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The Mediterranean region, which is one of the world's leading tourist destinations, is vulnerable to climate change and impacted by human water demand. Tourism is recognized as a major water-consuming sector, and the growth in tourism establishments has been matched by a growth in water demand. Hotels represent the highest water consumption rates in the tourist sector. In this study, a survey was carried out in the Mediterranean region. Responses from 80 hotels of different categories and countries were gathered, discussed and compared regarding water supply, water consumption and monitoring, water-saving strategies, and environmental awareness and willingness for future improvements. [ABSTRACT FROM AUTHOR]

Forward osmosis (FO) has popularized lately due to its lower fouling propensity, higher pollutant rejection, and potentially lower energy consumption than other membrane technologies. Greywater (GW) is a good candidate for FO treatment for its further reuse due to its lower organic and solids content than other wastewater streams, but it contains organic micropollutants (OMP) that might pose a risk for its reuse. Seawater (NaCl) is widely used as draw solution, but the use of fertilizers instead offers the advantage of applying the diluted draw solution for irrigation. This study evaluated the performance of FO for GW treatment focusing on OMP rejection, by means of tests with fertilizers or NaCl as draw solutions and deionized water or GW as feed solutions. The main GW constituents were well rejected, except for sodium, which diffused to the draw solution. Excellent OMP rejection was obtained (>95% in most cases, average 98.5% rejection at the end of the experiments), which was influenced by experimental conditions and OMP properties. Highest rejections were observed for negatively charged OMP and for neutral/positive charged OMP with large molecular weight. Feed type and contact time between feed and draw solutions had the biggest influence on OMP rejection, which decreased over time and by using GW instead of deionized water as feed solution. The diluted draw solution proved safe for irrigation water reuse purposes although sodium content could be of concern. Further studies on the contact time between the solutions are required to foster further applications of FO, as it clearly influenced the rejection of OMP, aspect that is crucial for safe water reuse applications. [Display omitted] • Successful greywater treatment with forward osmosis. • High organic micropollutants rejection regardless of the feed and draw type. • Organic micropollutant rejection decreased with time. • Diluted draw solution proved to be safe for water reuse. [ABSTRACT FROM AUTHOR]

There is a need for water reuse technologies and applications to minimize the imminent water crisis, caused by the world population growth, the reduction of freshwater resources and the increasing water pollution. Fertilizer-drawn forward osmosis (FDFO) is a promising process capable of simultaneously extracting fresh water from low-quality sources as feed water (e.g., wastewater or greywater), while diluting fertilizer solutions for direct fertigation, avoiding the demand for freshwater for irrigation. Achieving an adequate level of dilution for direct fertigation is a key element to be evaluated for the implementation of FDFO. This study assessed the performance of the forward osmosis process to dilute fertilizer solutions to be applied directly in hydroponic systems. Experiments were carried out under conditions close to osmotic equilibrium to evaluate the process performance up to the maximum dilution point. Tests were carried out with individual and blended fertilizers (i.e. , (NH 4) 2 HPO 4 or DAP, and KNO 3) used as draw solution (DS) and with deionized water or individual salts (NaCl, MgCl 2 , Na 2 SO 4 , MgSO 4) in the feed solution (FS). Water fluxes and reverse salt fluxes indicated that both fertilizer DS composition and concentrations play a fundamental role in the process. Suitable nutrient concentrations to be directly applied without further dilution for N, P and K (119, 40, 264 mg.L−1 respectively) were obtained with deionized water as FS and blended DAP (0.025 M) and KNO 3 (0.15 M) as DS. However, important fertilizer losses from DS to FS were observed, being the highest for NO 3 − (33–70% losses from DS to FS). The presence of salts in FS decreased the water fluxes and the DS dilution due to the osmotic equilibrium caused by a greater loss of nutrients from DS to FS (up to 100%), compared with tests using just deionized water as FS. This study points out the potential limitations of the FDFO process, due to the high solute fluxes and low water fluxes in conditions close to osmotic equilibrium. [Display omitted] • Proper dilution for hydroponic achieved with mixed DAP and KNO 3 as DS and DI as FS. • Reverse solute fluxes led to important draw solution nutrients losses. • Salts presence in FS resulted in high reverse fluxes of NH 4 +, K+ and NO 3 − to FS. • Forward fluxes from FS to DS were minimal for all FS ions except for Na+. • Nutrient losses in osmotic equilibrium jeopardizes the potential of FDFO process. [ABSTRACT FROM AUTHOR]