HEDP

HEDP

HEDP

1-Hydroxyethylidene-1, 1-Diphosphonic Acid (HEDP)

HEDP is an organophosphoric acid corrosion inhibitor. 
It can chelate with Fe, Cu, and Zn ions to form stable chelating compounds. 
It can dissolve the oxidized materials on these metals surfaces. 

HEDP shows excellent scale and corrosion inhibition effects under temperature 250°C. 

HEDP has good chemical stability under high pH value, hard to be hydrolysed and hard to be decomposed under ordinary light and heat conditions. 
It’s acid/alkali and chlorine oxidation tolerance are better than that of other organophosphoric acids (salt). 
HEDP can react with metal ions in water systems to form hexa-element chelating complex, with calcium ions in particular. 
Therefore, HEDP has good anti-scale and visible threshold effects. 
When built together with other water treatment chemicals, it shows good synergistic effects. 

The solid state of HEDP is a crystalline powder, suitable for usage in winter and freezing districts. 
Due to its high purity, it can be used as a cleaning agent in electronic fields and as an additive in daily chemicals.

EC / List no.: 220-552-8
CAS no.: 2809-21-4
Mol. formula: C2H8O7P2

CAS No.    2809-21-4
EC No.    220-552-8
Synonyms: 1-Hydroxyethane-1,1-diphosphonic acid; 1-Hydroxyethylidene-1,1-diphosphonic acid; 1-hydroxyethylidenedi(phosphonic acid); Etidronic Acid; 1-Hydroxyethylidene-1,1-bis-(phosphonic acid); Ethane-1-hydroxy-1,1-diphosphonic acid; 1-Hydroxy-1,1-diphosphonoethane; Oxyethylidenediphosphonic acid

HEDP
1-Hydroxy Ethylidene-1,1-Diphosphonic Acid and its salts (e. g. HEDP Na4)

INDUSTRIES
HEDP is used as chelating agent (especially for metal ions such as Fe, Cu and Zn), corrosion inhibitor and stabilizing agent (water hardness, peroxides) in the detergents industry, water treatment, metallurgy and dyeing industry.

HEDP is a 1,1-bis(phosphonic acid) that is (ethane-1,1-diyl)bis(phosphonic acid) having a hydroxy substituent at the 1-position. It inhibits the formation, growth, and dissolution of hydroxyapatite crystals by chemisorption to calcium phosphate surfaces.

Usage
HEDP is used as a scale and corrosion inhibition in circulating cool water systems, oil field and low-pressure boilers in fields such as electric power, chemical industry, metallurgy, fertilizer, etc. 
In light woven industry, HEDP is used as detergent for metal and non-metal. 
In the dyeing industry, HEDP is used as peroxide stabilizer and dye-fixing agent; in non-cyanide electroplating, HEDP is used as chelating agent. 
The dosage of 1-10 mg/L is preferred as a scale inhibitor, 10-50 mg/L as corrosion inhibitor, and 1000-2000 mg/L as detergent. 
Usually,HEDP is used together with poly-carboxylic acid. 

etidronic acid has role antineoplastic agent 
etidronic acid has role bone density conservation agent 
etidronic acid has role chelator 
etidronic acid is a 1,1-bis(phosphonic acid) 
etidronic acid is conjugate acid of etidronic acid(2−) 
etidronic acid(2−) (CHEBI:77356) is conjugate base of etidronic acid 

Product Name/Synonyms: Hydroxyethylidene Diphosphonic Acid; Sal HEDP Phosphonate; HEDP (A); HEDPA; ETIDRONIC ACID;1-Hydroxy Ethylidene-1,1-Diphosphonic Acid; Hydroxyethylidene-1,1-diphosphonicacid(HEDP); 1-HYDROXYETHYLIDENEDIPHOSPHONIC ACID; Hydroxyethylidene Diphosphonic acid (HEDP);1-hydroxy-1,1-Ethanediyl ester
CAS No.: 2809-21-4

Name:Etidronic acid
CAS Number: 2809-21-4
Synonyms:(1-Hydroxyethylidene)bisphosphonic acid, 1-Hydroxy-1,1-diphosphonoethane, Etidronic acid, (1-Hydroxyethylidene)bis(phosphonic acid), (1-Hydroxyethylidene)diphosphonic acid, (Hydroxyethylidene)diphosphonic acid, 1-Hydroxyethane-1,1-bisphosphonic acid, 1-Hydroxyethane-1,1-diphosphonate, 1-Hydroxyethane-1,1-diphosphonic acid, 1-Hydroxyethanediphosphonic acid, 1-Hydroxyethylidene-1,1-bisphosphonate, 1-Hydroxyethylidene-1,1-diphosphonic acid, Acetodiphosphonic acid, EHDP, Ethane-1-hydroxy-1,1-diphosphonate, Ethane-1-hydroxy-1,1-diphosphonic acid, HEDP, Hydroxyethane-1,1-diphosphonic acid, Hydroxyethanediphosphonic acid, Phosphonic acid, (1-hydroxyethylidene)bis-, Phosphonic acid, (1-hydroxyethylidene)di-

Name:    (1-hydroxy-1-phosphonoethyl)phosphonic acid

1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP) is a cost effective scale inhibitor used in various industrial applications such as industrial water treatment and detergents. It further shows good stability in presence of chlorine as well as corrosion inhibition properties in presence of zinc and other phosphates. HEDP can be also used as chelating agent in the textile industry.

HEDP is an organophosphoric acid corrosion inhibitor. 
HEDP can chelate with Fe, Cu, and Zn ions to form stable chelating compounds.
Hydroxyethylidene Diphosphonic Acid can dissolve the oxidized materials on these metals’ surfaces. 
HEDP shows excellent scale and corrosion inhibition effects under temperature 250℃. 
HEDP has good chemical stability under high pH value, hard to be hydrolyzed, and hard to be decomposed under ordinary light and heat conditions. 
Its acid/alkali and chlorine oxidation tolerance are better than that of other organophosphoric acids (salt). 
HEDP can react with metal ions in water system to form hexa-element chelating complex, with calcium ion in particular. 
Therefore, HEDP has good antiscale and visible threshold effects. 
When built together with other water treatment chemicals, it shows good synergistic effects.

