The treatment of wastewater from chemical industry park with ultrafiltration flat membrane

There are many chemical plants in the chemical industry park, which produce a lot of high concentration organic poison wastewater. The amount of the wastewater is large, the composition is complex, the content of toxic and harmful pollutants is high, and the water quality and quantity change greatly. An economic and feasible treatment method is to treat the sewage produced by enterprises in the park to a low standard or to a degree conducive to subsequent treatment, and then concentrate on the centralized treatment, discharge and reuse of the sewage in the comprehensive treatment plant of the park after reaching the standard.

There are five common methods of wastewater treatment in chemical industry park

1. Chemical treatment

Chemical method is the use of chemical reaction to remove organic and inorganic impurities in water. It mainly includes chemical coagulation, chemical oxidation, electrochemical oxidation and so on. The main objects of chemical coagulation are micro suspended solids and colloidal substances in water. The colloid is unstable, precipitated and removed by coagulation and flocculation by adding chemical reagent.

2. Physical therapy

Physical methods include filtration, gravity sedimentation and air flotation.

3. Photocatalytic oxidation technology

Photocatalytic oxidation technology combines O2, H2O2 and other oxidants with light radiation through photo excited oxidation. UV light, including UV-H2O2 and uv-o2, is mainly used to treat refractory substances such as CHCl3, CCl4 and polychlorinated biphenyls in wastewater. In addition, there is a synergistic effect between ultraviolet light and iron ions, which greatly speeds up the decomposition of H2O2 to produce hydroxyl radicals and promotes the oxidative removal of organic matter.

4. Ultrasonic technology

Organic compounds can be degraded and separated by controlling the frequency of ultrasonic wave and saturated gas. The cavitation effect of power ultrasound provides a unique physical and chemical environment for the degradation of harmful organic compounds in water, thus realizing the purpose of ultrasonic treatment of wastewater.

5. Magnetic separation

There are three main magnetic separation methods for chemical industrial park wastewater: direct magnetic separation, indirect magnetic separation and microbial magnetic separation. Using magnetic technology to treat wastewater mainly uses the coagulability and additivity of pollutants.

Flat membrane is one of the common membrane components in membrane bioreactor system. Compared with hollow fiber membrane module, flat membrane has the advantages of anti pollution, wear resistance, no broken wire, no winding and so on. In the process of use, the flat membrane can tolerate higher sludge concentration and improve the treatment efficiency of MBR system.

At present, MBR flat membrane process has been used to treat wastewater in some chemical industry parks. The results show that the MBR flat membrane has a good removal effect on COD, ammonia nitrogen and SS. Compared with the original CASS process, flat membrane bioreactor has great advantages in effluent quality, treatment efficiency, impact load resistance and floor area. At the same time, the flat membrane has the advantages of simple structure, convenient installation and easy disassembly, which makes the cleaning more convenient and suitable for large-scale industrial application.

The advantages of ultrafiltration flat membrane are as follows:

1. Ultrafiltration Flat Membrane is composed of diversion support plate, non-woven support layer and membrane. The structure is relatively simple. Flat membrane module can maintain high flux and stable operation under higher activated sludge concentration.

2. ultrafiltration Flat membrane module is more tolerant to impurities such as hair and is rarely affected by these impurities.

3. The ultrafiltration flat membrane has good mechanical strength and no broken fiber phenomenon. The non-woven fabric is used as the support layer in the membrane, which makes its wear resistance better.

4. The ultrafiltration flat membrane is easy to replace. If any damaged membrane is found, it can be replaced by itself. The damaged membrane can be replaced directly by removing the pressing plate and the pressing strip.