Design and assessment of UV filters and slow sand for efficient nutrient recycling in closed soilless farming

Abstract

Recirculating the leachate in soilless farming systems may increase the efficiency of water and nutrient utilization. However,
untreated leachate includes root pathogens and particle debris that might clog drip emitters and endanger crop health if
reintroduced into the system. In order to improve the slow sand filter's effectiveness in eliminating root infections, an
ultraviolet (UV) filter was created as a supplement. In order to determine how well the UV filter removed pathogens—
specifically, Dickey zeae and Xanthomonas—from the leachate in a closed soilless cultivation system, the experiment was
carried out in 2019 and 2020 at Punjab Agicultural University in Ludhiana, Punjab. To assess the UV filter's effectiveness,
measurements were taken both before and after treatment 40 and 80 days after transplanting (DAT). The findings showed
that the raw leachate was significantly treated by a combination of UV and slow sand filters. The pathogen clearance
effectiveness was 94.8% at 40 DAT and 92% at 80 DAT. With a notable increase in the total removal efficiency of root
pathogens from the leachate, the results demonstrate the significance and efficacy of using the UV filter as an extra treatment
step in closed soilless cultivation systems.