Recovery and revalorization of urban effluents in the context of circular economy

The DigesTake is an industrial research project whose main objective is to develop new processes and technologies for the treatment, recovery, revalorization and reuse of resources of liquid and gaseous effluents (waste gases from biogas) resulting from the anaerobic digestion of EDARs, following the principles of eco-sustainability and energy efficiency. Transversal facilitating technologies will be applied in other areas such as biotechnology, advanced materials or ICTs to meet the technological challenges that involve multiple disciplines and areas of expertise (chemical engineering, electronics, materials science, automation, electrochemistry, microbiology) through laboratory experiments and pilot tests.

The research activity will be carried out in the framework of four main axes or activities: “carbon” (Activity 1), “phosphorus” (Activity 2), “nitrogen” (Activity 3) and “water and concentration of nutrients” (Activity 4). The “carbon” activity will focus on the conversion of carbon dioxide from biogas into organic compounds with added value through bioelectrochemical systems. For the recovery of phosphorus (A2), two alternative processes are proposed, the recovery of struvite using as reagents by-products of the mining sector, and a new process of bio-induced precipitation of phosphorus in a partial nitrite reactor-Anammox (NPA). At the same time, an eco-sustainable biosensors system will be developed for in-situ phosphorus measurement to track the processes. The “nitrogen” activity includes the recovery of ammonium salts with adsorption-desorption systems through regenerable zeolites, and a process to eliminate excess nitrogen contained in water with low energy consumption in micro-aerobatic conditions. Finally, in activity 4 (“water and concentration of nutrients”), the membranes and extractive solutions of a direct osmosis process will be investigated.

It is expected that the project will have a scientific, technological, environmental and economic impact relevant to the whole chain of value of the recovery of wastewater resources (exploiters and constructors of WWTPs, service companies, public administration) but also for the potential users of the new products (organic compounds of added value, fertilizers of different composition, a system of biosensors of phosphorus compounds) and technologies (new membranes of direct osmosis, removal of nitrogen in an NPA reactor in microaerobic conditions) located in the chemical, agro-food or energy sectors, among others.