Resource recovery from desalination, the case of small islands

Unidad de excelencia María de Maeztu CEX2019-000940-MThis work explores resource recovery coupled to seawater desalination in small islands. As small islands depend on seawater desalination for water access, they make an excellent ground for exploring the trade-offs associated to resource recovery, like potential economic gains, energy use, and environmental impacts. Here, we investigated these tensions in the context of Lampedusa, in Italy. We then developed and evaluated scenarios for the recovery of additional water, Mg, and other resources from brines, to identify if and how resource recovery is an interesting approach for the island vis-à-vis these tensions. We have found that the potential to increase water production with water recovery from brine is an interesting alternative for small islands, especially when harnessing waste heat. However, while some technologies offer possibilities for recovering additional resources, in places like small islands the potential benefits from additional recovery do not seem to justify the costs to the local system

Aspects of environmental impacts of seawater desalination : Cyprus as a case study

Acknowledgements The authors are grateful to the European Commission for supporting the activities carried out in the framework of the H2020 European project ZERO BRINE (project under grant agreement No. 730390). The authors would equally like to thank the TOTAL Foundation (Project “Diversity of brown algae in the Eastern Mediterranean”) and the UK Natural Environment Research Council for their support to FCK (program Oceans 2025 – WP 4.5 and grants NE/D521522/1 and NE/J023094/1). This work also received support from the Marine Alliance for Science and Technology for Scotland pooling initiative. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. The authors would also like to thank representatives from competent authorities in Cyprus providing data, and specifically Nicoletta Kythreotou from the Department of Environment, George Ashikalis from the Transmission System Operator, Dr. DinosPoullis and Lia Georgiou from the Water Development Department.Peer reviewedPublisher PD

Resource recovery from desalination, the case of small islands

This work explores resource recovery coupled to seawater desalination in small islands. As small islands depend on seawater desalination for water access, they make an excellent ground for exploring the trade-offs associated to resource recovery, like potential economic gains, energy use, and environmental impacts. Here, we investigated these tensions in the context of Lampedusa, in Italy. We then developed and evaluated scenarios for the recovery of additional water, Mg, and other resources from brines, to identify if and how resource recovery is an interesting approach for the island vis-`a-vis these tensions. We have found that the potential to increase water production with water recovery from brine is an interesting alternative for small islands, especially when harnessing waste heat. However, while some technologies offer possibilities for recovering additional resources, in places like small islands the potential benefits from additional recovery do not seem to justify the costs to the local system

Ultra-High recovery Multi-Effect Distillation for nearly-liquid discharge desalination

The availability of water is still one of the most important factors for the growth and sustainability of a country. Although many countries have free access to an inexhaustible source of water, the sea, this source cannot, as it is, be used for human purposes. To face this problem, desalination has been proposed for fresh water production, though the limitation in recovery of conventional RO plants and the generation of a waste brine effluent pose some issues of actual sustainability. Multiple Effect Distillation (MED) has been proposed in this work to be coupled with a NanoFiltration unit in order to dramatically enhance the conversion ratio of the process, thus reducing the brine volume produced. A 2-effects MED pilot plant, with a capacity of about 1.5 m3/d, has been installed as part of the treatment chain of the Watermining project, within the premises of the power station of the island of Lampedusa (Sicily, Italy) and is fully powered by waste heat at 70-80°C from the diesel engines of the power station. Several operating conditions were investigated using real saline stream produced as a permeate of the NF unit. A recovery ratio above 80% has been achieved and an effluent brine conductivity between 250 and 300 mS/cm was produced, which is close to the saturation in NaCl, thus being excellent for being sent into evaporative ponds. A temperature between 40°C and 55°C has been maintained in the evaporator, suitable for integration with very low temperature waste heat sources. In all cases the distillate productivity and the conductivity of the produced water were maintained close the nominal values, with the latter typically ranging between 10 and 20 μs/cm

