Application of Reverse Osmosis Membrane and Related Technologies in Water Treatment
- Wastewater treatment
Wastewater treatment is a core application of reverse osmosis membranes. Through reverse osmosis technology, heavy metal or oil containing wastewater generated by power plants and printing and dyeing factories can be effectively treated. It can also be used to treat urban sewage, garbage leachate, etc., achieving water resource recovery.
In the process of thermal power generation, a large amount of circulating cooling water is used, which usually contains various impurities and high turbidity. If directly discharged, it will cause pollution to the environment. The combination of hollow fiber ultrafiltration membrane elements and polyamide composite reverse osmosis membrane can treat circulating cooling water into reusable water with water turbidity below 0.02 NTU and pollution index below 0.7.
The wastewater generated by printing and dyeing factories contains a large amount of salt ions, color ions, and other substances. The use of ultrafiltration and reverse osmosis dual membrane technology can filter out organic matter, salt ions, etc. in wastewater, and the chemical oxygen consumption of the produced water is not higher than 10 mg/L, indicating a significant water treatment effect.
In traditional wastewater treatment processes containing heavy metals, chemical agents need to be added, and the treatment operation requirements are high. The use of reverse osmosis membranes and multi-stage reverse osmosis technology to treat these wastewater can effectively remove heavy metal elements contained in the wastewater.
The components contained in urban garbage leachate are numerous and complex. The use of polyamide reverse osmosis membrane for its treatment can purify the leachate of garbage to a discharge level, achieving the treatment of leachate of garbage.
- Pure water production
Purified water has a wide range of applications in domestic drinking water, industrial production, and pharmaceuticals. These applications have high requirements for water, and the use of reverse osmosis membranes for water treatment requires compliance with necessary production standards.
Due to the relatively mature production process of ultrapure water, corresponding permeable membrane components can be used in ultrapure water production. The reverse osmosis system can control the water flux to reach 650 m ³/h and produce ultrapure water with a conductivity of 0.3 μ S/cm. The problem of membrane fouling during water treatment can be solved through chemical cleaning methods. The currently commonly used pure water treatment system is the reverse osmosis electrodeionization system.
In terms of industrial water production, in order to meet the demand for use, domestic researchers have proposed a solution to build a reverse osmosis system using ultra-low pressure roll type composite membrane components. The single membrane water production of the permeable membrane in this scheme can reach 41.4 cubic meters per day, with a retention rate of not less than 99.7%, which can fully meet the water demand of caustic soda industry production.
In addition, in the production of chlor alkali industry, it is necessary to filter out Ca ² ⁺ and Mg ² ⁺ ions in the water during the production process. Therefore, PVD reverse osmosis membrane can be used to remove them, while ensuring a low retention rate for sodium chloride, to achieve water treatment and purification in chlor alkali industry production.
In pharmaceutical production, using an ultra-low pressure polyamide composite permeable membrane module ion separation system and applying a two-stage reverse osmosis method to produce pure water required in the pharmaceutical production process can achieve good production results. This water treatment scheme has a recovery rate of no less than 80% after secondary reverse osmosis, which brings significant economic benefits to pharmaceutical companies.