G.M. Ayoub, L. Dahdah, I. Alameddine, L. Malaeb
Journal of Hazardous Materials, volume 280, p. 279287, (2014)
Transfer of bacteria through water vapor generated at moderate
temperatures (30–50 °C) in passive solar stills, has scarcely been
reported. The objective of this research was to investigate whether
bacteria in highly humid atmospheres can get transferred through water
vapor in the absence of other transfer media to find their way to the
distillate. To achieve this objective, passive solar reactors were
chosen as the medium for experimentation, and distillation experiments
were conducted by spiking a pure bacterial culture (Escherichia coli, Klebsiella pneumonia or Enterococcus faecalis)
in low mineralized water vs. highly mineralized water in the dark under
moderate temperatures ranges (30–35 °C, 40–45 °C and 50–55 °C). Results
showed that bacteria indeed get transferred with the vapor in stills
when not exposed to solar U.V. radiation. The trends observed were
adequately explained by a zero-modified Hurdle–Poisson model. The
numbers of cultivable bacterial colonies transferred were bacterial
size, water type and temperature dependent with highest transfers
occurring in E. faecalis > E. coli > K. pneumonia
at the 40 °C range in low mineralized water. Proper management
strategies are recommended to achieve complete disinfection in solar
stills.