For a seafood reservation/holding tank or intensive culturing pond, a co-current protein skimmer using a Venturi injector is a relatively simple way to remove dissolved and colloidal organic matter while simultaneously adding oxygen.
1. Main benefits
a. Organic waste removal: Removes proteins, mucus, uneaten feed, feces-derived dissolved organics and fine particles before they decompose.
b. Better water clarity: Foam fractionation captures fine suspended/colloidal material that a conventional mechanical filter may miss.
c. Lower BOD/COD pressure: Removing organic material reduces the amount available for bacterial decomposition and oxygen consumption.
d. Higher DO: The Venturi introduces air/O₂ and creates fine bubbles, increasing gas–liquid contact.
e. Reduced bacterial load indirectly: Removing organic substrates can limit the environment supporting heterotrophic bacterial proliferation. It does not replace disinfection.
f. Reduced odor: Particularly useful in seafood holding systems where mucus, feces and feed residues accumulate rapidly.
g. Compact and simple: Pump + Venturi + reaction column + foam collector can form the entire system.
h. Continuous operation: Particularly suitable for holding tanks and recirculating pond systems where water exchange is limited.
2. Why "co-current" is attractive for seafood holding
In a co-current design, water and bubbles move upward together. This makes the hydraulic arrangement simple and gives a strong airlift effect.
For a seafood reservation tank,
Fish/shrimp → organic waste → Venturi fine bubbles → foam concentration → waste removal
