Anaerobic membrane bioreactors face the problem of the formation of cake layer, which is prone to form with high filtration resistance. How to control the formation of the cake layer is an important issue that affects the energy consumption and membrane life of anaerobic membrane bioreactors. Around the formation mechanism of the sludge layer, different hypotheses have been proposed and some progress has been made. However, due to the lack of in-depth understanding of the mechanism and even confusion, the related methods to control the formation of sludge layer are still in the stage of blooming but not in the valuable direction of in-depth research.
After an in-depth analysis of the existing studies, it can be found that the formation of the cake layer is closely related to the microscopic force of tiny particles on the membrane surface in the reactor. The essence of the various methods of controlling the formation of the sludge layer, which are of different kinds, is to reduce the number of tiny particles and increase the force of tiny particles leaving the membrane surface. Although microparticles are subjected to many different forces at the microscopic level, shear-induced diffusion forces, membrane suction tugging forces and membrane-applied XDLVO forces are the key forces. Controlling the size of microparticles is a very effective way of influencing the force conditions on microparticles and preventing sludge layer formation. The size of microparticles can be achieved by applying flocculants in a rational and continuous manner.
Subsequent research should focus on how to construct an intelligent method of continuous flocculant application to automate the control of sludge layer formation.
The paper has been published at 《Critical review in environmental science and technology》. The journal is ranked number 1 in the field of Water Science and Technology, Environmental Engineering, Waste Management and Disposal, according to the Scopus website.
The link to the paper:
https://www.tandfonline.com/doi/full/10.1080/10643389.2024.2346446
