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Source publication
The aim of this paper was to study the influence of microbial biofilms on the high copper levels measured in the drinking water of rural houses. Drinking water parameters and copper pipe surfaces were analysed in the copper plumbing systems of rural and urban houses. The water in rural houses had pH values of 6.2 and alkalinity values of 63 mg/L as...
Contexts in source publication
Context 1
... The surface of the copper pipes in two rural houses was completely and uniformly covered with bluish green corrosion products, which were identified as mala- chite by XRD analysis (Table 3). The copper pipe sampled from one of the rural houses did not contain bluish green corrosion products and the surface had a reddish brown colour. ...
Context 2
... copper pipe sampled from one of the rural houses did not contain bluish green corrosion products and the surface had a reddish brown colour. In this case, only cuprite was detected by XRD (Table 3). In addition, the SEM images show that the corrosion scales covering the surfaces of copper pipe samples of the three rural houses were porous. ...
Context 3
... SEM analysis of copper pipe sections from the urban houses showed no presence of biofilms (Figs. 1d and e) and XRD analysis showed that the inner surface was covered solely with cuprite and tenorite (Table 3). Visual inspection of these samples showed more uniform and compact corrosion scales in comparison with the rural houses. ...
Context 4
... observed in rural houses, such as infrequently used pipes, giving rise to very long stagnation periods (472 h) and the length of the pipes (Table 3) contributed to the biofilm growth such as that which has been reported ( Bremer et al., 2001;Geesey et al., 1994). Due to the multiple evidences shown before, we concluded that the microbial biofilms along with the aggressive water quality could be the main factors involved in the high levels of copper by-product liberation in rural houses. ...
Citations
... The Swedish and Finnish KBS-3 concept has chosen copper as the container material due to its comparatively high chemical resistance in the environment, unlike steel [4,5]. The corrosion of copper in storage facilities is characterised not by continuous (general) corrosion, but by localised corrosion, in particular in the presence of hydrogen [6], chloride [7], hydrocarbonate [8] and sulfide [9], and as a result of microbial corrosion (MIC) [10][11][12][13]. ...
This paper presents the results of microbial corrosion tests on M0-grade copper under conditions simulating a geological repository for radioactive waste at the Yeniseisky site (Krasnoyarsk Krai, Russia). The work used a microbial community sampled from a depth of 450 m and stimulated with glucose, hydrogen and sulfate under anaerobic conditions. It was shown that the maximum corrosion rate, reaching 9.8 µm/y, was achieved with the addition of sulfate (1 g/L) with the participation of microorganisms from the families Desulfomicrobiaceae, Desulfovibrionaceae and Desulfuromonadaceae. It was noted that the most important factor leading to copper corrosion was the accumulation of hydrogen sulfide during the activation of sulfate-reducing microorganisms of the genera Desulfomicrobium, Desulfovibrio and Desulfuromonas. During the development of the microbial community under these conditions, the content of copper can have a significant toxic effect at a concentration of more than 250 mg/L.
... Rahman et al. (1997) reported contradictory results indicating that an elevated zinc value of 4.02 mg/l was detected in several locations throughout Karachi. Zinc leaching through pipes and fittings can result in substantially greater zinc concentrations in tap water (Reyes et al., 2008;Xu et al., 2006). Demyelinating disease occurs in the human body if the Zn concentration is higher (Mora et al., 2009). ...
