International Journal of Microbiology and Immunology Research Vol. 3(2), pp. 011-019, March 2015 ISSN 2327-7769 ©2015 Academe Research Journals

Full Length Research Paper

Pseudomonas aeruginosa removal from water using electrophotocatalytic method

Kashi, Giti

Department of Environmental Health Engineering, Faculty of Health, Islamic Azad University, Tehran Medical Sciences Branch, Khaghani St, Shariati Ave, Tehran, Iran. E-mail: g.kashi@yahoo.com. Tel: +982122006667; Fax: +982122006666.

ABBREVIATIONS USED: AC - Alternative Current; AOPs - Advanced Oxidation Processes; BHI - Brain Heart Infusion; DCP - Dichlorophenol; EPC - Electrophotocatalytic; LED - Light Emitted Dynode; MPN - Most Probable Number; OD - Optical Density; OH˙ - Hydroxyl; O₂˙ - Superoxide Radical Anion; PCP - Pentachlorophenol; PECFC - Photoelectrolytic Fuel Cell; ROS - Reactive Oxygen Species; THMs - Ttrihalomethanes; TiO₂ - Titanium oxide; UV - Ultraviolet; Zn - Zinc; ZnO - Zinc oxide.

Accepted 11 February, 2015

Abstract

Application of electrophotocatalytic (EPC) methods for drinking water disinfection was broadly used in the recent years. These methods led to production of strong oxidant agents such ashydroxyl (OH˙) radical. The goal of this applied-analytical research was to investigate Pseudomonas aeruginosa as a source of nosocomial infection caused by waterborne bacteria, removal from urban drinking water by batch EPC reactor with usage of zinc oxide (ZnO) nanoparticles immobilized on zinc (Zn) sheet-copper electrode, and lamp emitting dynode (LED) ultraviolet-A (UV-A) lamp. The contaminated water sample was prepared by adding 10²-10³ cells of P. aeruginosa bacteria per ml of drinking water. The studied variables were pH (6-8), the number of bacteria (10²-10³ cells/ml), the lamp intensity (360-600 mW/cm²), radiation time (7.5-30 min), the distance between lamp and electrode (1.5 cm), layering of zinc oxide nanoparticles (1-3), and current density (3-9 mW/cm²). The results showed the correlation between removal of cells and UV-A lamp intensity, current density, and radiation time. Optimal removal (0) was obtained at pH 8, radiation time: 7.5 min, 2- layer of ZnO nanoparticles, and current density of 6 mW/cm². The findings indicated that removal efficiency was increased with increasing current density, radiation time, and lamp intensity.

Key words: Bacterium, lamp emitting dynode, electrophotocatalytic, nosocomial infection, Pseudomonas aeruginosa, urban drinking water.