The solid state of HEDP is crystal powder, suitable for usage in winter and freezing districts. Because of its high purity, it can be used as cleaning agent in electronic fields and as additives in daily chemicals. 

Use: Is a bisphosphonate used in detergents, water treatment, cosmetics and pharmaceutical treatment. Etidronic acid (Didronel -) is a bisphosphonate used to strengthen bone, treat osteoporosis, and treat Paget’s disease of bone.

This product is a colourless to pale yellow clear liquid. HEDP is widely used as a sequestrant, chelating and deposit control agent, and provides excellent control of calcium and other metal salts (including iron and manganese) by acting as a strong crystal modifying agent and threshold inhibitor.
HEDP is a 60% active aqueous solution and is part of the Bisphosphonic Acid Group. It is highly water soluble and stable under harsh conditions, which makes it ideal for water treatment. The main uses in the water treatment industry are, reverse osmosis formulation, cooling water treatment, boiler water treatment, swimming pools, scale and corrosion inhibitor.

HEDP also known as etidronic acid shows multifunctional properties that includes scale inhibition and corrosion inhibition. It can chelate metal ions like Fe, Cu and Zn. It shows good chemical stability under high pH value. Furthermore, it is difficult to hydrolyze and decompose under ordinary light and heat conditions.
HEDP is used in several end use applications that include detergents, paper and personal care, oilfield, textile, water treatment. Furthermore, it can be used for formulating RO membrane antiscalants, thermal desalination antiscalants, formulation for treating sterilizers etc. It can be used directly also for such applications.

Alternate name/synonyms:
HEDP(A);HEDPA;
Etidronic Acid;
1-Hydroxy Ethylidene-1,1-Diphosphonic Acid;
Hydroxyethylidene-1,1-diphosphonic acid (HEDP);
1-Hydroxyethylidenediphosphonic Acid;
Hydroxyethylidene Diphosphonic acid (HEDP);

1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP)
1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP) acid with its CAS number 2809-21-4​  is a cost effective scale inhibitor used in various industrial applications such as industrial water treatment and detergents.

1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP) further shows good stability in presence of chlorine as well as corrosion inhibition properties in presence of zinc and other phosphates and can also be used as chelating agent in the textile industry.

Main Applications for HEDP are as follows:

Cooling water systems / industrial water treatment
Industrial detergents
Swimming pools
Metal surface treatment as a corrosion inhibitor for steel
Stabilizer in H2O2 solutions
Sequestering agent in textile auxiliaries
 

HEDP is used as scale and corrosion inhibition in circulating cool water system, oil field and low-pressure boilers in fields such as electric power, chemical industry, metallurgy, fertilizer, etc.. In light woven industry, HEDP is used as detergent for metal and nonmetal. In dyeing industry, HEDP is used as peroxide stabilizer and dye-fixing agent; In non-cyanide electroplating, HEDP is used as chelating agent. The dosage of 1-10mg/L is preferred as scale inhibitor, 10-50mg/L as corrosion inhibitor, and 1000-2000mg/L as detergent. Usually, HEDP is used together with polycarboxylic acid.

Hydroxy ethylene diphosphonic acid (HEDP), another name: HEDP; HEDPA; (1-hydroxy ethylene) di 2 ethylhexyl phosphonic acid; 1-hydroxy ethylene-1, the 1-di-phosphate.CAS No.2809-21-4, molecular formula C 2H 😯 7P 2, relative molecular mass: 206.02, structural formula is:
HEDP belongs to organic phosphine acids anti-incrustation corrosion inhibitor, 
HEDP can form stable complex compound with multiple metals ions such as iron, copper, aluminium, zinc, can the surperficial oxide compound of dissolution of metals.

Application: Complexing agent for liquid detergent formulations

HEDP (Hydroxyethylidene Diphosphonic Acid) is an odourless organic phosphorus chemical compound. For one thing, it is colourless to yellowish acidic liquid   Moreover, HEDP is an organic phosphonic acid corrosion inhibitor. HEDP acid is used in various industrial applications. Such as industrial water treatment corrosion inhibitor and detergents. It further shows good stability in presence of chlorine.  The same good as corrosion inhibition properties in presence of zinc and other phosphates.
Another key point, HEDP can dissolve the oxidized materials on these metals’ surfaces. It shows excellent scale and corrosion inhibition effects under temperature 250℃. Hydroxyethylidene diphosphonic acid has good chemical stability at high pH value. For this reason, it hard to be hydrolyzed and decomposed under ordinary light and heat conditions. Its acid/alkali and chlorine oxidation tolerance are better than that of other organic phosphonic acids (salt).
The solid state of Hydroxyethylidene Diphosphonic Acid is crystal powder. Because of its high purity, HEDP is suitable for usage in winter and freezing districts. Solid state HEDP can be used as a cleaning agent in electronic fields and as additives in daily chemicals. (There are too many impurities in the liquid, so it can’t be used for electronic cleaning and daily use.)
HEDP can chelate with Fe, Cu, and Zn ions to form stable chelating compounds. In other words, HEDP acid can react with metal ions in the water system to form a hexa-element chelating complex, with calcium ion in particular. Therefore, HEDP has good antiscale and visible threshold effects. When built together with other water treatment chemicals, HEDP shows good synergistic effects. Hydroxyethylidene diphosphonic acid can be also used as chelating agent in the textile industry.

Applications
Used as scale and corrosion inhibitor in cooling water systems

Used as scale and corrosion inhibitor in industrial water treatment

Used as industrial detergentsUsed in Swimming pools

Used in metal surface treatment as corrosion inhibitor for steel

Used as stabilizer in H2O2 solutions

Used as sequestering agent in textile auxiliaries

In the electrochemical mechanical polishing (ECMP) of copper, hydroxyethylidene diphosphonic acid (HEDP) can work with other water treatment agents to suppress electrolysis and smooth the metal surface.

