HEDP: Leave "scaling" in the past and "green" for the future.

Due to increasingly strict environmental regulations, countries in Europe, America, the Middle East and the Asia-Pacific region have successively lowered the total phosphorus limit for wastewater and imposed heavy fines and credit downgrades for excessive emissions. This has restricted the use of traditional high-phosphorus scale inhibitors. However, HEDP (Etidronic acid), with its environmental friendliness, has a promising market prospect.

Etidronic acid, also known as 1-hydroxyethane-1,1-diphosphonic acid, has the chemical formula C₂H₈O₇P₂, CAS number 2809-21-4, and a molecular weight of 206.03. At room temperature, it appears as white crystalline granules or pale beige powder, with a melting point of 198 to 199 degrees Celsius and a density of 2.1±0.1 g/cm³. It is readily soluble in water, methanol, and ethanol, and its aqueous solution is a colorless to pale yellow liquid.

Compared with traditional phosphorus-based scale inhibitors, HEDP can effectively inhibit the formation of common water scale such as CaCO₃ and CaSO₄. Due to its low phosphorus content, it remains stable at high temperatures and is suitable for high-temperature environments such as boilers and heat exchange systems. It can also be compounded with other water treatment agents to enhance the overall corrosion inhibition and scale inhibition effect. These characteristics make HEDP an ideal choice for industrial circulating water, central air conditioning cooling water, oilfield injection water and other systems.

With the development of the water treatment industry towards green and intelligent, HEDP can be used in conjunction with new corrosion inhibitors and biocides to improve the overall treatment effect. In the process of seawater desalination, it can effectively prevent salt deposition, extend the service life of reverse osmosis membranes, and improve the overall treatment effect.