How to Treat Canteen Kitchen Wastewater

Catering wastewater is a high-strength pollution source. Grease solidifies and clogs drains; COD/BOD loads harm aquaculture. How should canteen kitchen wastewater be treated? CHINENG explains.

Sources and hazards

Wastewater comes from ingredient washing, rice rinsing, warewashing, and floor cleaning. It carries fiber, protein, and grease that can eutrophy water bodies. After grease separation and screening, emulsified colloids still need advanced treatment before discharge.

Treatment methods

1. Pretreatment:

A. Grease interceptor: density separation; overflow goes to further treatment for emulsified oil.

B. Screens/gratings at channel and sump inlets intercept large solids to protect pumps and reduce downstream load.

C. Equalization tank: balances flow/quality, pH, and temperature, with optional pre-aeration and emergency storage.

2. Coalescence: oleophilic media catch fine oil into films that form larger droplets and float for separation.

3. Electrochemical treatment: redox reactions break pollutants toward simpler organics or CO₂/H₂O, then biological treatment or municipal sewer discharge.

4. Biological contact oxidation: media plus bottom aeration keep wastewater moving for even biofilm contact.

5. Physical oil–water separators: screens remove solids; demulsification and adsorption float oil to a collection trough while clean water exits at the bottom.

CHINENG partners with major brands to supply integrated grease, organics, and solids reduction systems that cut harmful discharge. Follow the CHINENG website for kitchen engineering support.