PSA Oxygen Generator for Wastewater Aeration | 90–95% O₂ | Qingdao Green Power

A PSA oxygen generator produces oxygen on site with zeolite molecular sieve (ZMS) in a twin-tower pressure swing adsorption system: nitrogen is adsorbed while oxygen passes through at 90–95% purity, and the two towers alternate for a continuous supply.

In wastewater treatment the generator is applied to oxygen-enhanced aeration of the biological stage, where raising the oxygen available to the biomass supports the treatment process.

The published output range is 1–500 Nm³/h at an outlet pressure of 0.1–0.4 MPa, with energy use of 0.3 to 0.5 kWh per Nm³ of oxygen produced and a start-up time of 30 minutes or less to rated purity.

Because the oxygen is generated at the plant, the system avoids delivered-gas logistics and can be sized to the aeration duty rather than to a standard delivery size.

The PSA oxygen range is published as a purity and capacity configuration rather than a numbered model table: fix the required oxygen flow first, then confirm purity, outlet pressure and energy use for the duty.

• Adsorption towers: two adsorber vessels alternate between adsorption and regeneration, so the oxygen supply is continuous.
• Molecular sieve: zeolite molecular sieve (ZMS) selectively adsorbs nitrogen from the compressed air so oxygen passes through as product gas at 90–95% purity.
• Air dryer: the package includes an air dryer that brings the compressed-air moisture load down so the feed-air dew point requirement is met before the air reaches the sieve bed.
• Filtration: filtration stages remove oil aerosol and dust carried over from the compressor and receiver, protecting the sieve bed.
• Air receiver: a buffer tank (air receiver) between the compressor and the PSA towers steadies the feed-air supply.
• Control cabinet: PLC automatic control with an optional HMI touch screen; the control cabinet manages the valve cycle and the operating parameters.
• Purity monitoring: an oxygen analyser monitors the purity of the product oxygen, and its calibration is checked on schedule.
• Feed air: compressed air at 0.6–0.8 MPa with a dew point of -40°C or lower, oil-free.

• Biological treatment aeration: provides oxygen for oxygen-enhanced aeration of the biological stage.
• Municipal plants: supports aeration duty where on-site oxygen generation is preferred to delivered gas.
• Industrial wastewater: feeds oxygen into aeration duties at industrial wastewater treatment plants.
• Load and peak support: adds oxygen capacity alongside existing aeration equipment during peak load.
• Compact installation: generates oxygen at the plant using the same feed-air conditioning package as our other PSA systems.
• Retrofit and expansion: raises treatment capacity where the existing blower system is at its limit.

• Confirm the required purity and flow, since these set the ZMS charge and the system size.
• Check the outlet pressure against the 0.1 to 0.4 MPa range.
• Note the energy use of 0.3 to 0.5 kWh per Nm³ when sizing the power supply and operating cost.
• Confirm the feed air is oil-free with a dew point of -40°C or lower, conditioned by an air dryer and filtration stages.
• State the aeration duty and operating schedule so the generator is sized to average demand.
• Where the aeration has to run continuously, plan the maintenance window around the start-up time of 30 minutes or less.