The Development Journey of Reverse Osmosis

2025-04-08

Reverse osmosis (RO) has emerged as a revolutionary technology in the field of water treatment, with its development journey spanning several decades. This process, which involves forcing a solvent from a region of high solute concentration through a semipermeable membrane to a region of low - solute concentration by applying pressure in excess of the osmotic pressure, has transformed the way we purify water.

The concept of osmosis, on which reverse osmosis is based, was first observed in a laboratory setting in 1748 by Jean - Antoine Nollet. He used a pig's bladder as a membrane and proved that a solvent could pass selectively through a semi - permeable membrane due to natural osmotic pressure. However, it was not until the 20th century that the idea of reverse osmosis began to take shape.

In the 1950s, the University of California and the University of Florida were at the forefront of research into using osmosis and semipermeable membranes to remove salt from seawater. In 1953, C. E. Reid, a professor at the University of Florida, first proposed the concept of reverse osmosis for seawater desalination, and the research was incorporated into the US national plan. In 1960, the University of California successfully prepared the world's first non - symmetric cellulose acetate reverse osmosis semi - permeable membrane with a high desalination rate (98.6%), which was a significant milestone in the development of RO technology. This led to the first application of RO technology in seawater and brackish water desalination.

The 1960s also saw important developments in membrane module manufacturing. In 1961, the American company Hevens first proposed a method for manufacturing tubular membrane modules, and in 1964, the United States developed a spiral - wound reverse osmosis module. In 1965, the University of California created a tubular reverse osmosis device for brackish water desalination.

The 1970s was a crucial experimental stage for RO technology. During this period, research was carried out on cellulose acetate (CA) hollow fiber and spiral - wound reverse osmosis membrane modules. In 1971, DuPont introduced the aromatic polyamide hollow fiber reverse osmosis device "Permasep B - 9", which significantly improved the performance of RO technology. In 1972, Cadotte made a breakthrough in the interfacial polymerization method for preparing reverse osmosis membranes, a method still used by major membrane manufacturers today. Based on this, the first industrial - scale seawater desalination reverse osmosis project was established in 1974.

The 1980s witnessed the industrialization of RO technology. The composite membranes invented in the 1980s, composed of an ultrathin reverse osmosis membrane, a porous support layer, and a fabric reinforcement layer, had high water permeability and a salt rejection rate of up to 99%, making them ideal reverse osmosis membranes. RO membranes were also found to be particularly effective in separating small - molecule organic compounds, enabling their application in various industrial fields such as organic chemical industry, brewing industry, and waste treatment.

In the 1990s, the performance of RO membranes was further enhanced with the advent of low - pressure reverse osmosis composite membranes, which were considered the third - generation RO membranes. RO technology has been widely used in industrial water treatment, including oily and degreasing wastewater, fiber industry wastewater, paper industry wastewater, and radioactive wastewater. It has also been applied in brackish water desalination, pure and high - purity water preparation, the pharmaceutical industry, and special chemical processes.

Today, reverse osmosis technology is an integral part of various water treatment equipment. It is widely used in domestic water purification, industrial water treatment, seawater desalination, and wastewater recycling. As environmental awareness grows and the demand for clean water increases, RO technology is expected to continue to evolve, with further improvements in membrane performance, energy efficiency, and cost - effectiveness. This will enable it to play an even more significant role in meeting the global water challenges in the future.