Industrial Wastewater Is More Than Waste

Traditional industrial wastewater treatment follows a straightforward principle: remove pollutants and ensure that the treated water meets discharge requirements.

But there is another question worth asking:

Where do the pollutants go after they are removed?

In many cases, they do not simply disappear. Instead, they are transferred from the water into sludge, sediment, concentrated streams, or other residuals.

This means industrial wastewater treatment is not necessarily only about consuming energy, chemicals, and equipment to eliminate pollutants. As resource scarcity, energy demand, and environmental pressures continue to grow, a different approach is gaining attention:

Can valuable materials be recovered while pollutants are being treated?

This concept is known as resource recovery.

1. A New Case: Recovering Copper from Industrial Wastewater

In August 2026, the international academic journal Nature Sustainability published a study on copper recovery from industrial wastewater. The researchers used a sulphur-mediated electrochemical technology to selectively extract copper from real industrial wastewater and recover it as high-purity metal. More notably, the process could also generate net electricity.

Copper is a good example of the changing role of industrial wastewater pollutants.

Copper can enter wastewater from industries such as electroplating, electronics manufacturing, PCB production, metal processing, and mining. From an environmental perspective, copper is a pollutant that needs to be controlled. From a resource perspective, however, it is also a valuable metal that can potentially be recovered and reused.

The same substance can therefore have two very different identities:

It is a pollutant from an environmental perspective, but a resource from a recovery perspective.

This is what makes resource recovery particularly interesting.

Traditional treatment focuses on removing pollutants. Resource recovery takes the next step by asking how those materials can be captured and put back to use.

The new study does not mean that every copper-containing wastewater stream can already be treated using the same technology at commercial scale. Instead, it highlights an important direction for the industry: pollution control and resource recovery do not necessarily have to be separate processes.

2. What Else Can Be Recovered from Industrial Wastewater and Sludge?

Copper is only one example.

Industrial wastewater and sludge can contain a much wider range of potentially recoverable resources. Research into industrial wastewater resource recovery has explored metals, nutrients, sulphur, hydrogen, heat, and other valuable components.

Metals: Copper, Nickel, Zinc and More

Metals are among the most obvious targets for resource recovery from industrial wastewater.

Electroplating and metal-processing wastewater, for example, may contain copper, nickel, zinc, chromium, and other metals. Depending on their concentration and chemical form, different treatment technologies can be used to separate, concentrate, and recover them.

Once these metals are transferred into sludge, the sludge itself may also become a secondary resource. Research has explored the selective recovery of metals such as copper, nickel, and chromium from electroplating sludge.

This changes the way industrial sludge can be viewed.

Rather than being simply a waste product requiring disposal, sludge from certain industrial processes may also serve as a secondary source of valuable metals.

3. Phosphorus and Nitrogen: Turning Nutrients into Resources

Beyond metals, nutrient recovery is another important area of wastewater resource recovery.

Phosphorus is essential for agriculture and is also an important pollutant that needs to be controlled in wastewater treatment. Recovering phosphorus from wastewater or sludge and converting it into useful products could address two challenges at once – reducing the nutrient load released into the environment while reducing dependence on virgin resources.

Researchers are exploring a range of approaches, including chemical precipitation, crystallisation, and other separation technologies.

Nitrogen presents a similar opportunity. Conventional wastewater treatment generally focuses on converting and removing nitrogen from the water. Resource recovery takes a different perspective by exploring how nitrogen can be captured in forms that can potentially be reused.

The question is therefore changing from:

How do we remove nitrogen and phosphorus?

to:

How can we recover and reuse them?

4. Organic Matter: Sludge Can Also Be an Energy Resource

Resource recovery is not limited to materials that can be physically extracted and reused.

The organic matter contained in sludge can also be a valuable resource.

Through anaerobic digestion, microorganisms break down organic matter and produce biogas. The resulting biogas can then be used for electricity generation, heating, or further upgrading into renewable natural gas.

This is one reason why modern sludge treatment is increasingly moving beyond simple sludge disposal towards integrated sludge management and resource recovery.

In this process chain, sludge thickening and dewatering remain important steps.

