Weak base anion (WBA) exchange resins contain tertiary amine functional groups attached to the polymer matrix and operate in the free base form. WBA resins do not split neutral salts but only react with strong acids such as hydrochloric acid (HCl), nitric acid (HNO3), and sulfuric acid (H2SO4). WBA resins are typically regenerated with sodium hydroxide (NaOH), ammonia (NH3), or sodium carbonate (Na2CO3). Compared with strong base anion (SBA) exchange resins, WBA resins are easier to regenerate and can be efficiently regenerated with a small amount of NaOH. In addition, WBA resins have greater capacities for mineral acids, better chemical stability and stronger resistance to organic fouling than SBA resins.
WBA resins are used for partial demineralization. In larger plants, WBA resin beds paired with strong SBA units can be used for complete demineralization applications, and WBA resins can also effectively act as total organic carbon (TOC) barriers ahead of SBA beds. WBA resins are also used for acid adsorption applications, including the removal of chloride, sulphate, nitrate, and other anions associated with strong acids, but they are not effective for removal of weak acids such as silica (SiO2) and carbon dioxide (CO2).
Amerigo Scientific offers two types of WBA resins, gel type and macroporous type, with an acrylic, styrene or mixed matrix. These WBA resins can be used in pharmaceutical, food, chemical and other industries to remove mineral acid, organic acids, and other organic materials.