Piloting the Commercial Adaptation of UV Sterilization of Water Discharge from a Fish Processing Facility

Summary:
Disease causing pathogens endemic in BC coastal waters may be found in farmed and wild finfish and shellfish. Following the outbreak of Infectious Hematopoietic Necrosis virus (IHN) in farmed Atlantic salmon in 2001-2003, fish processing facilities became interested in the development of environmentally sound, practical and cost-effective methods for treating blood water effluent to neutralize pathogens and minimize waste impact on the surrounding environment. Disinfection of discharged water in fish processing plants is particularly important since pathogens may become concentrated due to the large volume of fish being processed.  Implementation of an established disinfection system that is currently employed by other industries that deal with treatment of effluent water would increase the industry’s environmental stewardship and decrease the chances of spreading pathogens to the surrounding environment.  In this project, a novel industrial-scale ultraviolet sterilization system was implemented at a fish processing facility (Walcan Seafood Ltd. Quadra Island, BC). In addition, preliminary tests to evaluate the efficacy of UV technology for neutralizing viral and bacterial pathogens were conducted on a laboratory-scale unit and, finally, on the commercial scale unit.  The results of the assessment demonstrated that 1) at the laboratory level, common fish viruses and enteric bacteria were sensitive to UV treatment, and their inactivation response was UV dose-dependent, and 2) for the full-scale unit, there was a reduction in total bacterial counts as the effluent blood water flowed through the UV system. Another resulting outcome from the evaluation performed at the processing plant facility was that efficacy of the UV system was affected by the presence and size of the particles of suspended solids in the effluent.

Exploring alternatives to reduce the presence and size of solids such as high speed spinning  or pre-screening systems such as mesh screens of different sizes (in addition to the existing 500 micron filtration unit) would be highly recommended. This is the first time that an UV system has been tested in a processing plant facility, and the success of this pilot study funded by AIMAP invites further applied investigation to address not only the technical challenges that emerged, but also to make UV treament of processing plant effluent a safe and reliable innovation application that would add further value to fish processing facilities.

Project Lead: Walcan Seafoods Ltd.

Total Project Cost: $293,420
           
DFO-AIMAP Contribution: $189,750

Other Financial Support:

• Recipient: Walcan Seafood Ltd.
• BC Center for Aquatic Health Sciences
• Independent and BC Agriculture and Lands

For more information please contact the regional coordinator.

Pacific Region: Sean.Irvine@dfo-mpo.gc.ca