The hydrophobic PTFE membrane with hollow fiber structure has a very high specific surface area and provides a mass transfer interface for the two-phase mass transfer. Because PTFE material has good hydrophobicity and chemical stability, compared with other membrane materials (such as polypropylene PP or polyvinylidene fluoride PVDF, etc.), PTFE membrane has a long service life and stable operating performance.
In the traditional stripping process, the high ammonia nitrogen wastewater after alkali addition and dissociation first enter the stripping tower, and a large amount of compressed air is used for stripping. After the stripping, the exhaust gas needs to enter the acid absorption tower to absorb the ammonia in the exhaust gas to avoid entering. The atmosphere pollutes the environment.
In the membrane absorption process, the membrane contactor completely replaces the functions of the stripping tower and the desorption tower and combines them into a membrane contactor. In the membrane contactor, the ammonia desorption and absorption processes can be performed simultaneously. Because the PTFE hollow fiber membrane in the membrane contactor has a thin filament structure, the contact area is large, the reaction efficiency is improved, and the equipment footprint can be greatly reduced. In addition, because the membrane absorption process does not use air blowing off, it will not cause secondary pollution of the process and has strong technical advantages.
PTFE deammonia nitrogen membrane is a high-performance hydrophobic microporous membrane. The specific process applied to the treatment of high ammonia nitrogen wastewater is as follows: adjust the pH value of the wastewater to free ammonia nitrogen in the form of NH3. When the high ammonia nitrogen wastewater passes through the pipe side of the PTFE membrane module, the wastewater is dissociated. NH3 can pass through the micropores in the wall of the PTFE hollow fiber membrane, and then be absorbed by the dilute sulfuric acid solution flowing in the shell side of the membrane module, to achieve the effect of efficiently removing ammonia nitrogen in wastewater.
The PTFE deamination nitrogen membrane technology uses membrane modules to replace the stripping tower and absorption tower in the traditional process, which has significant advantages:
* No air and steam consumption, process energy consumption and wastewater treatment costs are greatly reduced,
* Fully enclosed short process avoids ammonia leakage and secondary pollution;
* The membrane module can provide a very high specific surface area, ~2000 m/m, while the absorption tower is only 100-250 m/m;
*Membrane wire size is small, mass transfer driving force is high, and process efficiency is high;
*The technology is modular, can be linearly amplified, and the operation flexibility is good;
* PTFE has excellent chemical inertness, long life and renewable;
*The membrane material has good hydrophobic properties and good operation stability