The sewage diffusion effect under deep water was carried out between different diffuser design parameters based on the hydraulic model test, and Huizhou Dayawan sewage marine disposal project was taken as an example. The experimental results show that the design parameters are significant for sewage diffusion at the near field. For Dayawan project, jet angle was controlled to be 20 degree, and horizontal angle was controlled to be 90 degree. It not only can ensure that sewage fully diluted mixed, also can avoid the premature convergence and sewage lifting. It is feasible for selecting large angle nozzle under deep water and there are some technical bases have been provided for other sewage marine disposal project.

The sewage diffusion is an environmental material for protecting marine environment. It plays an important role in port engineering. Its effect under deep water was carried out between different diffuser design parameters based on the hydraulic model test, and YangKou sewage marine disposal project was taken as an example. For YangKou project, jet angle was controlled to be 0 degree, and horizontal angle was controlled to be 0 degree. It not only can ensure that sewage fully diluted mixed, also can avoid the premature convergence and sewage lifting. It is feasible for selecting large angle nozzle under deep water and there are some technical bases have been provided for other sewage marine disposal project.

The sewage diffusion is an environmental material for protecting marine environment. It plays an important role in port engineering. Its effect under deep water was carried out between different diffuser design parameters based on the hydraulic model test, and Cao Fei-dian SCIP sewage marine disposal project was taken as an example. For this project, jet angle was controlled to be 0 degree, and horizontal angle was controlled to be 0 degree. It not only can ensure that sewage fully diluted mixed, also can avoid the premature convergence and sewage lifting. It is feasible for selecting large angle nozzle under deep water and there are some technical bases have been provided for other sewage marine disposal project.