Journal of Hazardous Materials, Vol.329, 211-221, 2017
Comparison of three corrosion inhibitors in simulated partial lead service line replacements
Partial lead service line replacements (PLSLR) were simulated using five recirculating pipe loops treated with either zinc orthophosphate (1 mg/L as P), orthophosphate (1 mg/L as P) or sodium silicate (10 mg/L). Two pipe loops served as "inhibitor-free" (Pb-Cu) and "galvanic free" (Pb-PVC) controls. Changes in water quality (CSMR [0.2 or 1], conductivity[approximate to 330 mu S/cm or approximate to 560 mu S/cm], chlorine [1.4mg/L]) were not observed to provide a significant impact on lead or copper release, although galvanic corrosion was shown to be a driving factor. Generally, both orthophosphate and zinc orthophosphate provided better corrosion control for both total and dissolved lead (30 min, 6 h, 65 h) and copper (30 min, 6 h), when compared to either the inhibitor-free control or the sodium silicate treated system. This work highlights the importance of understanding the complex interplay of corrosion inhibitors on particulate and dissolved species when considering both lead and copper. (C) 2017 Elsevier B.V. All rights reserved.
Keywords:Orthophosphate;Zinc orthophosphate;Sodium silicate;Partial lead service line replacement;Galvanic corrosion;Chloride-to-sulfate mass ratio