Reverse osmosis membrane fouling
Possible contaminant location Pressure drop Inlet pressure Desalination rate decreases
Metal oxide contamination (Fe, Mn, Cu, Ni, Zn)
, The frontmost membrane element rapidly increases rapidly increasing rapidly
Colloidal contamination (organic and inorganic mixtures)
A, the most front-end membrane element gradually increased gradually increased slightly
Mineral scale (Ca, Mg, Ba, Sr)
At the end, the final end of the membrane element moderately increased with mild increase in the general increase
Polymeric silicon deposits
The final, last-end membrane element generally increases in general increase
Biological pollution
In any position, typically the front end membrane element is significantly increased by a significant increase in the general increase
Organic contamination (insoluble NOM)
All segments were gradually increased and decreased
Scale inhibitor pollution
The most severe general increase in the general increase
Oxidative damage (Cl2, Ozone, KMnO4)
No matter how perfect reverse osmosis system design, and how to improve the measures taken, membrane fouling is inevitable. When the performance of the reverse osmosis system is reduced to an unacceptable level and other factors have been excluded, it can be concluded that the membrane has been contaminated and needs to be cleaned to restore its performance.
At present, relying on experience to determine the membrane fouling, and choose different cleaning agents to try again and again, this method is usually implied more subjective content, the results of the film have different degrees of damage.
Membrane contaminants are commonly known as silt, particulates, colloids, fats, oils, proteins, insoluble salts, polymeric polysaccharides, and extracellular polymers. From the actual situation analysis, membrane fouling is often not a single, but a variety of complex sediments, that will be a variety of membrane pollutants classified analysis, is an ideal approach.
Successful practice has shown that not only is it simple to judge membrane fouling by experience, but also scientific detection techniques such as atomic absorption spectroscopy, electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, mass spectrometry and DNA detection. , To accurately identify the actual membrane contaminants, so that the correct choice of film cleaning agent and cleaning process.
