Electrodialysis Water Treatment – All You Need To Know
Water purification, as a process, involves the removal of biological, chemical and many other undesirable water contaminants. Principally, its major aim is to clean contaminated water to a level fit for human consumption, food processing, and agricultural use. Nowadays, people can utilize several water purification methods. For instance, they can use simple techniques such as filtration, flocculation, and sedimentation to advanced ones such as electromagnetic radiation. However, those who want an effective alternative may use electrodialysis.
What is Electrodialysis?
Electrodialysis is a water desalination system that uses electrical potential to remove charged impurities from water. Principally, it generates an electric current that separates chloride and sodium ions as water passes through the system. The system comprises of an anode and a cathode. These attract negative and positively charged ions respectively and trap them in semipermeable membranes fitted on both ends. As a result, it flushes off ions and releases pure water that people can use for various activities.
Which areas can people use this water treatment process?
Individuals can apply electrodialysis in batch or continuous production processes. While using the batch system, people will have to re-circulate water streams in the electrodialysis system until they achieve the needed quality. In contrast, continuous production systems are fitted with ample electrodialysis stacks that yield the required quality with a single run. Independent of the system used, individuals can use electrodialysis in the following areas:
- De-ionization of salty water and salt production
- Production of drinking water (small, medium, or high production) by hotels or hospitals
- Water reuse systems
- Food processing
What are the pros of using electrodialysis?
While using this type of process, people will have a number of advantages which include:
Low energy consumption: Electrodialysis systems purify water without changing its phase. For example, it does not require conversion of water to gas then cooling to release pure water. As a result, it lowers energy consumption and thus lowers the cost of production.
Limited post-treatment: When people use electrodialysis systems to desalt drinking water, they need to carry out limited treatment to bring it to the required purity level. Thus, they may only need to chlorinate the water to make it fit for consumption.
Longevity: As compared to other systems, electrodialysis uses few chemicals and is durable. Generally, its membrane can last for a period of up to 10 years. Therefore, individuals enjoy a high pure water recovery rate for a long duration.
These and other properties make electrodialysis an effective water purification method.
How About The Cons?
Although this system offers an efficient water purification system, it also has some cons.
Although electrodialysis is efficient in removing low molecular weight ions, it has limitations when it comes to removing less-mobile ions or non-charged ones. In addition, it does not remove colloids and other organic matter.
People have to pre-treat water before channelling them as streams in the systems. This helps to prevent fouling or scaling the electrodialysis stacks.
Generally, even though electrodialysis is an efficient water purifying systems, its users must buy quality membranes that are compatible to their systems. It is therefore, imperative that they only buy goods from reputable local or online retailers.