Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-02T23:36:53.549Z Has data issue: false hasContentIssue false

Synthesis of Lead Pyrophosphate, Pb2P2O7, in Water

Published online by Cambridge University Press:  04 July 2008

Darren A. Lytle*
Affiliation:
U.S. Environmental Protection Agency, Treatment Technology Evaluation Branch, Cincinnati, OH 45268, USA
Colin White
Affiliation:
U.S. Environmental Protection Agency, Treatment Technology Evaluation Branch, Cincinnati, OH 45268, USA
Michael R. Schock
Affiliation:
U.S. Environmental Protection Agency, Treatment Technology Evaluation Branch, Cincinnati, OH 45268, USA
*
Corresponding author. E-mail: [email protected]
Get access

Abstract

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.

Type
Materials Applications
Copyright
Copyright © Microscopy Society of America 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

APHA-AWWA-WEF. (2005). Standard Methods for the Examination of Water and Wastewater, 21st ed.Washington, DC: American Public Health Association.Google Scholar
Argyle, H. (1960). Dilatometric and X-ray data for lead compounds, I. J Am Ceram Soc 43, 452.Google Scholar
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.Google Scholar
Boffardi, B.P. (1993). The chemistry of polyphosphate. Mater Perform 8, 5053.Google Scholar
Boffardi, B.P. & Sherbondy, A.M. (1991). Control of lead corrosion by chemical treatment. NACE Corr 27(12), 966975.CrossRefGoogle Scholar
Brixner, L.H., Bierstedt, P.E. & Foris, C.M. (1973). Crystal growth and properties of lead pyrophosphate, Pb2P2O7. J Solid State Chem 6, 430432.CrossRefGoogle Scholar
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.Google Scholar
Edwards, M. & MacNeill, L.S. (2002). Effect of phosphate inhibitors on lead release from pipes. J Am Water Works Assoc 94(1), 7990.CrossRefGoogle Scholar
Eysel, W. & Wetzel, A. (1992). Mineral.-Petrogr. Institut der Universitaet, Heidelberg, Germany [ICDD Grant-in-Aid].Google Scholar
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.Google Scholar
Federal Register. (1991b). Maximum Contaminant Level Goals and National Primary Drinking Water Regulations for Lead and Copper. U.S. Environmental Protection Agency, 56, 26460.Google Scholar
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.Google Scholar
Guler, H. & Kurtulus, F. (2005). A microwave-assisted route for the solid-state synthesis of lead pyrophosphate, Pb2P2O7. J Mater Sci 40, 65656569.CrossRefGoogle Scholar
Hach Company (1990). DR2000 Spectrophotometer Instrument Manual. Loveland, CO: Hach Company.Google Scholar
Hatch, G.B. (1952). Protective film formation with phosphate glasses. Ind Eng Chem 44, 17751780.Google Scholar
Hatch, G.B. & Rice, O. (1940). Corrosion control with threshold treatment. Ind Eng Chem 32, 15721579.CrossRefGoogle Scholar
Hatch, G.B. & Rice, O. (1945). Threshold treatment of water systems—Corrosion control and scale prevention with glassy phosphate. Ind Eng Chem 37, 710715.CrossRefGoogle Scholar
Henry, C.R. (1950). Prevention of the settlement of iron. J Am Water Works Assoc 42, 887896.CrossRefGoogle Scholar
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.CrossRefGoogle Scholar
Hunter, R.J. (1981). Zeta Potential in Colloid Science. London: Academic Press.Google Scholar
Illig, G.L. (1960). Use of sodium hexametaphosphate in manganese stabilization. J Am Water Works Assoc 52, 867873.CrossRefGoogle Scholar
Klueh, K.G. & Robinson, R.B. (1988). Sequestration of iron in groundwater by polyphosphates. J Environ Eng 114, 11921199.CrossRefGoogle Scholar
Lamb, J.C. & Eliassen, R. (1954). Mechanism of corrosion inhibition by sodium metaphosphate glass. J Am Water Works Assoc 46, 445460.Google Scholar
Lytle, D.A. & Schock, M.R. (2005). Formation of Pb(IV) oxides in chlorinated water. J Am Water Works Assoc 97, 102114.Google Scholar
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.CrossRefGoogle Scholar
Manahan, S.E. (1991). Environmental Chemistry. Chelsea, MI: Lewis Publishers, Inc.Google Scholar
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.CrossRefGoogle Scholar
Stumm, W. & Morgan, J.J. (1996). Aquatic Chemistry. New York: John Wiley & Sons, Inc.Google Scholar
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.CrossRefGoogle Scholar
Van Wazer, J.R. & Callis, C.F. (1958). Metal complexing by phosphates. Chem Rev 58, 1011.Google Scholar