This study aimed to assess the impact of tap water application on reducing the generation of ultrafine particles from the wheel-rail contact using a twin-disk rig under dry and wet conditions, with train velocities of 45 and 80 km/h. A small amount of 0.3 L/min tap water was applied at the wheel-rail contact, and a diffusion dryer was used to eliminate water vapor. The Fast Mobility Particle Sizer measured the number concentration (NC) of nano-sized wear particles in the range of 6 to 560 nm. The tap water application method effectively reduced the NC of ultrafine and fine particles by 67-72% and 86-88%, respectively. Positive reduction rates were observed for all diameters at 45 km/h and for most diameters, except for approximately 70 nm and 80 nm, at 80 km/h. Even with a small amount of water, this approach successfully decreased nano-sized wear particle generation. However, the potential influence of mineral crystals in tap water on NC requires further investigation. Overall, this method shows promise for enhancing air quality and public health by mitigating nano-sized wear particle generation in subway systems.
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http://dx.doi.org/10.3390/toxics11100873 | DOI Listing |
RSC Adv
January 2025
Phenikaa University Nano Institute (PHENA), Phenikaa University Hanoi 12116 Vietnam
Surface-enhanced Raman spectroscopy (SERS) is widely recognized as a powerful analytical technique, offering molecular identification by amplifying characteristic vibrational signals, even at the single-molecule level. While SERS has been successfully applied for a wide range of targets including pesticides, dyes, bacteria, and pharmaceuticals, it has struggled with the detection of molecules with inherently low Raman scattering cross-sections. Urea, a key nitrogen-containing biomolecule and the diamide of carbonic acid, is a prime example of such a challenging target.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Iodinated DBPs (I-DBPs), many more toxic than regulated chlorinated and/or brominated DBPs, are a major challenge in the supply of safe drinking water. While over 800 DBPs have been identified, the occurrence and precursors of toxic I-DBPs remain poorly understood. Herein, natural organic matter from two raw drinking waters was fractionated using ultrafiltration membranes into different groups based on molecular weight (MW).
View Article and Find Full Text PDFEnviron Pollut
January 2025
University of Arizona, Chemical and Environmental Engineering Department.
Despite their potential risks to human health and the environment at ng/L to μg/L concentrations, there has been relatively little effort to measure trace organic compounds (TOrCs) in surface waters of Central America. The concentrations of eighteen TOrCs detected at eleven surface water sites in the Lempa River basin of El Salvador and four sources of drinking water for the cities of San Salvador, Antiguo Cuscatlán, Soyapango, and Santa Tecla are reported here. All samples were analyzed via liquid chromatography with tandem mass spectrometry (LC-MS/MS).
View Article and Find Full Text PDFTalanta
December 2024
Department of Food Science and Engineering, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China; Shenzhen Key Laboratory of Food Macromolecules Science and Processing, Shenzhen University, Shenzhen 518060, China. Electronic address:
The simultaneous detection and removal of Ag from drinking water was crucial for preventing human health, while it was also extremely challenging due to bifunctional materials that combine both Ag adsorption and detection functions rarely being explored. In this study, a benzotrithiophene-based covalent organic framework (TAPA-BTT) was synthesized and applied to detect and remove Ag. TAPA-BTT exhibited high crystallinity, a large specific surface area, and good thermal stability.
View Article and Find Full Text PDFWater Res
December 2024
The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou 324000, China.
Drinking water flavor, a critical water quality metric, exhibits substantial regional variations across China, influenced by local geology and chemistry. Despite growing consumer concerns about water flavor, a spatial assessment of the determinants of water flavor in China has been notably lacking. This study bridges this gap by conducting a spatially comprehensive analysis of 78 tap water samples throughout China.
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