2019, 11, 5479 .
AMA StyleClaudia S. Karlsen, Mogens R. Flindt, Melanie J. Sønderup, Martin H. Madsen, Sara Egemose. Impact of Land Use and Runoff on Stream Quality. Sustainability. 2019; 11 (19):5479.
Chicago/Turabian StyleClaudia S. Karlsen; Mogens R. Flindt; Melanie J. Sønderup; Martin H. Madsen; Sara Egemose. 2019. "Impact of Land Use and Runoff on Stream Quality." Sustainability 11, no. 19: 5479.
Kasper Reitzel; William Bennett; Nils Berger; Will J. Brownlie; Sander Bruun; Morten Christensen; Dana Cordell; Kimo Van Dijk; Sara Egemose; Herbert Eigner; Ronnie N. Glud; Outi Grönfors; Ludwig Hermann; Sabine Houot; Michael Hupfer; Brent Jacobs; Leon Korving; Charlotte Kjærgaard; Henrikki Liimatainen; Mark C.M. Van Loosdrecht; Katrina A. Macintosh; Jakob Magid; Frederico Maia; Julia Martin-Ortega; John McGrath; Roel Meulepas; Michael Murry; Tina-Simone Neset; Günter Neumann; Ulla G. Nielsen; Per H. Nielsen; Vincent O’Flaherty; Haiyan Qu; Jakob Santner; Verena Seufert; Bryan Spears; Lindsay C. Stringer; Marc Stutter; Peter H. Verburg; Philipp Wilfert; Paul N. Williams; Genevieve Metson. New Training to Meet the Global Phosphorus Challenge. Environmental Science & Technology 2019, 53, 8479 -8481.
AMA StyleKasper Reitzel, William Bennett, Nils Berger, Will J. Brownlie, Sander Bruun, Morten Christensen, Dana Cordell, Kimo Van Dijk, Sara Egemose, Herbert Eigner, Ronnie N. Glud, Outi Grönfors, Ludwig Hermann, Sabine Houot, Michael Hupfer, Brent Jacobs, Leon Korving, Charlotte Kjærgaard, Henrikki Liimatainen, Mark C.M. Van Loosdrecht, Katrina A. Macintosh, Jakob Magid, Frederico Maia, Julia Martin-Ortega, John McGrath, Roel Meulepas, Michael Murry, Tina-Simone Neset, Günter Neumann, Ulla G. Nielsen, Per H. Nielsen, Vincent O’Flaherty, Haiyan Qu, Jakob Santner, Verena Seufert, Bryan Spears, Lindsay C. Stringer, Marc Stutter, Peter H. Verburg, Philipp Wilfert, Paul N. Williams, Genevieve Metson. New Training to Meet the Global Phosphorus Challenge. Environmental Science & Technology. 2019; 53 (15):8479-8481.
Chicago/Turabian StyleKasper Reitzel; William Bennett; Nils Berger; Will J. Brownlie; Sander Bruun; Morten Christensen; Dana Cordell; Kimo Van Dijk; Sara Egemose; Herbert Eigner; Ronnie N. Glud; Outi Grönfors; Ludwig Hermann; Sabine Houot; Michael Hupfer; Brent Jacobs; Leon Korving; Charlotte Kjærgaard; Henrikki Liimatainen; Mark C.M. Van Loosdrecht; Katrina A. Macintosh; Jakob Magid; Frederico Maia; Julia Martin-Ortega; John McGrath; Roel Meulepas; Michael Murry; Tina-Simone Neset; Günter Neumann; Ulla G. Nielsen; Per H. Nielsen; Vincent O’Flaherty; Haiyan Qu; Jakob Santner; Verena Seufert; Bryan Spears; Lindsay C. Stringer; Marc Stutter; Peter H. Verburg; Philipp Wilfert; Paul N. Williams; Genevieve Metson. 2019. "New Training to Meet the Global Phosphorus Challenge." Environmental Science & Technology 53, no. 15: 8479-8481.
