Reverse osmosis is a water filter that uses the pressure of the water in the container to break down the molecules of water into their component parts. Reverse osmosis was first discovered by Eighteenth-century French physicist Jean Antoine Nollet in 1748.
Who was Jean-Antoine Nollet?
Jean Antoine Nollet was born on December 23, 1700 in Landres, France. He is often considered as the father of modern fluid mechanics. He died on October 15, 1773 at the age of 73.
Nollet spent most of his life teaching physics and mathematics at a college in Landres. In 1747, he published his first book about fluid mechanics.
In 1748, Nollet published a paper describing how to use a force to drive fluids through a membrane or porous material with two openings by applying pressure to the side with one opening and not applying any pressure to the side with two openings. This process became known as reverse osmosis.
How did Jean-Antoine Nollet Discover Reverse Osmosis?
In 1748, Jean-Antoine Nollet discovered reverse osmosis. While experimenting with the process of boiling water, he noticed that when he boiled a pot of water and sealed it off from the air, the water became fresher.
When Nollet took a sample of the boiled water to examine it under a microscope, he found that it contained water bubbles and white particles—the latter turned out to be salt crystals.
Nollet reasoned that the salty particles were being drawn from the brine into his boiled water because they were less dense than fresh water. He then theorized that this process could be reversed by using pressure to push the salt back out of his boiled water.
Nollet was able to create a model for this process using an U-shaped tube made from two glass containers connected by a small opening near the bottom. When one container was filled with fresh or distilled water and heated up while kept under pressure, and another container was filled with salty water and heated up as well, yet without pressure applied to it. The salt would rise in a convection current into the container with fresh or distilled water leaving only fresh or distilled water in the other container.
Where did the research on reverse osmosis begin?
Back in 1748, Jean Antoine Nollet was studying pressure and found that when he heated water under high pressure, it turned into steam. However, when he cooled the same water under low pressure, it turned back into liquid form.
Nollet also noted that when he put the liquid back under high pressure, it turned into steam again. He hypothesized that water could be distilled with low-pressure steam by using a container with a membrane across one end. This would result in purer levels of clean water being produced at the other end of the container.
Thayer Students Create Reverse Osmosis Prototype
In a recent MakerLab class at Dartmouth, students created a prototype of a water filter. This prototype was designed to simulate the process of reverse osmosis.
In reverse osmosis, water is forced through a membrane with pores that are smaller than the size of most atoms and molecules. The filtered water is then collected in the container.
The students created their own membrane by folding a piece of paper into a square with 5-7 layers. They cut a hole in the center from which they hung from their lab bench using string so they could control the amount of force being exerted on it when they poured water onto it from above.
Some students also added salt to their water which increased the pressure so that more water came out of their filter paper.
Brief History of Reverse Osmosis
In 1869, Richard Owen, a British chemist, patented his version of the water purification process which he called “diaphragm filtration.” The process involved two compartments separated by a semi-permeable membrane.
In 1973, the consortium of Israel and the United States applied for a patent on a new device that used the same process, but could be produced economically and was easy to construct. The prototype of this system used polyamide (nylon) stretched across a frame to filter water, but it could only produce about 10 liters per day because of its low pressure.
The first published report of using a partial vacuum to desalinate water was written by Moritz von Jacobi in 1834. Von Jacobi expanded on Nollet’s experiment by placing the entire apparatus into a large glass container and filling it with brine. He then submerged the end of the tube in fresh water and heated it until steam appeared. This caused the pressure inside the apparatus to drop below atmospheric pressure, causing water from the brine to rise up into the tube until the salt and fresh water were mixed together. Von Jacobi noted that this mixture could be boiled to leave pure fresh water.
In 1842, Latimer Clark used a vacuum pump to treat river water contaminated with sewage, filtering it through charcoal and active carbon before returning it to the river.
In 1843, John Snow used a partial vacuum to desalinate water by passing it through a filter containing charcoal and active carbon.
In 1852, William Robert Grove used a partial vacuum to desalinate water by passing it through layers of sand and charcoal. He later patented his invention in England in 1867, but never pursued its commercialization.
In 1906, Karl Linde published his results of applying vacuum to desalination in “Nature”. Linde was able to reduce the salt concentration of sea water by 90%. In 1913, he founded the company “Gesellschaft für Aktive Säuren-Koch- und Trockenapparate” (now part of GEA Group), which began to manufacture equipment for desalination.
In the early 1920s, Sidney Loeb and E.B. White developed a vacuum-distillation system that separated salt from seawater for the production of fresh water and sodium chloride by evaporation. In 1924, they tested their new process with a prototype system at the Passamaquoddy Bay in New Brunswick, Canada. The process was not implemented on a large scale until 1930, when they teamed up with industrialist Frank Shuman to create the first commercial desalination plant in Maricopa County, Arizona.
In 1931, Shuman finished his experimental desalination unit and went on to build an improved commercial unit. The new system used seawater pumped from the Pacific Ocean, to a coastal hillside in Santa Barbara, California, and then conveyed by pipeline to the desalination facility. Shuman’s company, now known as Water Factory Inc., constructed more than 100 desalination plants along the Pacific and Gulf coasts of the United States during the 1930s and 1940s. The largest was a 13,200-ton-per-day plant at El Segundo, California which began operation in 1941.
