Optimalisatie filtratie : Voorkomen en bestrijden emissies kasteelten 2 (WP2)

Summary

Rinsing water from filtration systems is one of the issues hampering zero emission cultivation in greenhouse horticulture. A screening at 20 growers has shown that water quality is very much depending on the cultivation system and type of growing medium used. It was shown in pilot tests that multiple step filtration with a fine final filtration step (3 – 10 μm) could improve water quality. Applied filters were not absolute filters. By means of two demonstration tests at growers the long term effect of these multiple step filtration systems were tested. From the results it can be concluded that fine filtration improved water quality. The applied method for dealing with rinsing water also proved valuable. It proved difficult to substantiate visual observations with measurements: measurement of particle size distribution did not always show a clear difference before and after filtration. Also measurement of TSS (total suspended solids) were not uniform. Improved filtration should lead to enhanced efficiency of disinfection equipment, based on UV or ozone. However, dissolved particles that have a large effect on the disinfection efficacy, are not removed by the applied filtration technologies. Enhanced functioning of this equipment could therefore not be underpinned.