Integrated buffer zones (IBZs) have recently been introduced in the Northwestern Europe temperate zone to improve delivery of ecosystem services compared with the services associated with long-established vegetated buffer zones. A common feature of all the studied IBZ sites is that tile drainage, which previously discharged directly into the streams, is now intercepted within the IBZ. Specifically, the design of IBZs combines a pond, where soil particles present in drain water or surface runoff can be deposited, and a planted subsurface flow infiltration zone. Together, these two components should provide an optimum environment for microbial processes and plant uptake of nutrients. Nutrient reduction capacities, biodiversity enhancement, and biomass production functions were assessed with different emphasis across 11 IBZ sites located in Denmark, Great Britain, and Sweden. Despite the small size of the buffer zones (250-800 m) and thus the small proportion of the drained catchment (mostly <1%), these studies cumulatively suggest that IBZs are effective enhancements to traditional buffer zones, as they (i) reduce total N and P loads to small streams and rivers, (ii) act as valuable improved habitats for aquatic and amphibian species, and (iii) offer economic benefits by producing fast-growing wetland plant biomass. Based on our assessment of the pilot sites, guidance is provided on the implementation and management of IBZs within agricultural landscapes.
Dominik Zak; Marc Stutter; Henning S. Jensen; Sara Egemose; Mette V. Carstensen; Joachim Audet; John A. Strand; Peter Feuerbach; Carl C. Hoffmann; Benjamin Christen; Sandra Hille; Mads Knudsen; Jenni Stockan; Helen Watson; Goswin Heckrath; Brian Kronvang. An Assessment of the Multifunctionality of Integrated Buffer Zones in Northwestern Europe. Journal of Environmental Quality 2019, 48, 362 -375.
AMA StyleDominik Zak, Marc Stutter, Henning S. Jensen, Sara Egemose, Mette V. Carstensen, Joachim Audet, John A. Strand, Peter Feuerbach, Carl C. Hoffmann, Benjamin Christen, Sandra Hille, Mads Knudsen, Jenni Stockan, Helen Watson, Goswin Heckrath, Brian Kronvang. An Assessment of the Multifunctionality of Integrated Buffer Zones in Northwestern Europe. Journal of Environmental Quality. 2019; 48 (2):362-375.
Chicago/Turabian StyleDominik Zak; Marc Stutter; Henning S. Jensen; Sara Egemose; Mette V. Carstensen; Joachim Audet; John A. Strand; Peter Feuerbach; Carl C. Hoffmann; Benjamin Christen; Sandra Hille; Mads Knudsen; Jenni Stockan; Helen Watson; Goswin Heckrath; Brian Kronvang. 2019. "An Assessment of the Multifunctionality of Integrated Buffer Zones in Northwestern Europe." Journal of Environmental Quality 48, no. 2: 362-375.
The impact of human activities on watercourses has led to increased contamination, eutrophication, erosion and reduced biodiversity in streams and rivers. Increased urbanization is one of the factors that may influence the water quality. Wet stormwater ponds are a commonly used buffer structure to delay and treat the water before it reaches the recipient – often streams as studied in this paper. However, knowledge on how stormwater outlets from wet ponds may affect downstream recipients is still limited. We studied the impact of six outlets from wet stormwater ponds to streams in 2016 and 2017, by measurements in the streams upstream and downstream of the outlet. The aim was to study possible effects on physical conditions, sediment grain size and invertebrate community composition. The Fauna Index showed no significant differences between upstream and downstream stations. However, we found a significant decrease in biodiversity (Shannon-Wiener) and a significantly lower evenness downstream of the stormwater outlets, even though the water was delayed and treated in a pond first. The physical conditions were both positively and negatively affected depending on the specific outlet. Finally, the smallest particle fraction (<63 µm) in the stream sediments was reduced at downstream sites compared to upstream sites at four outlets indicating possible erosion effects. Our study shows that the stormwater outlets have an effect on the recipients, but whether it is measurable depends on the methods utilized.
Lukasz Koziel; Mette Arnoldsen Juhl; Sara Egemose. Effects on biodiversity, physical conditions and sediment in streams receiving stormwater discharge treated and delayed in wet ponds. Limnologica 2019, 75, 11 -18.
