Photo-Fenton Treatment of a Pharmaceutical Industrial Effluent Under Safe pH Conditions

Abstract

This chapter aims to present the effect of treating a pharmaceutical industrial effluent by photo-Fenton catalyzed with a Fe-pillared bentonite. XRD proved the pillaring process successful, and by N2 physisorption, it was established that the specific surface area of bentonite (34 m2/g) increased to 277 m2/g and pore volume increased from 0.058 to 0.106 cm3/g. Active Fe species were identified by Mössbauer spectroscopy. The effect of reaction variables such as catalyst loading, pH, H2O2 concentration, and initial concentration of total organic carbon (TOC) is also presented. It was concluded that to reach near 100% mineralization, an acidic pH (2.7) should be observed. A high mineralization under these conditions, however, does not directly correlate with a low toxicity. Actually, the oxidative stress biomarkers only decreased when pH was not modified (pH = 8) albeit the attained mineralization was only 51%. It is worth noticing that the use of pillared clays allows carrying out photo-Fenton treatment under pH conditions other than acidic. The synthesized catalyst exhibited magnetism and this can be used for an easier recovery.