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ABSTRACT Due to the potential occurrence of heavy metals in tap water, it is critical to examine their interactions with plastic potable water pipe surfaces, as these pipes may undergo physicochemical degradation induced by residual disinfectants over time. Thus, this study investigated the influence of plastic pipe degradation and water alkalinity on the release of Pb, Cu, and Zn from crosslinked polyethylene type A (PEX‐A) pipes after they underwent heavy metal accumulation experiments. For this purpose, an accelerated aging process was conducted by exposing pipes to a solution with a total chlorine concentration of 2500 mg L−1at 70°C for 6 days. Disinfectant decay and organic leaching characteristics were examined for new and aged pipes in both cold and hot water. Surface chemistry analyses of pipes after accelerated degradation revealed the formation of oxidized carbon surface functional groups and etched‐like surface morphology. Aged pipes demonstrated higher heavy metal accumulation in the presence of alkalinity compared to conditions without alkalinity. Cu accumulation was found to be the most prominent, followed by Pb and Zn. The new PEX‐A pipes released more metals than aged PEX‐A pipes at pH 6.0. This pH was selected to assess the sensitivity of metal release to pH changes under more aggressive water chemistry. For hot water, both new and aged PEX‐A pipes exhibited a significant reduction in total chlorine residual concentration after 12 h, with aged pipes showing a faster chlorine decay rate. Hot water also promoted organic leaching from both new and aged pipes at pH 6.0.
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Truck Impact on Buried Water Pipes in Interdependent Water and Road Infrastructures
In the development of sustainable and resilient infrastructures to adapt to the rapidly changing natural and social environment, the complexity of the dependencies and interdependencies within critical infrastructure systems need to be fully understood, as they affect various components of risk and lead to cascading failures. Water and road infrastructures are highly co-located but often managed and maintained separately. One important aspect of their interdependence is the impact of vehicle loading on a road on underlying water pipes. The existing studies lack a comprehensive evaluation of this subject and do not consider possible critical failure scenarios. This study constructed finite element models to analyze the responses of buried water pipes to vehicle loads under an array of scenarios, including various loads, pipe materials, pipe dimensions, and possible extreme conditions, such as corrosion in pipes and a sinkhole under the pipe. The results showed negligible impact of heavy trucks on buried water pipes. The pipe deflection under a maximum allowable truck load in the worst condition was still within the allowable range specified in standards such as those from the American Water Works Association. This implies that the impact of heavy vehicles on water pipes may not need to be considered in the context of the interdependency between water and road infrastructures, which leads to a more unidirectional dependency between these two infrastructures.
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- Award ID(s):
- 1638301
- PAR ID:
- 10354626
- Date Published:
- Journal Name:
- Sustainability
- Volume:
- 13
- Issue:
- 20
- ISSN:
- 2071-1050
- Page Range / eLocation ID:
- 11288
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.3390/su132011288
