Comparative analysis of solar pasteurization versus solar disinfection for the treatment of harvested rainwater
Date
2016-12-09
Journal Title
Journal ISSN
Volume Title
Publisher
BioMed Central
Abstract
Background: Numerous pathogens and opportunistic pathogens have been detected in harvested rainwater.
Developing countries, in particular, require time- and cost-effective treatment strategies to improve the quality of
this water source. The primary aim of the current study was thus to compare solar pasteurization (SOPAS; 70 to
79 °C; 80 to 89 °C; and ≥90 °C) to solar disinfection (SODIS; 6 and 8 hrs) for their efficiency in reducing the level
of microbial contamination in harvested rainwater. The chemical quality (anions and cations) of the SOPAS and
SODIS treated and untreated rainwater samples were also monitored.
Results: While the anion concentrations in all the samples were within drinking water guidelines, the concentrations
of lead (Pb) and nickel (Ni) exceeded the guidelines in all the SOPAS samples. Additionally, the iron (Fe) concentrations
in both the SODIS 6 and 8 hr samples were above the drinking water guidelines. A >99% reduction in Escherichia coli
and heterotrophic bacteria counts was then obtained in the SOPAS and SODIS samples. Ethidium monoazide bromide
quantitative polymerase chain reaction (EMA-qPCR) analysis revealed a 94.70% reduction in viable Legionella copy
numbers in the SOPAS samples, while SODIS after 6 and 8 hrs yielded a 50.60% and 75.22% decrease, respectively.
Similarly, a 99.61% reduction in viable Pseudomonas copy numbers was observed after SOPAS treatment, while SODIS
after 6 and 8 hrs yielded a 47.27% and 58.31% decrease, respectively.
Conclusion: While both the SOPAS and SODIS systems reduced the indicator counts to below the detection limit,
EMA-qPCR analysis indicated that SOPAS treatment yielded a 2- and 3-log reduction in viable Legionella and
Pseudomonas copy numbers, respectively. Additionally, SODIS after 8 hrs yielded a 2-log and 1-log reduction in
Legionella and Pseudomonas copy numbers, respectively and could be considered as an alternative, cost-effective
treatment method for harvested rainwater.
Description
CITATION: Strauss, A., et al. 2016. Comparative analysis of solar pasteurization versus solar disinfection for the treatment of harvested rainwater. BMC Microbiology, 16:289, doi:10.1186/s12866-016-0909-y.
The original publication is available at http://bmcmicrobiol.biomedcentral.com
The original publication is available at http://bmcmicrobiol.biomedcentral.com
Keywords
Solar pasteurization, Solar disinfection, Harvested rainwater, Microbial contamination
Citation
Strauss, A., et al. 2016. Comparative analysis of solar pasteurization versus solar disinfection for the treatment of harvested rainwater. BMC Microbiology, 16:289, doi:10.1186/s12866-016-0909-y