TABLE 8 - uploaded by Michael R Schock
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Field data from various copper monitoring studies and Lead and Copper Rule compliance data are often inappropriate and misleading for reliably determining fundamental chemical relationships behind copper corrosion control. A comprehensive solubility model for copper in drinking water has been developed, that is consistent with available data for co...
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Context 1
... the several experiments conducted thus far, one is particularly relevant to the issues of this investigation, and will be covered here. The water quality summary for this experiment is summa- rized in Table 8. ...
Context 2
... most directly-applicable data collected thus far for establishing verification of modeled pH/DIC effects were generated from the USEPA recirculation solubility experiments described above. A background water quality data summary for the experiments with DIC=5 mg C/L at pH 7, 8 and 9 is given in Table 8. Figures 21a-21c show the saturation indices for malachite, tenorite and cupric hydroxide versus time. ...
Citations
... Copper corrosion in water is a complex electrochemical process influenced by several interrelated factors. Among these parameters, temperature (Rushing and Edwards 2004), dissolved oxygen content (Huang et al. 2022), pH (Schock et al. 1995), and the presence of contaminants play crucial roles in determining the corrosion rate and mechanisms. Water chemistry properties, including the levels of chloride, sulfate, alkalinity, and hardness, can significantly impact the corrosivity of the aqueous environment towards copper (Lytle and Nadagouda 2010;Zlatanović et al. 2017). ...
This review examines copper corrosion mechanisms and their key influencing factors, including micro-structure effects, surface treatments, manufacturing conditions, temperature, water chemistry parameters, fluid velocity, and microbial effects in water-based systems, with a particular focus on heat exchangers. This addresses a critical gap in the existing literature, which often examines copper corrosion in a broader context. By critically analyzing the literature, the review provides an in-depth understanding of the factors that govern copper corrosion in heat exchanger applications. Copper corrosion in heat exchangers can have significant technical and social detrimental consequences, leading to substantial economic losses. By focusing on heat exchangers, the review offers valuable insights and best practices for engineers, researchers, and practitioners working with copper in this domain. Furthermore, the review evaluates the latest mitigation strategies, including advancements in material selection, surface treatments, water treatment techniques, and robust monitoring/maintenance methods. Finally, the review explores promising new concepts for corrosion prevention for long-term performance, paving the way for future research in developing innovative technologies and refining highly effective strategies under diverse operating conditions relevant to combat deleterious copper corrosion effects in heat exchanger applications.
... Because pH is a "master variable" (Stumm & Morgan, 1996) for metal solubility (Schock et al., 1995;Wahman et al., 2021), buffer intensity provides information related to the mechanisms by which pH is derived and set in natural and drinking waters (Weber & Stumm, 1964, 1963. Multiple studies have focused on the role of buffer intensity in implementing corrosion control in drinking water as it relates to distribution systems and pH stability (Benjamin et al., 1996;Snoeyink & Wagner, 1996;Stumm, 1960;USEPA, 2019). ...
An established body of research over many decades has identified the importance of both bulk‐water and pipe scale surface microenvironment buffering to meet distribution system pH targets and reduce corrosivity toward metallic piping and components. Buffer intensity quantifies the ability of water to resist pH changes, and the greater the buffer intensity, the more resistant the water is to pH changes. To provide a practical tool for exploring buffer intensity, a buffer intensity simulator (BIS) was implemented in open‐source R code, incorporating typical chemical species (e.g., carbonate and orthophosphate) that contribute to drinking water buffer intensity along with temperature and ionic strength impacts. The BIS was verified against a parallel spreadsheet implementation and is publicly available at https://github.com/USEPA/BIS . Simulations were conducted to illustrate impacts related to buffer intensity using three practical scenarios: carbonate buffering in drinking waters, temperature impacts, and free ammonia presence from chloramine use and/or source water presence.
... This inhibits the anodic reaction of copper in an environment with ammonia. The main factors affecting copper corrosion include pH levels, temperature, total organic carbon, dissolved inorganic carbon, and chloride ions [74][75][76][77][78][79]. ...
