There is a European program Interreg Vlaanderen-Netherlands (2014-2020) regarding “RECirculatie zonder Uitspoeling of Puntlozing tijdens de opkweek van Aardbei” shortly named RECUPA. Translated Recuperation of water without draining water during the growth of strawberries.

As of 01/01/2021 each strawberry grower needs to capture the first 100 m³ of water and reuse it. Therefore disinfection is necessary. In Belgium there are 502 strawberry growers active.

The project has a goal of developing a circular watersystem for strawberries to make the drainwater of the trayfield suitable for fertigation. A part of the project is the evaluation of different disinfection techniques to make recirculation of water feasible. Proefstation Hoogstraten (PH) and Proefstation Groente teelt Sint-Katelijne Waver (PSKW) are working together on this project. PSKW: testing will be done from different disinfection techniques on the cultivation of Lettuce as this culture also has big volumes of water with low transmission (comparable to strawberries).

Proefstation Groente teelt Sint-Katelijne Waver:

Proefstation Hoogstraten: will test on the trayfields on strawberries:

The projects runs over a period of 3 years (2019 – 2021). Each year certain techniques will be tested:

ProMinent participated in the testing by supplying to PSKW a M&C panel for peroxide (with the new testing probe Perox H -3 E-mA 50ppm and a pure chlorine unit.

Proefstation Groente teelt Sint-Katelijne Waver: The techniques that have been evaluated are:

• Ultrafiltration
• H₂O₂
• UV
• Pure Chlorine unit from VDH
• Ozone

The system set up is like:

Proefstation Groente teelt Sint-Katelijne Waver did the testing without our M&C and just flow proportional. They discovered they had a lot of issues in getting the required value of H₂O₂ .

Afterwards they connected the dosing pump to our online measurement and the concentration was constantly controlled and measured. Good results towards concentration were obtained. PSKW evaluated our M&C and H₂O₂ probe as a necessary tool when dosing of is H₂O₂ considered.

                             Pure Chlorine Unit

VDH has developed a pure chlorine unit:

It works as a C-V but all NaOH is going to the drain or used for other purposes. Na⁺ is toxic for certain fruits and vegetables and therefore cannot be dosed into the water.

Results of the pure chlorine unit have been proven by a company called Karo in the Netherlands. They have some units running with excellent results towards disinfection and chlorate levels. As the treated water is at the optimum pH range they state no chlorate is being formed in the water that has been treated.

Proefstation Groente teelt Sint-Katelijne Waver tested it and they analyzed on chlorate and NO chlorate was detected in the water.

Results were much better than for instance UV:

Final report will be available at the end of this year normally and will be shared with ProMinent.

Next steps for the future

Proefstation Groente teelt Sint-Katelijne Waver will send the official and final report from their testing by the end of this year

Proefstation Hoogstraten needs to continue the tests.

The peroxide testing was not effective as they did not link it to a measurement. The M&C panel will be delivered to PH for a new test round.

Proefstation Hoogstraten will also evaluate our Pure Chlorine unit and if possible integrate it in the testing for 2020.

Testing facility at Proefstation Hoogstraten: