Impact of chlorinated disinfection on copper corrosion in hot water systems

Abstract In France, hot water quality control inside buildings is occasionally ensured by disinfection treatments using temperature increases or addition of sodium hypochlorite (between 0.5 ppm and 1 ppm residual free chlorine). This disinfectant is a strong oxidiser and it could interact with metallic pipes usually used in hot water systems. This work deals with the study of the impact of these treatments on the durability of copper pipes. The objective of this work was to investigate the influence of sodium hypochlorite concentration and temperature on the copper corrosion mechanism. Copper samples were tested under dynamic and static conditions of ageing with sodium hypochlorite solutions ranging from 0 to 100 ppm with temperature at 50 °C and 70 °C. The efficiency of a corrosion inhibitor was investigated in dynamic conditions. Visual observations and analytical analyses of the internal surface of samples was studied at different ageing duration. Corrosion products were characterised by X-ray diffraction and Raman spectroscopy. Temperature and disinfectant were found to considerably affect the copper corrosion mechanism. Surprisingly, the corrosiveness of the solution was higher at lower temperatures. The temperature influences the nature of corrosion products. The protection efficiency is then strongly depend on the nature of the corrosion products formed at the surface of copper samples exposed to the aggressive solutions containing different concentration of disinfectant.

[1]  J. Montes.  Impacts des stratégies d'exploitation de réseaux intérieurs sur la durabilité de canalisations d'eau chaude , 2011 .

[2]  Jeyong Yoon,et al.  Enhanced disinfection efficiency of mechanically mixed oxidants with free chlorine. , 2005, Water research.

[3]  R. Frost.  Raman spectroscopy of selected copper minerals of significance in corrosion. , 2003, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[4]  S. Pehkonen,et al.  Copper corrosion in distribution systems: evaluation of a homogeneous Cu2O film and a natural corrosion scale as corrosion inhibitors , 2000 .

[5]  I. Vargas,et al.  Influence of solid corrosion by-products on the consumption of dissolved oxygen in copper pipes , 2009 .

[6]  Michel Bouchard-Abouchacra.  Evaluation des capacités de la microscopie Raman dans la caractérisation minéralogique et physico-chimique de matériaux archéologiques: métaux, vitraux et pigments , 2001 .

[7]  J. Coombs,et al.  The corrosion of copper by chlorinated drinking waters , 1982 .

[8]  H. Pickering,et al.  A Rotating Disk Study of the Corrosion Behavior of Cu‐9.4Ni‐1.7Fe Alloy in Air‐Saturated Aqueous NaCl Solution , 1984 .

[9]  M Kelm,et al.  Spectroscopic investigation on the formation of hypochlorite by alpha radiolysis in concentrated NaCl solutions , 1999 .

[10]  Erez N. Allouche,et al.  Evaluation of the resistance of mortars coated with silver bearing zeolite to bacterial-induced corrosion , 2008 .

[11]  Huijuan Liu,et al.  The formation and distribution of haloacetic acids in copper pipe during chlorination. , 2008, Journal of hazardous materials.

[12]  U. W. Gedde,et al.  Deterioration of polyethylene pipes exposed to chlorinated water , 2004 .

[13]  I. Vargas,et al.  Empirical model for dissolved oxygen depletion during corrosion of drinking water copper pipes , 2010 .

[14]  Laurie S. McNeill,et al.  Some effects of aqueous silica on the corrosion of iron. , 2003, Water Research.

[15]  Kerry J. Howe,et al.  Corrosion of aluminium in the aqueous chemical environment of a loss-of-coolant accident at a nuclear power plant , 2008 .

[16]  S. Adeloju,et al.  The corrosion of copper pipes in high chloride-low carbonate mains water , 1986 .

[17]  M. Edwards,et al.  Effect of aluminium solids and chlorine on cold water pitting of copper , 2004 .

[18]  K. L. Tan,et al.  The corrosion behaviour of copper in neutral tap water. Part I: Corrosion mechanisms , 1996 .

[19]  Jeffrey L. Parks,et al.  Rapid free chlorine decay in the presence of Cu(OH)2: chemistry and practical implications. , 2011, Water research.

[20]  A. Atrens,et al.  Atmospheric corrosion of copper and the colour, structure and composition of natural patinas on copper , 2006 .

[21]  Guoan Zhang,et al.  Effect of direct current electric field on atmospheric corrosion behavior of copper under thin electrolyte layer , 2011 .