Microbial corrosion is the deterioration of materials associated with microorganisms in environments, especially in oil- and gas-dominated sectors. It has been widely reported to cause great losses to industrial facilities such as drainage systems, sewage structures, food-processing equipment, and oil and gas facilities. Generally, bacteria, viruses, and other microorganisms are the most important microorganisms associated with microbial corrosion. The destructive nature of these microorganisms differs based on the kind of bacteria involved in the corrosion mechanism. Amongst the microorganisms related to microbial corrosion, sulfate-reducing bacteria (SRB) is reported to be the most common harmful bacteria. The detailed mechanistic explanations relating to the corrosion of pipelines by sulfate-reducing bacteria are discussed. The mechanism of microbial corrosion in pipelines showing the formation of pitting corrosion and cathodic depolarization is also reported. The current review provides theoretical information for the control and protection of pipelines caused by microbial corrosion and how new eco-friendly protection methods could be explored.
... This means that the corrosion by products accumulate on the interior of the pipe. It was found that pure water does not contribute significantly to the corrosion of copper pipes [84]. Generally, there are three types of scale in pipes made from: ...
... The main factors that were found to affect the copper corrosion and later to cause the leaching of the corrosion products in the drinking water are: The components of the scale formed by the corrosion products were products of Cu (I): cuprite (Cu2O) and copper (I) hydroxide (CuOH) and products of Cu(II) : CuO, copper (II) hydroxide (Cu(OH)2), and malachite (Cu2CO3(OH)2) [84]. ...
The inner walls of drinking water distribution system (DWDS) are expected to be clean to ensure a safe quality of drinking water. In reality, complex physical, chemical and biological processes take place when water comes into contact with the pipe surface. This paper describes the impact of leaching different compounds from the water supply pipes into the drinking water and subsequent risks. Among these compounds there are heavy metals. It is necessary to prevent these metals to get into the DWDS. Those compounds are susceptible to impact the quality of the water delivered to population either by leaching dangerous chemicals into the water or by enhancing the development of microorganism growth on the pipe surface. The corrosion process of different pipes materials, scale formation mechanisms and the impact of bacteria formed in corrosion layers are discussed. Water treatment processes and the pipe materials also affect the water composition. Pipes materials act differently in the flowing and stagnation conditions. Also, they age differently (e.g metal based pipes are subjected to corrosion while polymer based pipes have a decreased mechanical resistance) and are susceptible to enhance bacterial film formation. This review helps to clarify what are the possible sources of compounds responsible for drinking water quality degradation. Also, it gives guidance on the measures that are needed to maintain a stable and safe drinking water quality.
... The average copper content of recent Icelandic basaltic lava is low, in the range of 10-200 ppm (μg/g) (Eason & Sinton, 2009;Gibson et al., 1982), with occasional higher values found in older Miocene volcaniclastic rocks . Similarly, the copper content of Icelandic groundwater is also low, ranging from 0.00015 to 0.00209 ppm (Gunnarsdottir et al., 2015) where the Cu(II) ion is the more common oxidation state (Schock et al., 1995). However, copper is a semi-volatile element that can partition into a volatile-rich fluid that can physically separate from magma (Candela & Holland, 1984). ...
... While Figure 8 and 10 show a single copper phase, Figure 9 boasts a more complex precipitate, with discrete layers of copper silicates, copper phosphates, manganese oxides, and carbonate-bearing species. The copper phases present are expected to be mostly in the Cu(II) oxidation state, as this is the ion more readily available in the groundwater (Schock et al., 1995), and because of the prominent blue color (Cu(I) minerals are generally red/brown). ...
Lava tubes on Mars hold exciting potential for the preservation of biosignatures, which may survive on geological timescales in these isolated, stable environments. To support the development of future astrobiological mission concepts, we turn to terrestrial lava tubes, host to a variety of microbial communities and secondary minerals. Following a multidisciplinary sampling protocol, we retrieved biological, molecular, and mineralogical data from several lava tubes in Iceland. We report on blue‐colored copper‐rich secondary minerals and their associated bacterial communities using a multi‐method approach, and an amalgam of 16S rRNA gene sequencing, Raman spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy data sets. We found numerous bacterial genera known for their high metal resistance and ability to survive in low‐nutrient environments. Both are characteristics to be expected for any potential life in Martian lava tubes, and should be considered when checking for contaminants in Mars mission preparations. Associated with the microbial mats, we identified several types of copper‐rich secondary minerals, indicating localized copper enrichments in the groundwater, possibly stemming from overlying ash deposits and nearby hyaloclastite formations. Molecular analysis revealed carotenoid signals preserved within the copper speleothems. If found in Martian lava tubes, blue copper‐rich mineral precipitates would be deserving of astrobiological investigation, as they have potential to preserve biosignatures and harbor life.
