Reverse Osmosis Concentrated Water Treatment Technology Research

Abstract

With the national “double carbon” goal, energy saving and consumption reduction strategic plan to promote, more and more enterprises will be “zero discharge” of wastewater as the ultimate goal of industrial wastewater. Reverse osmosis (RO) process is the most common way of water treatment process, in the treatment of water treatment and pure water preparation at the same time, will be accompanied by a variety of inorganic and organic pollutants contained in the by-products of concentrated water, these difficult to deal with high salt, complex composition of the reverse osmosis concentration of water, not directly discharged without treatment, not only to make a lot of water in the concentration of water to be a waste of water resources, will be a large extent on the ocean, soil and other natural environments to cause irreversible damage. Reversible damage to the ocean, soil and other natural environments. Therefore, it is of great significance to protect the environment by finding an economical and efficient treatment method for RO concentrated water. For the regeneration of fresh water resources of RO concentrated water, there have been many international reports on the development of zero liquid discharge (ZLD) or near-zero liquid discharge technology, through the membrane technology to reverse osmosis concentrated water concentration, water recycling, reduce the volume of concentrated water, and then based on the thermal technology of concentrated water desalination, evaporation and crystallization process leads to the recovery of water, and at the same time, the process of solid by-products after dehydration, purification, can also produce a considerable amount of water. At the same time, the solid by-products produced in the process can be dehydrated and purified, which can also produce considerable economic value of commodities. Concentrated water concentration process around how to achieve low-cost RO concentrated water concentration process, in the disc tube reverse osmosis (DTRO), electrodialysis (ED), membrane distillation (MD) and forward osmosis (FO) and other new membrane concentration technology field carried out a wide range of research on the concentration of further concentrated water to provide more prospects for application. Solidification crystallization through reasonable crystallization control and solid-liquid separation technology, can achieve effective separation and purification of solutes, for various industries to provide solid products in line with the quality requirements, commonly used evaporation crystallization, cooling crystallization, solvent crystallization, ion exchange methods and other ways. Through the study of reverse osmosis concentrated water concentration treatment, crystallization and solidification of the two important links of the production process plan, summarize the practicality of various technologies and advantages and disadvantages, integration of existing technologies, research suitable for reverse osmosis concentrated water resources utilization of economic technology solutions, optimize the treatment process, and ultimately realize the application of engineering examples, is the direction of the efforts of researchers in recent years.