[22]  K. W. Kwong,et al.  Peanut-shaped nanoribbon bundle superstructures of malachite and copper oxide , 2004 .

[23]  Christos G. Takoudis,et al.  OXIDE FILM FORMATION AND OXYGEN ADSORPTION ON COPPER IN AQUEOUS MEDIA AS PROBED BY SURFACE-ENHANCED RAMAN SPECTROSCOPY , 1999 .

[24]  Cheng Sun,et al.  Influence of organic matter on orthophosphate corrosion inhibition for copper pipe in soft water , 2004 .

[25]  Yee San Su,et al.  Chemical kinetics of calcium hypochlorite decomposition in aqueous solutions , 2009 .

[26]  T. Lim,et al.  Evaluation of the effect of dosage, pH and contact time on high-dose phosphate inhibition for copper corrosion control using response surface methodology (RSM) , 2008 .

[27]  G. Gagnon,et al.  Disinfectant efficacy in distribution systems: a pilot-scale assessment , 2008 .

[28]  M. Nadagouda,et al.  A comprehensive investigation of copper pitting corrosion in a drinking water distribution system , 2010 .

[29]  M. Edwards,et al.  Phosphate inhibition of soluble copper corrosion by-product release , 2002 .

[30]  J. Ferguson,et al.  Accelerated Testing of Copper Corrosion , 1993 .

[31]  G. Gambarini,et al.  Chemical stability of heated sodium hypochlorite endodontic irrigants. , 1998, Journal of endodontics.

[32]  M. Edwards,et al.  Inorganic Anions and Copper Pitting , 1994 .

[33]  Michael R. Schock,et al.  Effect of pH, DIC, Orthophosphate and Sulfate on Drinking Water Cuprosolvency , 1996 .

[34]  K. L. Tan,et al.  Corrosion Mechanisms and Products of Copper in Aqueous Solutions at Various pH Values , 1997 .

[35]  Y. Hisamatsu,et al.  The pitting corrosion of copper tubes in hot water , 1983 .

[36]  O. Correc,et al.  Ageing of polyethylene at raised temperature in contact with chlorinated sanitary hot water. Part I – Chemical aspects , 2012 .

[37]  John F. Ferguson,et al.  The pitting corrosion of copper , 1994 .

[38]  M. Edwards,et al.  Acceleration of galvanic lead solder corrosion due to phosphate , 2011 .

[39]  M. Valcarce,et al.  Phosphate ions used as green inhibitor against copper corrosion in tap water , 2010 .

[40]  D M MacQuarrie,et al.  Greater Vancouver Water District drinking water corrosion inhibitor testing , 1997 .

[41]  W. Kautek,et al.  In-situ grazing incidence X-ray diffractometry observation of pitting corrosion of copper in chloride solutions , 1999 .

[42]  D. Smith,et al.  Catalogue of 45 reference Raman spectra of minerals concerning research in art history or archaeology, especially on corroded metals and coloured glass. , 2003, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[43]  M. Edwards,et al.  Role of temperature, chlorine, and organic matter in copper corrosion by-product release in soft water. , 2001, Water research.

[44]  Gordon P. Treweek,et al.  Pilot‐plant Simulation of Corrosion in Domestic Pipe Materials , 1985 .

[45]  Luke C. Adam,et al.  Hypochlorite Ion Decomposition: Effects of Temperature, Ionic Strength, and Chloride Ion. , 1999, Inorganic chemistry.

[46]  R. Webster,et al.  Voltammetric and Raman microspectroscopic studies on artificial copper pits grown in simulated potable water , 2004 .

[47]  R. Cienfuegos,et al.  Increase of the concentration of dissolved copper in drinking water systems due to flow-induced nanoparticle release from surface corrosion by-products , 2010 .

[48]  W. S. Li,et al.  Raman spectra of CuO nanocrystals , 1999 .

[49]  G. Beuchle,et al.  Copper corrosion by-product release in long-term stagnation experiments. , 2002, Water research.

[50]  Zhijiang Tang,et al.  Effects of blending on surface characteristics of copper corrosion products in drinking water distribution systems , 2007 .

[51]  L. Audouin,et al.  Aging of polyethylene pipes transporting drinking water disinfected by chlorine dioxide. I. Chemical aspects , 2009 .

[52]  T. Fujii,et al.  The effect of water quality on pitting corrosion of copper tube in hot soft water , 1985 .