1-Hydroxyethylidene-1,1-diphosphonic acid Chemical Properties,Uses,Production

Chemical Properties
light beige powder

Originator
Etidron,Gentili,Italy,1977

Uses
Etidronate (Didronel) is a human protein tyrosine phosphatase inhibitor with IC50 of 0.2 μM.

Definition
ChEBI: A 1,1-bis(phosphonic acid) that is (ethane-1,1-diyl)bis(phosphonic acid) having a hydroxy substituent at the 1-position. It inhibits the formation, growth, and dissolution of hydroxyapatite crystals by chemisorption to calcium phosphate surfaces.
Manufacturing Process
Phosphorous acid was premixed with acetic acid to form a 50 wt % solution of phosphorous acid dissolved in acetic acid. 
The acids were mixed on a molar basis of 1.36:1, acetic acid to phosphorous acid, and this corresponded on a mol percentage basis to 57.6% acetic acid and 42.4% phosphorous acid. Acetic anhydride was continuously metered into a stream of the phosphorous acid-acetic acid mixture to form the reaction solution. The acetic anhydride was metered into the acid mixture at a mol ratio of 1.33 mols of acetic anhydride per mol of phosphorous acid. The metering rates were 18.5 lb/hr of the phosphorous acid/acetic acid premixed solution and 15.1 lb/hr acetic anhydride. The reaction solution was continuously passed through a heat exchanger where it was heated to 190°F then it was continuously fed into a two stage back-mix reaction zone where due to the heat of reaction the temperature rose to 275°F. 
The average residence in the reaction zone was 27 min. The reaction zone consisted of two back-mix reacto s each having a capacity of 7.5 pounds of the reaction solution. 
A stream of reaction solution was continuously with drawn from the second reactor and continuously mixed with a stream of water which was being metered at a rate of 2 lb/hr. This amount of water corresponded to 18% excess over the theoretical amount necessary to hydrolyze all of the acetyl-containing compounds in the reaction solution to free acids. The hydrolyzed solution was continuously passed through a heat exchanger and cooled to room temperature after which the solution was continuously passed to a crystallizer where, with agitation, the ethane-1-hydroxy-1,1-diphosphonic acid crystallized. The slurry was then filtered and the crystals were recovered and dried. Analysis of the product showed a conversion rate of phosphorous acid to ethane-1-hydroxy-1,1- diphosphonic acid of 86%. Sodium hydroxide may be used to give the disodium salt.

Didronel (Millot Laboratories, France); Didronel (Procter & Gamble).
Therapeutic Function
Bone calcium regulator
1-Hydroxyethylidene-1,1-diphosphonic acid Preparation Products And Raw materials

Raw materials
Diethylenetriamine Phosphorus oxychloride Phosphorus trichloride Hydrochloric acid Acetic acid Acetyl

Synonyms:
HEDP;HEDP(A);HEDPA;

Etidronic Acid;

1-Hydroxy Ethylidene-1,1-Diphosphonic Acid;

Hydroxyethylidene-1,1-diphosphonicacid(HEDP);

1-Hydroxyethylidenediphosphonic Acid;

Hydroxyethylidene Diphosphonic acid(HEDP);

1-Hydroxy-1,1-Ethanediyl ester;

Oxyethylidenediphosphonic Acid(OEDP)

Оксиэтилидендифосфоновая кислота(ОЭДФ -кислота )

Phosphonates are a class of chelating agents and scale inhibitors. Three acids, aminotris(methylene phosphonic acid) (ATMP), 1-hydroxyethylidene diphosphonic acid (HEDP) and diethylenetriamine penta(methylene phosphonic acid (DTPMP), have been assessed. They are used in household cleaning products, personal care products, institutional cleaners and industrial cleaning processes, and as water treatment additives in various applications.

Phosphonates are multifunctional acids, which structurally have the phosphonic acid group – PO3H2 in common. The phosphonate groups are placed on different backbones, often bound through a methylene group to amines (amine methylenephosphonates), or directly onto a carbon atom. Being multifunctional acids, phosphonates will form salts or complexes of different composition, depending on the chemical composition and the pH of the environment. These substances are used primarily as acids and as sodium salts. Their behaviour in the body or in the environment does not depend on the presence of sodium as the counter ion.

Phosphonates adsorb strongly on sediments and suspended particles, which further reduces the exposure of organisms. Sediment/water adsorption coefficients in the range 250 – 3900 were observed at concentration of 0.05 and 0.1 mg/l (Michael et al, 1980). At these concentrations, the concentration of the phosphonates in the water was reduced by two to three orders of magnitude. Although varying somewhat by the stucture of the molecules, adsorption is consistently much higher than what can be expected for highly water soluble, low Log Kow chemicals. In addition, adsorption is more pronounced at lower concentrations. Similar results have been obtained by Fischer for HEDP. Freundlich “k” values for clay minerals ranged from 293 to 2378 (Fischer, 1991), for sediments from 407 to 2107 and for sewage sludge from 907 to 2718 (Fischer, 1992) depending on the specific clay, sediment or sewage sludge. For this assessment the mid-value of the reported range was used. 
The missing K values for DTPMP were assigned based on the similarity with ATMP and HEDP. In addition to the high sorption coefficients, Michael et al (1980) and Fischer (1993) found that the adsorption of phosphonates is only partially reversible, and that only part of the adsorbed material can be desorbed again

Chelation is another important property to understand the behaviour and effects of phosphonates in the environment. Phosphonates form strong complexes with transition metals and with calcium and magnesium

Sequestration and surface effects due to adsorption, are also responsible for the performance characteristics of phosphonates in detergent products. The functional characteristics of phosphonates in laundry detergents are fourfold (Solutia, undated): 1) sequestration, in particular of heavy metals. This improves the stability of peroxide (perborate, percarbonate) and bleach systems. It also improves the removal of specific stains, such as tea, coffee, wine, etc. 2) Threshold effect on phosphate, carbonate and sulphate scales. This prevents the precipitation of insoluble salts and protects the fiber by inhibiting incrustation. 3) Deflocculation. This keeps soil from the laundry in suspension, preventing redeposition on the fabric and helping to retain the colours. These properties improve the performance of other consumer detergent products in a similar way.

