Zimpro® Wet Air Oxidation

Zimpro Wet Air Oxidation (WAO) and Wet Oxidation systems are used primarily for treatment of high strength industrial wastewater streams.

Zimpro wet air oxidation system for spent caustic treatment.

The Wet Oxidation Process

Wet air oxidation is the oxidation of soluble or suspended components in water using oxygen as the oxidizing agent. When air is used as the source of oxygen the process is referred to as wet air oxidation (WAO). The oxidation reactions occur at temperatures of 150º C to 320º C (275º F to 608º F) and pressures from 10 to 220 barg (150 to 3200 psig). The wet oxidation process can pretreat difficult wastewater streams, making them amenable for discharge to a conventional biological treatment plant for polishing. The process is also used for oxidation of contaminants in production liquors for recycle/reuse.

The following diagram illustrates a typical wet air oxidation flow diagram. Click on parts of the diagram for more information about the process.

Typical Wet Air Oxidation Flow Diagram

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Applications

Common wet air oxidation applications include:

treatment of high strength wastewater, including spent caustic streams generated by ethylene crackers and refineries
in-process, for treatment and recycle/recovery of process liquor streams
biological sludge conditioning and destruction.

Wet oxidation has historically been used for municipal wastewater sludge applications. At lower temperatures and pressures, sludge is conditioned to improve dewatering. This is referred to as Low Pressure Oxidation (LPO). At higher temperatures and pressures, biological sludge can be destroyed, as an alternative to incineration.

Features and Benefits

Pretreatment of high strength wastewater to produce biodegradable residual organics
Destruction of specific compounds
Elimination of toxicity or reactivity
Process liquor treatment for recycle/recovery
Gross reduction of Chemical Oxygen Demand (COD)

Our wet air oxidation capabilities include:
Treatability Testing
Manufacturing

Wet Air Oxidation Applications:
Spent Caustic Treatment