TITLE:
Disinfection of Primary Municipal Wastewater Effluents Using Continuous UV and Ozone Treatment
AUTHORS:
Yaneth Bustos, Mabel Vaca, Raymundo López, Erick Bandala, Luis Torres, Neftalí Rojas-Valencia
KEYWORDS:
Disinfection; Ozone Treatment; UV Treatment; Wastewater
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.1,
January
15,
2014
ABSTRACT: UV radiation and ozonation were investigated as
disinfection alternatives for the wastewater treatment plant. The inactivation
of total and fecal coliforms using ozone and ultraviolet radiation as separate
treatments was evaluated. Different ozone concentrations (3 to 40 mg O3/L)
were applied and UV fluencies ranging from 8.5 to 12 mJ/cm2 at
different pH values (from 5 to 9) were tested. Best results were obtained for
ozone doses near 20 mg/min with removals of 72% and 78% of fecal
and total coliforms, respectively. The ozone also was capable of oxidizing
organic matter in the effluent measured as COD (the highest removal obtained
was 36% for 20 mg O3/min). Maximum bacterial resistance was observed
at pH 7 in both cases. The UV light offered a high bacterial inactivation (over
80%) and the lowest bacterial inactivation was observed at pH 7. Finally, we
obtained the electric energy per order (EEO, kWh/m3/order),
defined as the electric energy (kW-h) required to degrade a contaminant by one
order of magnitude in a unit volume of contaminated water, being noteworthy
that EEO values for the UV
process resulted were lower than those determined for the process with ozone in all the water
flow tested.