Uv-led Disinfection Optimization for Fungal Pathogen: A Comparative Study of Spore Inactivation and Photoreactivation

The presence of fungal spores in water systems represents a significant challenge for public health and water quality management. Traditional disinfection methods, such as chlorination and ozonation, have shown limited efficacy against fungal spores due to their high resistance and potential for reactivation. Ultraviolet (UV) radiation, particularly UV-LED technology, has emerged as a promising alternative, offering wavelength flexibility, enhanced energy efficiency, and environmental sustainability compared to conventional low-pressure mercury (LP-UV) lamps. This study evaluates the inactivation kinetics of Aspergillus niger and Penicillium sp. spores under UV-LED exposure at 265 nm and 280 nm, analyzing the required UV doses for achieving a 99% reduction (D₂ values) and assessing photoreactivation potential under post-treatment light and dark conditions. The results indicate that Penicillium sp. exhibits higher susceptibility to UV treatment but also a greater capacity for photoreactivation (up to 54% recovery under light exposure), whereas A. niger demonstrates greater resistance but lower reactivation potential. A marginal but notable increase in disinfection efficiency was observed at 280 nm compared to 265 nm, suggesting potential optimization strategies for minimizing energy consumption and operational costs. Furthermore, a comparative analysis between UV-LEDs and LP-UV lamps was conducted, highlighting key differences in required doses, energy efficiency, operational lifespan, and scalability. While LP-UV remains the standard for large-scale treatment systems, UV-LED technology offers mercury-free operation, longer lifespan, and wavelength tunability for targeting specific microbial contaminants. However, challenges remain in achieving sufficient intensity for continuous water treatment and addressing cost barriers for large-scale implementation. The study also explores the implications of photoreactivation across different water matrices, emphasizing that untreated potable water stored in open reservoirs or exposed to light may require additional protective measures. Future research directions include evaluating a broader spectrum of fungal species (Fusarium, Cladosporium, Alternaria), integrating UV-LEDs with advanced oxidation processes (AOPs), and optimizing reactor designs for improved inactivation performance.