In the present study, piped water samples from Gulshan-e-Iqbal Town, Karachi, were evaluated for their Health Risk Assessment (HRA) and Water Quality Index (WQI). For this, different physicochemical and microbiological parameters were analyzed, and the results were evaluated according to the guidelines established by the WHO (2011) and the National Standards for Drinking Water Quality (NSDWQ) (2008). With the exception of sulphate, all physicochemical parameters were well within the guideline values. The mean concentrations of the metals in the samples were in the following order: Ca²⁺ > Mg²⁺ > Zn > Fe > Pb > Ni > Cr > As. More than 70% of the samples tested for Total Coliform Count (TCC), Total Faecal Coliform Count (TFC), Total Feacal Streptococci (TFS), and Total Aerobic Count (TAC) were feacal contaminated. E. coli was also isolated in almost 84.61% of the tested piped water samples. Results from the WQI revealed that 95.6% of samples had good physico-chemical characteristics, and 26% of the piped water samples had good microbiological quality. The WQI readings of all the samples for metals showed that they were unfit for human consumption. The mean Chronic Daily Intake (CDI) and Hazard Quotient (HQ) values, respectively, were in the following order: Zn > Fe > Pb > Ni > Cr > As, and Pb > As > Ni > Cr > Zn > Fe. All HQ values for As and Pb were greater than 1, and 50% of piped water samples had an HQ value for Ni that was greater than 1, indicating that people may suffer serious health issues as a result. All of the piped water samples except the area of block 13 D (S-5), had HQ values of less than 1 in relation to iron, but Zn HQ values of less than 1 indicated only mild health problems. Discharge of untreated sewage and cross-contamination are all potential sources of contamination that could result in diseases that are harmful to the public’s health. Water monitoring and management projects should be implemented in order to improve pipeline infrastructure and reduce sewage leakages.
... Microbial induced corrosion together with scale accumulation may damage the pipeline resulting in pipe leakage or bursting. Biofilm formation can contribute to the acceleration of metallic pipes corrosion [92][93][94][95]180]. Pitting corrosion starts at the interface biofilm -metallic pipe because the water pH is modified by the release of metabolic degradation compounds [95]. ...
... Microbial induced corrosion together with scale accumulation may damage the pipeline resulting in pipe leakage or bursting. Biofilm formation can contribute to the acceleration of metallic pipes corrosion [92][93][94][95]180]. Pitting corrosion starts at the interface biofilm -metallic pipe because the water pH is modified by the release of metabolic degradation compounds [95]. ...
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.
... High copper concentration in drinking water was linked to Variovorax sp. biofilms in the system of copper plumbing, and the ability of bacteria to cause microbial induced corrosion was observed [22][23][24][25]. Numerous studies showed that, compared to suspension cells, immobilized microbes improve hazardous chemical tolerance and breakdown [26][27][28]. ...
Background
Despite being necessary, copper is a toxic heavy metal that, at high concentrations, harms the life system. The parameters that affect the bioreduction and biosorption of copper are highly copper-resistant bacteria.
Results
In this work, the ability of the bacterial biomass, isolated from black shale, Wadi Nakheil, Red Sea, Egypt, for Cu²⁺ attachment, was investigated. Two Cu²⁺ resistance Bacillus species were isolated; Bacillus pumilus OQ931870 and Bacillus subtilis OQ931871. The most tolerant bacterial isolate to Cu²⁺ was B. pumilus. Different factors on Cu²⁺ biosorption were analyzed to estimate the maximum conditions for Cu biosorption. The qmax for Cu²⁺ by B. pumilus and B. subtilis determined from the Langmuir adsorption isotherm was 11.876 and 19.88 mg. g⁻¹, respectively. According to r², the biosorption equilibrium isotherms close-fitting with Langmuir and Freundlich model isotherm. Temkin isotherm fitted better to the equilibrium data of B. pumilus and B. subtilis adsorption. Additionally, the Dubinin-Radushkevich (D-R) isotherm suggested that adsorption mechanism of Cu²⁺ is predominately physisorption.
Conclusion
Therefore, the present work indicated that the biomass of two bacterial strains is an effective adsorbent for Cu²⁺ removal from aqueous solutions.
... These cell densities do not necessarily mean that there is a risk for human health, but from an operational point of view, could cause problems with the piping, such as microbial induced corrosion and biofouling for example 3,30 To ensure that no pathogenic bacteria are present, regular microbiological tests are a must. Except for the single drinking water analysis performed at the end of the experiment, no coliform or bacteriological tests were performed during the 20 day run. ...
