Experimental and computational hazard prediction associated with reuse of recycled car tire material

The paper presents research on the emission of pollutants from used car tires in the form of microparticles. Due to the large amount of waste generated in the form of used car tires, a method is being sought to utilize this material as secondary raw material. More and more frequently, this waste is used in civil engineering. To do this, it is necessary to determine the environmental impact of this waste. 2 g of microplastic samples with fractions of 3000-8000, 1000-3000, 1000, and 600 µm were incubated in water protected from light. The influence of pH (3, 7, and 10), incubation time (1, 3, 5, 7, and 14 d) and temperature (20, 60, and 90 °C) on the degree of emission of selected phthalic acid esters and other tire components was investigated. Additionally, the influence of the decomposition of the analyzed material on the emission of methane and carbon dioxide at the temperature of 20 °C during 30, 180, and 360 days was investigated. The analysis of the amount of released substances was carried out using a gas chromatograph coupled with a mass spectrometer. Greenhouse gas analysis was performed using a gas chromatograph with a Barrier Discharge Ionization Detector. The research carried out confirmed that, depending on the environmental conditions, tire particles leach out, among others, phthalates, benzenediamine, phenol, benzothiazole, and benzene. Influence of particle size, pH value, incubation time, and temperature on the degree of emission of selected plasticizers was investigated. An innovative aspect of the research was the use of artificial neural networks to identify the validity of using machine algorithms in environmental research. An additional negative aspect of the implementation of tire particles in the water-soil environment is the emission of carbon dioxide and methane that are greenhouse gases.