Organophosphonates are derived from phosphorous acid, which is produced from phosphorus trichloride or as a byproduct. 
The aminomethylene phosphonates ATMP and DTPMP are produced by reaction of phosphorous acid, an amine and formaldehyde. 
HEDP is made by reacting anhydrous phosphorous acid with acetic anhydride. 

HEDP is used in laundry detergents as additives providing a range of properties such as sequestration/complexation, anti-redeposition and dispersion. 
HEDP is also used in laundry detergents as perborate and percarbonate stabilisers, preventing decomposition by transition metals, in automatic dish washing products and in hard surface cleaners. 
The major other application of HEDP is in water treatment of cooling and boiler water as scale inhibitors. Other applications include reverse osmosis water treatment, the photographic industry, the paper and pulp industry and the textile industry. 
Phosphonates are further used as stabilisers for hydrogen peroxide solutions and formulations.

Etidronic acid, also known as etidronate, is a bisphosphonate used as a medication, detergent, water treatment, and cosmetic.

It was patented in 1966 and approved for medical use in 1977

Medical
Etidronic acid is a bisphosphonate used to strengthen bone, treat osteoporosis, and treat Paget’s disease of bone.
Bisphosphonates primarily reduce osteoclastic activity, which prevents bone resorption, and thus moves the bone resorption/formation equilibrium toward the formation side and hence makes bone stronger on the long run. Etidronate, unlike other bisphosphonates, also prevents bone calcification. For this reason, other bisphosphonates, such as alendronate, are preferred when fighting osteoporosis. To prevent bone resorption without affecting too much bone calcification, etidronate must be administered only for a short time once in a while, for example for two weeks every 3 months. When given on a continuous basis, say every day, etidronate will altogether prevent bone calcification. This effect may be useful and etidronate is in fact used this way to fight heterotopic ossification. But in the long run, if used on a continuous basis, it will cause osteomalacia.

Chemical
Main article: Corrosion inhibitor
HEDP is used as a retardant in concrete, scale and corrosion inhibition in circulating cool water system, oil field and low-pressure boilers in fields such as electric power, chemical industry, metallurgy, fertilizer, etc. In light woven industry, HEDP is used as detergent for metal and nonmetal. In dyeing industry, HEDP is used as peroxide stabilizer and dye-fixing agent; In non-cyanide electroplating, HEDP is used as chelating agent. The dosage of 1–10 mg/L is preferred as scale inhibitor, 10–50 mg/L as corrosion inhibitor, and 1000–2000 mg/L as detergent. Usually, HEDP is also used together with polycarboxylic acid (superplasticizer), in which it acts as reducing agent.
Chelating agent and antioxidant
Etidronic acid is a chelating agent and may be added to bind or, to some extent, counter the effects of substances, such as calcium, iron or other metal ions, which may be discharged as a component of grey wastewater and could conceivably contaminate groundwater supplies. As a phosphonate it has corrosion inhibiting properties on unalloyed steel. Etidronic acid also acts to retard rancidification and oxidation of fatty acids.
HEDP and its salts are added to detergents and other cleaning agents to prevent the effects of hard water. It is also used in peroxide bleaching to prevent degradation of peroxides by transition metals.
Etidronic acid is listed as an ingredient of several cosmetic formulations where it is used for suppressing radical formation, emulsion stabiliser and viscosity control. While etidronic acid has not been limited from inclusion in cosmetics and does have legitimate uses, it is recommended that, as with most cosmetic products (particularly soaps), the product should be thoroughly rinsed from the skin after use.
Etidronic acid is also included among swimming pool chemicals. It is used as a stain inhibitor to prevent metal ions coming out of solution and staining the sides of swimming pools

CAS Registry Number: 2809-21-4
CA Index Name: Phosphonic acid, (1-hydroxyethylidene)bis-

Synonyms:
(1-HYDROXYAETHYLIDEN)-DIPHOSPHONSAEURE
(1-Hydroxyethylidene)-1,1-bis(phosphonic acid)
(1-Hydroxyethylidene)-1,1-diphosphonic acid
(1-Hydroxyethylidene)bisphosphonic acid
(1-Hydroxyethylidene)diphosphonic acid
1000SL
1-Hydroxy-1,1-diphosphonoethane
1-Hydroxyethane-1,1-bisphophonic acid
1-Hydroxyethane-1,1-bisphosphonic acid
1-Hydroxyethane-1,1-diphosphonic acid
1-Hydroxyethane-1,1-diyldiphosphonic acid
1-Hydroxyethanediphosphonic acid
1-HYDROXYETHYLIDENE BISPHOSPHONIC ACID
1-HYDROXYETHYLIDENE(1,1-DIPHOSPHONIC ACID)
1-Hydroxyethylidene-1,1′-diphosphonic acid
1-Hydroxyethylidene-1,1-diphosphonic acid
1-Hydroxyethylidene-1,1-diphosphoric acid
1-Hydroxyethylidene-1,1-disphosphonic acid
Acetodiphosphonic acid
Acide etidronique
acido etidronico
Acidum etidronicum
Anti Cal 5
Belclene 660
Briquest ADPA 60A
Briquest ADPA-A
Chelate 101
Chelest PH 210
Cublen K 60
Defloc EH 06
Dequest 16
Dequest 2010
Dequest 2010CS
Dequest 2010LA
Dequest 2015
Dequest Z 010
EHDP
ETHANE-1,1-DIPHOSPHONIC ACID, 1-HYDROXY-
Ethane-1-hydroxy-1,1’diphosphonic acid
Ethane-1-hydroxy-1,1-diphosphonic acid
Ethidronate
Ethydronate
ETHYLIDENE DIPHOSPHONIC ACID, 1-HYDROXY-
ETIDRONATE
etidronic acid
Etidronisaure
Feliox 115
Feliox 115A
Feliox CY 115
Ferrofos 510
HDEPA
HEDP
HYDROXYETHANE-1-1-DIPHOSPHONIC ACID
Hydroxyethanediphosphonic acid
HYDROXYETHYLIDENEDIPHOSPHONIC ACID
Ksidifon
Lonza 106
Mascol P 210
Masquol P 210
Mayoquest 1500
NSC 227995
OEDF
OEDFK
OEDP
Oxyethylidenediphosphonic acid
Phosphonic acid, (1-hydroxyethylidene)bis
Phosphonic acid, (1-hydroxyethylidene)bis-
Phosphonic acid, (1-hydroxyethylidene)di-
PHOSPHONIC ACID, (1-HYDROXYETHYLIDINE)BIS-
Phosphonic acid, P,P’-(1-hydroxyethylidene)bis-
Phosphonic acid,(1-hydroxyethylidene)bis
Phosphoric acid,(1,hydroxyethlidene)bis-
RP 61
Sequion 10H
Sone 16
Tecquest 360
Terpil SL
Turpinal SL
Turpinal SLR
Unihib 106
Wayplex
Xidiphone
Xydiphone

