Key Points of MBR Process Design

MBR membrane technology is now more and more widely used, and its stable and clear effluent has attracted much more attention. However, its huge amount of maintenance also makes many users headaches, so if you want to minimize the intensity of maintenance work during use, you need to pay attention to a few issues at the design stage:

1. Design numbers of the MBR membrane module 

The design of the number of MBR membrane modules mainly depends on the total amount of water production per day, the actual operating time of the MBR system per day and the type of wastewater. We generally select the appropriate operating model and flux of MBR membrane according to the type of wastewater, and then calculate the number of MBR membrane modules based on the actual operating time of the MBR.

2. Design space between MBR membrane

Keep a certain distance between the MBR membranes. If the membrane itself has a high density of membrane filaments, then the effective spacing should be appropriately widened. The purpose of this is to keep the flushing airflow to the top membrane filaments smoothly, and it can also reduce the hardening and entrapment between membrane filaments and reduce the frequency of membrane module cleaning.

3. Placement direction of MBR membrane

The MBR membrane can be installed horizontally or vertically, depending on the installation space. If the MBR membrane is installed horizontally, the membrane filaments should be kept slightly sagging, so that the residual contaminants between the membrane filaments can be reduced. But we still recommend vertical installation, because when the MBR membrane is installed vertically, the filtration efficiency and service life are better than horizontal installation.

4. The design size of Membrane Module

Generally we don’t make the membrane module very large, because the membrane installation density will be larger for bigger membrane module, and the same aeration volume will be insufficient for it. Moreover, when the dirt accumulated on the membrane is washed, the installation of the membrane too dense will increase the difficulty of washing the inner membrane.

5. The spacing of MBR membrane modules in the membrane pool

The MBR membrane module is located in the center of the aeration tank as much as possible, and ensure that the space around the membrane module is maintained at least more than 30% of the membrane module size. Keep the distance between the top of the membrane module and the water surface above 350mm, the distance between the top of the MBR tank and the water surface above 500mm, the distance between the bottom of the membrane module and the aeration pipe should be no less than 180mm, and the distance between the aeration pipe and the bottom of the pool should be no less than 150mm.

Therefore, when designing MBR membrane modules, we must pay attention to the total water production per day, the size of the MBR membrane module design, the spacing and placement direction of the MBR membrane, so that to minimize the problems of MBR membrane modules in the entire project operation, and to improve the MBR process filter efficiency and extend its service life.