Membrane regeneration methods in wastewater treatment

Membrane technologies have become widespread in recent years and have a big chance of eventually replacing the classic wastewater treatment system that no longer meets the needs of the modern world. The method of membrane separation, combined with previous biological treatment, is characterized by a high degree of purification, stability of the system irrespective of load fluctuations, and low environmental impact. However, there are several disadvantages among all the positives, the main ones being the high cost and the membrane fouling. These problems are interrelated, so if you solve the problem of membrane fouling, then the high cost will pay off over time. Hundreds of scientific studies in this field have succeeded in minimizing the negative effects of membrane fouling and clogging/sludging, which have long been the main limiting factors for widespread introduction of membrane technologies. To reduce the limiting effect of fouling on the membrane, a number of indicators can be adjusted, including hydrodynamic mode, peculiarities of membrane operation and purification, quality of feeding water and concentration of impurities, and characteristics and material of the membranes. Although the techniques for minimizing fowling have been developed in different directions, when developing the right approach, they can be combined with a much better effect, for example, combined membrane purification, including backwashing, relaxation, and chemical periodic treatment. In the last decade, membrane technologies have become widespread, and their introduction into existing wastewater treatment plants continues to grow in various countries all over the world, including Sweden, China, Singapore, the United States, Korea, and others. Provided effective inhibition of membrane fouling, such systems have the potential to become the main wastewater treatment plants. In the review article the basic methods of membranes purification – from classical to the recent developments – are systematized