AMA StyleLukasz Koziel, Mette Arnoldsen Juhl, Sara Egemose. Effects on biodiversity, physical conditions and sediment in streams receiving stormwater discharge treated and delayed in wet ponds. Limnologica. 2019; 75 ():11-18.
Chicago/Turabian StyleLukasz Koziel; Mette Arnoldsen Juhl; Sara Egemose. 2019. "Effects on biodiversity, physical conditions and sediment in streams receiving stormwater discharge treated and delayed in wet ponds." Limnologica 75, no. : 11-18.
Integrated buffer zones (IBZs) represent a novel form of edge-of-field technology in Northwest Europe. Contrary to the common riparian buffer strips, IBZs collect tile drainage water from agricultural fields by combining a ditch-like pond (POND), where soil particles can settle, and a flow-through filter bed (FILTERBED) planted with Alnus glutinosa (L.), a European alder (black alder). The first experimental IBZ facility was constructed and thoroughly tested in Denmark for its capability to retain various nitrogen (N) and phosphorus (P) species within the first three years after construction. We calculated the water and nutrient budget for the total IBZ and for the two compartments, POND and FILTERBED, separately. Furthermore, a tracer experiment using sodium bromide was conducted in order to trace the water flow and estimate the hydraulic residence time in the FILTERBEDs. The monthly average removal efficiency amounted to 10-67 % for total N and 31-69 % for total P, with performance being highest during the warm season. Accordingly, we suggest that IBZs may be a valuable modification of dry buffer strips in order to mitigate the adverse impacts of high nutrient loading from agricultural fields on the aquatic environment.
Dominik Zak; Brian Kronvang; Mette Vodder Carstensen; Carl Christian Hoffmann; Ane Kjeldgaard; Soren Erik Larsen; Joachim Audet; Sara Egemose; Charlotte Adam Jørgensen; Peter Feuerbach; Flemming Gertz; Henning S. Jensen. Nitrogen and Phosphorus Removal from Agricultural Runoff in Integrated Buffer Zones. Environmental Science & Technology 2018, 52, 6508 -6517.
AMA StyleDominik Zak, Brian Kronvang, Mette Vodder Carstensen, Carl Christian Hoffmann, Ane Kjeldgaard, Soren Erik Larsen, Joachim Audet, Sara Egemose, Charlotte Adam Jørgensen, Peter Feuerbach, Flemming Gertz, Henning S. Jensen. Nitrogen and Phosphorus Removal from Agricultural Runoff in Integrated Buffer Zones. Environmental Science & Technology. 2018; 52 (11):6508-6517.
Chicago/Turabian StyleDominik Zak; Brian Kronvang; Mette Vodder Carstensen; Carl Christian Hoffmann; Ane Kjeldgaard; Soren Erik Larsen; Joachim Audet; Sara Egemose; Charlotte Adam Jørgensen; Peter Feuerbach; Flemming Gertz; Henning S. Jensen. 2018. "Nitrogen and Phosphorus Removal from Agricultural Runoff in Integrated Buffer Zones." Environmental Science & Technology 52, no. 11: 6508-6517.
Runoff is often delayed and treated in wet ponds to retain particles and particulate substances. To increase the treatment efficiency, a sand filter can be placed before the outlet. The filter material is often renewed after 10–15 years due to presumed clogging by trapped particles, but often it clogs much earlier. Knowledge of how clogging develops over time is therefore important. This study has examined two filters, focusing on particle size, content and placement of particles, organic matter (OM) and phosphorus (P) retained in the filter. The study concludes that both particles and P are retained in the upper few cm’s of the filter, causing clogging after a few years, thus leaving the deeper filter material unused. Even small particles (<63 µm) are efficiently retained as long as clogging is avoided. This is preferable, as runoff is rich in small particles and as particulate P is associated with the small particles.
Sara Egemose. Removal of particulate matter and phosphorus in sand filters treating stormwater and drainage runoff: a case study. Urban Water Journal 2018, 15, 388 -391.
AMA StyleSara Egemose. Removal of particulate matter and phosphorus in sand filters treating stormwater and drainage runoff: a case study. Urban Water Journal. 2018; 15 (4):388-391.