The principle of testing is to convert 1-hydroxyethylidene-1 1-diphosphonic acid (HEDP) to ortho phosphorus. And then to measure phosphorous.

The aim of the test is to detect the content of phosphorus (total phosphorus) in water. This testing is divided into two parts. They are inorganic phosphorus and organic phosphorus. The inorganic phosphorus portion may be composed of orthophosphoric and polymeric phosphorus. The organophosphorus moiety consists solely of 1-hydroxyethylidene-1 1-diphosphonic acid.

The content of orthophosphate representing total phosphorus. The content of orthophosphate representing inorganic phosphorus. The difference between the two is the content of organophosphorus (i.e., HEDP) based on the phosphonate.

If several phosphonic acids coexist in the water, this method cannot be distinguished. What is measured is the total amount of various phosphonic acids.

1. Determination of positive phosphorus content (standard HG 5-1513-85).
1.1 Phosphomolybdenum blue spectrophotometry.

Orthophosphate and sodium molybdate form a phosphomolybdate heteropolyacid in an acidic medium. It is reduced to phosphorus molybdenum blue with stannous chloride. And then spectrophotometry was carried out at 660nm.

1.2 phosphorus vanadium molybdenum yellow spectrophotometry.

Orthophosphate and ammonium molybdate and ammonium metavanadate form a yellow phosphorus vanadium molybdenum heteropoly acid in an acidic medium. And then use the spectrophotometrically to measure at 420nm.

2. Determination of inorganic phosphorus content (standard: HG 5-1514-85).
2.1 Phosphomolybdenum blue spectrophotometry.

Under acidic boiling conditions. The polymeric phosphorus is gradually hydrolyzed to normal phosphorus. Then, a phosphorus molybdenum heteropoly acid is formed with sodium molybdate. After reduction with barium sulfate to form phosphorus molybdenum blue. Spectrophotometry was carried out at 660nm.

2.2 Phosphorus, vanadium, molybdenum and yellow spectrophotometry.

The hydrolyzed polymeric phosphorus is heated to positive phosphorus in a strongly acidic solution. The phosphorous is reacted with ammonium molybdate and ammonium metavanadate to form a yellow phosphorus vanadium molybdenum heteropolyacid. Spectrophotometry was carried out at 420nm.

3. Determination of total phosphorus content (standard: HG 5-1515-85).
3.1 Phosphomolybdenum blue spectrophotometry.

The organic phosphorus and polyphosphoric are decomposed into positive phosphorus by the strong oxidizing agent ammonium persulfate. Then, it reacts with sodium molybdate to form a phosphorus molybdenum heteropolyacid. After reduction with barium sulfate into phosphorus molybdenum blue. Spectrophotometry was carried out at 660nm.

3.2 Phosphorus, vanadium, molybdenum and yellow spectrophotometry.

The organic phosphorus and polyphosphoric are decomposed into positive phosphorus by the strong oxidizing agent ammonium persulfate. It is then reacted with ammonium molybdate and ammonium metavanadate to form a yellow phosphorus vanadium molybdenum heteropolyacid. Spectrophotometry was carried out at 420nm.

If it is known that there is no inorganic phosphorus in the water. The 1-hydroxyethylidene-1 1-diphosphonic acid can be oxidized by excess sulfuric acid in an acidic solution. In the presence of a ferrous standard solution. The excess sorghum sulfate is then back titrated in the presence of a ferrous target. The content of 1-hydroxyethylidene-1 1-diphosphonic acid HEDP in water can be determined from the number of milliliters of the ferrous standard solution consumed.

RESEARCH ARTICLE| MAY 01 1986
Effect of 1-Hydroxyethylidene-1, 1-Diphosphonic Acid on the Corrosion of SS 41 Steel in 0.3% Sodium Chloride Solution 
I. Sekine ; Y. Hirakawa
CORROSION (1986) 42 (5): 272–277.
https://doi.org/10.5006/1.3584904

Abstract
The effectiveness of 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) as a corrosion inhibitor was investigated by measuring corrosion weight losses and polarization curves of SS 41 steel in 0.3% NaCl. 
In concentrations lower than 50 ppm of HEDP, the corrosion of SS 41 steel was inhibited in accordance with the Langmuir adsorption isotherm of HEDP on the steel. 
The adsorption was believed to be a chemical adsorption resulting from the value of adsorption heat. 
In concentrations greater than 50 ppm of HEDP, the iron complex of HEDP developed, and the inhibition effect was decreased. 
Instead, it caused rust to be removed from the steel surface. 
The mutual inhibition effect by adding both HEDP and the Zn2+ ion in 0.3% NaCl solution was progressively more increased. 
It was shown that HEDP does not easily decompose.

