What method is used to remove inorganic dissolved solids from wastewater?

The method of ion exchange is particularly effective for removing inorganic dissolved solids from wastewater. This process relies on the exchange of ions between the wastewater and a solid material, typically a resin that holds specific ions. As water passes through the ion exchange medium, undesirable ions present in the wastewater (such as heavy metals or hardness ions like calcium and magnesium) are exchanged for more desirable ions (like sodium or hydrogen) that are bound to the resin.

Ion exchange is highly versatile and can be fine-tuned to target specific contaminants, making it suitable for various applications in wastewater treatment where the reduction of inorganic solids is necessary. This method is often used in industries where high purity water is essential or where regulations limit the concentration of certain ions in the discharge of treated wastewater.

Other methods, such as filtration, focus primarily on the physical removal of solids rather than targeting dissolved ions. Chemical precipitation involves adding chemicals that react with dissolved substances to form solid particles that can then be removed, but it may not be as effective for certain inorganic dissolved solids as ion exchange. Activated sludge primarily addresses organic matter through biological processes and may not directly affect inorganic dissolved solids.