Investigation on the Heterogeneous Photocatalytic Remediation of Pyrene and Phenanthrene in Solutions Using Nanometer TiO₂ under UV Irradiation

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) represent an important group of pollutants, which are known to be mutagenic, teratogenic, carcinogenic and relatively unwavering in the environment. The photocatalytic decomposition employing nano-based semiconductor photocatalyst has been a promising method for the elimination of organic pollutants in water and atmosphere. Photocatalytic remediation of pyrene (Py) and phenanthrene (Phe) by TiO₂ in aqueous solutions was investigated under UV light irradiation along with chemical oxygen demand (COD) measurements. Moreover, UV–vis spectrophotometry and gas chromatography (GC) techniques were used to monitor the degradative reaction process. Fast and effective removal of pyrene and phenanthrene was achieved in this system. Catalyst TiO₂ accelerated the photoremediation of Py and Phe significantly, with their half-lives being 40.005 and 60.0086 min⁻¹, respectively. Statistical analysis showed high correlation coefficient and significant negative relation with COD and concentration of PAHs with time. All results indicated that the photocatalytic method in the presence of TiO₂ nanoparticles is an advisable choice for the treatments of PAHs polluted wastewaters in nature.

KEYWORDS:

• Gas chromatography (GC)
• phenanthrene (Phe)
• pyrene (Py)
• TiO₂ nanoparticles

Acknowledgment

The authors would like to thank Sophisticated Instrumentation Centre for Advanced Research and Testing (SICART), Vallabh Vidyanagar, Gujarat, for the analysis of samples.