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.
MULTIFILE
The rain gardens at Bryggen in Bergen, Western Norway, is designed to collect, retain, and infiltrate surface rainfall runoff water, recharge the groundwater, and replenish soil moisture. The hydraulic infiltration capacity of the Sustainable Drainage System (SuDS), here rain gardens, has been tested with small-scale and full-scale infiltration tests. Results show that infiltration capacity meets the requirement and is more than sufficient for infiltration in a cold climate. The results from small-scale test, 245–404 mm/h, shows lower infiltration rates than the full-scale infiltration test, with 510–1600 mm/h. As predicted, an immediate response of the full-scale infiltration test is shown on the groundwater monitoring in the wells located closest to the infiltration point (<30 m), with a ca. 2 days delayed response in the wells further away (75–100 m). Results show that there is sufficient capacity for a larger drainage area to be connected to the infiltration systems. This study contributes to the understanding of the dynamics of infiltration systems such as how a rain garden interacts with local, urban water cycle, both in the hydrological and hydrogeological aspects. The results from this study show that infiltration systems help to protect and preserve the organic rich cultural layers below, as well as help with testing and evaluating of the efficiency, i.e., SuDS may have multiple functions, not only storm water retention. The functionality is tested with water volumes of 40 m3 (600 L/min for 2 h and 10 min), comparable to a flash flood, which give an evaluation of the infiltration capacity of the system.
City growth threatens sustainable development of cities. Over the past decades increased urbanization has created more pressure - not only on the suburban outskirts - but also in the inner core of the cities, putting important environmental issues such as water management and cultural heritage under stress. Cultural heritage, either standing monuments or archaeological remains, is internationally recognized as an important legacy of our history. The European Convention on the Protection of the Archaeological Heritage incorporates concepts and ideas that have become accepted practice in Europe. Conservation and enhancement of archaeological heritage is one of the goals of urban planning policies. One of the key objectives of the European policy is to protect, preferably in-situ, archaeological remains buried in the soil or seabed and to incorporate archaeological heritage into spatial planning policies. Conflicts with prior uses and unappreciated impacts on other subsurface resources, amongst them archaeological heritage, make use of underground space in cities suboptimal. In terms of ecosystem services, the subsurface environment acts either as a carrier of archaeological heritage in situ (stewardship) or supports above-ground cultural heritage. Often, it’s not enough to protect the heritage site or monument itself: new developments outside a specific protected area can lead to changes in groundwater level, and cause serious damage to heritage buildings and archaeological deposits. This paper presents good practices in cultural heritage management and the use of subsurface knowledge in urban areas.
Climate change is increasing the challenges for water management worldwide. Extreme weather conditions, such as droughts and heavy rainfall, are increasingly limiting the availability of water, especially for agriculture. Nature-Based Solutions (NBS) offer potential solutions. They help to collect and infiltrate rainwater and thus play an important role in climate adaptation.Green infrastructure, such as rain gardens (sunken plant beds) and wadis (sunken grass fields for temporary storage of rainwater), help to restore the urban water balance. They reduce rainwater runoff, stabilize groundwater levels and solve problems with soil moisture and temperature. Despite these advantages, there is still much ignorance in practice about the possibilities of NBS. To remedy this, freely accessible knowledge modules are being developed that can help governments and future employees to better understand the application of these solutions. This research, called GINA (Green Infrastructure in Urban Areas), aims to create more sustainable and climate-resilient cities by developing and sharing knowledge about NBS, and supports local governments and students in effectively deploying these green infrastructures.
INXCES will use and enhance innovative 3D terrain analysis and visualization technology coupled with state-of-the-art satellite remote sensing to develop cost-effective risk assessment tools for urban flooding, aquifer recharge, ground stability and subsidence. INXCES will develop quick scan tools that will help decision makers and other actors to improve the understanding of urban and peri-urban terrains and identify options for cost effective implementation of water management solutions that reduce the negative impacts of extreme events, maximize beneficial uses of rainwater and stormwater for small to intermediate events and provide long-term resilience in light of future climate changes. The INXCES approach optimizes the multiple benefits of urban ecosystems, thereby stimulating widespread implementation of nature-based solutions on the urban catchment scale.INXCES will develop new innovative technological methods for risk assessment and mitigation of extreme hydroclimatic events and optimization of urban water-dependent ecosystem services at the catchment level, for a spectrum of rainfall events. It is widely acknowledged that extreme events such as floods and droughts are an increasing challenge, particularly in urban areas. The frequency and intensity of floods and droughts pose challenges for economic and social development, negatively affecting the quality of life of urban populations. Prevention and mitigation of the consequences of hydroclimatic extreme events are dependent on the time scale. Floods are typically a consequence of intense rainfall events with short duration. In relation to prolonged droughts however, a much slower timescale needs to be considered, connected to groundwater level reductions, desiccation and negative consequences for growing conditions and potential ground – and building stability.INXCES will take a holistic spatial and temporal approach to the urban water balance at a catchment scale and perform technical-scientific research to assess, mitigate and build resilience in cities against extreme hydroclimatic events with nature-based solutions.INXCES will use and enhance innovative 3D terrain analysis and visualization technology coupled with state-of-the-art satellite remote sensing to develop cost-effective risk assessment tools for urban flooding, aquifer recharge, ground stability and subsidence. INXCES will develop quick scan tools that will help decision makers and other actors to improve the understanding of urban and peri-urban terrains and identify options for cost effective implementation of water management solutions that reduce the negative impacts of extreme events, maximize beneficial uses of rainwater and stormwater for small to intermediate events and provide long-term resilience in light of future climate changes. The INXCES approach optimizes the multiple benefits of urban ecosystems, thereby stimulating widespread implementation of nature-based solutions on the urban catchment scale.
Water treatment companies are more and more interested in chemical-free water treatment. This is a solution that might not only decrease costs of chemicals, but also decrease possible formation of by-products and contribute to decreasing the introduction of emerging contaminants in the environment. A possible route for this is the use of magnetic fields based treatment. Magnetic fields exist around us (our planet is surrounded by such fields) but are not broadly used in water treatment. A reason for this situation isthe fact that water treatment is a rather traditional market and magnetic treatment, conversely, a rather controversial and (still) not completely understood. Even with such resistance, recently it has been shown that magnetic fields applied to drinking water resulted in significant structural change of its microbiome [1]. This community structural change was clearly detected with a newly developed flow cytometry method, where the phenotypic characteristics of the entire microbial community could be analysed instantly [2-9]. Lab-scale batch experiments have shown that magnetic fields can selectively boost the growth of smaller bacteria [1][3] and indicated as a next step that the same principle could be addressed in pilot scale tests. ISusMag is structured to apply the robust and instant flow cytometry method to examine the effect of magnetic fields on drinking water at pilot scale under realistic field conditions. For this purpose, groundwater will be evenly distributed into two (pipe)lines of the same length: one will be magnetically treated, and one will be used as control. Samples will be taken at the end of the two pipes for flow cytometry examination. Measurement results can help drinking water companies to understand whether a magnetic treatment is an alternative to control the growth of pathogenic bacteria instead of classical chemical treatment (disinfection).
