Polo López, María InmaculadaMartínez García, AzaharaAbeledo Lameiro, María JesúsGómez Couso, HipólitoAres Mazás, María ElviraReboredo Fernández, AuroraMorse, Tracy D.Buck, LyndonLungu, KingsleyMcGuigan, Kevin G.Fernández Ibáñez, Pilar2020-04-142020-04-142019Polo-López, M.I.; Martínez-García, A.; Abeledo-Lameiro, M.J.; H. Gómez-Couso, H.; E. Ares-Mazás, E.; Reboredo-Fernández, A.; Morse, T.D.; Buck, L.; Lungu, K.; McGuigan, K.G.; Fernández-Ibáñez, P. Microbiological Evaluation of 5 L- and 20 L-Transparent Polypropylene Buckets for Solar Water Disinfection (SODIS). Molecules 2019, 24, 2193.http://hdl.handle.net/10347/21400Background: Solar water disinfection (SODIS) is an appropriate technology for household treatment of drinking water in low-to-middle-income communities, as it is effective, low cost and easy to use. Nevertheless, uptake is low due partially to the burden of using small volume polyethylene terephthalate bottles (1.5–2 L). A major challenge is to develop a low-cost transparent container for disinfecting larger volumes of water. (2) Methods: This study examines the capability of transparent polypropylene (PP) buckets of 5 L- and 20 L- volume as SODIS containers using three waterborne pathogen indicators: Escherichia coli, MS2-phage and Cryptosporidium parvum. (3) Results: Similar inactivation kinetics were observed under natural sunlight for the inactivation of all three organisms in well water using 5 L- and 20 L-buckets compared to 1.5 L-polyethylene-terephthalate (PET) bottles. The PP materials were exposed to natural and accelerated solar ageing (ISO-16474). UV transmission of the 20 L-buckets remained stable and with physical integrity even after the longest ageing periods (9 months or 900 h of natural or artificial solar UV exposure, respectively). The 5 L-buckets were physically degraded and lost significant UV-transmission, due to the thinner wall compared to the 20 L-bucket. (4) Conclusion: This work demonstrates that the 20 L SODIS bucket technology produces excellent bacterial, viral and protozoan inactivation and is obtained using a simple transparent polypropylene bucket fabricated locally at very low cost ($2.90 USD per unit). The increased bucket volume of 20 L allows for a ten-fold increase in treatment batch volume and can thus more easily provide for the drinking water requirements of most households. The use of buckets in households across low to middle income countries is an already accepted practice.eng© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).https://creativecommons.org/licenses/by/4.0/Drinking waterHousehold water treatment and storageSODISE. coliMS2-phageCryptosporidiumjournal article10.3390/molecules241121931420-3049open access