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

Societal and economic aspects of a novel circular system for the valorisation of desalination brine and waste heat from a power plant

Direct disposal of concentrate brines produced in industrial plants can have a relevant impact to environmental systems. For this reason, brine treatment and valorisation could help to avoid disposal and produce marketable salts, thus representing a possible economic benefit. With this aim, a novel process, where advanced separation technologies are combined with waste heat recovery, is proposed within the EU-funded WATER MINING project. The Case Study presented in this work concerns the power plant in Lampedusa island, where waste heat and desalination brine are available to implement the process via a pilot plant to be installed for alternative thermal treatment of the brine. The aim is to achieve energy and water valorisation and producing high-quality salts (NaCl, Na2SO4, Mg(OH)2) and chemicals (HCl and NaOH). Beside the technological aspects, the novel process’ impacts to society, market and policy were investigated through a Value Sensitive Design approach (VSD) (Palmeros Parada et al., 2018). VSD is a design approach to proactively accommodate stakeholder values during the design of technologies (Friedman, 2017). For this, quantitative and qualitative data was collected from a review of the literature, and through interviews with four different type of stakeholders: (a) innovative technology suppliers (ResourSEAs), (b) local salt supplier (SoSALT); (c) innovation ecosystem representatives (ARCA); and (d) desalination user (SOFIP). From these data, societal values and tensions around the development and implementation of the innovative technologies, as well as both market and policy barriers and enablers have been identified. Stakeholders have been invited to participate in what we call a Community of Practice (CoP). Through the CoP, stakeholders have discussed the identified values, tensions, barriers, and opportunities for implementing the seawater desalination and brine treatment processes. In particular, societal concerns around impacts on water and energy use, especially considering the scarcity of these resources in the island, were analysed. The aim was to derive recommendations for the development of the technologies and their implementation. Overall, stakeholders have participated with enthusiasm to this experience by bringing their vast amount of practitioners’ knowledge and market insights that were explored, indispensable for setting a discussion on the market systems for circularly produced wastewater products

Techno-economic analysis of a novel hybrid system for the valorisation of SWRO brines in a minor Sicilian island

In small remote islands, freshwater scarcity is an issue to which several viable solutions have already been found employing constantly evolving desalination technologies. The several RO plants in the Canary and minor Sicilian Islands are just an example . However, the beneficial application of seawater desalination is accompanied by a problematic matter: the production of high salinity brines. Not only do they compromise the aquatic ecosystem but their treatment in order to respect environmental regulations is costly too. Worth noting how these so-called “wastewater streams” present a high concentration of valuable raw materials, such as magnesium and calcium or sodium chloride, that are essential to many industrial sectors (food, pharmaceutical, etc.) . In this work, a novel hybrid system is introduced to valorize SWRO brines produced in the minor Sicilian island of Pantelleria. The treatment chain consists in the coupling of four different separation processes, each with a specific purpose: (i) Nanofiltration (separation of bivalent from monovalent ions), (ii) MF-PFR crystallizer (selective recovery of magnesium and calcium), (iii) Multi-effect distillation (freshwater production and NaCl brine concentration) and (iv) Evaporative crystallizer (recovery of sodium chloride). The chain not only recovers valuable minerals and fresh water but contemporarily reduces the volume of the final brine that will be discharged into the Mediterranean Sea and enhance the overall process sustainability by utilizing waste or solar thermal energy for powering some of the integrated units. Process models for each technology have been developed and integrated in an advanced simulative platform, which includes tools for the estimate of economic performance indicators, allowing to perform a full techno-economic analysis. Numerous scenarios, characterized by different operating conditions and energy sources of the single technologies, are taken into examination. The purpose is to identify the set of operative conditions that best yields an economically and environmentally sustainable brine treatment process, thus implementing the concept of circular economy

Valorisation of SWRO brines in a remote island through a circular approach: Techno-economic analysis and perspectives

Nowadays, small remote islands rely heavily on desalination technologies to overcome freshwater scarcity. Unfortunately, these technologies are accompanied by the production of brines which can affect the receiving water bodies i.e., the aquatic ecosystem. Yet, it is extremely appealing how such brines constitute an abundant source of valuable raw materials (such as magnesium). In this work, a novel hybrid system is introduced to capture the value of seawater reverse osmosis (SWRO) brines produced in the minor Sicilian island of Pantelleria. The “Minimal Liquid Discharge” (MLD) process consists of: (i) Nanofiltration NF (separation of bivalent from monovalent ions), (ii) Mg Reactive Crystallizer MRC (selective recovery of magnesium and calcium), (iii) Multi- Effect Distillation MED (freshwater production) and (iv) NaCl Thermal Crystallizer NTC (sodium chloride re- covery). The economic and environmental performances of the process have been evaluated by implementing and integrating the techno-economic models of each unit in a simulation platform called RCE (Remote Component Environment). Results revealed important economic benefits in comparison to conventional brine disposal methods. In addition, the proposed MLD chain turned out to be an attractive alternative for the pro- duction of high purity minerals/salts, achieving lower selling prices than the current market price

From wastewater to resource

Eighty percent of wastewater is left untreated or not reused, exacerbating the water quality challenge, especially in vulnerable communities. This Voices asks: how can we improve wastewater management and convert wastewater into a resource

Polychaetes (Annelida) of Cyprus (Eastern Mediterranean Sea): An Updated and Annotated Checklist including New Distribution Records

The diversity and distribution of polychaetes in the coastal area and the EEZ of the Republic of Cyprus is presented based on both the literature records and new data acquired in a wide range of environmental monitoring programmes and research projects. A total of 585 polychaete species belonging to 49 families were reported in Cyprus waters; among them, 205 species (34%) were recorded based on the literature only, 149 (26%) were new records based on our own data, and a total of 231 spp. (40%) were recorded from both the literature and new data. A total of 51 polychaete species were identified as non-indigenous; among them, 32 were confirmed as alien species, 4 were considered cryptogenic, and 15 were considered questionable as there were doubts about their identity. The Indo-Pacific Schistomeringos loveni was reported for the first time in the Mediterranean Sea, while four species already reported in the literature, namely, Bispira melanostigma, Fimbriosthenelais longipinnis Leonnates aylaoberi, and Rhodopsis pusilla, were added to the list of non-indigenous polychaetes in the Mediterranean Sea. The current work highlights the importance of implementing environmental monitoring programmes and carrying out research surveys targeting benthic macrofauna assemblages