Using UV to get rid of acid

Laurens Maliepaard produces tulip bulbs in Stad aan ’t Haringvliet, the Netherlands. Laurens is the fourth generation in the family company, which has more than 100 hectares now. Like many other entrepreneurs in the sector, he is worried about acid: “In recent years it has become an increasing problem.”

Laurens: “Many factors play a part in the development of Fusarium. An important factor is the distribution by rinse water. That’s why a number of colleagues have stopped rinsing, but that’s not an option for us. Our customers demand their bulbs are rinsed, resulting in many challenges.”

That’s why the search was started for a method to safeguard rinse water against the traces caused by acid. The options of chlorine and ozone were extensively researched. “But in the end, UV seemed like the cleanest and simplest solution.”

UV was also researched. Laurens: “We’re dealing with 500 cubics per hour, so we needed a great number of UV sanitisers. It wasn’t very practical, and quite costly.” Laurens therefore entered into a cooperation with Hegro Agri Service and CleanLight. The goal was to develop a solid UV system that can be built into every diver in every rinse water basin in the Netherlands.

“That resulted in what we call ‘UV Racks.’ CleanLight calculated that we, in our particular case, have to build eight of these UV Racks in our rinse water basin to kill off the fusarium traces in our water flow of 500 cubics. And it works, reports from Eurofins confirm the fusarium pressure in our rinse water has decreased by 95 to 99 per cent.”

“Besides the UV, we also set up a rigorous programme for flocculants. Because of that, organic matter drops quicker in the basin. That also contributes to lower disease pressure. And that naturally makes the UV more effective, which is why Dutch drinking-water companies also use UV to guarantee the safety of clear Dutch drinking-water.”