Application of Blower-Pressurized Jet Aeration in Leather Wastewater Treatment

1. Conditions Before Retrofit

Quanzhou Quangang Pu'an Leather Wastewater Treatment Plant serves as the centralized wastewater treatment facility for multiple leather manufacturers in the Quanzhou Quangang Pu'an centralized control area, also known as the leather industrial park. The plant mainly uses biological treatment. As the production scale of the leather manufacturers expanded, wastewater volume increased accordingly, creating a need for greater treatment capacity.

The original aeration system combined blower-fed medium-pore aeration with multi-blade plug-flow aerators. Because medium-pore aeration has relatively low oxygen utilization, and the later-added plug-flow aerators had insufficient oxygenation capacity, the system became increasingly unable to meet process demand. Over time, the medium-pore aeration pipes became clogged, rusted, and corroded. Oxygen utilization declined, shock-load resistance was weak, and the system required regular shutdown, drainage, and maintenance. These issues affected downstream treatment and made it difficult for the final effluent to meet the discharge standard consistently.

To solve these problems, the plant purchased eight GW1200 jet aerators from Chengdu GreenWater Technology Co., Ltd. for the retrofit. Each jet aerator was equipped with four N70 efficiency-enhancing nozzles.

2. Retrofit Arrangement

The customer installed four GW1200 jet aerator sets in the equalization aeration tank and four sets in the aeration tank. Air intake used a blower-pressurized arrangement, drawing air from the existing blower main pipe. Each jet aerator delivered an actual oxygenation capacity of 37.5kg/h. The matched water pump had a head of 15m, a flow rate of 260m³/h, and a power rating of 18.5kW.

Because jet aeration provides high oxygen utilization of about 30%, the aeration system gained a total oxygenation increase of 240.8kg/h even though the blower air volume remained unchanged. The installation of efficiency-enhancing nozzles and piping inside the tank was straightforward, and no change to the original system was required.

3. Results After Retrofit

1. Shock-load resistance was improved. Treatment capacity increased from 4100m³/d to 6200m³/d, a relative increase of 50%.
2. Effluent quality improved from unstable discharge, with average COD_cr ≥120mg/L, to stable compliance with COD_cr ≤75mg/L.
3. The aeration system's unit energy consumption for wastewater treatment decreased from 3.05kWh/m³ to 2.21kWh/m³.

4. Conclusion

The retrofit at Quanzhou Quangang Pu'an Leather Wastewater Treatment Plant demonstrated that GW jet aerators from Chengdu GreenWater Technology Co., Ltd. provide the following advantages under blower-pressurized operating conditions:

1. High oxygen utilization and high power efficiency in blower-pressurized jet aeration;
2. Strong shock-load resistance, with wastewater treatment capacity increased by 50%, solving the original plant's problems of rising leather wastewater volume and insufficient oxygenation capacity in the existing aeration system;
3. Stable final effluent meeting the Class I wastewater discharge standard;
4. A 27.5% relative reduction in unit energy consumption for wastewater treatment.