COMPARISON OF SOME CHEMICAL AND NON-CHEMICAL TREATMENTS TO DISINFECT A RECIRCULATING NUTRIENT SOLUTION
Closed hydroponic growing systems have a better water use efficiency (WUE) and a lower use of fertilizers, but a larger risk of spreading soil-borne pathogens all over the crop compared to open systems. In climates or regions where availability of water is limited closed systems should be preferred above open systems but the risk of spreading soil-borne pathogens should be minimized. Disinfection of the nutrient solution is a valuable method, but it often demands high investments. A desk study was made to compare the performance of some chemical and non-chemical treatments. For larger companies (>2 ha) heat treatment and UV radiation are still the best options. For smaller companies (<1 ha) slow sand filtration is a good option. Ozone and membrane filtration are good methods but expensive. Sodium hypochlorite (NaOCl) and hydrogen peroxide are cheap methods, but performance against pathogens is poor. They can be better used to sanitize pipe lines and equipment. Chlorine dioxide may be a promising method but little is known about dosage-effect relations against pathogens. Besides, safety measures and environmental restrictions may limit the use of this method. Investigations should be extended. Copper/silver ionisation and active carbon are not methods to be used for disinfecting the solution. Performance against pathogens is poor.
van Os, E.A. (2009). COMPARISON OF SOME CHEMICAL AND NON-CHEMICAL TREATMENTS TO DISINFECT A RECIRCULATING NUTRIENT SOLUTION. Acta Hortic. 843, 229-234
closed system, hydroponics, hydrogen peroxide, sodium hypochlorite, water use efficiency, disinfection, slow sand filtration, UV radiation