Nanoscale surface characterization of aqueous copper corrosion: Effects of immersion interval and orthophosphate concentration

Quartz Crystal Microbalance with Dissipation: A New Approach of Examining Corrosion of New Copper Surfaces in Drinking Water

“…The QCMD analyses showed that both increasing water pH from 6.5 to 9.0 and the addition of 6 mg/L PO 4 at a water pH of 6.5 and 9.0 effectively inhibited Cu mass changes. The mass changes corresponded to physiochemical changes on Cu surfaces based on QCMD measurements, which was also in agreement with observations of early Cu corrosion in water by others. − Previous studies, for example, showed that increasing water pH reduced Cu release by reducing the solubility of Cu corrosion byproducts deposited on the surface via influencing the diffusion process from the passivating film layer. ,, …”

“…Five water conditions (designated as A−E) were tested with four water chemistries (A−D) adapted from Daniels et al (Table S1). 20 Condition A was considered the "baseline" water and had a pH of 6.5, and contained 10 mg C/L DIC, 120 mg SO 4 /L sulfate, 60 mg/L chloride, and 3 mg Cl 2 /L free chlorine. To examine the impact of water pH and PO 4 on the initial stages of corroding new Cu surfaces, conditions B− D were adjusted as follows: conditions (B) pH 9.0, (C) pH 6.5 with 6 mg/L PO 4 water and (D) pH 9.0 with 6 mg/L PO 4 water.…”

“…Therefore, early corrosion and associated mineralogical changes of Cu surfaces are extremely important in Cu surface passivation and degradation because of its potential impact on the Cu levels in tap water that are regulated via the Lead and Copper Rule (LCR) via the Safe Drinking Water Act. , The LCR requires no more than 1.3 mg/L of total Cu in selected home tap water, and adjusting water parameters such as water pH, dissolved inorganic carbon (DIC), and phosphate inhibitors are recommended for Cu surface passivation and reducing total Cu levels in tap water. Previous studies focused on examining the ex situ long-term (up to years) impact of water quality changes and disruptive events on Cu corrosion cuprosolvency and scale passivation. − Only a few studies have examined the impact of water pH, phosphate inhibitors, and DIC on the surface roughness, structures, and morphology of the formed nanoscale corrosion byproducts during the early Cu corrosion (<24 h). − As Cu continues to be commonly used to construct drinking water plumbing in new homes and buildings, a better understanding of early in situ interfacial interactions between the drinking water and new Cu surfaces is needed. It can provide insight into the kinetics of early Cu corrosion and immediate Cu surface changes in response to water quality changes.…”

Antibacterial Metallic Touch Surfaces

“…The main reason behind copper’s resistance to such corrosion is the formation of a protective layer of Cu 2 O during the early stages of chemical interaction [ 123 ]. Daniels et al [ 124 ] investigated the changes in roughness of several copper coupons submerged in an aqueous solution at pH 6.5, 7, 8 and 9. After 24 h, AFM imaging of these coupons revealed an increase in roughness caused by the formation of a Cu 2 O layer (0.26 µm for pH 6.5, 0.5 µm for pH 7 and 0.12 for pH 8).…”

Microelectrode investigation of iron and copper surfaces aged in presence of monochloramine

“…Iron and copper pipes are widely used in drinking water distribution systems and premise plumbing (AWWA Research Foundation, 1996;Li et al, 2016;Lytle & Liggett, 2016), and understanding the reactivity of pipe surfaces is vital to providing a holistic understanding of chloramine biofilm penetration. Moreover, studies have shown that orthophosphate is successful in inhibiting or decreasing iron and copper corrosion and interfering with reactions between chloramine and reactive pipe materials in distribution systems (Daniels et al, 2013;Nguyen et al, 2012;Sarin et al, 2003). In addition, distribution system water quality modeling with software such as EPANET relies on knowing (or assuming) wall reaction rate constants to implement reactions occurring at pipe surfaces that consume disinfectants (Rossman, 2000).…”