Sustainable Disinfection of Horticulture Industry Water Using UV-C Light-Emitting Diodes

The development of effective water disinfection treatment processes will be crucial to help food producers save water and cope with the inevitable challenges resulting from increases in human population and climate change, while promoting sustainable agriculture. The inactivation efficiency of UV-C light emitting diodes (LEDs) that emit light at 280 nm was tested as a disinfection method. Water samples from a horticulture industry were collected and characterized in terms of total microorganisms, total coliforms, Escherichia coli and enterococci as well as parameters that influence photolysis such as the percent transmittance of the irrigation water (that, due to the nutrients added for plant growth, was extremely low and varied between 40 and 55%). Nevertheless, laboratory scale results showed that three single small UV LEDs that emit light at 280 nm were extremely efficient for the inactivation of microorganisms present at occurrence levels in the irrigation water samples, as well as Phytophthora capsici and Escherichia coli spiked in sterile distilled water and filtered irrigation water samples. Overall, the findings demonstrate that UV-C LEDs operating at 280 nm represent a promising sustainable disinfection strategy for modern food production systems facing tightening environmental and public-health pressures.