The network’s activities were primarily focused on the following four research objectives:
1) The assessment of water quality and the prediction of its response towards arisen environmental stresses. A comprehensive screening of contaminants using both target and untarget approaches was performed through four sampling campaigns at Monte Bianco (Italy) for snow and river water, one campaign in Lillestrøm (Norway), focusing on the Brånåsen landfill and Nitelva River and one river campaign along the Serpis River in Spain. These investigations allowed to identify a broad spectrum of pollutants spanning from hydrocarbons, halogenated compounds, esters, and aromatic compounds to pharmaceuticals, personal-care products, industrial chemicals, and pesticides. In parallel a study of the persistence and photochemical fate of sulfamethoxazole in different water matrices, and the photochemical behavior of 3-aminosalicylic acid and acetophenone in artificial snow and aqueous systems was performed. A biofilm-based passive sampler (Prebio Cell), was developed, optimized and coupled with non-target analysis (NTA) and bioassays then successfully applied to wastewater matrix. In parallel, bioactivity and bioavailability of CECs were assessed using high-throughput optical microrespirometry, a non-invasive, miniaturized that enables high-resolution testing of multiple samples, across a range of organisms (bacteria, algae, small invertebrates, fish embryos) thus covering multiple trophic levels and enhancing environmental relevance. The goal is to investigate the toxicity of degradation by-products and confirm that treatments effectively reduce the toxicity of contaminated water.
2) Restore water quality while approaching the zero-waste discharge. Several green strategies to produce materials for pollutant removal while minimizing waste were explored. These include biochar from sewage sludge, carbon quantum dots from plant residues, humic-like substances derived from different refuses of importance in the Mediterranean Sea Basin, such as grape bagasse, olive oil mill waste, lemon and orange peels as well as WWTP sludge. Additionally, metals extracted via phytomining were investigated for their use in photocatalytic applications. The removal of CECs has also been studied by using a range of photocatalysts for integration into NF membranes, including: FeTiO3, C3N4, MIL-101-Fe, CuWO4, CuWO4-x, Fe2TiO5, FeWO4, WO3, K-C3N4, FeTiO3/C3N4, FeWO4/C3N4. Reference water-quality parameters have been defined providing a quantitative basis for interpreting matrix effects on AOP performance and to support the standardization of future tests. In addition, microbial pathogens and genes resistant to antibiotics (ARGs) were included as water quality targets to compare the performance of the treatment technologies under evaluation.
3) Scale up and process integration. Hybrid purification systems combining nanofiltration and advanced oxidation processes (NF-AOPs) were optimized for target applications. Two membrane fabrication methods were explored: phase inversion and Meyer rod coating. In addition, solar/chlorine disinfection experiments in simulated and real aquaculture effluents, monitoring bacterial inactivation, was assessed in parallel to solar experiments in a raceway-pond reactor using peroxymonosulfate (PMS) and sodium hypochlorite (NaOCl) to reduce total organic content in real wastewater effluent. Emphasis is placed on upscaling, validation, energy efficiency, and assessment of economic, environmental and health impacts to ensure sustainable operation. In addition, solar photo-Fenton experiments, at laboratory scale and at different concentrations of persulfate and Fe3+-IDHA, were performed to simulated hydroponic and aquaculture effluents. A Life Cycle Inventory (LCI) spreadsheet has been created to allow to share data performance on the different technologies applied for the recovery of aquaculture, hydroponics and urban wastewaters.
