The characteristics of MBBR process mainly include the following aspects:

1. Nitrogen and phosphorus removal can be enhanced

 The activated sludge - suspension filler composite process can be used to separate the sludge age of different functional microorganisms in the same reactor. The denitrifying bacteria (nitrifying bacteria) are generally of long mud age, requiring longer mud age (15-25d). The dephosphorization bacteria (phosphorus accumulating bacteria) are generally of short mud age, and need short mud age (3-7d). Mud age is too long, easy to lead to poor microbial activity, treatment load reduction, aging difficult to aggregate and reduce sedimentation performance, etc., the actual traditional denitrification and dephosphorization process in the sludge age is irreconcilable contradictions.

Due to the addition of biological filler, the compound process provides the carrier for the growth of nitrifying bacteria, prolongs its sludge age, and improves the denitrification effect. At the same time, controlling the activated sludge system for short sludge age can enhance the effect of phosphorus removal. Mud - membrane is fully fluidized under the influence of aeration and water flow to promote the renewal of the biofilm and prevent the sludge from being too old and the sludge aging treatment performance from decreasing. In winter, when the water temperature is low and the activated sludge system is not conducive to the growth of nitrifying bacteria, the shed biofilm can continuously inoculate the activated sludge and maintain the nitrification performance of the system.

2. Strong impact load resistance and good treatment effect

 The impact load is mainly manifested as water quality impact of conventional pollutants, water quality impact of toxic pollutants and water quantity impact, which is essentially the effect of the change of pollutant quantity borne by microorganisms on the treatment effect per unit surface area per unit time. The age of sludge in MBBR process is long, and the abundance of microorganism population is increased, which is beneficial to the treatment of refractory organic matter.

Under low temperature, high salt, low matrix and other harsh water quality conditions, MBBR has long mud age and local aerobic and hypoxic microenvironment, which is conducive to the screening and enrichment of microorganisms under harsh water quality conditions, as well as the enrichment of domestic cold-loving bacteria and high-salt-tolerant bacteria.

The mass transfer of biofilm is slower than that of activated sludge, and the heat generated by biodegradation is also slower to exchange with water, which increases the local environmental temperature of microorganisms, which is conducive to the maintenance of bacterial activity. It is shown that MBBR has a good treatment effect for low temperature, high salt, low matrix and other harsh water quality conditions.

3. Activated sludge is not easy to expand

 Pure MBBR system is adopted, because it is pure film method, no sludge swelling problem. When the activated sludge - suspension filler composite process is adopted, the proportion of inorganic matter of biofilm falling off due to aging is higher, and the density is large, which is easy to settle. In addition, the extracellular polymer of biofilm is more than the activated sludge, which has the effect of contact flocculation, improving the sludge aggregation performance and sludge settling performance.

The sludge yield of the biofilm method is only half of that of the activated sludge process. The use of MBBR process can significantly reduce the residual sludge yield, and the improvement of sludge settling performance is easy to reduce the sludge moisture content, which can save the cost of sludge disposal.

4. Not easily blocked and no backwash is required

 Problems such as uneven water distribution and easy dead zone, need for regular backwashing and extra energy consumption, need for supporting facilities, and red bug trouble to reduce nitrification performance often occur in fixed bed technology. Since packing and water flow can be mixed in the whole volume of the biological pool, the possibility of blockage of the biological pool is fundamentally eliminated, and the pool capacity is fully utilized without backwashing.

5. Long life of MBBR suspension packing system

 The packing is wear-resistant and durable. The agitator adopts banana type stirring blade, which has soft contour and does not damage the packing. The whole agitation and aeration system is easy to maintain and manage, and perforated aeration can be used to improve the safety of the aeration system and prolong the maintenance period, due to the cutting effect of filler on the bubbles to improve the oxygen transfer efficiency.

6. Suitable for upgrading and upgrading of sewage treatment plants and three-dimensional expansion

 MBBR process has high flexibility in operation, and can adopt various pool types without affecting the processing effect of the process. At the same time, the fillers with different specific surface areas and filling rates can be selected flexibly. When the actual operation water quality or water quantity changes, only by increasing the filling rate, can ensure the original design biological pool capacity unchanged, to achieve the purpose of physical capacity expansion, to achieve both efficient treatment and long-term expansion of the treatment scale without increasing the pool capacity requirements.