European Urban Wastewater Treatment Directive
How UV technology can contribute to the EU's wastewater treatment targets

Ozon oxidation and UV advanced oxidation haven proven to be effective technologies for removal of micro-pollutants in wastewater. Because these technologies use (renewable) electrical energy and produce no waste, they have potential to help water utilities to reduce the CO2-footprint and reach their neutrality target.

We partner with UV professionals globally to create energy efficient UV systems at the lowest total costs of ownership. Integrating energy efficient UV drivers helps to reduce operational costs and carbon footprint, creating future proof UV systems.

Author: Olga Kruidhof
20 February 2024
Agreement on European Urban Wastewater Treatment Directive

On January 29th, the Council and the European Parliament’s negotiators reached a provisional political agreement on a proposal to review the urban wastewater treatment directive. The revised directive is one of the key deliverables under the EU’s zero-pollution action plan.

In the agreement, the co-legislators aligned the thresholds and timelines for quaternary treatment (the removal of a broad spectrum of micro-pollutants). By 2045, Member states will have to ensure the application of quaternary treatment in larger plants of 150,000 population equivalent and above, with intermediate targets in 2033 and 2039 for quaternary treatment.

Energy neutrality and renewables

The co-legislators also agreed that the urban wastewater treatment sector could play a significant role in significantly reducing greenhouse gas emissions and helping the EU achieve its climate neutrality objective. They introduced an energy neutrality target, meaning that by 2045 urban wastewater treatment plants will have to produce energy from renewable sources, based on regular energy audits, with progressive intermediate targets. This energy can be produced on or off-site, and up to 35% of non-fossil energy can be purchased from external sources. This percentage only applies to the final target.

Designing systems with optimal electrical efficiency has always been our focus. Now it’s even more relevant because of the sustainability ambitions of governments.

Bart Bouwhuis
Electronic design engineer Nedap
Energy efficiency in water management

Energy efficiency is increasingly important for governments and industries. It is seen as the first building block for any energy strategy and stated in the COP28 declaration. In Germany, wastewater treatment facilities currently account for 20% of energy consumption, making them the biggest municipal energy consumers (source: FONA). In the coming decades, a further shortage of conventional energy sources and an increase in energy costs can be expected. Increasing energy and resource efficiency in water management is therefore of crucial importance worldwide.

Advancements in oxidation technologies

The opportunity for advanced oxidation processes (AOPs) in water and wastewater treatment is growing concurrently with the increasing drive towards water reuse and stricter regulations for wastewater discharge. This brings AOPs to the forefront of dealing with new treatment challenges.

Leading the way

With more than 16,000 publicly owned wastewater treatment systems, the United States forms a large potential market for UV vendors. The industry is familiar with UV-hydrogen peroxide treatment due to several decades of experience. UV treatment coupled with the addition of hydrogen peroxide is the most commonly employed AOP for municipal water and wastewater, either for drinking water or municipal water reuse. This is due to the simple fact that it often comes out as the most cost-effective solution. The UV/hydrogen peroxide combination has been installed in major treatment plants since the early 2000s, with the 2008s Orange County, CA being the first ‘toilet-to-tap’ treatment plant in the USA.

Combining technology increases effectiveness and efficiency

Ozon oxidation and UV advanced oxidation have proven to be effective technologies for removal of micro-pollutants in wastewater. Because these technologies use (renewable) electrical energy and produce no waste, they have potential to help water utilities to reduce the carbon footprint and reach their neutrality target. Several pilots have been conducted to compare the carbon footprint (meanly energy costs) of UV peroxide oxidation and ozonation with other technologies, like Granular Activated Carbon (GAC) or Powdered Activated Carbon in Activated Sludge (PACAS).


> Image: The MicroForce++ technology combines ozonation and biological oxidation and has a removal efficiency of 80%, low carbon footprint and low cost per m3 treated water.

Customization being the standard

The pilots and full-scale applications have set a clear rule: there is no one size fits all approach. The make-up of streams that require treatment varies wildly from industry to industry (and sometimes between streams in one facility) and technology application requires large amounts of customization. Full scale pilot studies do show that when combining filtration technologies with ozonization or an AOP step with UV and hydrogen peroxide, the removal efficiencies greatly increase. This results in high quality water that for example can be reused in the industrial processes.


> Image: The Ozone treatment technology of MicroForce shows that the total CO2 footprint only slightly increases compared to the reference situation without post-treatment, and that this increase is almost entirely due to the energy required to generate and introduce the ozone.

Lower CO2 Footprint of UV Treatment

Dutch research conducted by Witteveen + Bos (2023) showed that UV peroxide oxidation technology can have a lower or comparable environmental impact in certain cases compared to activated carbon and ozonation. This is highly dependent on the UV transmission of the wastewater. Higher transmission means lower energy consumption. In case of low transmission, the wastewater can be pretreated with a sand filter and flocculation.


> Image: The Advanox AOP system combines UV-C light with hydrogen peroxide to effectively break down micro-pollutants. The CO2- footprint primarily consists of the required electronic energy. This consumption is the smallest when the water has high transmission values (70% T10); then the technology works most efficiently, and the CO2 footprint is lower compared to other technologies. If renewable energy is also utilized, the impact decreases even further.
Source: (Sept. 2023)

How Nedap UV driver technology helps to reduce energy consumption

Within the proven UV technology, there are two main streams: low-pressure and medium-pressure systems. Low-pressure UV systems are more energy-efficient compared to the more compact medium-pressure systems. By accurately and smartly controlling the large, multi-lamp systems, the system can become even more energy efficient. The electrical efficiency of the UV lamp drivers also makes a difference.  This is exactly what distinguishes Nedap driver technology.  


> Image: St Anthony Village is the 35th public water system in North America to specifically treat 1,4 Dioxane using Advanced Oxidation with UV-Peroxide. The six (6) Trojan UVPhox Reactors each contain 144 low-pressure high-output UV lamps. The overall system can remove more than 99% of 1,4 Dioxane at Peak Flow Conditions of 3,000 GPM. Source: (August 2017)

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