Wastewater filtering goes natural Using the ground below us to help filter wastewater is an important part of the process of recycling wastewater into fresh water. Research in this direction is especially beneficial for developing countries. Climate Change and Environment © Thinkstock Clean water is a must for every community around the globe, yet is a resource that is becoming scarce in many developing countries. Recycling wastewater is one promising solution, particularly using Aquifer Recharge (AR) technology which involves natural treatment. The EU-funded project 'Water reclamation technologies for safe artificial groundwater recharge' (Reclaim Water) worked on providing safe and cost-effective technology for reclaiming water and managing AR. It investigated how to effectively rid wastewater of microbial and chemical contaminants to produce viable water that can supplement fresh water supplies, especially in developing countries. To achieve its aims, the project analysed microbial contaminants and antibiotic resistance genes in wastewater, as well as various organic compounds that could be harmful to the water. Reclaim Water undertook different water reclamation and AR studies, focusing on removal of microorganisms and organic compounds. This involved 8 test sites around the globe to treat municipal wastewater effluent and to recharge aquifers with rainwater, with extensive monitoring of 50 wastewater parameters and contaminants. In all, the project identified different options to upgrade quality before groundwater recharge, costing less than EUR 1 and 1 kilowatt per hour for each cubic metre. The most promising of these were natural systems such as soil passage and soil aquifer treatment (SAT) that, despite posing filtering limitations to be overcome, proved more efficient than membrane filtering. While the initiative was not able to outline definitive solutions for pre-treatment, it ascertained the importance of aquifer barriers in treating wastewater. It also emphasised the use of technologies such as size exclusion chromatography (SEC) and excitation emission measurements (EEM) to monitor effluent organic matter versus natural organic matter during water treatment. These advances are important in safeguarding health, environment and socioeconomic wellbeing in developing countries. The results of the project were disseminated through numerous publications and are expected to play a valuable role in perfecting and exploiting this new wastewater technology.
