1. Removal of heavy metal ions: chelating agents can form stable complexes with heavy metal ions in water, so as to fix them in water to achieve the purpose of removing heavy metal ions.
2. Prevent scale: Chelating agents can prevent the calcium and magnesium plasma in water from forming scale, because they can form complexes that are stable with these ions.
3. Catalysis: Some chelating agents can promote the occurrence of certain water treatment reactions, such as reducing the residual amount of chlorinated disinfectants in water.
4. Increase water stability: Some chelating agents can increase water stability and prevent it from being contaminated by microorganisms or other pollutants.
Common chelating agents are as follows:
1. EDTA (ethylenediamine tetraacetic acid) : used to remove heavy metal ions from water, such as copper, iron, nickel and zinc.
2. DTPA (diisopropyltriamine pentaacetic acid) : It is mainly used to remove iron, manganese and nickel plasma from water.
3. NTA (N-acetyl-2-amino-acetic acid or triethanolamine tetraacetic acid) : mainly used to remove iron, zinc, copper and nickel plasma from water.
4. HEDTA (ethylenetetraacetic acid-n-hydroxyethylenediamine) : It is often used to remove calcium and magnesium plasma from water.
5. Citric acid (Citric acid) : used to remove calcium, magnesium, iron and zinc plasma from water, which can be used in the food industry, cosmetics industry and water treatment industry.
6. Oxalic acid: It can be used to remove calcium, copper, iron and manganese plasma from water, and can also be used to clean boilers and drinking water equipment.
7. TPED (triethylene diamine tetraacetic acid) : It can be used to remove copper, iron, zinc and nickel plasma from water, and is widely used in the petrochemical industry.
These chelators can stabilize and form complexes with metal ions to achieve the purpose of removing heavy metal ions or other water treatment functions.
