Predicting the effect of water quality on water distribution cast iron and steel pipes using two novel indices

2017 ◽  
Vol 18 (2) ◽  
pp. 524-538
Author(s):  
Marc Philibert ◽  
Sofia Mendaza ◽  
Flavia Zraick ◽  
Benjamin Rabaud
Keyword(s):  
Cast Iron ◽  
Corrosion Rate ◽  
Water Distribution ◽  
Iron Particle ◽  
Distribution Networks ◽  
Pilot Scale ◽  
Internal Corrosion ◽  
Iron And Steel ◽  
Particle Release ◽  
Steel Pipes

Abstract The internal corrosion of cast iron and steel pipes is one of the main issues that drinking water distribution operators are facing. This study evaluated the relevance of 10 known corrosion indices according to their estimate of corrosion rate and iron particle release for 20 different water qualities. Pilot-scale contact trials were run over 45 days using cast iron and steel coupons. Corrosion rate was measured by coupon weight-loss and by an online linear polarization rate probe. Particle release was monitored by an online turbidimeter. The results showed that none of the indices properly predicted the level of risk associated with each water and that corrosion and particle release were not correlated. Two novel indices were developed to predict the corrosion and particle release risks independently of each other. The corrosion index showed a strong linear correlation with the corrosion rate of cast iron and slightly less reliable results for steel. The Particle Emission Index presented good correlation with turbidity in waters following contact with cast iron. These two indices thus showed interesting potential as tools to limit internal corrosion risks for metal pipes in water distribution networks.

Water treatment to reduce internal corrosion in the drinking water distribution system in Oslo

2001 ◽  
Vol 1 (3) ◽  
pp. 91-96 ◽  
Author(s):  
L.J. Hem ◽  
E.A. Vik ◽  
A. Bjørnson-Langen
Keyword(s):  
Water Treatment ◽  
Corrosion Rate ◽  
Distribution System ◽  
Water Distribution ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Corrosion Monitoring ◽  
Copper Corrosion ◽  
Iron Corrosion ◽  
Internal Corrosion

In 1995 the new Skullerud water treatment plant was put into operation. The new water treatment includes colour removal and corrosion control with an increase of pH, alkalinity and calcium concentration in addition to the old treatment, which included straining and chlorination only. Comparative measurements of internal corrosion were conducted before and after the installation of the new treatment plant. The effect of the new water treatment on the internal corrosion was approximately a 20% reduction in iron corrosion and a 70% reduction in copper corrosion. The heavy metals content in standing water was reduced by approximately 90%. A separate internal corrosion monitoring programme was conducted, studying the effects of other water qualities on the internal corrosion rate. Corrosion coupons were exposed to the different water qualities for nine months. The results showed that the best protection of iron was achieved with water supersaturated with calcium carbonate. Neither a high content of free carbon dioxide or the use of the corrosion inhibitor sodium silicate significantly reduced the iron corrosion rate compared to the present treated water quality. The copper corrosion rate was mainly related to the pH in the water.

scholarly journals INHIBITOR EFFICACY AND COMPOSITION OF OAK BAR EXTRACT

2020 ◽  
Vol 2020 (60) ◽  
pp. 107-117
Author(s):  
Olha HULAI ◽  
◽  
Vasylyna SHEMET ◽  
Vasyl ZHILKO ◽  
Olena KLYMOVYCH ◽  
...  
Keyword(s):  
Cast Iron ◽  
Corrosion Rate ◽  
Bark Extract ◽  
Selective Detection ◽  
Stationary Potential ◽  
Alcohol Extract ◽  
Iron And Steel ◽  
Inhibition Effect ◽  
Weight Method ◽  
Corrosive Environments

