Vehicle ferry Bowen Queen, operated by the British Columbia Ferry Corporation
(BCFC), has been retrofitted with Hydroxyl's enclosed wastewater treatment system
. The Hydroxyl system uses ozone to disinfect the effluent rather than chlorine, thereby eliminating the need for chemical storage
on the vessel.
In biological treatment systems, bacteria are used to "eat" the organic products and chlorine is subsequently added to disinfect the effluent prior to discharge. Non-biological systems screen the solids but the harmful byproducts of using chlorine are still evident and the soluble organics are not removed.
As a result, this type of system cannot reliably meet the effluent discharge standards required by BCFC in anticipation of Marine Protected Areas being created on the routes where this vessel will operate.
The Hydroxyl process utilizes two non-biological treatment processes: the Positive Flotation Mechanism (PFM) and the Oxidation Process. The resulting effluent is clear and odorless, low in biochemical oxygen Demand (BOD5) and total suspended solids (TSS).
The system is designed to exceed IMO standards of effluent quality i.e. TSS, BOD5 and faecal coliform concentrations less than 50 mg/l, 50 mg/l and 250/100 ml, respectively. Typical effluent quality is significantly better that these minimum standards in the order of 10mg/l TSS, 10mg/l BOD5 and