Chicago/Turabian StyleSara Egemose. 2018. "Removal of particulate matter and phosphorus in sand filters treating stormwater and drainage runoff: a case study." Urban Water Journal 15, no. 4: 388-391.
Measures such as storm water ponds, constructed wetlands and buffer strips along streams are used to reduce diffuse phosphorus (P) loading to surface waters. These systems often retain particulate P well, whereas the retention of dissolved P is less efficient and might require addition of P adsorbents. In this study, we screened waterwork ochre sludge (WWS) originating from groundwater treatment and ochre sludge from ochre precipitation basins along streams for their applicability as P adsorbents at ambient P concentrations. We compared with a commercial ferric hydroxide (CFH 12™) for which adsorption properties is well described. The adsorption capacity of 9 products was measured over 24 h at different P concentrations (5–2000 µg L−1), a range that covers Danish drainage water and stormwater. WWS desorbed phosphate at concentrations below 50–200 µg P L−1 and should only be considered for use in systems with a constantly high load of dissolved P. High affinity combined with little or no desorption characterized the commercial product and the ochre sludge from the precipitation basins, rendering these useful for treating drainage water and storm water. The study underlines that waste products may act as potentially effective P adsorbers at environmentally relevant P levels.
Charlotte A. Jørgensen; Henning S. Jensen; Sara Egemose. Phosphate adsorption to iron sludge from waterworks, ochre precipitation basins and commercial ferrihydrite at ambient freshwater phosphate concentrations. Environmental Technology 2016, 38, 2185 -2192.
AMA StyleCharlotte A. Jørgensen, Henning S. Jensen, Sara Egemose. Phosphate adsorption to iron sludge from waterworks, ochre precipitation basins and commercial ferrihydrite at ambient freshwater phosphate concentrations. Environmental Technology. 2016; 38 (17):2185-2192.
Chicago/Turabian StyleCharlotte A. Jørgensen; Henning S. Jensen; Sara Egemose. 2016. "Phosphate adsorption to iron sludge from waterworks, ochre precipitation basins and commercial ferrihydrite at ambient freshwater phosphate concentrations." Environmental Technology 38, no. 17: 2185-2192.
114 lakes treated with aluminum (Al) salts to reduce internal phosphorus (P) loading were analyzed to identify factors driving longevity of post-treatment water quality improvements. Lakes varied greatly in morphology, applied Al dose, and other factors that may have affected overall treatment effectiveness. Treatment longevity based on declines in epilimnetic total P (TP) concentration averaged 11 years for all lakes (range of 0–45 years). When longevity estimates were used for lakes with improved conditions through the end of measurements, average longevity increased to 15 years. Significant differences in treatment longevity between deeper, stratified lakes (mean 21 years) and shallow, polymictic lakes (mean 5.7 years) were detected, indicating factors related to lake morphology are important for treatment success. A decision tree developed using a partition model suggested Al dose, Osgood index (OI, a morphological index), and watershed to lake area ratio (related to hydraulic residence time, WA:LA) were the most important variables determining treatment longevity. Multiple linear regression showed that Al dose, WA:LA, and OI explained 47, 32 and 3% respectively of the variation in treatment longevity. Other variables (too data limited to include in the analysis) also appeared to be of importance, including sediment P content to Al dose ratios and the presence of benthic feeding fish in shallow, polymictic lakes
Brian J. Huser; Sara Egemose; Harvey Harper; Michael Hupfer; Henning Jensen; Keith M. Pilgrim; Kasper Reitzel; Emil Rydin; Martyn Futter. Longevity and effectiveness of aluminum addition to reduce sediment phosphorus release and restore lake water quality. Water Research 2016, 97, 122 -132.
AMA StyleBrian J. Huser, Sara Egemose, Harvey Harper, Michael Hupfer, Henning Jensen, Keith M. Pilgrim, Kasper Reitzel, Emil Rydin, Martyn Futter. Longevity and effectiveness of aluminum addition to reduce sediment phosphorus release and restore lake water quality. Water Research. 2016; 97 ():122-132.
