Skip to main content Accessibility help

Synthesis of Lead Pyrophosphate, Pb2P2O7, in Water

  • Darren A. Lytle (a1), Colin White (a1) and Michael R. Schock (a1)


Polyphosphates are used in drinking water to prevent the precipitation of cations such as calcium and iron. The possible negative impact of using polyphosphates is the undesirable complexation of lead that could result in elevated lead levels in consumers' tap water. Although the water industry has focused on complexation, lead polyphosphate solids such as lead pyrophosphate, Pb2P2O7, have been considered in other fields and not been shown to form in water. The ability to form lead pyrophosphate in water could have a potential impact on the strategies used to reduce lead levels in drinking water distribution systems. The objective of this work was to determine whether lead pyrophosphate could form under simulated potable drinking water conditions. Lead pyrophosphate was synthesized in water (pH 8.2, 10 mg C/L, 2.7 mg Cl2/L) after 13 days of aging. The formation of lead pyrophosphate was confirmed by X-ray diffraction and microscopy analysis. Synthesis did not require elevated temperatures or microwave assisted approaches used by past researchers. The findings suggest that lead (and possibly other metal) pyrophosphates could conceivably form in real drinking water systems, although much more work is necessary to determine the chemistry and kinetic boundaries.


Corresponding author

Corresponding author. E-mail:


Hide All
APHA-AWWA-WEF. (2005). Standard Methods for the Examination of Water and Wastewater, 21st ed.Washington, DC: American Public Health Association.
Argyle, H. (1960). Dilatometric and X-ray data for lead compounds, I. J Am Ceram Soc 43, 452.
ASTM. (1996). Standard Practices for Identification of Crystalline Compounds in Water-Formed Deposits by X-Ray Diffraction, Volume 11.02, D 934-80. Conshohocken, PA: American Society for Testing and Materials.
Boffardi, B.P. (1993). The chemistry of polyphosphate. Mater Perform 8, 5053.
Boffardi, B.P. & Sherbondy, A.M. (1991). Control of lead corrosion by chemical treatment. NACE Corr 27(12), 966975.
Brixner, L.H., Bierstedt, P.E. & Foris, C.M. (1973). Crystal growth and properties of lead pyrophosphate, Pb2P2O7. J Solid State Chem 6, 430432.
Brixner, L.H. & Foris, C.M. (1973). Crystal growth and X-ray data of the lead phosphates, Pb4P2O9 and Pb8P2O13. J Solid State Chem 7, 149154.
Edwards, M. & MacNeill, L.S. (2002). Effect of phosphate inhibitors on lead release from pipes. J Am Water Works Assoc 94(1), 7990.
Eysel, W. & Wetzel, A. (1992). Mineral.-Petrogr. Institut der Universitaet, Heidelberg, Germany [ICDD Grant-in-Aid].
Federal Register. (1991a). Drinking Water Regulations; Maximum Contaminant Level Goals and National Primary Drinking Water Regulations for Lead and Copper. 40 CRF Parts 141 and 142. U.S. Environmental Protection Agency, July 15, 56, 32112.
Federal Register. (1991b). Maximum Contaminant Level Goals and National Primary Drinking Water Regulations for Lead and Copper. U.S. Environmental Protection Agency, 56, 26460.
Federal Register. (1992). Drinking Water Regulations: Maximum Contaminant Level Goals and National Primary Drinking Water Regulations for Lead and Copper. 40 CFR Parts 141 and 142. U.S. Environmental Protection Agency, 57, 28785.
Guler, H. & Kurtulus, F. (2005). A microwave-assisted route for the solid-state synthesis of lead pyrophosphate, Pb2P2O7. J Mater Sci 40, 65656569.
Hach Company (1990). DR2000 Spectrophotometer Instrument Manual. Loveland, CO: Hach Company.
Hatch, G.B. (1952). Protective film formation with phosphate glasses. Ind Eng Chem 44, 17751780.
Hatch, G.B. & Rice, O. (1940). Corrosion control with threshold treatment. Ind Eng Chem 32, 15721579.
Hatch, G.B. & Rice, O. (1945). Threshold treatment of water systems—Corrosion control and scale prevention with glassy phosphate. Ind Eng Chem 37, 710715.
Henry, C.R. (1950). Prevention of the settlement of iron. J Am Water Works Assoc 42, 887896.
Holm, T.R. & Schock, M.R. (1991). Potential effects of polyphosphate products on lead solubility in plumbing systems. J Am Water Works Assoc 83, 7482.
Hunter, R.J. (1981). Zeta Potential in Colloid Science. London: Academic Press.
Illig, G.L. (1960). Use of sodium hexametaphosphate in manganese stabilization. J Am Water Works Assoc 52, 867873.
Klueh, K.G. & Robinson, R.B. (1988). Sequestration of iron in groundwater by polyphosphates. J Environ Eng 114, 11921199.
Lamb, J.C. & Eliassen, R. (1954). Mechanism of corrosion inhibition by sodium metaphosphate glass. J Am Water Works Assoc 46, 445460.
Lytle, D.A. & Schock, M.R. (2005). Formation of Pb(IV) oxides in chlorinated water. J Am Water Works Assoc 97, 102114.
Lytle, D.A. & Snoeyink, V.L. (2002). Effect of ortho- and polyphosphates on the properties of iron particles and suspensions. J Am Water Works Assoc 94, 8799.
Manahan, S.E. (1991). Environmental Chemistry. Chelsea, MI: Lewis Publishers, Inc.
Rangel, C.M., Damborenea, D., De Se, A.I. & Simplicio, M.H. (1992). Zinc and polyphosphates as corrosion inhibitors for zinc in near neutral waters. Br Corr J 27, 207211.
Stumm, W. & Morgan, J.J. (1996). Aquatic Chemistry. New York: John Wiley & Sons, Inc.
Uhlig, H.H., Triadis, D.N. & Stern, M. (1955). Effect of oxygen, chlorides, and calcium ion on corrosion inhibition of iron by polyphophates. J Electrochem Soc 102, 5966.
Van Wazer, J.R. & Callis, C.F. (1958). Metal complexing by phosphates. Chem Rev 58, 1011.



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed