Membrane systems filter and remove impurities from wastewater. Membrane systems are used in water treatment facilities to separate impurities from water that must be recycled back into the distribution pipeline. Pumps are used in these systems, which use a variety of filtration methods such as reverse osmosis, nano-filtration, ultrafiltration, and microfiltration.
Membrane systems use technology to separate water from other substances like oil and gas. Chemicals are rarely used in these systems to remove impurities from the water. Membrane systems filter all types of water, including ground, waste, and surface water. The systems are typically used in manufacturing plants or wastewater treatment facilities and are of industrial size.
A semi-porous wall within the system catches a certain amount of solid waste. The wall allows water to pass through while trapping heavier and thicker liquids. Because the wall does not always stop all pollutants, some wastewater treatment plants use additional treatments to remove hazardous substances.
Some membrane systems used in industrial settings are housed in water tanks, while others rely on a pressurized system involving multiple pumps. Membrane technology can remove up to 98 percent of water pollutants, depending on the make and model. Different processing speeds and filtration methods can be tailored to the needs of the plant.
To catch larger-sized solids, treatment plants typically use micro and ultra filtration methods. The pressure in these membrane systems is usually lower, but the amount of water they process is quite large. Plants that need to be as productive as possible and treat water that does not contain small foreign substances may use this type of filtration.
When smaller particles need to be removed from water, nano-filtration and reverse osmosis may be used. Many bottled and spring water distributors use reverse osmosis as a filtration method to purify drinking water. Because many of the impurities in drinking water are microscopic, reverse osmosis is commonly used in at-home filtration systems that attach to faucets. Because of the high pressure used in these filtration methods, productivity is typically lower.
Membrane systems that are designed to eliminate small particles have higher levels of selectivity. Nano-filtration and reverse osmosis use a technique called diffusion to separate the particles from the water rather than a semi-porous wall. Using a series of random movements, this technique spreads the impurities apart.