... In oxic and disinfected drinking waters, Cu 2+ [Cu(II)] mineralogy and chemistry largely controls copper release into the water (Ferguson et al., 1996;MWH, 2005). The relationship between Cu(II) solubility in tap water and important water quality parameters such as pH and dissolved inorganic carbon (DIC) are well established (Ferguson et al., 1996;Schock et al., 1995aSchock et al., , 1995b. For example, Cu(II) solubility decreases with increasing pH, and DIC complexes in new plumbing (i.e., cupric hydroxide assumed to control copper solubility) have been found to dominate copper speciation above pH 6.5, resulting in increased Cu(II) solubility with increasing DIC (Schock et al., 1995a;Figure 1a). ...
... The relationship between Cu(II) solubility in tap water and important water quality parameters such as pH and dissolved inorganic carbon (DIC) are well established (Ferguson et al., 1996;Schock et al., 1995aSchock et al., , 1995b. For example, Cu(II) solubility decreases with increasing pH, and DIC complexes in new plumbing (i.e., cupric hydroxide assumed to control copper solubility) have been found to dominate copper speciation above pH 6.5, resulting in increased Cu(II) solubility with increasing DIC (Schock et al., 1995a;Figure 1a). Temperature also has an important role in copper solubility and water quality (Boulay & Edwards, 2001;Rushing & Edwards, 2004). ...
... The prediction of copper levels in tap water is complicated by the reported aging phenomena of copper minerals. Over time (years to decades), scale and its mineralogy changes which can result in decreased Cu(II) solubility Lagos et al., 2001;Schock et al., 1995a;Turek et al., 2011). The cupric hydroxide model provides a conceptual understanding of copper solubility changes as Cu(II) solids age in water (Schock et al., 1995a). ...
The study goal was to better understand the risks of elevated copper levels at US schools and childcare centers. Copper health effects, chemistry, occurrence, and remediation actions were reviewed. Of the more than 98,000 schools and 500,000 childcare centers, only 0.2% had copper water testing data in the federal Safe Drinking Water Information System database. Of the facilities designated public water systems, about 13% had reported an exceedance. Schools that were not designated a public water system (PWS) also had exceedances. Few studies document levels in schools and childcare centers. Widely different sampling and remedial actions were reported. Flushing contaminated water was the most evaluated remedial action but was unreliable because copper quickly rebounded when flushing stopped. Building water treatment systems have been used, but some were not capable of making the water safe. The health risk was difficult to determine due to the limited occurrence data and lack of best management practice studies. A national drinking water testing campaign and field studies are recommended.
... Despite that, the chemical precipitation could depress the urease activity by strongly alkaline pH of surrounding conditions, degrading the degree of urea hydrolysis (Mobley and Hausinger, 1989;Schock et al., 1995;Ferris et al., 2004;Hu et al., 2021c) (see Figure 2D). On the other hand, NH 4 + concentration under any of the calcium sources always approaches 0 for Cu remediation (see Figure 2A). ...
Heavy metal contamination not only causes threat to human health but also raises sustainable development concerns. The use of traditional methods to remediate heavy metal contamination is however time-consuming, and the remediation efficiency may not meet the requirements as expected. The present study conducted a series of test tube experiments to investigate the effect of calcium source on the lead and copper removals. In addition to the test tube experiments, numerical simulations were performed using Visual MINTEQ software package considering different degrees of urea hydrolysis derived from the experiments. The remediation efficiency degrades when NH4 ⁺ and OH⁻ concentrations are not sufficient to precipitate the majority of Pb²⁺ and Cu²⁺. It also degrades when CaO turns pH into highly alkaline conditions. The numerical simulations do not take the dissolution of precipitation into account and therefore overestimate the remediation efficiency when subjected to lower Pb(NO3)2 or Cu(NO3)2 concentrations. The findings highlight the potential of applying the enzyme-induced carbonate precipitation to lead and copper remediations.
