Case Study: Fish Processing Plant Wastewater Treatment

This presentation describes the full scale installation of a wastewater treatment system at the Ocean Gold Seafood ("OCS") plant in Westport, Washington, USA. Local Government requires that fish processors remove total suspended solids (TSS), fats, oil and grease (FOGs) and colloidal materials almost completely in order to allow for efficient disinfection. The OCS plant had only a limited amount of space. Clean Water Technology, Inc. ("CWT") and OCS teams designed the system with an underground equalization tank, 1/8 inch rotating drum screens, flocculation – flotation ("GEM System") and chlorination – dechlorination. Hybrid centrifugal – dissolved air flocculation – flotation (the GEM System), is the key component of the wastewater treatment plant. The GEM System built to treat 500 GPM of wastewater required only an 8' – 16' area. The System has operated since 2004. TSS and FOGs are almost completely removed to less than 20 mg/l and 1 mg/l, respectively. This allowed for successful breakpoint chlorination – dechlorination and fecal coliform removal (99.995%). The produced sludge after overnight drainage contains over 15% of solids. Novel ultrahigh molecular weight polyacrylamide flocculants used in the process enabled TSS and FOG removal even at high salinity. The GEM System variable mixing energy inside hydrocylone heads and columns enabled activation of flocculant long polymeric chains without chain or floc breakage that occurs with classical impeller high energy mixing.