Industrial Water Reuse: A Circular Approach To Solve The Water Crisis

As the planet temperature increases more and more, water will become the holy grail of the future for millions of people. Although the clock is ticking, we don’t need to reinvent the wheel. In this article, we’ll dive into a well of circular solutions designed to recover and reuse industrial water. Before tapping into these, let’s see why we need immediate action for industrial water reuse.

The climate-driven water crisis

Prolonged drought is one of the major climate changes caused by the increased CO₂ concentration in the atmosphere. This is depleting water reserves in many parts of the globe, especially in the Mediterranean region.

For instance, in February 2024 Spain declared a state of emergency and imposed water restrictions in Catalonia after reservoir water levels dropped to below 16% of their capacity. Also, the country was forced to import drinking water from Valencia and Marseille. Sicily has been in the same hot waters, with people grappling with shortages for over 6 months. Not to mention the damages to agriculture, estimated to be €2.7 billion in 2024. On the other hand, the agri-business is also a major cause of water scarcity. Farming is responsible for nearly 70% of all water withdrawals. This rises up to 95% in some developing countries.

A new study found that drought in Sicily was made 50% more likely by global warming. Unfortunately, the future trends are not encouraging. According to a recent report, nearly half of the world faces water scarcity for at least one month a year by 2050.

Industrial activities are exacerbating water shortages. In 2020, industry was responsible for 45% of freshwater withdrawals in the EU, 47% in the USA and 76% in Canada, against a global average of 15%. Within the EU, the figure rose to 81% in Belgium and 92% in Estonia. Therefore, along with minimising leaks across the water network, engineers must find more efficient solutions to recover and reuse industrial water.

Turning Industrial Wastewater Into A Resource

Industry is a major global water stressor, using huge volumes in processes such as cleaning, cooling and rinsing. Other unused sources of water include often-contaminated groundwater and wastewater treatment plants (WWTPs) effluents, which need to be purified in order to be used.

Industries may be able to reuse treated water from sources including: WWTP effluent; industrial processes, condensation, cleaning and rinsing; cooling; and groundwater.

The following impurities are typically found, and require treatment before the water can be reused:

• Process water: COD, BTEX, PAH, AOX
• Rinsing water: COD, detergents, soaps
• Cooling water: COD, residual oils
• Condensation water: Residual solvents
• WWTP effluent: COD, micropollutants
• Groundwater: COD, BTEX, PAH, AOX

The case for industrial water reuse

Investing in industrial water reuse is becoming critical for many sectors for several reasons:

• First of all, industrial water reuse boosts circularity and sustainability, reducing the pressure on the local environment. This in turn improves a company’s reputation among neighbours and customers.
• Besides the obvious benefits for the planet, this practice allows plants to continue operations during times of drought and restrictions, when drinking water supplies become prioritised for human consumption and pumping in nearby rivers is restricted. This ensures companies can continue to operate safely and at their usual standards of cleanliness, avoiding costly production downtime.
• Finally, with the Water Reuse Regulation and other legislations being enforced, a robust industrial water reuse system is becoming an important future-proofing measure for many firms.

Typically, the end-use of treated water is the same as its original source, e.g. process water is reused in industrial processes, and water from cooling reactors is recycled for the same use. In addition to that, other potential applications comprise metal quenching, steam production, cooling reactors and/or effluents, washing of facilities, stockpiles of extinguishing water, cleaning of vehicles and equipment, irrigating soil, and removing dust.

Industries that are large water consumers, such as the paper industry or the food industry, are already looking into these industrial water reuse solutions to become more resilient in the future.

The key role of water purification

Industrial water reuse can be safely pursued as far as wastewater is treated via an adequate purification method such as activated carbon filtration.

Often, activated carbon filtration is used as a polishing step after existing WWTPs. Sometimes, sand filters are placed before the filters to remove suspended solids, which could cause blockages in carbon filters.

Activated carbon filtration is BAT for removing many of the typical pollutants found in industrial wastewater to be purified for reuse, such as COD, BTEX, PAH, AOX, detergents and PFAS to name a few.

PFAS have been in the spotlight over the last few years. Because of their outstanding persistence, these compounds are literally everywhere. Not surprisingly, they’ve been nicknamed as “forever chemicals”. Nevertheless, activated carbon-based filtration solutions proved to efficiently remove PFAS (including the long-chain perfluorooctane sulfanate (PFOS)) from wastewater and groundwater, thus potentially making the water effluent suitable for industrial reuse.

Conclusions

With extreme drought becoming second nature on a climate-altered planet, industry players have the onus of leading the way in implementing water saving and reuse strategies.

Harnessing DESOTEC’s purification technology is an efficient solution to upcycle wastewater into a supply of freshwater for the public while providing companies with an invaluable stock to avoid production shutdown during long dry spells.

Adopting this circular route can water down the effects of water scarcity.