Chicago/Turabian StyleBrian J. Huser; Sara Egemose; Harvey Harper; Michael Hupfer; Henning Jensen; Keith M. Pilgrim; Kasper Reitzel; Emil Rydin; Martyn Futter. 2016. "Longevity and effectiveness of aluminum addition to reduce sediment phosphorus release and restore lake water quality." Water Research 97, no. : 122-132.
Traditional wet detention ponds and sand filters remove particles efficiently, whereas only a minor part of the dissolved and bioavailable load is removed. To improve the retention of dissolved substances, we tested crushed concrete as a filter material simultaneously with a traditional sand filter placed after an existing wet pond. The particulate fractions (particles, organic matter, phosphorus, and heavy metals) were removed efficiently in the pond and both filter materials, with the concrete filter often being best seen over a year. Dissolved heavy metals (lead (Pb), nickel (Ni), copper (Cu), chromium (Cr), and cadmium (Cd)) were largely retained, though a washout was observed from the pond (Ni and Cu), concrete filter (Cr), and sand filter (Ni) during the first month. The pond only retained total dissolved phosphorus (TDP) during summer. Crushed concrete and sand had a high (>70%) retention of TDP within the first months of operation, but the retention dropped in both filters due to a large oil load into the system (4 kg impermeable ha(-1) in 1 month). The poor retention might to some degree be due to mineralization processes turning particulate phosphorus (PP) into TDP. The massive oil load was retained efficiently (99.3%) in the pond and both filters, clearly illustrating that both filter materials were able to retain either oil or TDP. An additional pilot study showed that at residence times of 1 h, crushed concrete bound 90% TDP whereas sand only bound 22% TDP. Retention of TDP and PP decreased with shorter residence time in both materials, but fastest in sand.
Melanie J. Sønderup; Sara Egemose; Timm Bochdam; Mogens R. Flindt. Treatment efficiency of a wet detention pond combined with filters of crushed concrete and sand: a Danish full-scale study of stormwater. Environmental Monitoring and Assessment 2015, 187, 1 -18.
AMA StyleMelanie J. Sønderup, Sara Egemose, Timm Bochdam, Mogens R. Flindt. Treatment efficiency of a wet detention pond combined with filters of crushed concrete and sand: a Danish full-scale study of stormwater. Environmental Monitoring and Assessment. 2015; 187 (12):1-18.
Chicago/Turabian StyleMelanie J. Sønderup; Sara Egemose; Timm Bochdam; Mogens R. Flindt. 2015. "Treatment efficiency of a wet detention pond combined with filters of crushed concrete and sand: a Danish full-scale study of stormwater." Environmental Monitoring and Assessment 187, no. 12: 1-18.
Stormwater ponds are a common way to handle urban runoff. Different pond designs have been tested for decades to retain as much water as possible. Lately, also retention of nutrients and organic matter has become increasingly important, to reduce the eutrophication of downstream aquatic systems and thereby e.g. fulfill the European Water Framework Directive. We have examined the load of particulate and dissolved fractions of organic matter, phosphorus, nitrogen and iron in 66 Danish ponds to determine the importance of catchment type (66 ponds) and the retention efficiency of the ponds (39 ponds) dependent on their type, age, size and design. The results showed that discharge from nutrient enriched and industrial areas is the most polluted, while urban and developing areas are the least polluted. Wet ponds combined with vegetated sand filters have higher retentions of the particulate fractions (40–80 %) compared to traditional wet ponds (10–20 %). Generally, optimized retention requires a ratio between pond volume and impermeable catchment area of >250 m3 red.ha (reduced or impermeable hectare). Young ponds have higher retention than older ones, especially regarding the particulate fractions of organic matter, phosphorus and nitrogen. Here 40–50 % is retained in ponds 10 years. For the dissolved fractions, the trend is the same, but with lower retentions. Therefore, management and maintenance should be considered for all ponds, to avoid problems of internal loading, filling and resuspension. This article is protected by copyright. All rights reserved.
Melanie J. Sønderup; Sara Egemose; Anders S. Hansen; Anna Grudinina; Martin H. Madsen; Mogens R. Flindt. Factors affecting retention of nutrients and organic matter in stormwater ponds. Ecohydrology 2015, 9, 796 -806.
