Investigation of Pseudomonas aeruginosa removal from drinking water using photo-electrochemical method

Water disinfection by electrochemical methods is widely used in the recent years. The goal of this research is to investigate of Pseudomonas aeruginosa, as a source of nosocomial infection caused by waterborne bacteria, removal from drinking water by batch photoelectrochemical reactor using zinc-copper electrode and lamp emitting dynode UV-A lamp. In this study, the contaminated water sample was prepared through adding 102 and 103 P. aeruginosa per ml of drinking water. Different conditions were studied, including pH (6-8), number of bacteria (102-103 per milliliter), radiation time (7.5-45 min), lamp intensity (360-600 mW / cm2), distance between lamp and electrode (1.5 cm), and current density (3-9 mW / cm2). In electrochemical reactor, percentage of 103 bacterium / ml removal in distance 1.5 cm, current density 6 mW / cm2 and electrolysis time 7.5 min in pHs 6, 7, and 8 were obtained 95%, 96.5%, and 95.9%, respectively. In electrochemical reactor, percentage of 102 bacteria / ml removal in distance 1.5 cm, current density 6 mW / cm2 and electrolysis time 7.5 min in pHs 6, 7, and 8 were obtained 95.2%, 100%, and 100%, respectively. In photoelectrochemical reactor, percentage of 103 bacterium / ml removal in distance between lamp and electrode 1.5 cm, radiation intensity 600 mW/cm2, current density 6 mW / cm, and radiation time 7.5 min in pHs 6, 7, and 8 were obtained 96%, 100%, and 100%, respectively. In photoelectrochemical reactor, percentage of 102 bacteria / ml removal in distance between lamp and electrode 1.5 cm, radiation intensity 600 mW/cm2, current density 6 mW / cm2 and radiation time 7.5 min in pHs 6, 7, and 8 were obtained 100%, 100%, and 100%, respectively. The findings indicated that bacterium removal efficiency was increased with increasing current density, increasing radiation time, increasing lamp intensity, and decreasing number of bacteria.