Fraunhofer Institute for Surface Engineering and Thin Films IST
Water-purification technology enabling the use of wastewater for irrigation purposes
Challenge
The provision of clean water is one of the most important global challenges and is being considerably intensified as a result of climate change. In order to be able to utilize clear water from wastewater treatment plants as an additional source of water for irrigation, it must be purified of organic micropollutants, such as pharmaceutical residues, which would otherwise accumulate in field crops or in the environment.
Solution
With the goal of reducing micropollutants, SERPIC will test a fourth treatment step for wastewater treatment plants. Nanofilters create a pollutant-free permeate stream which, following disinfection with chlorine dioxide, is to be used for irrigation. The concentrate stream contains the pollutants, which are degraded by means of UV-stimulated electrochemical oxidation. The oxidants are created with high efficiency in electrolyzers with the aid of diamond electrodes. A prototype plant in Ciudad Real will verify the irrigation suitability of the purified water in test fields.
Added value
In contrast to previously tested cleaning techniques, the SERPIC technology offers the potential to achieve a higher degradation rate as well as better sustainability through the use of in-situ-generated solar power. Concepts are being developed for the transfer of the technology to other – in particular poorly developed – regions including South Africa.
Insights into the project
SERPIC reduces micropollutants from the water generated by wastewater treatment plants and makes it available for irrigation.
Diamond electrodes produce oxidants with high energy efficiency.
Funding reference
The authors would like to thank the EU and Bundesministerium für Bildung und Forschung, Germany, Ministero dell’Università e della Ricerca, Italy, Agencia Estatal de Investigación, Spain, Fundação para a Ciência e a Tecnologia, Portugal, Norges forskningsråd, Norway, Water Research Commission, South Africa for funding, in the frame of the collaborative international consortium SERPIC financed under the ERA-NET AquaticPollutants Joint Transnational Call (GA Nº 869178). This ERA-NET is an integral part of the activities developed by the Water, Oceans and AMR Joint Programming Initiatives.
