A combination of straw filtration and nanofiltration was investigated for the first time as a sus-tainable approach aimed at valorizing olive mills wastewaters (OMWs) within a circular economy strategy. Ground straw filters with different granulometry (120, 250 and 500 m) were tested in the first step to clarify the raw wastewater. The 500m filter offered the best performance due to a lower exposed surface of the filtering fibers and a shorter filtering time allowing to reduce about 70% of the COD of the raw wastewater. Three different commercial membranes in flat-sheet con-figuration with molecular weight cut-off (MWCO) in the range 150-500 Da were tested to frac-tionate the clarified wastewater according to a dead-end configuration. Among the investigated membranes the NFA-12A membrane exhibited the highest productivity in selected operating conditions (steady-state values of 11.4 L/m2h at 20 bar and 24 ± 2 °C). In addition, flux decays for this membrane resulted lower than the other two tested membranes indicating a lower propensity to fouling phenomena. Higher rejections towards total polyphenols and TAA (76.6% and 73.2%, respectively) were also observed for this membrane. Flavanols and hydroxycinnamic acids were retained for more than 99%. The combination of straw filtration and NF with NFA-12A membrane allowed to reduce the COD of raw OMWs up to 97.6%. The retentate fraction of this membrane exhibited a TAA of 18.9 ± 0.7 mM Trolox supporting its propensity for the development of inno-vative formulations of interest in food and nutraceutical applications.

Information regarding physiological and molecular plant responses to the treatment with new biofertilizers is limited. In this study a fast-composting soil amendment (FCA), obtained from solid waste by means of a Fenton reaction, was tested to evaluate the effects on the growth of Lactuca sativa L. var. longifolia seedlings. Growth rate, leaves and roots biomass, chlorophyll concentration and total soluble proteins of seedlings treated with the 2% FCA soil amendment showed significant increase in comparison with control seedlings. Leaf proteomic analysis revealed that the FCA soil amendment induced the up-regulation of proteins belonging to photosynthesis machinery, carbohydrate metabolism and promoted the up-regulation of the water stress response. Root proteomics indicated that FCA strongly induced the organs morphogenesis and developments; root cap development, lateral root formation, post-embryonic root morphogenesis were the main biological processes enriched by the treatment. Overall, our data suggest that addition of FCA formulation to the base soils might ameliorate plant growth by inducing carbohydrates primary metabolism and the differentiation of a robust root system.