Photooxidation of Tire Wear Particles Leachate in Controlled Physiochemical Conditions

Tire wear particles (TWPs) from routine road use are a major source of non-exhaust emissions, with significant environmental presence. Understanding the fates of pollutants within these particles is crucial. TWPs contain various components, including additive chemicals, aromatic oils, synthetic rubbers, and natural rubbers. Compounds like 6PPD, its oxidized form 6PPD-quinone, and Hexamethoxymethylmelamine (HMMM) are of particular concern due to their acute and chronic toxicity to aquatic organisms. These compounds and their transformation products, formed through photodegradation and other processes, have been detected in water bodies, especially following road runoff after rainfall, indicating their persistence. This study examines the photooxidation of leached chemical additives from TWPs under controlled conditions using UPLC-Orbitrap Mass Spectrometry for high-resolution mass measurements, employing targeted and untargeted approaches. Tire particles were incubated in Milli-Q water, artificial seawater, and sterilized Lavaca River water for 2 days, followed by exposing the leachate to simulated solar radiation for 3 days to monitor the degradation and transformation. While research is ongoing, preliminary data reveal insights into the degradation rates of 6PPD, the photoproduction of 6PPD-Q and other leachate compounds. This study contributes to a more comprehensive understanding how environmental factors influence solar-driven breakdown and formations of various tire additives compounds when released into aquatic ecosystems.

Presentation Preference: Poster

Primary Presenter: Leah Cogar, Texas A&M University-Corpus Christi (lcogar@islander.tamucc.edu)

Authors:

Nigel Lascelles, Texas A&M University-Corpus Christi  (nlascelles@islander.tamucc.edu)

Justin Elliott, Texas A&M University-Corpus Christi  (jelliott@islander.tamucc.edu)

Hussain Abdulla, Texas A&M University-Corpus Christi  (Hussain.Abdulla@tamucc.edu)