Etidronic acid

(1-Hydroxy-1,1-ethandiyl)bis(phosphonsäure) [German] [ACD/IUPAC Name]
(1-Hydroxy-1,1-ethanediyl)bis(phosphonic acid) [ACD/IUPAC Name]
(1-hydroxyethane-1,1-diyl)bis(phosphonic acid)
1-Hydroxyethane-1,1,-diphosphonic acid
1-Hydroxyethylidenediphosphonic acid
220-552-8 [EINECS]
2809-21-4 [RN]
Acide (1-hydroxy-1,1-éthanediyl)bis(phosphonique) [French] [ACD/IUPAC Name]
acide etidronique [French] [INN]
acide etidronique
acido etidronico [Spanish] [INN]
acido etidronico
acidum etidronicum [Latin]
acidum etidronicum
Didronel IV
Etidronate
Etidronic acid [BAN] [INN] [USAN] [Wiki]
Hdepa
HEDP
MFCD00070585 [MDL number]
OEDFK
Osteoscan
Phosphonic acid, (1-hydroxyethylidene)bis- [ACD/Index Name]
(1-hydroxy-1-phosphonoethyl)phosphonic acid
(1-hydroxy-1-phosphono-ethyl)phosphonic acid
(1-Hydroxy-1-phosphono-ethyl)-phosphonic acid
(1-hydroxyethane-1,1-diyl)diphosphonic acid
(1-Hydroxyethylene)diphosphonic acid
(1-Hydroxyethylidene)bis(phosphonic acid)
(1-Hydroxyethylidene)bisphonic acid
(1-Hydroxyethylidene)bisphosphonic acid
(1-Hydroxyethylidene)diphoshonic acid
(1-hydroxy-ethylidene)diphosphonic acid
(1-Hydroxyethylidene)diphosphonic acid
(HYDROXYETHYLIDENE)DIPHOSPHONIC ACID
[2809-21-4]
1,1,1-Ethanetriol diphosphonate
100511-44-2 [RN]
106908-76-3 [RN]
107904-06-3 [RN]
129130-42-3 [RN]
1-Hydroxy Ethylidene
1-Hydroxy Ethylidene-1,1-Diphosphonic Acid
1-Hydroxy-1,1-diphosphonoethane
1-hydroxy-1-phosphonoethylphosphonic acid
1-hydroxyethane 1,1-diphosphonic acid
1-Hydroxyethane-1, 1-bisphosphonic acid
1-Hydroxyethane-1,1-bisphosphonic acid
1-Hydroxyethane-1,1-diphosphonate
1-hydroxyethane-1,1-diphosphonic acid
1-hydroxyethane-1,1-diyldiphosphonic acid
1-Hydroxyethanediphosphonic acid
1-Hydroxyethylidene-1, 1-diphosphonic acid
1-Hydroxyethylidene-1,1-biphosphonate
1-Hydroxyethylidene-1,1-bisphosphonate
1-Hydroxyethylidene-1,1-diphosphonic acid
1-HydroxyEthylidene-1,1-DiphosphonicAcid
249-559-4 [EINECS]
25211-86-3 [RN]
2809-21-4 (freeacid)
29329-71-3 [RN]
51888-66-5 [RN]
66216-98-6 [RN]
774173-70-5 [RN]
85985-26-8 [RN]
86159-18-4 [RN]
8PH
9005-49-6 [RN]
Acetodiphosphonic acid
acide étidronique
Acide etidronique [INN-French]
ácido etidrónico
Acido etidronico [INN-Spanish]
Acidum etidronicum [INN-Latin]
DB01077
Dequest Z 010
Didronel;HEDPA;HEDP
EHDP
Ethane-1-hydroxy-1, 1-diphosphonate
Ethane-1-hydroxy-1,1-bisphosphonate
ethane-1-hydroxy-1,1-bisphosphonic acid
Ethane-1-hydroxy-1,1-diphosphonate
Ethane-1-hydroxy-1,1-diphosphonic acid
Etidron
Etidronic acid 60% aqueous solution
ETIDRONIC ACID-D3
Etidronic Acid-d3 Sodium Salt
Etidronsaeure
Etidronsäure
Ferrofos 510
HEDPA
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:4907
Hydrogen [(1r)-2-(3-Decyl-1h-Imidazol-3-Ium-1-Yl)-1-Hydroxy-1-Phosphonoethyl]phosphonate
Hydroxyethane-1,1-diphosphonic acid
Hydroxyethanediphosphonic acid
Ksidifon
Oxyethylidenediphosphonic acid
Phosphonic acid, (1-hydroxyethylidene)di-
Phosphonic acid, 1-hydroxy-1,1-ethanediyl ester
phosphonic acid, 1-hydroxyethylidenedi-
trihydroxy-(1-hydroxy-1-trihydroxyphosphaniumylethyl)phosphanium
trihydroxy-(1-hydroxy-1-trihydroxyphosphaniumyl-ethyl)phosphanium
trihydroxy-(1-hydroxy-1-trihydroxyphosphaniumylethyl)phosphonium
trihydroxy-(1-hydroxy-1-trihydroxyphosphaniumyl-ethyl)phosphonium
Turpinal SL
Xidiphone
этидроновая кислота
حمض إيتيدرونيك
依替膦酸

MORE PHOSPHONATES
PHOSPHONATES
ATMP
PBTC
DTPMPA
EDTMPA
HEDP

1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP) 

HEDP used as chelating agent during OpQP bleaching sequence of Acacia mangium kraft pulp

Pang, J.-J., Liu, Z., Hui, L.-F., Jiang, H.-P., and Si, C.-L. (2012). “HEDP used as chelating agent during OpQP bleaching sequence of Acacia mangium kraft pulp,” BioRes. 7(4), 5200-5210.
________________________________________
Abstract
In an effort to resolve problems related to the difficulty of degradation of the chelating agents EDTA and DTPA, this study used a kind of water treatment agent, 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), as the chelating agent in the OPQP bleaching sequence of Acacia mangium kraft pulp. The Q stage was optimized with the use of response surface methodology (RSM) based on the Box-Behnken design (BBD). The results showed that the optimum chelating conditions for subsequent hydrogen peroxide bleaching were the following: Temperature of 54 °C, hold time 32 min, and dosage of agents 0.4%. These conditions resulted in the highest brightness value of 80.12% ISO and the selectivity coefficient of 0.46. Under these optimum chelating conditions, the results showed that the effect of HEDP in bleaching is better than that of EDTA with regard to viscosity of pulp, and that HEDP is similar to EDTA and DTPA in other properties.

