By: Kate
Email:kate@aquasust.com
Date: 10th February 2025
The problems of traditional biological treatment methods are becoming increasingly prominent. In contrast, the advantages of membrane bioreactor (MBR) treatment process are very obvious, mainly manifested in the following aspects:
(1) The solid-liquid separation efficiency of the sedimentation tank of the traditional activated sludge treatment method (CASS) is low, and the equipment volume load is low. Due to the mechanical interception effect of the membrane, MBR largely avoids the loss of microorganisms in the aeration tank, and the sludge concentration in the reactor is high, which greatly improves the volume load of the equipment.
(2) CASS effluent generally still contains a large amount of suspended matter and cannot meet higher requirements. The effluent quality of MBR can meet the current strict international sewage discharge standards.
(3) Traditional processes generally have primary and secondary sedimentation tanks, with many structures and a large land area, which is inconsistent with the current situation of increasingly scarce land. The MBR process is compact, and the bioreactor replaces the secondary sedimentation tank, greatly reducing the floor area of the structure.
(4) Traditional methods generally produce a large amount of residual sludge, which increases the difficulty and cost of subsequent treatment processes. In the MBR process, the interception effect of the membrane prolongs the sludge age, and the reactor acts as a sludge digester, which reduces the sludge production and makes subsequent treatment easier.
(5) Traditional processes generally have weak resistance to water quality, water volume and toxic substance shock loads, and are unstable in operation. The concentration of activated sludge in MBR can change with the concentration of organic matter entering the reactor to achieve a dynamic balance, making the effluent stable and resistant to shock loads.
(6) Traditional methods require special denitrification equipment to achieve a certain denitrification effect. In the MBR process, a longer sludge age is conducive to the interception, growth and reproduction of slow-growing nitrifying bacteria, so that the system has a better removal effect on ammonia nitrogen and some difficult-to-degrade organic matter.
(7) The traditional method is complex and inconvenient to operate and manage, and it is also necessary to prevent sludge swelling. The MBR process has fewer equipment, is easy to integrate and automatically control, and is very convenient to operate and manage. In addition, the hydraulic retention time and sludge age can be separated, and the operation control is more flexible and stable.
(8) The traditional method is generally only suitable for the treatment of medium and low concentration wastewater. High concentration wastewater needs to be diluted before it can be treated. The MBR process is suitable for the treatment of wastewater of any concentration and can achieve good treatment effects.
(9) It is generally very difficult to transform one traditional process into another traditional process, and it is more economical to build a new one. However, it is relatively easy to transform ordinary activated sludge treatment equipment into an MBR process, and there is no need to build a new one.