Regulations and societal pressure force the greenhouse industry to come with solutions for discharge of PPPs. Next to developments towards completely closed, zero-discharge production systems, the potential is investigated of technologies from the water purification industry for short term application in horticulture for purification of discharge water.
Promising technologies are first tested with standardised horticultural discharge water (‘Standardised Water’) with a total concentration of PPPs of 26µg/L.
Advanced oxidation technologies like H2O2 combined with low pressure UV or with middle pressure UV, ozone in combination with low pressure UV and the combination of ozone, H2O2 and low pressure UV are technically able to break down a large part of the PPPs: 80-98%, depending on settings and treatment mode.
Equal results are achieved at 10 times higher concentrations of PPPs; if the concentration is however increased 100 times (this is worst case!), the effectiveness of H2O2 – UV combinations decrease a couple percent.
Treatment with ozone combined with an activated carbon filter at short loading times of the filter achieves >99% purification, also for increased PPP concentrations.
An endurance test is being performed to find the filters’ loading times with Standardised Water before efficiency drops and the filter needs to be replaced. This will have consequences for the cost price of the technology.