Full Article
HEDP used as chelating agent during OPQP Bleaching Sequence of Acacia mangium Kraft Pulp
Jin-Jiang Pang, Zhong Liu,* Lan-Feng Hui, Hua-Peng Jiang, and Chuan-Ling Si
In an effort to resolve problems related to the difficulty of degradation of the chelating agents EDTA and DTPA, this study used a kind of water treatment agent, 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), as the chelating agent in the OPQP bleaching sequence of Acacia mangium kraft pulp. The Q stage was optimized with the use of response surface methodology (RSM) based on the Box-Behnken design (BBD). The results showed that the optimum chelating conditions for subsequent hydrogen peroxide bleaching were the following: Temperature of 54 °C, hold time 32 min, and dosage of agents 0.4%. These conditions resulted in the highest brightness value of 80.12% ISO and the selectivity coefficient of 0.46. Under these optimum chelating conditions, the results showed that the effect of HEDP in bleaching is better than that of EDTA with regard to viscosity of pulp, and that HEDP is similar to EDTA and DTPA in other properties.
Keywords: 1-hydroxy ethylidene-1,1-diphosphonic acid; OPQP bleaching sequence; Box-Behnken design; Response surface methodology
Contact information: Tianjin Key Lab of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China; *Corresponding author: mglz@tust.edu.cn
INTRODUCTION
The effectiveness of hydrogen peroxide as a bleaching agent is limited by its poor selectivity, which is reflected in the severe loss of viscosity. It is generally accepted that the radicals generated during the decomposition of peroxide are responsible for this cellulose degradation (Gierer 1993). According to the Fenton reaction, the formation of these active radicals, namely HO• radicals, is catalyzed by transition metal ions such as iron, copper, and manganese (Cardona-Barrau et al. 2001; Duarte and Lachenal 2002; Cardona-Barrau et al. 2003; Abrantes et al. 2007).
The removal of manganese and iron from the pulp by way of chelation with DTPA (diethylene triamine pentaacetic acid) or EDTA (ethylene diamine tetraacetic acid) or by acid washing results in better selectivity during the subsequent hydrogen peroxide bleaching. These methods seem to be effective for the reduction of both peroxide decom-position and the cellulose degradation that results from it (de la Rosa et al. 2002; Duarte and Lachenal 2002; Lapierre et al. 2003).
Acid washing is what is mostly responsible for the viscosity decrease during pretreatment, as the chelation stage has very little effect on the cellulose. This is because acid hydrolysis becomes appreciable at pH values below 3 and at temperatures above 80 or 90 °C. Acid washing equipment requires special treatment to reduce acid corrosion, but in this case the equipment expenses will increase.
DTPA and EDTA are the most common compounds used in the chelating stage, and they gradually have become accepted by researchers. But they are likely to be poorly degraded in sewage treatment plants, as their synthetic compounds are commonly discharged in large amounts to surface water via runoffs of the sewage treatment plants without adequate degradation. This is due to the poor efficiency of wastewater treatment plants in removing various classes of organic pollutants such as antibiotics and other pharmaceuticals (Zhang et al. 2008; Loganathan et al. 2009; Matamoros et al. 2009). Although EDTA-chelates are normally non-toxic (Sillanpää et al. 2003), their presence could also affect the underlaying groundwater by enhancing the migration of trace metals and radionuclides from contaminated soils or disposal sites to the groundwater (Schmidt and Brauch 2005). 
Therefore, in order to promote the best environmental practices, a broad range of environmental technologies including biological processes and physico-c emical treatments have been explored in the interest of removing chelating agents from contaminated water (Rahman et al. 2009; Al-kdasi et al. 2004; Yang et al. 2005; Kurniawan et al. 2006a). Regarding degradation of HEDP chelation agents, Appelman and his assistants used a combination of O3 and H2O2 to attain an almost complete removal of HEDPA at an initial concentration of 100 mM at pH 9 (Appelman et al. 1996). In this regard, the ozonation of HEDPA in basic conditions results in the formation of phosphorus-containing intermediate by-products, while EDTA is not degradable in acidic environment (Sillanpää et al. 2011).
1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP for short), which was used in this work, is widely used in water treatment for the chelation of Fe2+, Cu2+, Zn2+, and Ca2+. It has been applied in the chelating stage as well. Response surface methodology (RSM) is a statistical technique for the modeling and optimization of multiple variables that determines the optimum process conditions by combining experimental designs with interpolation via first- or second-order polynomial equations in a sequential testing procedure. The optimization of chelating stage using the response surface methodology allowed a study on the influence of variables (chelated temperature, retention time, and dosage of chelator). The optimum results can be in comparison with the effect of the chelators including EDTA and DTPA.

HEDP was found to be extremely effective at removing a large percentage of Ca2+, though at the same time its removal of Mn2+ was equal to that of the other chelators, as illustrated in Table 8. However, the impact of HEDP on the removal of Cu2+ and Fe2+ was lower than that of EDTA or DTPA. Moreover, with an addition of 0.4% HEDP, the iron, copper, manganese and calcium content were reduced by 14.18%, 62.2%, 53.6% and 85.38%, respectively. The analysis of the metal content helped to explain some of the results seen previously in Table 4. Due to the fact that HEDP is a chelator, upon its addition to the Q stage it chelated and removed a large percentage of the metals during washing, thereby helping to produce a higher brightness and viscosity at a given degree of dosage. The results of the mean length and mean width of the fiber did not show any significant changes. Further work is needed to research the degradation of the HEDP chelate complex.
CONCLUSIONS
1.    The pulp brightness was found to be 80.12% ISO, and the selectivity coefficient was found to be 0.46 (kappa number 6.55, viscosity 698 mL/g) under the experimental conditions of 54 °C and 0.4% HEDP at 32 min. The validation of this model confirmed the agreement between the experimental results and the predicted response.
2.    Under the optimum experimental conditions, the results from the OP pulp chelated with HEDP are close to the results from the pulp chelated with DTPA or EDTA. As a water treatment agent, HEDP can remove large amounts of Ca ion scale formation and at the same time can remove Fe2+, Cu2+, and Mn2+, which protect the hydrogen peroxide. Furthermore, HEDP has the advantage of low cost over DTPA and EDTA.

