1. General influent should choose reverse osmosis process or ion exchange process?
In many influent conditions, the use of ion exchange resin or reverse osmosis is technically feasible, the choice of process should be determined by economic comparison. In general, the higher the salt content, the more economic reverse osmosis, the lower the salt content, the more economic ion exchange. Due to the popularity of reverse osmosis technology, the combination of reverse osmosis + ion exchange process or multi-stage reverse osmosis or reverse osmosis + other deep desalting technology has become a recognized more reasonable water treatment scheme in the technology and economic.
2. What are the influent requirements for RO membrane elements and IX ion exchange resins?
In theory, entry to RO and IX systems should not contain the following impurities:
Suspended solids, colloid, calcium sulfate, algae, bacteria, oxidants, such as residual chlorine, oil or lipid substances (must be lower than the detection limit of the instrument), organic and iron-organic complexes, iron, copper, aluminum corrosion products and other metal oxides, water quality will have a huge impact on the life and performance of RO elements and IX resin.
3. What's the difference between reverse osmosis and nanofiltration?
Nanofiltration is located between reverse osmosis and ultrafiltration membrane liquid separation technology, reverse osmosis can remove the smallest solute, molecular weight is less than 0.0001 micron, nanofiltration can remove the molecular weight of about 0.001 micron solute. Nanofiltration is essentially a type of low pressure reverse osmosis. It is used in situations where the purity of the water produced after treatment is not particularly strict. Nanofiltration is suitable for treating well water and surface water. Nanofiltration is suitable for water treatment systems without the need for high desalination rates like reverse osmosis, but it has a high removal capacity for the hardness components, and is sometimes called "softening film". The nanofiltration system has low operating pressure and lower energy consumption than the corresponding reverse osmosis system.
4. Can reverse osmosis remove microorganisms such as viruses and bacteria?
Reverse osmosis is very dense and has a very high removal rate for viruses, bacteriophages and bacteria, at least above 3log. However, it should also be noted that in many cases, microbial re-breeding may still occur on the membrane water-producing side, which mainly depends on the way of assembly, monitoring and maintenance. In other words, the ability of a system to remove microorganisms depends on the proper design, operation and management of the system rather than the nature of the membrane element itself.
5. What impurities can RO memrane remove?
RO membrane can remove ions and organic matter very well, reverse osmosis membrane has a higher removal rate than nanofiltration membrane, reverse osmosis can usually remove 99% of the salt in the water, the removal rate of organic matter in the water ≥99%.