AMA StyleMelanie J. Sønderup, Sara Egemose, Anders S. Hansen, Anna Grudinina, Martin H. Madsen, Mogens R. Flindt. Factors affecting retention of nutrients and organic matter in stormwater ponds. Ecohydrology. 2015; 9 (5):796-806.
Chicago/Turabian StyleMelanie J. Sønderup; Sara Egemose; Anders S. Hansen; Anna Grudinina; Martin H. Madsen; Mogens R. Flindt. 2015. "Factors affecting retention of nutrients and organic matter in stormwater ponds." Ecohydrology 9, no. 5: 796-806.
If dosed sufficiently relative to the pool of excess phosphorus (P) in the lake sediment and lake water, aluminum (Al) is hypothesized to block sediment P release and thereby improve water clarity in eutrophic lakes. Aluminum has been used in >200 lakes worldwide, but in some 30% of the known cases water clarity did not improve beyond the first year, likely because of underdosing or continued high external P loading. We evaluate the viability of the aluminum dosing hypothesis for six Danish lakes that received Al in a molar ratio of 2–3 years) improvement of water clarity was only observed in two lakes. Sediment P release rates, which were measured in four lakes, declined significantly but then increased gradually again in the two lakes receiving the lowest doses. We conclude that if external P-loading is sufficiently low, lasting improvement of water quality can be obtained if Al is dosed 10:1 or higher relative to the size of the mobile P pool.
Henning S. Jensen; Kasper Reitzel; Sara Egemose. Evaluation of aluminum treatment efficiency on water quality and internal phosphorus cycling in six Danish lakes. Hydrobiologia 2015, 751, 189 -199.
AMA StyleHenning S. Jensen, Kasper Reitzel, Sara Egemose. Evaluation of aluminum treatment efficiency on water quality and internal phosphorus cycling in six Danish lakes. Hydrobiologia. 2015; 751 (1):189-199.
Chicago/Turabian StyleHenning S. Jensen; Kasper Reitzel; Sara Egemose. 2015. "Evaluation of aluminum treatment efficiency on water quality and internal phosphorus cycling in six Danish lakes." Hydrobiologia 751, no. 1: 189-199.
Heavy metals have toxic effects on flora and fauna in the aquatic environments and are of great concern in stormwater. Heavy metal runoff was studied in 37 stormwater ponds in Denmark with varying heavy metal load, catchment type and pond design. The studied metals were Cu, Cr, Cd, Pb, Ni and Zn. The concentrations varied considerably depending on the catchment type, with the highest concentrations coming from industrial areas and the lowest from uncultivated and rural areas. Ponds can effectively remove heavy metals in particulate forms through sedimentation processes, but the dissolved forms are more difficult to retain. The removal efficiency in the ponds varied considerably, with the highest retention of Pb, Ni and Zn due to higher particulate fraction. The retention increased with increased pond volume-to-reduced catchment area ratio. In addition, the pond age affected the efficiency; whereas ponds less than 1-2 years efficiently removed all metals, 30-40-year-old ponds only removed Pb, Ni and Zn, but steeply decreasing over the years. Physical parameters such as pond size, age and sedimentation patterns were found to play a more significant role in the removal compared with chemical parameters such as pH, oxygen and organic matter. Input of metals to the ponds was reflected in the sediment content, but not significantly for all heavy metals probably due to low or varying retention caused by mineralization and re-suspension. The heavy metal concentration in the outlets was reduced to non-toxic levels, except for Cu and Cr at a few study sites.
Sara Egemose; Melanie J. Sønderup; Anna Grudinina; Anders S. Hansen; Mogens R. Flindt. Heavy metal composition in stormwater and retention in ponds dependent on pond age, design and catchment type. Environmental Technology 2014, 36, 959 -969.
AMA StyleSara Egemose, Melanie J. Sønderup, Anna Grudinina, Anders S. Hansen, Mogens R. Flindt. Heavy metal composition in stormwater and retention in ponds dependent on pond age, design and catchment type. Environmental Technology. 2014; 36 (8):959-969.
