Compared with the hollow fiber MBR, the flat membrane bioreactor can maintain stable high flux operation (i.e. membrane water production) under higher concentrations of activated sludge, with lower pre-treatment requirements. During actual use, although pre-treatment facilities such as grids and hair removal machines are available, some objects such as hair will inevitably enter the aeration tank. During the operation of the hollow fiber membrane bioreactor, the membrane filaments are always in an oscillating state in the aeration state, and these hair easily entangle the membrane filaments. When the sludge concentration reaches a certain level, mud clusters will appear, causing more and more membrane filaments to interweave, greatly reducing the effective membrane area of the hollow fiber, and making it difficult to solve the problem of rapid decline in membrane flux, which can only be replaced.
The connection between the two ends of the hollow fiber needs to be sealed with epoxy resin. The hollow fiber is always in a large range of vibration in the working state due to inflation, which will cause material fatigue in the long run. At the same time, epoxy resin itself is a brittle material. Once a filament is broken, it is often on a large scale. For membrane bioreactors, damage is fatal, not only affecting water quality, but also causing the entire component to be discarded if it is serious. In contrast, the MBR flat sheet membrane uses non-woven fabric as a guide layer internally, 3mm~5mm ABS board as a support layer, and the filter membrane material PVDF has good chemical stability and mechanical properties. Therefore, the strength of MBR flat sheet membrane is much higher than that of hollow fiber, and there will be no filament breakage, which can fully ensure the water quality of the effluent.
The online cleaning of hollow fiber MBR is relatively frequent, but the cleaning process is more complicated. The prepared chemicals need to be injected into the membrane filament through a metering pump to complete the cleaning. The online cleaning of the flat membrane is achieved through the aeration during operation and the online chemical cleaning. The flat membrane bioreactor can effectively flush the membrane surface by controlling the aeration amount of the bottom aeration system of the control module, prevent excessive sludge deposition on the membrane surface during suction, and control the membrane surface pollution during operation. The chemical cleaning (online cleaning) of the flat sheet membrane component is also simpler. Just inject the prepared drug from the inlet into the membrane and soak for a period of time.