The combined performance of UV light and chlorine during reclaimed water disinfection.
The combined effects of disinfectant agents on the microbiological quality of reclaimed water produced by two full-scale water reclamation plants in Catalonia, Spain, were examined in this work. All the disinfectant treatments tested led to the absence, or near absence, of E. coli in 100 mL samples of water, with log reductions of more than 3 log u. Hypochlorite reduced the bacterial concentrations. However, ultraviolet light was more effective than hypochlorite at reducing the concentrations of bacteriophages, viruses and pathogenic protozoa such as Cryptosporidium spp. We conclude that a combination of these two disinfectant agents is effective in protecting public health, as each agent acts to a different degree against the different groups of microorganisms studied. Further studies should investigate the combined action of disinfectant agents at water reclamation plants with ultraviolet light equipment in more favourable working conditions in order to assess their capacity to inactivate microorganisms.
Montemayor
M
M
Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda Diagonal, 645, 08028 Barcelona, Spain. michelmontemayor@hotmail.com
Costan
A
A
Lucena
F
F
Jofre
J
J
Muñoz
J
J
Dalmau
E
E
Mujeriego
R
R
Sala
L
L
D000818:Animals; D002713:Chlorine / Q000494:pharmacology*; D003247:Conservation of Natural Resources / Q000379:methods; D004202:Disinfectants / Q000494:pharmacology; D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects; D056890:Eukaryota / Q000187:drug effects / Q000528:radiation effects; D006997:Hypochlorous Acid / Q000494:pharmacology; D015203:Reproducibility of Results; D013030:Spain; D014466:Ultraviolet Rays; D014780:Viruses / Q000187:drug effects / Q000528:radiation effects; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis / Q000592:standards*
D004202:Disinfectants; D002713:Chlorine; D006997:Hypochlorous Acid