Vitens explores opportunities in advanced oxidation
Removal of vinyl chloride from a contaminated groundwater source
Removal of vinyl chloride from a contaminated groundwater source
Drinking water company Vitens is cautious when it comes to adopting new water treatment technologies , as they must be robust and reliable from the very first moment of application. Nevertheless, the Advanox system from Van Remmen UV Technology made a strong first impression during a pilot in Bilthoven. “It has proven to be highly effective against vinyl chloride. A promising foundation for further research.”
Vitens has been producing top-quality drinking water for many years, thanks to a carefully managed water treatment process and the use of the cleanest possible sources: groundwater. “Groundwater is naturally filtered through layers of soil and is often very clean,” says Martijn Tas of Vitens. “We then ensure, through methods such as sand filtration and membrane filtration, that any contaminants are removed or remain well within safety limits. If an abstraction site is seriously polluted, we look for a new source.”
This approach has been successful for a long time, since the Dutch drinking water is among the best in the world. Yet, Martijn Tas observes that the world is changing. ‘The available sources are decreasing, we’re increasingly facing water shortages and we’re seeing more and more contamination in groundwater. That means we have to look at alternative sources and certainly also at new water treatment technologies.’ A good test case for this was an abstraction well in Bilthoven. ‘There, we found concentrations of vinyl chloride, a carcinogenic substance, that were too high. This well has been disconnected from the drinking water supply and therefore poses no risk, but it offered an ideal experimental location for innovative technologies. In this case, advanced oxidation, in collaboration with Van Remmen UV Technology.
‘Advanced oxidation has the potential to greatly innovate the drinking water sector’, says Thomas van Remmen. ‘This technology has a low energy consumption, uses monochromatic light and causes no by-products. We were able to demonstrate that with our mobile water treatment system Advanox at the well in Bilthoven’. And it worked. ‘After some testing, we found the right settings in terms of energy and hydrogen peroxide usage. From there, the Advanox got to work:: breaking down the vinyl chloride in the water using a combination of UV-C light and hydrogen peroxide. A month later, we tested the water again and the results were excellent. The removal rate was over 95%. We weren’t surprised, as the Advanox is particularly well-suited to this type of application, where the water has a high UV transmittance.
Martijn Tas was also positively surprised. ‘We always find technologies that break down contaminants, instead of separating them, tricky. What by-product are left behind? But this introduction to advanced oxidation has been very positive. The results were good and the vinyl chloride was effectively oxidised.’ Thomas adds: ‘The contamination has been broken down and won’t return. It also doesn’t end up in the air or the sewage. With Advanox, it’s truly removed from the environment,’ Despite the strong results and a TCO of 4 cent per cubic metre, Vitens has chosen in this case to drill a new source to replace the well in Bilthoven. However, advanced oxidation remains firmly on the agenda for the coming years. ‘This experiment provides a solid foundation for further research and development.’
The aim is to follow up with a long-term test, says Martijn Tas. ‘This will allow us to monitor the results over time. In addition, we want to further research advanced oxidation in the so-called Living Lab-test, to assess whether this is a suitable technology for the production of drinking water from river water. Van Remmen UV Technology has been a pleasant partner, thanks to their in-depth knowledge of both the technology and its applications, as well as their flexible approach. Overall, it’s been a very positive introduction.’
Vitens
Bilthoven
Removal of vinyl chloride from a contaminated groundwater source
The Advanox Flex trailer