Srinidhi Lokesh, Siththarththan Arunthavabalan, Elie Hajj, Edgard Hitti and Yu Yang*,
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引用次数: 0
Abstract
N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD)-quinone (6PPD-Q), a transformation byproduct of 6PPD used in tires as an antiozonant and antioxidant, was recently discovered as the chemical primarily responsible for the acute lethal toxicity of urban storm runoff to coho salmon. The asphalt concrete (AC) surface layer is the primary medium to contact 6PPD-Q immediately upon its release from tires, and the addition of recycled tire rubber (RTR) to the asphalt binder and mixture is a widely accepted practice in asphalt production. Therefore, it is urgent to understand the fate of 6PPD-Q at the asphalt concrete surface layer–water interface. This study analyzed the sorption and desorption of 6PPD-Q by compacted and crushed loose (loose particles, ∼5 mm) rubberized asphalt mixtures and their mobilization from compacted asphalt mixtures during simulated rainfall events. It should be noted that the crushed loose asphalt mixtures demonstrated the physicochemical properties of the asphalt materials, while the compacted asphalt mixtures represent in-service AC layers. Sorption of 6PPD-Q by crushed loose and compacted asphalt mixtures reached equilibrium within 12 days, with a sorption coefficient of 151.57–257.51 L/kg for compacted asphalt mixtures. Within 12 days, desorption of 6PPD-Q from crushed loose and compacted rubberized asphalt mixtures (20 g particles/L) to the double deionized (DDI) water and synthetic stormwater was 0.01–0.09 and 0.025–0.05 μg/L, respectively. Through the rainfall simulation experiments, 0.0015–0.0049 μg/L 6PPD-Q was detected in the runoff water, much lower than the lethal concentration (LC50) of 6PPD-Q of 0.095 μg/L and 308.67 μg/L for coho salmon and zebrafish larvae. Our results indicate that, while the release of 6PPD-Q from compacted rubberized asphalt mixtures is minor, the mixtures can serve as sorbents for tire-derived 6PPD-Q and retain this emerging contaminant.
期刊介绍:
ACS Environmental Au is an open access journal which publishes experimental research and theoretical results in all aspects of environmental science and technology both pure and applied. Short letters comprehensive articles reviews and perspectives are welcome in the following areas:Alternative EnergyAnthropogenic Impacts on Atmosphere Soil or WaterBiogeochemical CyclingBiomass or Wastes as ResourcesContaminants in Aquatic and Terrestrial EnvironmentsEnvironmental Data ScienceEcotoxicology and Public HealthEnergy and ClimateEnvironmental Modeling Processes and Measurement Methods and TechnologiesEnvironmental Nanotechnology and BiotechnologyGreen ChemistryGreen Manufacturing and EngineeringRisk assessment Regulatory Frameworks and Life-Cycle AssessmentsTreatment and Resource Recovery and Waste Management