Globally, water scarcity is becoming an increasingly pressing issue. Due to climate change, extreme weather events such as droughts have become more frequent, making it hard for countries to supply their growing water demand, especially in dry regions. In fact, in the Mediterranean alone, one in five people faces constant water stress. Many Greek islands, for example, are experiencing water shortages due to growing tourist demand after the COVID-19 pandemic. This situation, however, extends beyond islands – to the entire world. According to the United Nation's Summary Progress Update 2021, around 29% of the world's population lives under constant water stress. And while the situation seems to be improving, with water-use efficiency increasing by 10% globally since 2015, much remains to be done.
Emerging solutions to water scarcity
This crisis has highlighted the need for initiatives on how to face water scarcity. Research on the topic has been highly prioritised globally, and potential emerging solutions are already being discussed. For instance, a recent study proposes iceberg towing as a possible way to face water stress. Surprisingly, this is not a novel idea, as this practice has been around for over 200 years. However, while icebergs are usually moved over short distances to prevent them from crashing with offshore oil and gas platforms near Canada, moving ice blocks large enough to help alleviate water stress over several thousand kilometres has never been done. Nevertheless, there has been increased scientific research into the topic, and towing icebergs to Cape Town, South Africa, and the United Arab Emirates has been suggested to alleviate water stress in these regions. However, the feasibility and cost of extrapolating this practice in other territories – as well as its upscaling – need further exploration.
It is becoming increasingly evident that a sustainable future is tightly linked to a circular economy
In parallel, more accessible approaches to solving the issue are being developed. Particularly, attention is being turned towards new ways of revalorising and incorporating the water cycle into our current value chain. It is becoming increasingly evident that a sustainable future is tightly linked to a circular economy. These ideas have already reached many industrial waste management and wastewater treatment industries and stakeholders. As a result, wastewater is now being perceived as a resource from which valuable materials can be extracted. Moreover, energy efficiency in these processes has also become a priority in recent years. In fact, in the EU, many projects are currently being funded to look into innovative solutions to face water scarcity. The goal is to invest in novel technologies that enhance the optimisation of energy consumption and exploitation of wastewater resources.
Untapping the potential of wastewater
"Currently, about 2 billion people are affected by water scarcity. And with the added pressure of climate change, things won't get any better. This means we must transition rapidly from a linear economy to a cycle-driven one," explains Dr Anne Kleyböcker, project manager at the Berlin Centre of Competence for Water (KWB). KWB is a partner in the project ULTIMATE, which aims to generate new economic value from industrial wastewater. Their approach is to create a "Water-Smart Industrial Symbiosis" (WSIS), promoting water recycling in a wide range of industrial settings such as agro-food processing, chemical, beverages, and biotechnology. They aim to recover, refine and reuse industrial wastewater while extracting and exploiting its energy and materials. "For example, in Greece, we have a factory that produces fruit juices, and wastewater is a byproduct of the process. As part of the ULTIMATE project, a new technology is now being used to clean that wastewater and recover valuable compounds from it," says Kleyböcker. This not only gives a second life to wastewater but also increases industrial production quality since the juice producer is able to reuse these compounds in the production process.
DARROW is working on AI models that will make wastewater treatment plants more autonomous and energy efficient
According to Kleyböcker, integrating wastewater into industrial value chains requires new tools and open knowledge transfer. Artificial intelligence (AI), for example, is very promising among the up-and-coming technologies applied to this sector. Dr Ion Irizar, Senior Researcher at CEIT and project coordinator of DARROW, explains how AI can encompass a wide range of possibilities for wastewater management. Currently, DARROW is working on AI models that will make wastewater treatment plants more autonomous and energy efficient. "The objective is to build an ecosystem of distributed AI-based software components that interact and complement each other while providing individual functionality and adapting to the heterogeneity of wastewater treatment," says Irizar. By combining traditional mathematical models with AI reinforcement learning models, the project hopes to optimise certain wastewater treatment steps, considering different operational objectives such as water quality, chemical dosage and process safety. This will save energy, increase resource recovery, and reduce greenhouse gas emissions. Furthermore, incorporating these new tools into our current wastewater treatment process would generate higher-quality water that could be reused for multiple purposes, such as irrigation.
Water as a source of critical materials
A completely different approach to the exploitation of water’s potential is that of SEA4VALUE. The project is developing new technologies for the selective recovery of 10 different metals and minerals, such as magnesium and gallium, from seawater brines. "Many countries have suddenly realised that they lack raw materials and need a way to find them," explains Juan Arévalo, research and development manager at Aqualia, one of the SEA4VALUE partners. "Almost every country in the world has access to the sea, so why not extract all of those materials from the seawater instead of importing them?" he adds. One of their aims is to make desalination plants the third source of valuable critical raw materials in the European Union. However, their technology can also be applied to other industries. Although the project focuses on exploiting the recovery of resources from seawater, it is a clear example of how a circular approach to water treatment and exploitation can provide global and comprehensive solutions to multiple issues."If the project is successful, the desalination industry will transition to chemical and water factories in the future. We will be producing water that can be used for industry and irrigation while extracting valuable critical raw materials," Arévalo points out.
Combining these different approaches and technologies could be extremely beneficial for all global areas facing water stress, especially those that highly rely on imported fresh water, such as remote islands. The ability to get fresh water from the sea, use it for industry and then incorporate it into a closed water-recycling loop could be revolutionary. In short, developing new technologies to treat and exploit water will tackle its scarcity and availability, simultaneously contributing to developing new circular economy models. Nevertheless, new technologies and approaches still require testing and development before they're fully incorporated into our daily lives.