Social life cycle assessment of a desalination and resource recovery plant on a remote island: Analysis of generic and site-specific perspectives

Supplementary data are available online at: https://www.sciencedirect.com/science/article/pii/S2352550923000611?via%3Dihub#s0095 .The sustainable supply of water is crucial, especially on islands where water is scarce. Our study applied the social life cycle assessment (S-LCA), under the organizational approach, to assess industrial water production on the island of Lampedusa, Italy. A novel plant for industrial water production considering a circular concept was compared with the existing linear production plant based on reverse osmosis. An online survey, brief literature review and generic analysis were conducted to prioritize impact subcategories selection for site-specific analysis that regarded six organizations in the system boundaries. These subcategories were Local employment, Access to material resources, Promoting social responsibility, End-of-life responsibility, Health and safety (Workers), and Public commitment to sustainability issues. The social performance of organizations involved was assessed based on equal weighting and weighting with cost values. The generic analysis showed that wastewater treatment in Italy is underdeveloped, and water scarcity can become a serious problem in the future. The site-specific analysis based on equal weighting showed that the novel water plant results in improving social performance for all considered impact subcategories by 88 % to 91 % due to co-production when compared with the existing plant. Even increasing impacts allocation to industrial water production social benefits are still expected due to co-production. The type of weighting based on cost values showed that two organizations are the main contributors to the social performance of the novel system, and improving their corporate conduct can result in improving impacts up to 25 %, such as Public commitment to sustainability issues. To conclude, the novel plan does provide social benefits but mainly due to co-production, thus, it should be investigated more how to apply the S-LCA to linear production systems as they become more circular.European Commission under the framework of the WATER-MINING (project under grant agreement No. 869474)

Making value out of the wastewater effluent generated from desalination plants, through the use of renewable energy for the recovery of water and the production of salt

