Using existing traditional Euro-Mediterranean know-how and recent developments in the field of biotechnology of aquatic microorganisms, our project aims at studying, designing, and disseminating a local circular strategy for rural wastewater treatment with minimal renewable energy input that will supply valuable goods and services (clean irrigation water, fertilizers, phytostimulants, etc…) to vulnerable rural communities. The intensive utilization of chemical fertilizers, pesticides, and herbicides for agriculture, together with largescale livestock farms, in the Euro-Mediterranean area, are contributing to the pollution of rural waters (relevant to nitrogen contamination). However, rural wastewater treatment in Euro-Mediterranean rural areas faces significant barriers such as high-cost, ineffective processes, or managing capacity. Conventional wastewater treatment processes such as activated sludge system are not applicable due to high investment and operation costs. Alternative processes (constructed wetlands and reed bed systems) exist but they are low efficient, and they do not allow the production of quality biomass that can add an economic value to the process and reduce costs. The WABA project principal goal is to develop an alternative eco-friendly and sustainable wastewater treatment process for rural areas based on a microalgae-bacteria consortium. The potential of microalgae for bioremediation of wastewater has recently received considerable interest. Compared to physical and chemical treatment processes, algae based treatment can potentially achieve nutrient removal in a less expensive and ecologically safer way with the added benefits of resource recovery and recycling. However, no study has analyzed the energetic benefits and techno-economic limitations of this concept in the context of Euro-Mediterranean rural areas. Bacteria-algae consortia can enjoy most of metabolic features of both components, and are potentially economically sustainable, thanks to their capacity to operate with minimal natural inputs such as sunlight, atmospheric CO2 and nutrients from wastewaters. Thus, this system can be energetically efficient, and ecologically friendly. The project will study the relationship between algae and bacteria to understand how we can improve this partnership and maximize non-energy intensive treatments of rural wastewater, combined with the production of algae-based agronomical useful products. Our preliminary data show that specific microbial consortia are able to uptake nitrogen better than algae on their own, thereby increasing removal nitrogen from wastewater, and decreasing eutrophication index. We will study the relationship between these organisms to understand and improve the removal of nitrogen and other pollutants. These consortia will be then fed with wastewater and the pollutant removal efficiency evaluated. A novel process will be developed to combine optimum consortia growth and wastewater bioremediation. Robust analytical methods based on FTIR spectroscopy will be developed to assess the contribution of the various components to the consortium, and further determine and monitor the biomass quality. The biomass generated will be evaluated as biofertilizer and biostimulant in a local agriculture context. Importantly, we will also perform optimization studies in order to improve the energy efficiency of the method and reduce the costs. Finally, the impact on rural economy will be assessed in two case studies (France and Morocco), and compared to current remediation systems