Destruction of anthracene and phenanthrene using PDS/UV, one of advanced oxidation processes in terms of degree of destruction and by-products.

Anthracene and phenanthrene belong to a group of persistent environmental contaminants called PAHs. Evaluation of the structural of two selected PAHs i.e. anthracene and phenanthrene on its resistance to destruction by UV-activated PDS was the aim of this study. Authors focused on two aspects of this problem: - role of so called ‘bay-region’, in the structure of phenanthrene, during PDS/UV oxidation - formation of substituted forms of these PAHs in absence and presence of three nitrogen containing compounds i.e. ammonia and nitrite or nitrate ions. Even though phenanthrene and anthracene have the same molecular formula, the difference in their ring assessment influence their degradability. Considering all the results, in all the cases anthracene was degraded faster and/or had higher degradation rate. That proves phenanthrene to be more stable and resistant for degradation however comparison of PDS/UV systems vs. UV– irradiation alone confirms that addition of PDS accelerate the degradation of anthracene and phenanthrene. Comparison of PDS/UV with the addition of three different nitrogen-containing compounds showed significant difference between anthracene and phenanthrene. In the experiments with phenanthrene were observed additional peaks with the absorption maximum between 230-240 cm-1 which is characteristic for nitro-group. Based on their absorption maximum and the addition of nitrogen-containing compounds, emerging by-products are assumed to be nitro-derivatives of phenanthrene.