With the use of on-line flow cytometric fingerprinting, we confirmed that cell densities in a RO permeate were caused by bacterial regrowth in the piping, and that there was no problem with the integrity of the membrane and resulting water quality.
... The settling of copper-tolerant bacteria on copper pipes allows the adhesion of noncopper-tolerant cells, resulting in significant biofilm complexity and increasing hazards due to possible adhesion of pathogens [13]. Likewise, biofilm metabolism creates a microenvironment where corrosion reactions are favored, a phenomenon known as biocorrosion [1,14]. ...
... A bacterium commonly found in copper piping systems is Variovorax sp., a Gram-negative bacillus that predominates in this environment due to its capability to grow as a biofilm and its high copper tolerance [14,15]. Variovorax sp. can grow with doses of up to 10 mM Cu [16]. ...
Copper is a metal well known for its antimicrobial properties. However, copper-made structures such as pipes and clinical supplies are prone to be colonized by copper-tolerant bacteria. Recent works have shown that modifications of the topography and surface chemistry of metals using direct laser interference patterning (DLIP) affect bacterial settlement. In this work, DLIP was used to texture copper surfaces with parallel line patterns on the size scale of a bacterium. The effects of texturing on the copper surface were characterized by scanning electron microscopy, atomic force microscopy, contact angle and corrosion analyses, and X-ray photoelectron spectroscopy. The antimicrobial properties were assessed by using the live/dead test. Experiments were performed on both the copper-tolerant bacterium Variovorax sp. and the noncopper-resistant bacterium Escherichia coli. Our results indicate that although the increase in Cu(OH)2 might influence the toxicity of the surface, the controlling factor of the antimicrobial activity of laser-textured copper surfaces is the contact area per bacterium. This work highlights the application of laser texturing technologies to enhance the antimicrobial behavior of metals.
... The settling of copper-tolerant bacteria on copper pipes allows the adhesion of noncopper-tolerant cells, resulting in significant biofilm complexity and increasing hazards due to possible adhesion of pathogens [13]. Likewise, biofilm metabolism creates a microenvironment where corrosion reactions are favored, a phenomenon known as biocorrosion [1,14]. ...
... A bacterium commonly found in copper piping systems is Variovorax sp., a Gram-negative bacillus that predominates in this environment due to its capability to grow as a biofilm and its high copper tolerance [14,15]. Variovorax sp. can grow with doses of up to 10 mM Cu [16]. ...
Copper is a metal well known for its antimicrobial properties. However, copper-made structures such as pipes and clinical supplies are prone to be colonized by copper-tolerant bacteria. Recent works have shown that modifications of the topography and surface chemistry of metals using direct laser interference patterning (DLIP) affect bacterial settlement. In this work, DLIP was used to texture copper surfaces with parallel line patterns on the size scale of a bacterium. The effects of texturing on the copper surface were characterized by scanning electron microscopy, atomic force microscopy, contact angle and corrosion analyses, and X-ray photoelectron spectroscopy. The antimicrobial properties were assessed by using the live/dead test. Experiments were performed on both the copper-tolerant bacterium Variovorax sp. and the noncopper-resistant bacterium Escherichia coli. Our results indicate that although the increase in Cu(OH)2 might influence the toxicity of the surface, the controlling factor of the antimicrobial activity of laser-textured copper surfaces is the contact area per bacterium. This work highlights the application of laser texturing technologies to enhance the antimicrobial behavior of metals.
... The metal content of copper with the minimum amount of nickel alloys is susceptible to several types of localized corrosion (Little et al. 1991). Meanwhile, microbes accelerate the material deterioration which causes the high release of Cu byproducts in the water bodies (Critchley et al. 2004;Reyes et al. 2008). Therefore several techniques (mechanical, chemical, electrochemical and biological etc.) have been performed to reduce the biocorrosion in CWS ( Li et al. 2018;Narenkumar et al. 2017a). ...