... The average copper content of recent Icelandic basaltic lava is low, in the range of 10-200 ppm (g/g) (Eason & Sinton, 2009;Gibson et al., 1982), with occasional higher values found in older Miocene volcaniclastic rocks . Similarly, the copper content of Icelandic groundwater is also low, ranging from 0.00015 to 0.00209 ppm (Gunnarsdottir et al., 2015) where the Cu(II) ion is the more common oxidation state (Schock et al., 1995). However, copper is a semi-volatile element that can partition into a volatile-rich fluid that can physically separate from magma (Candela & Holland, 1984). ...
... While Figure 8 and 10 show a single copper phase, Figure 9 boasts a more complex precipitate, with discrete layers of copper silicates, copper phosphates, manganese oxides, and carbonate-bearing species. The copper phases present are expected to be mostly in the Cu(II) oxidation state, as this is the ion more readily available in the groundwater (Schock et al., 1995), and because of the prominent blue color (Cu(I) minerals are generally red/brown). ...
... Phosphates are often added to drinking water supplies to minimise the corrosion of piping materials [21,28,47]. Increased water age influences the effectiveness of such corrosion control inhibitors by the provision of poorly buffered waters, which challenges pH management [48,49]. ...
This review critically analyses the chemical and physical parameters that influence the occurrence of opportunistic pathogens in the drinking water distribution system, specifically in premise plumbing. A comprehensive literature review reveals significant impacts of water age, disinfectant residual (type and concentration), temperature, pH, and pipe materials. Evidence suggests that there is substantial interplay between these parameters; however, the dynamics of such relationships is yet to be elucidated. There is a correlation between premise plumbing system characteristics, including those featuring water and energy conservation measures, and increased water quality issues and public health concerns. Other interconnected issues exacerbated by high water age, such as disinfectant decay and reduced corrosion control efficiency, deserve closer attention. Some common features and trends in the occurrence of opportunistic pathogens have been identified through a thorough analysis of the available literature. It is proposed that the efforts to reduce or eliminate their incidence might best focus on these common features.
... In practical applications, only total and, in some instances (e.g., with high NOM), soluble Cu can be misleading in terms of quantifying biocidal action because water chemistry can strongly influence Cu solubility via precipitation and complexation. 21,36,37 Estimating the Chick−Watson model disinfectant coefficient from Lin et al.'s work, using soluble copper measured in their experiment, yielded 3.53 × 10 −4 L μg −1 min −1 , and this is approximately 100 times higher than that estimated herein, resulting in much faster Cu-induced L. pneumophila disinfection rates. Some key differences in experimental conditions likely contribute to this difference, including strains used 26 and life stage, as demonstrated herein. ...
... Out of 33 surveyed utilities, 11 had data on phosphate, pH, and alkalinity available to predict Cu 2+ levels in both 1990 and 2018 using MINEQL+ software with the assumption that all 90th percentile copper was soluble. 37,38 Overall, results from 1990 indicated a range of predicted Cu 2+ , from 0 to 293 μg/L, with a median level of 11 μg/L (Figure 7). The 2018 results indicated a range of Cu 2+ from 0 to 54 μg/L and a median level of 1 μg/L. ...
Copper (Cu) is a promising antimicrobial for premise plumbing, where ions can be dosed directly via copper silver ionization or released naturally via corrosion of Cu pipes, but Cu sometimes inhibits and other times stimulates Legionella growth. Our overarching hypothesis was that water chemistry and growth phase control the net effect of Cu on Legionella. The combined effects of pH, phosphate concentration, and natural organic matter (NOM) were comprehensively examined over a range of conditions relevant to drinking water in bench-scale pure culture experiments, illuminating the effects of Cu speciation and precipitation. It was found that cupric ions (Cu²⁺) were drastically reduced at pH > 7.0 or in the presence of ligand-forming phosphates or NOM. Further, exponential phase L. pneumophila were 2.5× more susceptible to Cu toxicity relative to early stationary phase cultures. While Cu²⁺ ion was the most effective biocidal form of Cu, other inorganic ligands also had some biocidal impacts. A comparison of 33 large drinking water utilities’ field-data from 1990 and 2018 showed that Cu²⁺ levels likely decreased more dramatically (>10×) than did the total or soluble Cu (2×) over recent decades. The overall findings aid in improving the efficacy of Cu as an actively dosed or passively released antimicrobial against L. pneumophila.
