Novel photochemical advanced oxidation process for the removal of polycyclic aromatic hydrocarbons from polluted concrete

- Concrete pollution with PAHs determined.
- Analytical method of PAH determination developed.
- FHO3AOP method of PAH removal.
- Substantial and uniform oxidation of PAH in concrete achieved.
- The FHO3AOP method is feasible, economically viable and environmentally acceptable.

Polycyclic aromatic hydrocarbons (PAHs) are denoted by International Agency for Research on Cancer as mutagens, teratogens and carcinogenic to humans. In 2013, Vinča Institute of Nuclear Sciences was hired to determine whether PAHs are present in significant quantities in the concrete walls of newly built residential buildings (about 15,000 m2 of apartments), and to propose appropriate technical solution for PAH removal in this case. As PAH occurrence, determination and remediation in concrete is, to our knowledge, a completely new field, it was necessary to face a number of challenges, including lack of regulations considering contents of PAHs in concrete, investigation of the origin of PAH contamination in concrete (if established), as well as finding feasible and non-expensive remediation method, which would be appropriate for residential space. In first part of this study, a markedly high concentrations of 5 PAHs were detected by UPLC/PDA analysis in samples of both concrete walls and mineral oil used for coating of planks during formwork, while control concrete and mineral oil, taken from independent construction site, were taken as a reference. Such coincidence, as well as the fact that mineral oil has penetrated into the concrete which is proven by ASAP/MS analysis, pointed to the mineral oil as the most probable source of PAH contamination of the concrete. In the second part, an efficient and easy-applicable method for PAH oxidation in concrete (called FHO3AOP), using UV light, H2O2 and ozone, was presented and discussed in terms of previous literature data.