We are Manufacturer, Supplier, Exporter of Demineralization (DM) Plants / Deionized (DI) Water Treatment Plants and our setup is situated in Pune, Maharashtra, India. This product is also known as Deionized WTP, DI WTP. We also provide Installation, Annual Maintenance Contract (AMC) Services, Operation And Maintenance Contract Services, Chemicals, Equipments, Spares (Spare Parts) for our whole product range.
Ions are electrically charged atoms or molecules found in water that have either a net negative or positive charge. For many applications that use water as a rinse or ingredient, these ions are considered impurities and must be removed from the water.
Ions with a positive charge are called "Cations" and ions with a negative charge are called "Anions". Ion exchange resins are used to exchange non desirable cations and anions with hydrogen and hydroxyl, respectively, forming pure water (H20), which is not an ion. Below is a list of ions commonly found in municipal water.
Cations (Removed by Cation Resins) | Anions (Removed by Anion Resins) |
---|---|
Calcium (Ca2+) | Chloride ( Cl-) |
Magnesium (Mg2+) | Bicarbonate (HCO3-) |
Sodium (Na+) | Nitrate (NO3-) |
Potassium (K+) | Carbonate (CO32-) |
Iron (Fe+++) | Sulfates (SO4--) |
Hydrogen (H+) | Silica (SiO2-) |
Manganese (Mn++) | Hydroxyl (OH-) |
How does ion exchange work?
Ion exchange resins are used to produce Deionized water (dematerialized water or "DI
Water"). These resins are small plastic beads that are composed of organic polymer
chains that have charged functional groups built into the resin bead. Each functional
group has either a fixed positive or negative charge.
Cation resin has a negative functional group and therefore attracts positively charged
ions. There are two types of cation resins, weak acid cation (WAC) and strong acid
cation (SAC). Weak acid cation resin is used mainly in dealkalization and other unique
applications. For this reason we will focus on explaining the role of strong acid cation
resins used for producing deionized water:
Anion resin has a positive functional group and therefore attracts negatively charged
ions. There are two types of anion resins, weak base anion (WBA) and strong base anion
(SBA). Both types of anion resins are used to produce deionized water, however, they
have different characteristics listed below:
WBA resins do not remove silica, C02 or have the ability to neutralize weak acids and
has a lower than neutral pH when used in a dual separate bed system.
SBA resins remove all anions in the above table, including C02, and has a higher than
neutral pH when used in a dual separate bed system due to sodium leakage.
Mixed bed resins use SAC and SBA resins combined together.
In order to produce deionized water, cation resin is regenerated with Hydrochloric Acid
(HCl). The Hydrogen (H+) is positively charged and therefore attaches itself to the
negatively charged cation resin bead. The anion resin is regenerated with sodium
hydroxide (NaOH). Hydroxyl (OH-) is negatively charged and attaches itself to the
positively charged anion resin bead.