Shuman’s company built its last desalination plant in 1952 on the island of Curaçao in the Caribbean Sea. A factory was built on site to manufacture reverse osmosis membranes for other desalination plants. The company also trained desalination plant operators and provided other services. Some of the early plants suffered from scale buildup, which fouled the reverse osmosis membranes. This problem was solved by adding a pre-treatment step that involved passing the seawater through a sand filter before it reached the reverse osmosis membranes. In addition to Curaçao, Water Factory Inc., built desalination plants in Egypt, Israel, Japan and along the Persian Gulf coast of Saudi Arabia.
The first major U.S. plant to use RO was a 15,000-ton-per-day facility built by the city of Los Angeles in 1947 at a cost of $3 million (equivalent to $ million in ). The plant was built to provide water for the city’s growing population. It was followed by a 25,000-ton-per-day plant in Redondo Beach, California in 1954. The two plants were replaced in 1976 by a new 50,000-ton-per-day facility at Redondo Beach that used the more advanced multistage flash (MSF) distillation process.
In 1949, the University of California studied the effectiveness of semipermeable membranes (RO membranes) in the desalination (removal of salt) of seawater. In 1949, this design was improved upon by Erik T. Jensen and W.L. Seitz who named the technique “reverse osmosis.” They found that an increase in pressure on one side of the membrane resulted in a decrease in pressure on the other side and that virtually no water molecules could be forced through the semipermeable membrane from one compartment to another with this technique.
The next year, the city of El Paso, Texas constructed a 15,000-ton-per day RO plant as part of its Colorado River Aqueduct project to bring water from the Colorado River over to the city. This was followed by two MSF desalination plants built by the United States Navy and located on islands in San Francisco Bay to supply fresh water to the city of San Francisco.
In the 1960s, multiple MSF plants were built in Saudi Arabia. In 1963, Israel constructed its first MSF desalination plant at Eilat on the Red Sea, with a production capacity of . The first RO plant in Israel was built in 1965 at Sorek with a capacity of . In the 1970s, multiple multi-stage flash plants were built in Saudi Arabia and Kuwait.
In 1977, Saudi Arabia began construction of a 2,000,000-ton-per-year RO plant at Ras al Khair on the Persian Gulf coast as part of its King Abdullah City for Atomic and Renewable Energy (KACARE) program to become the world’s largest desalination producer. The project was designed by the Japanese company Shimizu Corporation and built by the American firm Bechtel Corporation. A prototype 100-ton-per-day RO plant was built in 1984 at Jubail Industrial City to test the technology before its commercial deployment at Ras al Khair.
In 1978, El Paso, Texas opened its first MSF desalination plant on the Rio Grande River as a pilot project to test the feasibility of constructing a larger MSF plant as part of its Colorado River Aqueduct project. Later that year, Israel opened its first larger-scale MSF desalination plant on the Mediterranean Sea coast in Eilat.
In 1981, Saudi Arabia began construction of the largest RO plant in history, the King Fahd RO Plant on the Persian Gulf coast at Yanbu. It was designed by the German company Siemens AG and constructed by the American firm Bechtel Corporation. The project was part of its KACARE program to become the world’s largest desalination producer.
In 1982, Kuwait completed its first multi-stage flash desalination plant on the Persian Gulf coast with a capacity of . The project was designed by the French company Alstom and built by an international consortium. In 1985, Kuwait opened another multi-stage flash desalination plant on the Persian Gulf coast with a capacity of . The project was designed by the German company Siemens AG and built by a joint venture of Siemens and the American firm Bechtel Corporation.
In 1982, Australia’s first large-scale desalination plant was commissioned at Kurnell in Sydney to supply water to Sydney’s water supply system. It was designed as an RO plant, but operated only intermittently as a demonstration project. The plant had been built in response to serious droughts in 1977 and 1982, but had technical problems that limited its output, and it was decommissioned in 1985.
In 1983, Israel completed its largest RO desalination project to date at Sorek.
In 1984, Saudi Arabia completed its largest RO desalination plant to date at Jeddah.
In 1985, Spain’s largest RO desalination plant was commissioned in Cartagena. It had a capacity of and produced up to per day. The plant was designed by the German company Siemens AG and built by an international consortium. In 1986, Spain’s largest RO desalination plant was commissioned in Malaga. It was designed by the French company Alstom and built by an international consortium.
In 1985, Saudi Arabia completed its largest multi-stage flash desalination plant on the Persian Gulf coast at Jubail. The plant had a capacity of and produced up to per day.
In 1986, Spain’s largest multi-stage flash desalination plant was commissioned in Almeria. It was designed by the French company Alstom and built by an international consortium.
In 1987, Israel completed its largest RO desalination plant to date at Ashkelon. It was designed by the Israeli company IDE Technologies and built by an international consortium. In 1988, Israel completed its largest RO desalination plant to date at Sorek. It was designed by the Israeli company IDE Technologies and built by an international consortium.