By Dorte Larsen, AAU Communication and Public Affairs

The pharmaceutical industry uses water when producing medicines, and large dairy chains use water in their production chain. The same applies to hospitals, fish factories, and the chemical industry. Even though the amount of industrial wastewater in Denmark is decreasing, companies are still faced with a problem: What measures should Danish manufacturing companies take to manage the remaining wastewater after production has ended?

One of the key challenges is the growing requirement for companies to treat their wastewater on-site prior to transferring it to municipal treatment plants.

Another significant challenge is the high water consumption of manufacturing companies. Denmark faces a resource limitation, as clean water is not an unlimited commodity. This issue is becoming even more pressing with the growing demand for clean water from emerging industries such as Power-to-X plants and data centers. As companies seek solutions, they are likely to face increased costs, not only for advanced technologies capable of purifying water more efficiently, but also for the procurement of additional clean water supplies.

Complicated production processes and complicated wastewater
Some companies, such as pharmaceutical and chemical companies, typically have complicated production processes and experience greater challenges with their wastewater. The complexity of modern production processes leads to wastewater composed of diverse and often challenging elements, necessitating advanced and targeted treatment methods.

In addition, companies have the cost of purchasing raw materials, a residue of which ends up in the wastewater. That's why Aalborg University is working on a solution to recover clean water and resources from wastewater.

Membrane technology could be the solution
At Aalborg University, researchers are actively developing various membrane technologies. Among these, membrane distillation shows particular promise for industrial wastewater treatment, as it is capable of meeting most water purification requirements.

With the use of this treatment technology, more than 90 percent of clean water can be achieved.

The technology makes it possible to separate the components of the residual concentrate so that lithium, phosphorus, and other valuable minerals from the wastewater can be collected and recovered. The water can also be recycled and reused in production.

The high treatment efficiency also means that the company will be able to meet the stricter requirements set by the municipal wastewater treatment plants.

Although it will be an expense for industrial companies to introduce membrane distillation, there will be money to save on, e.g., the purchase of raw materials, and the cost of high-water consumption can be reduced.