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In situ 2D maps of pH shifts across brass-lead galvanic joints using microelectrodes
Citation:
Ma, X., W. Lee, AND D. Lytle. In situ 2D maps of pH shifts across brass-lead galvanic joints using microelectrodes. Measurement Science and Technology. IOP Publishing, PHILADELPHIA, PA, 28(2):025101, (2016). https://doi.org/10.1088/1361-6501/28/2/025101
Impact/Purpose:
Galvanic corrosion in drinking water distribution systems, such as conditions following partial lead (Pb) service line replacement, has received recent attention. In order to better understand conditions at galvanic connections that lead to enhanced metal release and provide remedial strategies, the water-metal and anodic-cathodic interfaces at these locations must be better understood. In this paper, a pH microelectrode system was used to create in-situ 2D spatial images of the pH of water across two brass coupons connected by a leaded solder joint at 100 µm above the metal’s surface under flowing and stagnation conditions. Water stagnation resulted in significant pH changes across the surfaces compared to flow condition. Under stagnation, the pH above the anode (leaded solder) was 1.5 pH units below the bulk water and as much as 2.5 units below the cathode (brass). These conditions will enhance lead release at the anode which reflects different anodic-cathodic relationships of coupled metals primarily controlled by water flow.
Description:
Galvanic corrosion in drinking water distribution systems, such as conditions following partial lead (Pb) service line replacement, has received recent attention. In order to better understand conditions at galvanic connections that lead to enhanced metal release and provide remedial strategies, the water-metal and anodic-cathodic interfaces at these locations must be better understood. In this paper, a pH microelectrode system was used to create in-situ 2D spatial images of the pH of water across two brass coupons connected by a leaded solder joint at 100 µm above the metal’s surface under flowing and stagnation conditions. Water stagnation resulted in significant pH changes across the surfaces compared to flow condition. Under stagnation, the pH above the anode (leaded solder) was 1.5 pH units below the bulk water and as much as 2.5 units below the cathode (brass). These conditions will enhance lead release at the anode which reflects different anodic-cathodic relationships of coupled metals primarily controlled by water flow.
URLs/Downloads:
DOI: In situ 2D maps of pH shifts across brass-lead galvanic joints using microelectrodes
Free access through PubMed Central
http://iopscience.iop.org/article/10.1088/1361-6501/28/2/025101/meta