Desalination is increasingly playing a crucial role in balancing the water needs of water deficient areas, such as the Mediterranean Sea. In Greece, there are water basins which do not have sufficient water resources to cover local needs, with the islands of the Aegean being the most water scarce. In these islands, it is often required to employ costly water supply practices such as transportation of water with ships from the mainland of Greece (or from neighbouring islands). Today, more and more Greek islands turn to desalination to secure a stable and cost-efficient water supply. However, even though desalination comprises one of the most promising solutions to water shortage, it raises high environmental concerns, especially due to the saline impaired wastewater generated, called brine. This effluent is twice as salty as seawater and causes environmental degradation, if not managed properly.Today, five (5) practices are applied to manage this effluent: (a) Surface Water Discharge, (b) Sewer Discharge, (c) Deep Well Injection, (d) Evaporation Ponds and (e) Land application. Each of these practices involves different environmental risks and has different impacts. The main objective of this dissertation is to design an innovative system, in line with the Zero Liquid Discharge principle, that will be able to: (a) eliminate the environmental impacts associated with brine; and (b) make value out of desalination brine. After having reviewed the ZLD systems applied today, the innovative system is designed following a three-step design procedure: (a) conceptual design; (b) preliminary design; and (c) detailed design. The conceptual design aimed at identifying the process flow diagram, determining the process operation units. The preliminary design involved the sizing of the components and the detailed design the development of engineering drawings. The scale of the system was 2m3/day (pilot scale). The pilot brine treatment system comprises three (3) treatment steps: (a) the evaporator; (b) the crystallizer; and (c) the dryer unit. The evaporator comprises a customized Multiple Effect Distillation (MED), forward-feed design to reflect the specific needs for the application. The energy requirements of the system are provided through solar energy.After the completion of the design stage, the construction, installation and start-up operation of the pilot system followed. The pilot system was developed in the framework of the EU funded project with the acronym SOL-BRINE (LIFE09 ENV/GR/000299). The system was installed at the site of an existing desalination plant in the area of Agios Fokas, in Tinos Island, Greece. It was operated for approximately 1 year. With the aim to optimize its performance and assess its results, three series of experiments were conducted, according to the experimental protocol developed. Both liquid and water samples were collected from different stages of the brine treatment process and from the feed and exit streams of the desalination plant. The samples were transported to the Unit of Environmental Science and Technology (UEST) which belongs to the School of Chemical Engineering of the National Technical University of Athens. The samples were analysed with the use of suitable analytical equipment such as ICP, ICP-MS, photometer, Conductivity meter, XRD, SEM-EDS etc. The quality of the water recovered is close to distillate (TDS ~ 50 ppm), while the salts are recovered mixed, requiring therefore further treatment to recover purified salt products.From the laboratory results, the seawater desalination brine was then valorised. The value of 1 m3 of brine was determined on the basis of the product recovered with the use of the pilot brine treatment system (mainly distillate water) and also by making coherent assumptions of the potential to recover high purity salts (in the future). The determination of the value of brine was key for performing a feasibility study for the development of the brine treatment system at industrial scale (100 m3/day). Also, after having made suggestions for the development of the system at full-scale, the brine treatment cost was determined. The suggestions for the full-scale implementation involve two different scenarios: (a) hybrid solar powered system; and (b) recovery of waste heat. For both scenarios both CAPEX and OPEX cost parameters were estimated. Then the economic value and the treatment cost of 1 m3 were compared, provided critical insights for investigating the feasibility of developing the brine treatment system at larger scale. The results from the feasibility study suggest an economic value of 5.8€ per seawater desalination brine, while the treatment cost is estimated at 2.7€ per m3 and 3.7€ per m3 for the 1st and 2nd scenario respectively. This suggests that both scenarios seem to be economically viable.Finally, the water and salt markets are recorded and analysed with the view to determine suitable market opportunities to develop the system at full-scale in Greece.