Effect of Aluminum on Lead Release to Drinking Water from Scales of Corrosion Products

Environmental context Galvanic corrosion has been recently reported as the main cause of lead contamination in drinking water in urban cities. Conditions that can deter or promote galvanic corrosion, however, are not well understood. Fundamental investigations exploring the mechanisms and processes involved in galvanic corrosion in drinking water could help to implement proper corrective measures to safeguard public health from lead contamination. Abstract This study investigates the effects of pH value, chloride and sulfate concentrations on galvanic corrosion between lead and copper in drinking water. We hypothesised that galvanic corrosion would occur immediately when a lead–copper couple is first formed and that the release of lead would be suppressed by the subsequent formation of lead corrosion products. Therefore, unlike previous long-term studies using harvested lead pipes, batch experiments employing high-purity lead and copper (99.9%) wires under stagnant and completely mixed conditions were conducted for a 7-day period to test our hypotheses. It was found that enhanced lead release was indeed observed after the lead–copper couple was formed and the lead profiles after 48h were strongly influenced by lead corrosion products formed in the system. Under stagnant conditions, reducing pH and increasing either chloride or sulfate concentrations promoted lead release, leading to the formation of lead corrosion products such as cerussite and hydrocerussite as experiments proceeded. The effect of chloride concentration on total lead concentration measured in the aqueous phase was similar to that of sulfate at the same molar concentration, showing that the chloride-to-sulfate mass ratio may not provide a good indication for total lead concentration in water. This study provides essential information on fundamental mechanisms and processes involved in galvanic corrosion in drinking water and may be used to explain related phenomena observed in real drinking-water distribution systems.

Download Full-text

Effects of blending of desalinated water with treated surface drinking water on copper and lead release

Water Research ◽

10.1016/j.watres.2010.05.014 ◽

2010 ◽

Vol 44 (14) ◽

pp. 4057-4066 ◽

Cited By ~ 18

Author(s):

Haizhou Liu ◽

Kenneth D. Schonberger ◽

Gregory V. Korshin ◽

John F. Ferguson ◽

Paul Meyerhofer ◽

...

Keyword(s):

Drinking Water ◽

Desalinated Water ◽

Lead Release

Download Full-text

Bromide-assisted catalytic oxidation of lead(ii) solids by chlorine in drinking water distribution systems

Chemical Communications ◽

10.1039/c7cc02533e ◽

2017 ◽

Vol 53 (62) ◽

pp. 8695-8698 ◽

Cited By ~ 5

Author(s):

John Orta ◽

Samuel Patton ◽

Haizhou Liu

Keyword(s):

Drinking Water ◽

Catalytic Oxidation ◽

Distribution Systems ◽

Water Distribution ◽

Water Distribution Systems ◽

Redox Process ◽

Drinking Water Distribution Systems ◽

Drinking Water Distribution ◽

Lead Release

This study investigated the effect of bromide on the oxidation of three lead(ii) solids by chlorine – a redox process critical to the control of lead release in drinking water distribution systems.

Download Full-text

Key Parameters and Kinetics of Oxidation of Lead (II) Solid Phases by Chlorine in Drinking Water

Water Practice & Technology ◽

10.2166/wpt.2006.092 ◽

2006 ◽

Vol 1 (4) ◽

Author(s):

Haizhou Liu ◽

Gregory V. Korshin ◽

John F. Ferguson ◽

Wenju Jiang

Keyword(s):

Drinking Water ◽

Transition Phase ◽

Lag Phase ◽

X Ray Diffraction ◽

Water Parameters ◽

Carbonate Concentration ◽

Rapid Transition ◽

Lead Release ◽

Solid Phases ◽

Kinetics Of

Equilibria and kinetics of transformations in the Pb(II)/Pb(IV)/chlorine system have a great impact on lead release in drinking water. To explore this system, oxidation of representative Pb(II) solid phases, predominantly hydrocerussite was carried out in chlorinated water with various alkalinities and pH values. It was determined that the oxidation of hydrocerussite by chlorine proceeded via three phases. These included a lag phase, a rapid transition phase and a final quasi steady-state phase. The lag phase corresponded to the transformation of hydrocerussite to cerussite PbCO3, while during the transition phase, the oxidation of PbCO3 and formation of -PbO2 occurred. Key water parameters, such as pH, chlorine concentration and dissolved inorganic carbonate concentration had a pronounced impact on the duration of the lag phase. Data of X-ray diffraction and scanning electron microscopy demonstrated that cerussite PbCO3 was formed as a transient phase during hydrocerussite oxidation, and dispersed microcrystals of scrutinyite -PbO2 were formed when chlorine was consumed.

Download Full-text