Abstract: Taking the screen room in municipal sewage treatment plants (MSTPs) as the object, a new-type double medium pneumatic atomization spray system was developed based on the characterisctics of odour from scattered sources in MSTPs, and the operating parameters of the system were optimized. The system was applied in a MSTP in Beijing and its performence was studied. The results showed that the removal efficiency of hydrogen sulfide and ammonia in the screen room were 90.54%-97.80% and 93.75%-99.42%, respectively with a good deodorization effect. The investment cost of the system was 950 000 yuan, and the operating cost was 36 200 yuan/a. The water cost accounted for 51.10% of the operating cost. The new-type double medium pneumatic atomization spray system is suitable for the in-situ treatment of odour from scattered sources in MSTPs.