Application of Jet Aerator in Ozone Off-Gas Reuse and Pure Oxygen Aeration

The customer for this pure oxygen aeration project is Shanghai Chemical Industry Park Sino French Water Development Co., Ltd. Founded in 2002 by Sino French Water, Shanghai Chemical Industry Park Development Co., Ltd. and Shanghai Chemical Industry Park Investment Industrial Co., Ltd., the joint venture mainly provides integrated water supply and wastewater treatment services for Shanghai Chemical Industry Park.

Shanghai Chemical Industry Park Sino French Water Development Co., Ltd. has a wastewater treatment capacity of 50,000 tons per day and a COD load of 30 tons per day. Its treatment process includes ozone advanced oxidation, using pure oxygen to generate ozone and consuming 6000kg of pure oxygen per day. The conversion rate from pure oxygen to ozone is about 10%. In the original process, the off-gas after ozone reaction, containing about 90% pure oxygen, was discharged as waste gas, causing significant waste.

To reuse the oxygen in the ozone off-gas, Shanghai Chemical Industry Park Sino French Water Development Co., Ltd. commissioned our company to design an ozone off-gas reuse system. The system reuses ozone off-gas in the aerobic biochemical tank for aeration and oxygen supply, thereby reducing energy consumption in the aerobic biochemical tank.

The plant uses 6000kg of oxygen per day to generate ozone in the ozone advanced oxidation tank, equivalent to 4200Nm³/d. The oxygen content in the off-gas after the ozone contact tank is 5400kg/d. The farthest distance from the ozone advanced oxidation tank to the aerobic biochemical tank is 380m.

Before the retrofit, the aerobic tank had twelve 75kw surface aerators. Under the current treatment load, the oxygen demand of the aerobic tank is 8.6-9.2t/d.

This GW pure oxygen jet aeration system uses six GW1200 jet aerators and twelve sets of GWB02-140-Air/O2 secondary jet enhancement devices. The negative pressure generated entirely by the GW1200 jet aerators draws all 5400kg/d of pure oxygen in the ozone off-gas from the ozone tank 380m away back to the front aerobic tank. With a 90% oxygen utilization rate for pure oxygen jet aeration, the system can supply 4860kg/d of oxygen to the aerobic tank.

After the system was put into operation, the operating time of the original surface aerators was reduced, lowering power use by 25% under the current treatment load. The system has now passed acceptance and meets the design requirements.

Attached below are the PID flow diagram, layout rendering and site photos of this pure oxygen jet aeration system.