For a long time, high-concentration organic wastewater treatment has always been a difficult problem in wastewater treatment, which has plagued the healthy development of petrochemical, coalification and pharmaceutical industries. The membrane bioreactor (MBR) combines high-efficiency separation and biodegradation, and is a new wastewater treatment process that combines sewage biological treatment technology with membrane separation technology. The membrane module replaces the secondary sedimentation tank in the traditional activated sludge process, and can perform high-efficiency solid-liquid separation to achieve the purpose of water purification, and overcomes the deficiencies of the effluent water quality and the easy expansion of the sludge in the traditional process.

The whole system consists of anaerobic tank, anoxic tank, aerobic tank, membrane module and automatic control system.

The sewage is pumped into the anaerobic unit and the anoxic unit by the regulating tank, and then enters the aerobic unit. The membrane module intermittently discharges water under the action of the peristaltic pump, and the aeration device of the membrane unit is placed under the membrane.

The anaerobic tank and the anoxic tank are provided with a mixer, and the bottom of the aerobic tank is equipped with a microporous aerator. A perforated aeration tube is installed in the MBR tank and aerated by a blower. The MBR reactor is a plexiglass cylinder, and the membrane module is a hollow fiber ultrafiltration membrane. The material is modified polypropylene (PP), the membrane pore size is 0.1~0.2 μm, and the membrane effective area is 156 m2. Set the inverter to achieve real-time adjustment of the aeration amount.

The whole process is provided with two reflux systems: one is to return the mixture in the MBR pool to the anoxic tank to achieve denitrification and denitrification, and the other is to return the mixture in the anoxic tank to the anaerobic tank to achieve anaerobic phosphorus release.

Process advantages

I. The degradation performance of COD and NH3-N is good. After adding the bacteria, not only COD and NH3-N can be discharged, but also phenol and cyanide are degraded.

II. The investment cost is small. Since the high concentration COD and NH3-N can be effectively treated, the air flotation deoiling water of the original activated sludge method can be directly processed into the MBR reactor, and no dilution water is added. Not only reduce the processing facility volume, reduce the floor space, but also save a lot of water resources;

III. Lower operating costs. When the process is in normal operation, only a small amount of phosphate is added to the aerobic tank as a bacterial agent. Usually, the screwer is: C:N:P=200:5:1. Greatly reduce the amount of carbon source added;

IV. Less residual sludge. According to preliminary estimates, only 0.05kg of sludge is produced per treatment of IkgC0D, which is much less than the amount of sludge produced by the A0 process and the A2O process, which can save or greatly reduce sludge treatment equipment and operating costs.