Regional and international researchers have proven that natural products, plants and their extracts can be used to reduce the corrosion rate. Such studies are relevant because natural inhibitors are obtained from renewable sources, therefore they are environmentally friendly. Ukrainian scientists have investigated the inhibition effect of oak bark extracts, but no such studies have been performed on cast iron. What is more, it has not been established which substances cause this effect. The purpose of the study is to determine the corrosion resistance of 08kp steel and gray cast iron SCh-15 (common structural materials of food industry equipment) in acidic and neutral environments in presence of oak bark extracts; to define the qualitative composition of the extract. Structure of cast iron and steel samples was studied on a metallographic microscope MMP-14C. The corrosion rate of metals was evaluated by weight. To determine the corrosion potential, we used a setting of a cathode voltmeter, electrodes (test and saturated chloride-silver), an intermediate vessel with a saturated KCl solution and electrolytic keys filled with the test electrolyte and saturated KCl solution (for the comparison electrode). The extract was analyzed on a Shimadzu GCMS-QP2020 gas chromatograph with mass-selective detection. Using weight method, the inhibition effect of oak shavings alcohol extract was proved in acidic and neutral corrosive environments. Under the influence of oak bark extract (5%), the stationary potential of steel 08kp has shifted: in 3% NaCl solution (oxygen depolarization) – towards more negative values; in 5% HCl solution (hydrogen depolarization) – to less negative values. Gas chromatography with mass-selective detection (GC/MS) revealed that the active substance in the extract is a mixture of natural tannins – polyphenolic compounds with a molecular weight of 500 to 3000. The inhibition effect of natural tannins is probably enhanced by siloxane compounds.

scholarly journals The Unfavourable Impact of Street Traffic on Water Distribution Pipelines

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1086 ◽  
Author(s):  
Ioan Așchilean ◽  
Mihai Iliescu ◽  
Nicolae Ciont ◽  
Ioan Giurca
Keyword(s):  
Cast Iron ◽  
Water Supply ◽  
Water Distribution ◽  
Road Traffic ◽  
Distribution Networks ◽  
Negative Influence ◽  
Supply System ◽  
Water Supply System ◽  
Pipe Material

This article analyses the relation between the failures that occurred in the water supply network and the road traffic in the city of Cluj-Napoca in Romania. The calculations in this case study were made using the Autodesk Robot Structural Analysis Professional 2011 software. In the case study, the following types of pipes were analysed: steel, gray cast iron, ductile cast iron and high density polyethylene (HDPE). While in most studies only a few sections of pipelines, several types of pipelines and certain mounting depths have been analysed, the case study presented analyses the entire water supply system of a city with a population of 324,576 inhabitants, whose water supply system has a length of 479 km. The results of the research are useful in the design phase of water distribution networks, so depending on the type of pipe material, the minimum depth of installation can be indicated, so as to avoid the failure of the pipes due to road traffic. From this perspective, similar studies could also be carried out regarding the negative influence of road traffic on sewerage networks, gas networks and heating networks.

Corrosion rate and scale of cast iron in water distribution systems

2016 ◽  
Vol 22 (6) ◽  
pp. 516-524 ◽  
Author(s):  
Hao Guo ◽  
Yimei Tian ◽  
Haolin Chen ◽  
Yufen Fu ◽  
Xingfei Liu
Keyword(s):  
Cast Iron ◽  
Corrosion Rate ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems

scholarly journals Detection of Escherichia coli in Biofilms from Pipe Samples and Coupons in Drinking Water Distribution Networks

2007 ◽  
Vol 73 (22) ◽  
pp. 7456-7464 ◽  
Author(s):  
T. Juhna ◽  
D. Birzniece ◽  
S. Larsson ◽  
D. Zulenkovs ◽  
A. Sharipo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Cast Iron ◽  
Water Distribution ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Bacterial Number ◽  
E Coli ◽  
Drinking Water Distribution ◽  
Enzymatic Methods

