Degradation of polycyclic aromatic hydrocarbons in crumb tyre rubber catalysed by rutile TiO₂ under UV irradiation

Abstract

The polycyclic aromatic hydrocarbons (PAHs) in crumb tyre rubber were firstly degraded under UV irradiation in the presence of rutile TiO₂ and hydrogen peroxide. The effects of light intensity, catalyst amount, oxidant amount, initial pH value, co-solvent content, and reaction time on degradation efficiency of typical PAHs in crumb tyre rubber were studied. The results indicated that UV irradiation, rutile TiO₂, and hydrogen peroxide were beneficial to the degradation of PAHs and co-solvent could accelerate the desorption of PAHs from crumb tyre rubber. Up to 90% degradation efficiency of total 16 PAHs could be obtained in the presence of rutile TiO₂ (1 wt%) and hydrogen peroxide (1.0 mL) under 1800 µW cm⁻² UV irradiation for 48 h. The high molecular weight PAHs (such as benz(a)pyrene) were more difficult to be degraded than low molecular weight PAHs (such as phenanthrene, chrysene). Moreover, through the characterization of reaction solution and degradation products via GC–MS, it was proved that the PAHs in crumb tyre rubber were successfully degraded.

GRAPHICAL ABSTRACT

Keywords:

• polycyclic aromatic hydrocarbons
• crumb tyre rubber
• photocatalysis
• degradation
• rutile TiO₂

Acknowledgements

This work was supported by the National High Technology Research and Development Program of China under Grant (2012AA063008), the Specialized Research Fund for the Doctoral Program of Higher Education under Grant (20100031120029), Tianjin Key Laboratory of Circular Economy and Low-carbon Development, and the Fundamental Research Funds for the Central Universities.

Supplemental data

Supplemental data for this article can be accessed at http://dx.doi.org/10.1080/09593330.2014.971883.