Calcination-modified zeolite filtration and UV disinfection for contaminant Mitigation in groundwater

Abstract

Access to safe drinking water is a pressing global concern, necessitating innovative purification methods. This study investigated the efficacy of combining calcination-modified zeolite filtration with ultraviolet (UV) disinfection to mitigate microbial contamination in raw groundwater. A comparison was made between the treatment system employing calcination-modified natural zeolite and the system utilizing natural zeolite without modification. Results from isotherm and kinetic modeling revealed enhanced adsorption behavior and mechanisms in modified zeolite compared to its natural counterpart, leading to improved adsorption capacity and kinetics. Enhancements in removal efficiencies were observed for contaminants such as zinc, cadmium, and manganese, with increases from 30.25 % to 67.5 %, 55.75 %–82.75 %, and 64.04 %–69.52 %, respectively. Similarly, enhanced removal efficiencies for organic contaminants like phenol and cyanides were noted, rising from 59.99 % to 73.26 % and 59.22 %–65.05 %, respectively, with the modified zeolite. Furthermore, filtration with both natural and modified zeolites coupled with UV disinfection substantially reduced microbial contamination levels in raw groundwater, with total coliforms decreasing from 2245 CFU/mL to 8 CFU/mL post-filtration and UV treatment. Notably, surface area increased from 60 m2 /g to 220 m2 /g, and pore volume increased from 0.15 cm3 /g to 0.8 cm3 /g for modified zeolite. These findings underscore the potent antimicrobial efficacy and improved adsorption performance of the combined approach, contributing to advancing water purification technologies and addressing critical global health challenges.