Envirex Inc.

Orbal oxidation ditch introduced by US-based Envirex Inc., featuring three mutually nested concentric oval channels with rotating disc aeration; DO increases from the outer to the inner channel, forming anaerobic/anoxic/aerobic zones, enabling simultaneous nitrification and denitrification for phosphorus and nitrogen removal. Main product: Oxidation Ditch (Orbal); Representative model: Orbal (outer/middle/inner three-channel configuration).