5. Resource Recovery Is More Than Simply “Taking Something Out”

It may be tempting to think that if industrial wastewater contains valuable materials, the solution is simply to extract them.

In reality, resource recovery is much more complicated.

The feasibility of a recovery process depends on factors such as concentration, recovery efficiency, product purity, energy consumption, chemical requirements, and the economic value of the recovered material.

A substance may technically be recoverable without being economically worthwhile to recover.

For example, if a metal is present at a very low concentration while the recovery process requires significant amounts of energy and chemicals, conventional treatment may still be the more practical option.

The real question is therefore not simply:

Can it be recovered?

It is:

Can it be recovered efficiently, economically, and sustainably?

This will be one of the key factors determining whether resource recovery technologies can achieve wider commercial adoption.

6. Where Does Sludge Dewatering Fit into Resource Recovery?

Resource recovery is rarely achieved through a single piece of equipment. It is usually part of a larger treatment chain.

Industrial wastewater may undergo pretreatment and solid-liquid separation, generating sludge containing organic matter, metals, nutrients, or other compounds. Depending on the characteristics and intended use of the sludge, it may then go through thickening, dewatering, anaerobic digestion, drying, incineration, or further resource recovery processes.

This is where sludge dewatering becomes important.

Although dewatering is not necessarily the final stage of resource recovery, it can be an important link between sludge treatment and downstream resource utilisation.

By reducing water content, an effective sludge dewatering system can reduce the volume of material requiring transport and storage, increase solids concentration, and create more favourable conditions for subsequent treatment.

This can be particularly important for industrial sludge, as sludge characteristics vary significantly between industries. Metals, organic matter, and other potentially valuable components may also become concentrated in the sludge.

The value of sludge dewatering, therefore, is not simply about “making sludge drier”.

It is also an important volume reduction and conditioning step within the broader sludge management and resource recovery process.

7. The Next Step in Industrial Wastewater Treatment: From Treatment to Recovery

When conventional wastewater treatment is compared with resource recovery, the difference is more than technological. It is also a change in perspective.

Traditional treatment focuses primarily on removing pollutants and safely managing the resulting waste.

Resource recovery adds another objective: recovering and reusing valuable components while meeting environmental requirements.

The resources recovered from wastewater may include far more than water. They can include:

Metals, nutrients, energy, organic matter, and heat.

As this approach develops, wastewater treatment facilities may gradually evolve from conventional pollution control plants into resource recovery facilities that produce clean water, energy, and other useful resources.

The recent research into copper recovery from industrial wastewater is one example of this broader shift. It raises an important question for the future of the industry:

Can wastewater treatment move beyond removing pollutants to recovering more of what has value?

8. Haibar: Supporting More Efficient Sludge Management

Resource recovery requires the different stages of a wastewater treatment system to work together, and efficient sludge management is an important part of this process.

As a manufacturer of sludge dewatering equipment, Haibar provides belt filter presses and screw presses for municipal wastewater and industrial wastewater treatment applications.

By reducing sludge water content and volume while improving downstream handling efficiency, effective sludge dewatering can help wastewater facilities reduce the burden of sludge handling and transportation, while creating better conditions for subsequent digestion, drying, and resource recovery processes.

Sludge dewatering may not be the final destination of resource recovery, but it can be an important step towards turning waste treatment into resource utilisation.

What Are We Throwing Away?

Industrial wastewater treatment is undergoing an important shift in perspective.

In the past, the primary question was how to remove pollutants from wastewater. Increasingly, another question is emerging:

How much value remains in the materials we remove?

Copper can become a recovered metal. Phosphorus and nitrogen can become recovered nutrients. Organic matter can become a source of energy. And sludge itself can serve as a secondary resource containing potentially valuable materials.

Resource recovery will not replace pollution control. Instead, it adds another layer to wastewater treatment – finding opportunities to recover useful resources while meeting environmental requirements.

The future of wastewater treatment may not simply be about removing more, but about recovering more, reusing more, and creating more value.

From pollutants to resources, this may be the next major step in the evolution of industrial wastewater treatment.

Ready to improve your sludge management?

Talk to Haibar about a sludge dewatering solution tailored to your application.