Global water consumption has increased 7-fold since the start of the 20th century. Water resources are likely to start to run out due to population growth, agricultural demands and reduction in recharge with climate change. Alternatives such as desalination are costly and energy demanding. In Europe groundwater provides up to 98% of potable water supplies in some countries. Consequently it will become more important to protect and enhance groundwater resources both in Europe and around the world.
There is chronic and widespread contamination of European land and aquifers with contaminants from industrial, agricultural, mining, military and other activities. The European Environment Agency (EEA) estimates that there are currently around 130,000 instances of groundwater contamination in Europe alone, while 3 million sites have potentially polluting activities. Considering the typical costs to remediate each site, the replacement value of that unusable groundwater is around €39B.
This liability is set against the ambitions of the Water Framework Directive, which aims to protect and restore water resources across Europe and to ensure their long-term sustainable use. Linked to this are significant socio-economic pressures from brownfield redevelopment within urban regeneration programmes, which aim to return this asset back to good use for communities and reduce consumption of greenfield land. This philosophy is central to sustainable development.
Within this framework, there is a need to develop sustainable approaches for the remediation of contaminated groundwater resources. Traditional remediation methods for contaminated land and groundwater are widely acknowledged to be unsustainable in many cases, considering environmental impacts, costs, performance and treatment timescales. Sustainability can be increased during all phases of contaminated site remediation, but sustainability concepts have historically not been fully considered within management decisions and practice.
Sustainable remediation practices integrate all relevant technical, environmental, economic and social indicators to identify an acceptable balance which delivers net benefits. It allows sustainable development criteria to be formally incorporated within contaminated land and groundwater management strategies at all stages of decision-making, scales of operation and site development phases.
In situ remediation (ISR) is often the most sustainable management approach for soil and groundwater contamination. This field is relatively new, but with many innovative ISR concepts which offer tremendous potential to manage complex contamination problems which would not be possible with traditional methods. However, the practical implementation of sustainable ISR in Europe and beyond is significantly underdeveloped. This can only be improved by cross-disciplinary applied research that integrates the various scientific, technical, environmental and socio-economic aspects (e.g. fundamental process understanding, performance assessment, engineering design and cost-benefits) that affect decision-making, management strategies and technology applications for contaminated land and groundwater across different scales. ADVOCATE (Advancing Sustainable In Situ Remediation for Contaminated Land and Groundwater), aims to address this challenge.
Oksana Coban, early stage Research Fellow on ADVOCATE Project, has defended robustly and with great success her PhD titled "Microbial Nitrogen Transformations in Constructed Wetlands Treating Contaminated Groundwater".
Congratulations, Dr Coban, on your perseverance and success, and we wish you a bright future.
Further information on Oksana's research is available online in her technical bulletin and in our blog. Don't miss her video on the ADVOCATE website, where in less than 3 minutes she explains perfectly her work related to microbial nitrogen transformation in constructed wetlands using an easy-to-understand language.
Abstract
Groundwater is the main source for potable water and domestic use in numerous countries around the world. However, water quality can be affected by pollution, which influences the natural environment and human health. One of the widespread pollutants in water is ammonia which is toxic to fish and causes eutrophication of lakes and wetlands. Constructed wetlands are promising in situ water treatment methods thanks to enhanced microbial growth within the plants' rhizospheres, which creates an effective contaminant degradation zone. The ammonia in constructed wetlands can be removed either via total nitrification with further denitrification or partial nitrification coupled with anaerobic ammonium oxidation (anammox). However, so far, the role of anammox in constructed wetlands as well as its correlation with other nitrogen transformations remains unclear. The quantification of nitrogen turnover processes in constructed wetlands is difficult due to the complexity of the wetland systems. Accordingly, the main aim of this research is to investigate pathways of ammonium removal in constructed wetlands treating contaminated groundwater. For this, several approaches were applied.
This research demonstrated that combination of physico-chemical measurements with stable isotope and molecular biological approaches is an effective tool for investigation of nitrogen transforming processes in constructed wetlands. Such information is not only valuable for understanding of the processes ongoing inside these wastewater treatment facilities but also necessary for further technological improvement of constructed wetlands.
Vidhya Viswanathan, early stage Research Fellow on ADVOCATE Project, due to a hard and steadfast work, has achieved to defend her PhD titled "Effect of river restoration and hydrological changes on surface water quality - River reach-scale to catchment-scale study" with honours and great feedback coming from the expert panel.
The research has been developed at Swiss Federal Institute of Aquatic Science and Technology (EAWAG), in Switzerland being her PhD thesis evaluation committee:
Congratulations Dr Viswanathan and all the best for your brilliant future.
Further information on Vidhya's research is available online in her technical bulletin and in our blog. As well, don't miss her video on the ADVOCATE website, where she explains perfectly her work related to understanding the role of river restoration in maintaining good water quality.