Solar disinfection of wild Salmonella sp. in natural water with a 18 L CPC photoreactor: Detrimental effect of non-sterile storage of treated water

FREDERIC SCIACCA; JULIÁN ANDRÉS RENGIFO HERRE; JOSEPH WÉTHÉ; CESAR PULGARIN

SOLAR ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2011 vol. 85 p. 1399 - 1408

0038-092X

For the first time solar disinfection of liters of water containing wild Salmonella sp. and total coliforms was carried out in a compound parabolic collector (CPC) photoreactor at temperatures of almost 50 °C. Using surface water with high turbidity, this treatment was efficient in completely inactivating Salmonella sp. without regrowth during the subsequent 72 h of dark sterile storage. However if the solar treated water is poured in a non- sterile container, bacteria regrowth occurs even if 10 mg L−1 of H2O2 is added before the storage. On the other hand, 30 mg L−1 of H2O2 added when the irradiation started was completely depleted within 2 h and did not prevent bacterial regrowth during post-irradiation storage in non-sterile containers, demonstrating that storage of large volumes of water treated by solar irradiation was not optimal. Finally, total coliforms (Escherichia coli included) showed a far higher sensitivity than Salmonella sp. and demonstrated to be an inappropriate indicator for monitoring bacterial contamination in water during solar disinfection processes.