of ozonation on water quality in marine recirculation systems
M.S. Tango, G.A. Gagnon-2003
Aquacultural Engineering, 29(3-4): 125-137
Ozone (O3) is a powerful oxidant and is
becoming popular in various aquaculture systems for disinfection and
improving water quality by oxidation of inorganic and/or organic compounds.
However, the use of ozone in marine-based aquaculture systems has been
limited because of the potential to form bromate, which is formed during the
oxidation of naturally occurring bromide by ozone. Because bromate is a
human carcinogen, there are concerns with its chronic impact on fish health.
In addition, the use of O3 is hindered by lack of quantitative as
well as qualitative design and performance information on O3 for
recirculating systems. This study investigated the application of ozonation
to control pathogens and enhance the process water quality in a
recirculating aquaculture system while minimizing bromate formation. A field
scale monitoring program was conducted on process water quality from Atlantic
halibut (Hippoglossus hippoglossus) recirculating systems.
Ozonated modules showed reduction of 15% total organic carbon (TOC) and less
than 25 µg/l bromate concentration was formed. In addition, ozonated
modules showed reduction in nitrate, color and suspended solids, as compared
to those that did not use ozone. The results of this study elucidates the
formation of bromate in marine water recirculation systems.
(Department of Civil Engineering, Dalhousie
University, Halifax, NS, Canada B3J 1Z1, e-mail of G.A. Gagnon: firstname.lastname@example.org)