WATER TREATMENT

Water’s role in a circular economy

Freshwater resources have been under extreme pressure in recent years. The primary cause of this is overconsumption, which

National Geographic, 2022

is made worse by the interconnected global crises of waste, pollution, climate change, and the loss of nature and biodiversity. In fact, the greatest industry for water use and one of the main contributors to water pollution is agricultural and food production. The FAO 2019 states that if current trends continue, global demand for water could increase by 50 per cent by 2030

As such, one of the key challenges today is to sustainability ensure water security across all sectors. The circular economy of water (CEW) is a proposed framework that presents strategies for sustainable water management. In general, and in all sectors, the circular economy aims at overcoming the traditional linear model of “take, make, consume, and waste” and substituting it by the circular model in which resources are maintained for as long as possible and used for different purposes (UNEP, 2024).

Blank, 2023

UNEP, 2024

As outlined in the UNEP Foresight Brief 033, the strategy shown is proposed in order to implement circularity in water management. The overarching strategy is a re-conceptualization of the need for water, or to simply “rethink”. In order to do so, redesigning procedures, policies, facilities, technologies, and behaviours to support a more circular use of water is required.

As part of the “decreasing” strategy, Avoid, Reduce and Replace are the main components. The term “avoid” implies a 100% decrease, which is difficult to attain. Some examples of waterless alternatives include vacuum flush toilets, dry wash sprays, and atmospheric-plasma technologies for clothes. Reducing can be achieved by using water-saving gadgets in homes, precise irrigation in agriculture, and less water-demanding industrial processes. Finally, water can be replaced by alternatives such as foam or compost toilets and the use of synthetic hydrocarbons in industrial operations for example.

Secondly, the “optimising” component covers three points: Reuse, Recycle, and Cascading. Reuse is the act of using water for the same or a different purpose again without treatment. On the other hand, recycle requires water treatment. Finally, the term “cascading” describes the sequential application of water for various goals, combining various techniques. For instance, steam from the generation of energy can be used for irrigation, cleaning, and cooling following treatment.

The “retaining” component is the third and last, and includes two points: Store and Recover. In human-managed systems, store refers to the process of moving spent water to reservoirs for later use. Examples include pumping water back into reservoirs to produce energy or storing it in tanks for greenhouses. Alternatively, to recover water means to take out valuable materials and turn it into energy. Nutrients, precious metals, gasses, and organic compounds can all be recovered using a variety of techniques and technology. Methane extraction, thermal energy recovery, and hydraulic power are examples of energy recovery techniques.

In general, businesses can implement various water management initiatives that observe Circular Economy principles, including water recycling and smart water systems. Greywater can be recycled for tasks that don’t need clean water (e.g. car washing or cooling). This reduces the quantity of unclean water that needs to be treated and released from a site as well as the demand for potable water. As for industrial water, it can be restored to a quality appropriate for reuse in their operations by means of physical and chemical treatment procedures. When done correctly, this can result in a closed-loop system that can considerably lower additional water consumption. Finally, smart water systems can be installed to detect issues in real time and take immediate action. They can also collect data to analyze trends and detect time-varying events, including spikes in water pollution.

IDOM has taken on a variety of water projects that adopt Circular Economy principles as part of their main objectives. For instance, networks are being implemented in a large scale in order to treat wastewater and reuse it in appropriate sectors such as firefighting, cooling, and possibly agriculture when the quality required is met.

Water should be acknowledged as a driver for action and advancement toward all Sustainable Development Goals. In addition to the European Water Framework Directive, Integrated Water Resources Management, and WASH, among other policies and strategies for sustainable water resources management, there have been growing efforts at the national, international, and global levels to support sustainable water management.

References:

[1] Circular Economy of Water: Definition, Strategies and Challenges | Circular Economy and Sustainability (springer.com)

[2] Water as a Circular Economy Resource – Foresight Brief No. 033 February 2024 | UNEP – UN Environment Programme

[3] Europe’s water crisis is much worse than we thought (nationalgeographic.com)

[4] Circular Economy Vs. Linear Economy (circulayo.com)

[5] Sustaining the flow: Water’s role in a circular economy (slrconsulting.com)

[6] Sustaining the flow: Water’s role in a circular economy (slrconsulting.com)