Urban delta areas require innovative and adaptive urban developments to face problems related with land scarcity and impacts of climate change and flooding. Floating structures offer the flexibility and multi-functionality required to efficiently face these challenges and demands. The impact of these structures on the environment, however, is currently unknown and research on this topic is often disregarded. This knowledge gap creates a difficulty for water authorities and municipalities to create a policy framework, and to regulate and facilitate the development of new projects.Monitoring the effects of floating structures on water quality and ecology has been difficult until now because of the poor accessibility of the water body underneath the structures. In this work, a remote controlled underwater drone equipped with water quality sensors and a video camera was used to monitor dissolved oxygen near and under floating structures. The collected data showed that most water quality parameters remain at acceptable levels, indicating that the current small scale floating structures do not have a significant influence on water quality. The underwater footage revealed the existence of a dynamic and diverse aquatic habitat in the vicinity of these structures, showing that floating structures can have a positive effect on the aquatic environment. Future floating structures projects therefore should be encouraged to proceed.
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The need of an adaptive sustainable solution for the increased land scarcity, growing urbanization, climate change and flood risks resulted in the concept of the floating urbanization. In The Netherlands this new type of housing attracted the interest of local authorities, municipalities and water boards. Moreover, plans to incorporate floating houses in the urban planning have already been developed. However, the knowledge gap regarding the potential effect on the water quality halts the further development of the floating houses. This paper shows the results of a water quality measurement campaign, as part of the national program “Knowledge for climate”, at a small floating houses project in Delft and serves as a case study for addressing the environmental-ecological knowledge gap on this topic.
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Large floating projects have the potential to overcome the challenge of land scarcity in urban areas and offer opportunities for energy and food production, or even for creating sustainable living environments. However, they influence the physical, chemical, biological and ecological characteristics of water bodies. The interaction of the floating platforms affect multiple complex aquatic processes, and the potential (negative/positive) effects are not yet fully understood. Managing entities currently struggle with lack of data and knowledge that can support adequate legislation to regulate future projects.In the Netherlands the development of small scale floating projects is already present for some years (e.g. floating houses, restaurants, houseboats), and more recently several large scale floating photovoltaic plants (FPV) have been realized. Several floating constructions in the Netherlands were considered as case-studies for a data-collection campaign.To obtain data and images from underneath floating buildings, underwater drones were equipped with cameras and sensors. The drones were used in multiple locations to scan for differences in concentrations of basic water quality parameters (e.g. dissolved oxygen, electrical conductivity, algae, light intensity) from underneath/near the floating structures, which were then compared with data from locations far from the influence of the buildings. Continuous data was also collected over several days using multi-parameter water quality sensors permanently installed under floating structures.
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Constructed wetlands are one type of Sustainable Urban Drainage System (SUDS) that have been used for decades in The Netherlands. They provide stormwater conveyance and improve stormwater quality. European regulations for water quality dictate lower and lower concentrations for an array of dissolved pollutants. The increase in the required removal efficiency for these systems imposed in the Netherlands requires a better understanding of thecharacteristics of stormwater and the functioning of constructed wetlands as SUDs. This paper presents a brief overview of 5 different constructed wetlands from the Netherlands that have been implemented at least more than 10 years ago. Their efficiency and functioning is reviewed and a new method of assessment is described.
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Sinds 2010 produceert NieuWater ultrapuur water uit effluent van de RWZI Emmen. Dit water wordt als proceswater geleverd aan de NAM in Schoonebeek. De biologische actieve koolfiltratie met zuurstofdosering (BODAC), die als voorzuivering gebruikt wordt, lijkt ook een veelbelovende techniek om geneesmiddelen te verwijderen.
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The need of an adaptive sustainable solution for the increased land scarcity, growing urbanization, climate change and flood risks resulted in the concept of the floating urbanization. In The Netherlands this new type of housing attracted the interest of local authorities, municipalities and water boards. Moreover, plans to incorporate floating houses in the urban planning have already been developed. However, the knowledge gap regarding the potential effect on the water quality halts the further development of the floating houses. This paper shows the results of a water quality measurement campaign, as part of the national program “Knowledge for climate”, at a small floating houses project in Delft and serves as a case study for addressing the environmental-ecological knowledge gap on this topic.
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Urban delta areas are facing problems related with land scarcity and are impacted by climate change and flooding. To meet the current demands and future challenges, innovative and adaptive urban developments are necessary [de Graaf, 2009]. Floating urban development is a promising solutions, as it offers the flexibility and multifunctionality required to efficiently face the current challenges for delta cities. It provides flood proof buildings and opportunities for sustainable food and energy production
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The rapid implementation of large scale floating solar panels has consequences to water quality and local ecosystems. Environmental impacts depend on the dimensions, design and proportions of the system in relation to the size of the surface water, as well as the characteristics of the water system (currents, tidal effects) and climatic conditions. There is often no time (and budget) for thorough research into these effects on ecology and water quality. A few studies have addressed the potential impacts of floating solar panels, but often rely on models without validation with in situ data. In this work, water quality sensors continuously monitored key water quality parameters at two different locations: (i) underneath a floating solar park; (ii) at a reference location positioned in open water. An underwater drone was used to obtain vertical profiles of water quality and to collect underwater images. The results showed little differences in the measured key water quality parameters below the solar panels. The temperature at the upper layers of water was lower under the solar panels, and there were less detected temperature fluctuations. A biofouling layer on the floating structure was visible in the underwater images a few months after the construction of the park
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Introducing a hyperbolic vortex into a showerhead is a possibility to achieve higher spray velocities for a given discharge without reducing the nozzle diameter. Due to the introduction of air bubbles into the water by the vortex, the spray is pushed from a transition (dripping faucet) regime into a jetting regime, which results in higher droplet and jet velocities using the same nozzle diameter and throughput. The same droplet and jet diameters were realized compared to a showerhead without a vortex. Assuming that the satisfaction of a shower experience is largely dependent on the droplet size and velocity, the implementation of a vortex in the showerhead could provide the same shower experience with 14% less water consumption compared to the normal showerhead. A full optical and physical analysis was presented, and the important chemical parameters were investigated.
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Arsenic contamination of groundwater is a major public health concern worldwide. The problem has been reported mainly in southern Asia and, especially, in Bangladesh. Slow-sand filters (SSF) augmented with iron were proven to be a simple, low-cost and decentralized technique for the treatment of arsenic-contaminated sources. In this research, three pilot-scale SSF (flowrate 6 L·h−1) were tested regarding their capability of removing arsenic from groundwater in conditions similar to those found in countries like Bangladesh (70 µg As(III) L−1, 26 °C). From the three, two filters were prepared with mixed media, i.e., sand mixed with corrosive iron matter (CIM filter) and iron-coated sand (ICS filter), and a third conventional SSF was used as a reference. The results obtained showed that the CIM filter could remove arsenic below the World Health Organization (WHO) guideline concentration of 10 µg·L−1, even for inlet concentrations above 150 µg·L−1. After 230 days of continuous operation the arsenic concentration in the effluent started increasing, indicating depletion or saturation of the CIM layer. The effluent arsenic concentration, however, never exceeded the Bangladeshi standard of 50 µg·L−1 throughout the whole duration of the experiments.
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