Chicago/Turabian StyleSara Egemose; Melanie J. Sønderup; Anna Grudinina; Anders S. Hansen; Mogens R. Flindt. 2014. "Heavy metal composition in stormwater and retention in ponds dependent on pond age, design and catchment type." Environmental Technology 36, no. 8: 959-969.
The use of geoengineering techniques for phosphorus management offers the promise of greater and quicker chemical and ecological recovery. It can be attractive when used with other restoration measures but should not be considered a panacea. The range of materials being proposed for use as well as the in-lake processes targeted for manipulation continues to grow. With increasing political imperatives to meet regulatory goals for water quality, we recommend a coordinated approach to the scientific understanding, costs, and integration of geoengineering with other approaches to lake management.
Eleanor B. Mackay; Stephen C. Maberly; Gang Pan; Kasper Reitzel; Andy Bruere; Nicholas Corker; Grant Douglas; Sara Egemose; David Hamilton; Tristan Hatton-Ellis; Brian Huser; Wei Li; Sebastian Meis; Brian Moss; Miquel Lürling; Geoff Phillips; Said Yasseri; Bryan M. Spears. Geoengineering in lakes: welcome attraction or fatal distraction? Inland Waters 2014, 4, 349 -356.
AMA StyleEleanor B. Mackay, Stephen C. Maberly, Gang Pan, Kasper Reitzel, Andy Bruere, Nicholas Corker, Grant Douglas, Sara Egemose, David Hamilton, Tristan Hatton-Ellis, Brian Huser, Wei Li, Sebastian Meis, Brian Moss, Miquel Lürling, Geoff Phillips, Said Yasseri, Bryan M. Spears. Geoengineering in lakes: welcome attraction or fatal distraction? Inland Waters. 2014; 4 (4):349-356.
Chicago/Turabian StyleEleanor B. Mackay; Stephen C. Maberly; Gang Pan; Kasper Reitzel; Andy Bruere; Nicholas Corker; Grant Douglas; Sara Egemose; David Hamilton; Tristan Hatton-Ellis; Brian Huser; Wei Li; Sebastian Meis; Brian Moss; Miquel Lürling; Geoff Phillips; Said Yasseri; Bryan M. Spears. 2014. "Geoengineering in lakes: welcome attraction or fatal distraction?" Inland Waters 4, no. 4: 349-356.
Bryan M. Spears; Stephen C. Maberly; Gang Pan; Ellie Mackay; Andy Bruere; Nicholas Corker; Grant Douglas; Sara Egemose; David Hamilton; Tristan Hatton-Ellis; Brian Huser; Wei Li; Sebastian Meis; Brian Moss; Miquel Lürling; Geoff Phillips; Said Yasseri; Kasper Reitzel. Geo-Engineering in Lakes: A Crisis of Confidence? Environmental Science & Technology 2014, 48, 9977 -9979.
AMA StyleBryan M. Spears, Stephen C. Maberly, Gang Pan, Ellie Mackay, Andy Bruere, Nicholas Corker, Grant Douglas, Sara Egemose, David Hamilton, Tristan Hatton-Ellis, Brian Huser, Wei Li, Sebastian Meis, Brian Moss, Miquel Lürling, Geoff Phillips, Said Yasseri, Kasper Reitzel. Geo-Engineering in Lakes: A Crisis of Confidence? Environmental Science & Technology. 2014; 48 (17):9977-9979.
Chicago/Turabian StyleBryan M. Spears; Stephen C. Maberly; Gang Pan; Ellie Mackay; Andy Bruere; Nicholas Corker; Grant Douglas; Sara Egemose; David Hamilton; Tristan Hatton-Ellis; Brian Huser; Wei Li; Sebastian Meis; Brian Moss; Miquel Lürling; Geoff Phillips; Said Yasseri; Kasper Reitzel. 2014. "Geo-Engineering in Lakes: A Crisis of Confidence?" Environmental Science & Technology 48, no. 17: 9977-9979.
