title: Solar disinfection of Pseudomonas aeruginosa in harvested rainwater: a step towards potability of rainwater.
abstract: Efficiency of solar based disinfection of Pseudomonas aeruginosa (P. aeruginosa) in rooftop harvested rainwater was evaluated aiming the potability of rainwater. The rainwater samples were exposed to direct sunlight for about 8-9 hours and the effects of water temperature (°C), sunlight irradiance (W/m2), different rear surfaces of polyethylene terephthalate bottles, variable microbial concentrations, pH and turbidity were observed on P. aeruginosa inactivation at different weathers. In simple solar disinfection (SODIS), the complete inactivation of P. aeruginosa was obtained only under sunny weather conditions (>50°C and >700 W/m2) with absorptive rear surface. Solar collector disinfection (SOCODIS) system, used to improve the efficiency of simple SODIS under mild and weak weather, completely inactivated the P. aeruginosa by enhancing the disinfection efficiency of about 20% only at mild weather. Both SODIS and SOCODIS systems, however, were found inefficient at weak weather. Different initial concentrations of P. aeruginosa and/or Escherichia coli had little effects on the disinfection efficiency except for the SODIS with highest initial concentrations. The inactivation of P. aeruginosa increased by about 10-15% by lowering the initial pH values from 10 to 3. A high initial turbidity, adjusted by adding kaolin, adversely affected the efficiency of both systems and a decrease, about 15-25%; in inactivation of P. aeruginosa was observed. The kinetics of this study was investigated by Geeraerd Model for highlighting the best disinfection system based on reaction rate constant. The unique detailed investigation of P. aeruginosa disinfection with sunlight based disinfection systems under different weather conditions and variable parameters will help researchers to understand and further improve the newly invented SOCODIS system.
authors.affiliation: Alamoudi Water Research Chair, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Muhammad T
authors.initials: MT
authors.lastname: Amin
authors.affiliation: Alamoudi Water Research Chair, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Mohsin
authors.initials: M
authors.lastname: Nawaz
authors.affiliation: Department of Civil and Environmental Engineering, College of Engineering, King Faisal University, Al-Hofuf Al-Ahsa, Kingdom of Saudi Arabia.
authors.forename: Muhammad N
authors.initials: MN
authors.lastname: Amin
authors.affiliation: Civil and Environmental Engineering Department, Seoul National University, Shinrimdong, KwanakGu, Seoul, South Korea.
authors.forename: Mooyoung
authors.initials: M
authors.lastname: Han
mesh_terms: D004203:Disinfection / Q000379:methods*; D060766:Drinking Water / Q000382:microbiology*; D007700:Kinetics; D008954:Models, Biological; D011093:Polyethylene Terephthalates; D011550:Pseudomonas aeruginosa / Q000528:radiation effects*; D011891:Rain / Q000382:microbiology*; D013472:Sunlight
chemical_list: D060766:Drinking Water; D011093:Polyethylene Terephthalates