Combination of hydrogen peroxide with low UV radiation offers best return on investment

The Wageningen University & Research Centre (WUR) for Greenhouse Horticulture in the Netherlands has examined four methods of water purification for use in greenhouse horticulture. Three of these methods remove 80 to 100% of pesticides from discharge water. The tests showed that hydrogen peroxide combined with low pressure UV radiation offers the best return on investment.

New environmental targets

The motivation for the research was that the Dutch government and horticultural sector (i.e. the Platform for Sustainable Horticulture) have agreed on new environmental targets. These agreements were made because the concentrations of pesticides found in surface water are still too high. The horticultural sector faces a huge challenge if it is to meet the new targets set out in the 'Agricultural Activities Decree', which came into effect on 1 January.

Water purification methods

The Water Innovation and Demonstration Centre of WUR Greenhouse Horticulture examined a number of purification methods for their effectiveness and suitability in the horticultural sector. Various suppliers provided the systems for testing. These systems used the following purification methods: (1) Ozone with and without active carbon filter, (2) Hydrogen peroxide + low pressure UV radiation, (3) Hydrogen peroxide + medium pressure UV radiation and (4) Electrochemical flocculation. Testing was done at a semi-practical scale with Standard Water. This was standardised greenhouse discharge water containing normal amounts of fertilisers, pollutants and twelve pesticides. The research also compared this water with the discharge water from a rose nursery.

Purification efficiency

HortiMaX supplied the HortiMaX Vitalite H2O2 for the tests. This purification system breaks down the pesticides in the water by activating hydrogen peroxide (H2O2) with low pressure UV radiation. The tests showed that this method achieves an average purification efficiency of 80%, and an even higher level of efficiency for some substances. Of the three purification methods shown to be effective, the HortiMaX Vitalite (using hydrogen peroxide and low pressure UV radiation) has the lowest annual costs, making it the best return on investment.