Application characteristics of MBBR process

 Due to the unique mud film symbiosis system of MBBR process, the activated sludge process and the biofilm process can be organically combined, which has the significant advantages of mud film symbiosis technology, and the activated sludge process and the biofilm method can be skillfully combined.

The main purpose of this system is to use the biofilm method to resist low temperature, enhance the removal of organic matter and ammonia nitrogen in the aerobic section, so that their removal rate is higher than that of the mixture alone.

MBBR suspended filler in the production of biofilm nitrifying bacteria, biological membrane peeling can give a mixture of vaccination, and in the same mixture of suspended solid alone under the mean cell residence time of activated sludge process, compared to the biological membrane peeling and vaccination will significantly increase the nitrifying bacteria in mixture ratio, therefore the existence of the biofilm carrier is helpful to increase the rate of unit volume of nitrification pool, enhanced nitrification ability of secondary treatment process, so as to further improve the efficiency of ammonia nitrogen removal. Its main application features are as follows:

1. Suitable for cold areas with extremely low water inlet temperature

In Inner Mongolia and northeast China, the cold winter season usually lasts for half a year. When the inlet water temperature of sewage is kept low, the growth of activated sludge and the ability to degrade pollutants will be greatly affected. However, the MBBR process system has a biofilm system that is not provided by the ordinary activated sludge process, which has a better ability to resist low temperature.

2. Applicable to renovation and expansion projects

Because of MBBR process to cic biochemical pool suspended filler, biochemical pool suspended packing activated sludge bacteria can without affecting the original biochemical pool under the premise of bacteria growth, so that it can be realized in not built on the premise of the launch of a processing flow increase, greatly reducing the workload of the expansion project, reduce the construction land at the same time. However, while MBBR technology brings great convenience, it should also pay attention to design problems.

Add the proportion of suspended filler in the original biochemical pool wants moderate, can lead to excessive dosing suspended filler packing fluidization difficulty, according to the practical engineering experience, the largest suspended filler dosing ratio for 60% of aerobic zone ChiRong design are usually have allowance, adding the proportion of not more than 50%, otherwise packing fluidization difficulties will bring packing accumulation, jams mesh screen, serious problems such as biochemical pool overflow.

3. The screen flow area and aeration system should be designed reasonably

Due to the circular porous packing with a size of 25mm in the general MBBR process, the suspended packing is in the state of flow circulation in the aerobic zone. In order to avoid the flow of the suspended packing into the next structure resulting in the loss of the packing, an intercept screen shall be set in the MBBR process suspended packing area to intercept the suspended packing.

Design should be considered at the same time of intercepting packing should guarantee the sieve pore of traffic, such as insufficient or discharge at the bottom of the aeration system design is unreasonable, will lead to a suspended filler piled up on the screen, this will have negative impact across the flow, serious when suspended filler can all siltation in the screen, causing biochemical pool of water unable to enter the next unit, eventually lead to the risk pool.

During the design, the hydraulic principle should be fully applied, and a separate perforated aeration pipe should be designed at the screen to make the suspension packing at the screen in fluidized state, so as to give full play to the normal processing function of the suspension packing.