ABSTRACT Fluorescence in situ hybridization (FISH) was used for direct detection of Escherichia coli on pipe surfaces and coupons in drinking water distribution networks. Old cast iron main pipes were removed from water distribution networks in France, England, Portugal, and Latvia, and E. coli was analyzed in the biofilm. In addition, 44 flat coupons made of cast iron, polyvinyl chloride, or stainless steel were placed into and continuously exposed to water on 15 locations of 6 distribution networks in France and Latvia and examined after 1 to 6 months exposure to the drinking water. In order to increase the signal intensity, a peptide nucleic acid (PNA) 15-mer probe was used in the FISH screening for the presence or absence of E. coli on the surface of pipes and coupons, thus reducing occasional problems of autofluorescence and low fluorescence of the labeled bacteria. For comparison, cells were removed from the surfaces and examined with culture-based or enzymatic (detection of β-d-glucuronidase) methods. An additional verification was made by using PCR. Culture method indicated presence of E. coli in one of five pipes, whereas all pipes were positive with the FISH methods. E. coli was detected in 56% of the coupons using PNA FISH, but no E. coli was detected using culture or enzymatic methods. PCR analyses confirmed the presence of E. coli in samples that were negative according to culture-based and enzymatic methods. The viability of E. coli cells in the samples was demonstrated by the cell elongation after resuscitation in low-nutrient medium supplemented with pipemidic acid, suggesting that the cells were present in an active but nonculturable state, unable to grow on agar media. E. coli contributed to ca. 0.001 to 0.1% of the total bacterial number in the samples. The presence and number of E. coli did not correlate with any of physical and/or chemical characteristic of the drinking water (e.g., temperature, chlorine, or biodegradable organic matter concentration). We show here that E. coli is present in the biofilms of drinking water networks in Europe. Some of the cells are metabolically active but are often not detected due to limitations of traditionally used culture-based methods, indicating that biofilm should be considered as a reservoir that must be investigated further in order to evaluate the risk for human health.

The effect of pH adjustment on the internal corrosion rate of residential cast-iron and copper water distribution pipes

1988 ◽  
Vol 15 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Louise Millette ◽  
Donald S. Mavinic
Keyword(s):  
Cast Iron ◽  
Water Distribution ◽  
Copper Corrosion ◽  
Iron Corrosion ◽  
Internal Corrosion ◽  
Ph Adjustment ◽  
Water Pipes ◽  
Corrosion Rates ◽  
Copper Water ◽  
System Pressure

The Greater Vancouver Regional District distributes drinking water that displays several attributes of an aggressive water: low pH, low alkalinity, and high dissolved oxygen. A study, consisting of two experimental sessions, was conducted at the University of British Columbia to examine the effects of pH adjustment on internal corrosion of residential cast-iron and copper water distribution pipes.Because of its aggressive nature, this water accelerates the corrosion of water pipes, which not only increases maintenance costs, but also encourages high levels of metal in the water. This last finding was confirmed by a preliminary survey wherein, after one month's sampling of six dwellings, it was found that the recommended maximum level of 1.0 mg/L was exceeded in 67% of the morning cold water first-flush samples.Adjustment of pH with hydrated lime, Ca(OH)2, was used for corrosion control. Cast-iron and copper samples were exposed to pH-adjusted water for varying lengths of time, in two flow-through experimental systems (gravity-fed and system-pressure-fed).Although the corrosion rates were different for the two experimental sessions, analysis of the pH-related corrosion rates variation led to the same two findings. The corrosion rates of cast iron were 10 times those of copper; the increased pH enhanced these cast-iron corrosion rates by approximately 15%. However, a pH increase reduced copper corrosion by as much as 68%. The effects of increased pressure on corrosion were different for both metals; a higher pressure greatly enhanced cast-iron corrosion but had little effect on copper corrosion. Key words: aggressive water, cast iron, corrosion, copper, lime, pH adjustment, water pipes.

An analysis of pipe breakage in urban water distribution networks

1985 ◽  
Vol 12 (2) ◽  
pp. 286-293 ◽  
Author(s):  
A. J. Kettler ◽  
I. C. Goulter
Keyword(s):  
Cast Iron ◽  
Water Distribution ◽  
Distribution Networks ◽  
Failure Rates ◽  
Pipe Failure ◽  
Modes Of Failure ◽  
Asbestos Cement ◽  
Pipe Systems ◽  
Pipe Breakage ◽  
Joint Regression Analysis

The rates of pipe breakage with increasing pipe diameter and times are investigated. Failure rates for cast-iron pipe are found to decrease with increasing diameter. Changes in pipe failure rates for the various modes of failures are examined in detail. Asbestos-cement and cast-iron pipe overall failure rates are found to increase with time, but for different reasons. Analysis of the modes of failure shows that joint failure is predominant for cast-iron pipe systems with bolted and universal joints whereas the predominant mode of failure for asbestos-cement pipe systems is circumferential cracking. Key words: asbestos cement, cast iron, cracking, diameter, failure rate, joint, regression analysis.

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