Generally, wet ponds are constructed only to reduce the hydraulic load of downstream receiving water bodies. Often most particulate matter will be retained, whereas dissolved nutrients mostly will be unaffected by the pond due to short retention times. A suite of lab-experiments have demonstrated that crushed concrete has high affinity for dissolved phosphorus (TDP), and potentially could be an effective new measure to reduce discharge of phosphorus (P) to downstream located P-limited lakes and estuaries. To verify this potential we have developed a dynamic model for a combined sedimentation and infiltration pond in Denmark, using the software PowerSim. The model simulates retention of P and suspended particulate matter (SPM). It is possible to change the description of filter material in the model to either a traditional sand filter or a filter of crushed concrete, and thereby demonstrate the P-retention efficiency of the different materials. Two scenarios with changing wet volume and storage volume of the pond indicated that 400 and 50 m3 pr. reduced hectare (red. ha), respectively, would be optimal for retention of particles. In combination with this result, the model showed a significant increase in TDP retention with a concrete filter (≈60%) compared to a traditional sand filter (≈10%). This only applies for water actually percolating through the filters and not for the overflow. Because concrete is an alkaline material, pH in the discharge to the receiving water body will be high (>9.5) for approximately 100 days and then decrease to neutral. If adequate precautions against high pH in the discharge are put in place, crushed concrete can reduce the discharge of TDP to sensitive receiving water bodies.
Melanie J. Sønderup; Sara Egemose; Carl Christian Hoffmann; Kasper Reitzel; Mogens R. Flindt. Modeling phosphorus removal in wet ponds with filter zones containing sand or crushed concrete. Ecological Engineering 2013, 66, 52 -62.
AMA StyleMelanie J. Sønderup, Sara Egemose, Carl Christian Hoffmann, Kasper Reitzel, Mogens R. Flindt. Modeling phosphorus removal in wet ponds with filter zones containing sand or crushed concrete. Ecological Engineering. 2013; 66 ():52-62.
Chicago/Turabian StyleMelanie J. Sønderup; Sara Egemose; Carl Christian Hoffmann; Kasper Reitzel; Mogens R. Flindt. 2013. "Modeling phosphorus removal in wet ponds with filter zones containing sand or crushed concrete." Ecological Engineering 66, no. : 52-62.
Effects of pH, alkalinity and conductivity on the adsorption of soluble reactive phosphorus (SRP) onto lanthanum (La) modified bentonite clay (Phoslock(®)) were investigated in laboratory experiments using eight different types of filtered water representing freshwater with low and normal alkalinity and brackish water with high alkalinity. Different dose ratios (0-200; w/w) of Phoslock(®):P were applied to determine the maximum P binding capacity of Phoslock(®) at SRP concentrations typical of those of sediment pore water. The 100:1 Phoslock(®:)P dose ratio, recommended by the manufacturer, was tested with 12 days exposure time and generally found to be insufficient at binding whole target SRP pool. The ratio performed best in the soft water from Danish Lake Hampen and less good in the hard water from Danish Lake Langesø and in brackish water. The explanation may be an observed negative relationship between alkalinity and the SRP binding capacity of Phoslock(®). A comparative study of Lake Hampen and Lake Langesø suggested that the recorded differences in P adsorption between the two lakes could be attributed to a more pronounced dispersion of Phoslock(®) in the soft water of Lake Hampen, leading to higher fractions of dissolved (<0.2 μm) La and of La in fine particles. In the same two lakes, pH affected the SRP binding of Phoslock(®) negatively at a pH level above 8.1, the effect being reversible, however. The negative pH effect was most significant in hard water Lake Langesø, most likely because of higher [Formula: see text] concentrations.
Kasper Reitzel; Frede Østergaard Andersen; Sara Egemose; Henning S. Jensen. Phosphate adsorption by lanthanum modified bentonite clay in fresh and brackish water. Water Research 2013, 47, 2787 -2796.
AMA StyleKasper Reitzel, Frede Østergaard Andersen, Sara Egemose, Henning S. Jensen. Phosphate adsorption by lanthanum modified bentonite clay in fresh and brackish water. Water Research. 2013; 47 (8):2787-2796.
Chicago/Turabian StyleKasper Reitzel; Frede Østergaard Andersen; Sara Egemose; Henning S. Jensen. 2013. "Phosphate adsorption by lanthanum modified bentonite clay in fresh and brackish water." Water Research 47, no. 8: 2787-2796.