Είναι κοινά αποδεκτό ότι η αφαλάτωση διαδραματίζει ήδη, και θα διαδραματίσει στο μέλλον ολοένα και σημαντικότερο ρόλο, για το υδατικό ισοζύγιο άνυδρων περιοχών όπως στη Μεσόγειο Θάλασσα. Στην Ελλάδα, παρατηρείται ότι μερικά υδατικά διαμερίσματα παρουσιάζουν ελλειμματικό υδατικό ισοζύγιο. Το πλέον ελλειμματικό ισοζύγιο εντοπίζεται στο υδατικό διαμέρισμα των νήσων Αιγαίου. Στα νησιά αυτά πολλές φορές είναι απαραίτητη η χρήση πολύ δαπανηρών πρακτικών για την κάλυψη των αναγκών σε νερό, όπως με μεταφορά νερού με υδροφόρα πλοία. Για την ασφαλέστερη και οικονομικότερη παραγωγή νερού, σήμερα χρησιμοποιούνται σε πολλά από τα νησιά αυτά μονάδες αφαλάτωσης. Η αφαλάτωση, ως μία διεργασία που απομακρύνει άλατα από το θαλασσινό (ή υφάλμυρο) νερό, αναπόφευκτα παράγει υγρά απόβλητα που είναι σχεδόν διπλάσιας αλατότητας από το θαλασσινό νερό. Το απόβλητο αυτό λέγεται άλμη και μπορεί να προκαλέσει σημαντικές περιβαλλοντικές επιπτώσεις, αν δεν διαχειριστεί με το σωστό τρόπο.Σήμερα οι τρόποι διαχείρισης αυτού του αποβλήτου περιλαμβάνει τις ακόλουθες πέντε (5) τεχνικές: (α) Διάθεση σε επιφανειακά νερά (Surface Water Discharge), (β) Διάθεση σε συστήματα αποχέτευσης (Sewer Discharge), (γ) Έγχυση σε υπόγειους γεωλογικούς σχηματισμούς (Deep Well Injection), (δ) Λίμνες εξάτμισης (Evaporation Ponds), (ε) Άρδευση, αναφέρεται συχνά και ως διάθεση στο έδαφος (Land Application). Κάθε τεχνική προκαλεί, σε διαφορετικό βαθμό, περιβαλλοντικές επιπτώσεις. Στόχος αυτής της διδακτορικής διατριβής είναι ο σχεδιασμός ενός συστήματος, ο οποίος θα είναι σύμφωνος με την αρχή των μηδενικών υγρών αποβλήτων (Zero Liquid Discharge, ZLD). Το σύστημα αυτό έχει διττό στόχο: (α) να εξαλείψει τις περιβαλλοντικές επιπτώσεις που σχετίζονται με τη διάθεση της άλμης στο περιβάλλον και (β) να εξετάσει τη δυνατότητα αξιοποίησης της άλμης.Στη διατριβή αυτή, έχοντας αρχικά μελετήσει τα συστήματα ZLD, πραγματοποιείται ο σχεδιασμός ενός καινοτόμου συστήματος επεξεργασίας της άλμης σε τρία στάδια: (α) αρχικός σχεδιασμός, (β) προκαταρκτικός σχεδιασμός και (γ) αναλυτικός σχεδιασμός. Το κάθε στάδιο σχεδιασμού έχει τους δικούς του στόχους και μεθοδολογία, με τον αρχικό σχεδιασμό να στοχεύει στην επιλογή του διαγράμματος ροής, τον προκαταρκτικό σχεδιασμό στην διαστασιολόγηση των επιμέρους συνιστωσών και τον τελικό σχεδιασμό στην ανάπτυξη κατασκευαστικών σχεδίων. Η κλίμακα του συστήματος επεξεργασίας της άλμης που σχεδιάστηκε ήταν πιλοτική (2 m3/ημέρα). Το πιλοτικό σύστημα αποτελείται από τρεις (3) συνιστώσες: (α) τον εξατμιστήρα, (β) τον κρυσταλλωτήρα και (γ) τον ξηραντήρα. Η ενέργεια του συστήματος προσφέρεται από ηλιακή ενέργεια, με τη χρήση ηλιακών συλλεκτών κενού. Μετά το σχεδιασμό του, ακολούθησε η κατασκευή, εγκατάσταση και η start-up λειτουργία του πιλοτικού συστήματος. Η πιλοτική μονάδα κατασκευάστηκε στο πλαίσιο του ερευνητικού Ευρωπαϊκού Έργου SOL-BRINE (LIFE09 ENV/GR/000299). Εγκαταστάθηκε σε μονάδα αφαλάτωσης στην περιοχή του Αγίου Φωκά, στην Τήνο. Η λειτουργία και βελτιστοποίηση του συστήματος διήρκεσε 1 χρόνο. Για τη βελτιστοποίηση του συστήματος, πραγματοποιήθηκαν τρεις σειρές πειραματικών κύκλων, σύμφωνα με το πρωτόκολλο πειραμάτων που εκπονήθηκε. Έτσι, λήφθηκαν τόσο υγρά όσο και στερεά δείγματα από τα διάφορα στάδια επεξεργασίας, καθώς επίσης και από την εκροή και την τροφοδοσία της παρακείμενης μονάδας αφαλάτωσης. Τα δείγματα αυτά μεταφέρθηκαν στην Μονάδα Περιβαλλοντικής Επιστήμης και Τεχνολογίας, όπου αναλύθηκαν με τη χρήση κατάλληλου αναλυτικού εξοπλισμού (ICP, ICP-MS, Φωτόμετρο, Αγωγιμόμετρο, XRD, SEM-EDS). Από τις μετρήσεις και με χρήση επίσης της διεθνούς βιβλιογραφίας εκτιμήθηκε η οικονομική αξία της άλμης που παράγεται από μονάδες αφαλάτωσης θαλασσινού νερού. Η οικονομική αξία αυτή εκτιμήθηκε στη βάση των προϊόντων που ανακτήθηκαν κατά τη λειτουργία του πιλοτικού συστήματος (αποσταγμένο νερό) και στη δυνατότητα ανάκτησης (μελλοντικά) άλατα υψηλής καθαρότητας. Η γνώση της οικονομικής αξίας 1 m3 άλμης ήταν καταλυτικής σημασίας για την εκπόνηση μελέτης σκοπιμότητας ανάπτυξης του συστήματος σε μεγαλύτερη κλίμακα (100 m3/ημέρα). Έτσι, έχοντας διατυπώσει προτάσεις ανάπτυξης του συστήματος σε μεγάλη κλίμακα, εκτιμάται το κόστος επεξεργασίας της άλμης, λαμβάνοντας υπόψη τόσο το κόστος επένδυσης, όσο και το αναμενόμενο κόστος λειτουργίας. Το κόστος αυτό ανήχθηκε ανά m3 άλμης. Συγκρίνοντας το κόστος επεξεργασίας με την οικονομική αξία 1 m3 άλμης, εξάγονται σημαντικά συμπεράσματα σχετικά με τη σκοπιμότητα υλοποίησης ενός συστήματος επεξεργασίας της άλμης σε μεγαλύτερη κλίμακα. Τέλος, αποτυπώνεται η αγορά των αλάτων, του νερού και της αφαλάτωσης, με στόχο τον προσδιορισμό κατάλληλων ευκαιριών υλοποίησης μίας πιθανής εμπορικής εφαρμογής στην Ελλάδα

