Predicting the bactericidal efficacy of solar disinfection (SODIS): from kinetic modeling of in vitro tests towards the in silico forecast of E. coli inactivation

Regression models for predicting the die-off rate of E. coli in solar water disinfection

“…The result of the regression model shows that there is a strong linear relationship between SODIS treatment efficiency, on the one hand, and 5-h average midday UV intensity and maximum water temperature, on the other hand. A similar degree of correlation has been reported in recent studies that regressed the cumulative die-off rate of E. coli with irradiance and water temperature (Brockliss et al 2022;Samoili et al 2022). However, the values of VIF show that UV intensity and water temperature cannot be successfully combined in a single least-square regression model because of the strong correlation between the parameters.…”

“…Production of ROS can be enhanced by increasing the dissolved oxygen concentration of SODIS water through vigorous shaking of partially filled containers before topping to full volume (Reed 1997). Temperature kills microorganisms by its pasteurizing effect that denatures cell proteins and inhibit DNA repair mechanisms (McGuigan et al 1998;Samoili et al 2022). SODIS does not work well in highly turbid water (.30 NTU) because the colloidal particles that cause turbidity in water shield cells from direct solar exposure.…”

“…Castro-Alférez and coworkers proposed another mechanistic model (Castro-Alférez et al 2017b) that incorporated the actions of solar UV and the pasteurizing effect of mild heat to capture the synergy between UV and temperature in clear water and found excellent fitting between model results and experimental observations. A more recent study evaluated the effect of turbidity and dissolved organic matter on the inactivation rate kinetics of E. coli under simulated sunlight intensities (Samoili et al 2022). These models can only be used to describe the effect of diurnal variation in incident UV and water temperature on SODIS treatment efficiency.…”

The use of Moringa Oleifera and Salvia Hispanica as auxiliaries in the solar disinfection water treatment process by Sodis

“…The Solar Water Disinfection system, or SODIS, consists of exposing water to the sun in containers that allow the passage of solar radiation (Beattie et al, 2019;Morse et al, 2020), with the sun as an energy source, thus representing an accessible and safe system at low cost (McGuigan et al, 2012). This method was first presented in a brochure published by UNICEF in 1984 with good results and has been used as a solution in emergencies to replace conventional water treatments in low-and middle-incomes (Samoili et al, 2022;Wegelin and Meierhofer, 2002). The inactivation of microorganisms occurs due to the high load of UV rays or even the increase in temperature (reaching the level of pasteurization); the microorganisms undergo denaturation of proteins or oxidation in specific conditions of sun exposure, as they contain enzymes and absorbent components that are easily altered by radiation from the sun (García-Gil et al, 2022;Marques et al, 2013).…”