The development of environmentally acceptable benign techniques using purely natural methods is a cost-effective procedure with long-term benefits in all areas. With this consideration, myco synthesized silver nano particles (AgNPs) were studied and it acted as an impending corrosion inhibitor in the environment. Initially, AgNPs were evaluated by physical and surface characterizations and this evidence demonstrated that RYREʼs water-soluble molecules played an essential role in the synthesis of AgNPs in nano spherical size. The myco synthesized of AgNPs has showed an antibacterial activity against corrosive bacteria in cooling water system (CWS). Hence, the AgNPs were used in biocorrosion studies as an anticorrosive agent along with AgNO3 and RYRE was also checked. For this experiment, the copper (Cu) metal (CW024) which is commonly used was selected, the result of corrosion rate was decreased, and inhibition efficiency (82%) was higher in the presence of AgNPs in system IV. Even though, AgNO3 and RYRE had contributed significant inhibition efficiency on Cu at 47% and 61%, respectively. According to XRD, the reaction of AgNPs on Cu metal resulted in the formation of a protective coating of Fe2O3 against corrosion. EIS data also indicated that it could reduce the corrosion on the Cu metal surface. All of these findings point out the possibility that the myco-synthesized AgNPs were an effective copper metal corrosion inhibitor. As a result, we encourage the development of myco-synthesized AgNPs, which could be useful in the industrial settings.
Graphical abstract
... Reyes et al. investigated the MIC of copper pipes at a low pH. This was to simulate the drinking water conditions in a typical rural home [112]. They took various sections of the water system's copper pipes and analysed them using XRD. ...
Almost every abiotic surface of a material is readily colonised by bacteria, algae, and fungi, contributing to the degradation processes of materials. Both biocorrosion and microbially influenced corrosion (MIC) refer to the interaction of microbial cells and their metabolic products, such as exopolymeric substances (EPS), with an abiotic surface. Therefore, biofouling and biodeterioration of manufactured goods have economic and environmental ramifications for the user to tackle or remove the issue. While MIC is typically applied to metallic materials, newly developed and evolving materials frequently succumb to the effects of corrosion, resulting in a range of chemical reactions and transport mechanisms occurring in the material. Recent research on biocorrosion and biofouling of conventional and novel materials is discussed in this paper, showcasing the current knowledge regarding microbial and material interactions that contribute to biocorrosion and biofouling, including biofilms, anaerobic and aerobic environments, microbial assault, and the various roles microorganisms’ play. Additionally, we show the latest analytical techniques used to characterise and identify MIC on materials using a borescope, thermal imaging, Fourier transform infrared (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron microscopy (XPS), X-ray diffraction (XRD), optical and epifluorescence microscopy, electrochemical impedance spectroscopy, and mass spectrometry, and chemometrics.
... However, enhanced localized corrosion, which subsequently resulted in failure of the infrastructure, has been observed. This issue was linked to the growth of biofilms on copper pipes, which was also found responsible for increased metal concentration in drinking water (Bremer et al., 2001;Beech, 2004;Reyes et al., 2008;Kip and van Veen, 2014). These phenomena have been reported as an expensive problem in countries around the world like Scotland, Germany, England, Saudi Arabia, and United States (Keevil, 2004). ...
Regardless of the long record of research works based on microbiologically influenced corrosion (MIC), its principle and mechanism, which lead to accelerated corrosion, is yet to be fully understood. MIC is observed on different metallic substrates and can be caused by a wide variety of microorganisms with sulfate-reducing bacteria (SRB) being considered the most prominent and economically destructive one. Copper and its alloys, despite being used as an antimicrobial agent, are recorded to be susceptible to microbial corrosion. This review offers a research overview on MIC of copper and its alloys in anaerobic aqueous environments. Proposed MIC mechanisms, recent work and developments as well as MIC inhibition techniques are presented focusing on potable water systems and marine environment. In the future research perspectives section, the importance and possible contribution of knowledge about intrinsic properties of substrate material are discussed with the intent to bridge the knowledge gap between microbiology and materials science related to MIC.