Solar cooling using cooling structural elements

134 σ.Κλιματισμός χώρου μέσω υδρονικών panel οροφής . Η προτασσόμενη κλιματιστική συσκευή είναι ψυκτική μηχανή απορρόφησης με διμερές μίγμα LiBr-H2O και πηγή θερμότητας στην ατμογεννήτρια την ηλιακή ενέργεια που λαμβάνεται από τους ηλιακούς συλλέκτες . Αναπτύσσεται επίσης μεθοδολογία βέλτιστης διαστασιολόγησης του panel οροφής .Space cooling using hydronic roof panels . The suggested cooling device is a LiBr-H2O absorption unit using the solar energy absorbed by the solar collectors in the steam generator . A optimum-size selection of the roof panel is being developed.Δημήτριος Α. Ξεύγενο

Social life cycle assessment of a desalination and resource recovery plant on a remote island: Analysis of generic and site-specific perspectives

The sustainable supply of water is crucial, especially on islands where water is scarce. Our study applied the social life cycle assessment (S-LCA), under the organizational approach, to assess industrial water production on the island of Lampedusa, Italy. A novel plant for industrial water production considering a circular concept was compared with the existing linear production plant based on reverse osmosis. An online survey, brief literature review and generic analysis were conducted to prioritize impact subcategories selection for site-specific analysis that regarded six organizations in the system boundaries. These subcategories were Local employment, Access to material resources, Promoting social responsibility, End-of-life responsibility, Health and safety (Workers), and Public commitment to sustainability issues. The social performance of organizations involved was assessed based on equal weighting and weighting with cost values. The generic analysis showed that wastewater treatment in Italy is underdeveloped, and water scarcity can become a serious problem in the future. The site-specific analysis based on equal weighting showed that the novel water plant results in improving social performance for all considered impact subcategories by 88 % to 91 % due to co-production when compared with the existing plant. Even increasing impacts allocation to industrial water production social benefits are still expected due to co-production. The type of weighting based on cost values showed that two organizations are the main contributors to the social performance of the novel system, and improving their corporate conduct can result in improving impacts up to 25 %, such as Public commitment to sustainability issues. To conclude, the novel plan does provide social benefits but mainly due to co-production, thus, it should be investigated more how to apply the S-LCA to linear production systems as they become more circular.</p