IUPAC Name 
(1-hydroxyethane-1,1-diyl)bis(phosphonic acid)
INNs     Sources
acide étidronique Français    
ácido etidrónico Español    
acidum etidronicum LINGUA LATINA    
etidronic acid    KEGG DRUG
Synonyms     Sources
(1-Hydroxyethylene)diphosphonic acid    
(1-Hydroxyethylidene)bis(phosphonic acid)    
(1-Hydroxyethylidene)bisphosphonic acid    
(1-Hydroxyethylidene)diphosphonic acid    
(Hydroxyethylidene)diphosphonic acid    
1,1,1-Ethanetriol diphosphonate    
1-Hydroxy-1,1-diphosphonoethane    
1-Hydroxyethane-1,1-bisphosphonic acid    
1-Hydroxyethane-1,1-diphosphonate    
1-Hydroxyethane-1,1-diphosphonic acid    
1-Hydroxyethanediphosphonic acid    
1-Hydroxyethylidene-1,1-bisphosphonate    
1-Hydroxyethylidene-1,1-diphosphonic acid    
1-Hydroxyethylidene-1,1-diphosphonic acid    
Acetodiphosphonic acid    DrugBank
EHDP    DrugBank
ethane-1-hydroxy-1,1-bisphosphonic acid    ChEBI
Ethane-1-hydroxy-1,1-diphosphonate    
Ethane-1-hydroxy-1,1-diphosphonic acid    
etidronate    ChEBI
Etidronsäure Deutsch    
HEDP    DrugBank
Hydroxyethanediphosphonic acid    DrugBank
Oxyethylidenediphosphonic acid

 Trade name
(1-Hydroxyethylidene)-1,1-diphosphonic acid
(1-Hydroxyethylidene)bisphosphonic acid
(1-Hydroxyethylidene)diphosphonic acid
1-HYDROXYETHYLIDENEDIPHOSPHONIC ACID
1-Hydroxy Ethylidene-1,1-Diphosphonic Acid
1-Hydroxyethylidene- 1,1-Diphosphonic Acid (HEDP)
1-hydroxy-1,1-Ethanediyl ester
1-hydroxyethan-1,1-diphosphonsäure (HEDP)
Acetodiphosphonic acid
Aquacid 105CG
Aquacid-105EX
Aquacid-105NS
Briquest ADPA-60A
Cublen K 60
Cublen KT 600
EHDP
Ethane-1-hydroxy-1,1-diphosphonic acid
Etidronic acid
HDEPA
HEDP
HEDPA
Hydroxyethanediphosphonic acid
Hydroxyethylidene Diphosphonic acid(HEDP)
Uniphos 300

1-Hydroxyethylidene-diphosphonic acid
Cosmetic Products Regulation, Annex III – Restricted Substances
Etidronic acid

EC Inventory
Etidronic acid
etidronic acid
CAS names
Phosphonic acid, P,P’-(1-hydroxyethylidene)bis-

IUPAC names
(1 Hydroxy-1phosphonoethyl)-phosphonic acid

(1-hydroxy-1-phosphono-ethyl)phosphonic acid

(1-hydroxy-1-phosphonoethyl)phosphonic acid

(1-hydroxyethan-1,1-diyl)bis(phosphonic acid)

(1-Hydroxyethane-1,1-diyl)bis(phosphonic acid)
 
(1-hydroxyethane-1,1-diyl)bis(phosphonic acid)

(1-HYDROXYETHYLIDENE) BISPHOSPHONIC ACID

(1-hydroxyethylidene)bis-phosphonic acid,

(1-hydroxyethylidene)bisphosphonic acid

1-hydroxy ethylidene -1,1-diphosphonic acid

1-hydroxy ethylidene-1,1-diphosphonic acid

1-Hydroxyethane-1,1-diphosphonic acid

1-hydroxyethane-1,1-diphosphonic acid

1-Hydroxyethane-1,1-diphosphonic Acid (HEDP)

1-HYDROXYETHANE-1,1-DIPHOSPHONICACID

1-Hydroxyethane-1,1-diphosphonicacid
1-hydroxyethane-1,1-diyl)bis(phosphonic acid
1-hydroxyethylene (bis-Phosphonic acid)
1-Hydroxyethylidene- 1,1-diphosphonic acid
1-Hydroxyethylidene-1, 1-Diphosphonic Acid
1-Hydroxyethylidene-1,1-diphosphonic aci
1-Hydroxyethylidene-1,1-diphosphonic acid
1-hydroxyethylidene-1,1-diphosphonic acid
Editronic Acid
ETIDRONIC ACID
Etidronic Acid
Etidronic acid
etidronic acid 
Etidronic acid 
etidronic acid

HEDP

HEDP

Phosphonic acid, (1-hydroxyethylidene)bis-

Phosphonic acid, (1-hydroxyethylidene)di

phosphonic acid,(1-hydroxyethylidene)bis-

Trade names
(1-Hydroxyethylidene)-1,1-diphosphonic acid
(1-Hydroxyethylidene)bisphosphonic acid
(1-Hydroxyethylidene)diphosphonic acid
1-Hydroxy Ethylidene-1,1-Diphosphonic Acid
1-hydroxy-1,1-Ethanediyl ester
1-hydroxyethan-1,1-diphosphonsäure (HEDP)
1-Hydroxyethylidene- 1,1-Diphosphonic Acid (HEDP)
1-HYDROXYETHYLIDENEDIPHOSPHONIC ACID
Acetodiphosphonic acid
Aquacid 105CG
Aquacid-105EX
Aquacid-105NS
Briquest ADPA-60A
Cublen K 60
Cublen KT 600
editronic acid
EHDP
Ethane-1-hydroxy-1,1-diphosphonic acid
Etidronic Acid
Etidronic acid
Etidronihappo
HDEPA
HEDP
HEDPA
Hydroxyethanediphosphonic acid
Hydroxyethylidene Diphosphonic acid(HEDP)
Uniphos 300

Inquiry