UNCONVENTIONAL WATER: MICROALGAE PRODUCTS IN THE CONTEXT OF CIRCULAR ECONOMY

Water-scarce countries need a radical re-thinking of water resource planning to include the creative exploitation of unconventional water resources for sustainable development. The Circular Economy Action Plan mentions biomass and biomaterials as a priority, but an encompassing approach to their sustainable application, including biodiversity aspects and nutrient cycles, is lacking. A circular economy seeks to increase the proportion of renewable or recyclable resources and reduce the consumption of raw materials and energy in the economy, while, at the same time, protecting the environment through cutting emissions and minimizing material losses. Circular economy is an ecological concept that is based on the principle of optimizing the use of all biomass. Climate change has negative effects on food security and water security, rising globaltemperatures, extreme weather, changing climatic patterns, and loss of cultivable land will require drastic changes in current technology to minimize environmental impact through sustainable sourcing of commodities such as food, bioproducts, and bulk chemicals. The Non-conventional water sources refer primarily to water reclamation, in various degrees of quality, from urban wastewater, brackish groundwater, and seawater. Rain stimulation is also included in this category. Unconventional water resources are essential in building a water future in dry areas where water is recognized as a precious resource and a cornerstone of the circular economy. Desalinated water is an important water resource, which extends water supplies beyond what is available from the hydrological cycle, providing a climate-independent and steady supply of high-quality water; the world’s oceans contain over ۹۷% of the planet’s water resources, providing essentially unlimited raw material for seawater desalination. Desalination process removes salt from seawater (salt content between ۳۰,۰۰۰ and ۵۰,۰۰۰ mg/L) or brackish groundwater (salt content ranging from ۸۰۰ to ۱۰,۰۰۰ mg/L) to render such waters potable. Almost half of the desalination capacity (۴۴%) is in the still-growing Middle East market, but other regions are growing even faster, notably Asia, particularly China, the United States, and Latin America. Desalination technologies to produce potable water are divided into two categories – membrane-based and thermal evaporation-based. Over the last decade, Seawater Reverse Osmosis (SWRO), the most prevalent membrane-based technology, has become the method of choice for desalination worldwide due to its relatively lower energy use and cost of water production. With an estimated number of ۳۰,۰۰۰–۱,۰۰۰,۰۰۰ species, microalgae represent an exceptional natural resource to explore for the ۲۱st century. Dried algal biomass from GRAS-certified species is most commonly consumed as a powder and already marketed as dietary supplement to improve health, is often added to other foods, such as blended beverages. The removal efficiency for TDS from the halo-tolerant algal species varied between ۱۳% and ۶۳%. The presentation introduces the Microalgae cultivation in brine discharge of desalination process. A high growth rate, a high ability to bind carbon dioxide and the potential toaccumulate biogenic elements and light metals mean that algae can be used as a raw material for production of food, food additive, biofertilizers, biopesticides, feeds and feed additives. The development of innovative and low-cost technologies of algae production, including the possibilities of their use in rural areas, provide a basis for changes, improvements and modifications to the existing solutions in utilization of algae for food product manufacturing opens alternative ways for food acquisition, protecting both the food supply and the planet’s resources.