Photo-degradation of P-Nitro Toluene Using Modified Bentonite Based Nano-TiO2 Photocatalyst in Aqueous Solution

Abstract

In recent decades, Iran has been facing severe water deficiency. In all countries, industrial plants are the most water-consuming sectors; thus, industrial wastewater treatment is always a essential subject. Nitro-Toluene derivatives are extensively used in industries, especially the military industry, which itself has an abundant share in industrial wastewater contamination. These compounds are extremely dangerous for living beings and can have irreparable effects, so eradication of them in industrial wastewater is necessary. Photocatalytic processes are one of the particular approaches in industrial wastewater treatment from the advanced oxidation processes subdivision. One of the prominent and most widely used photocatalysts in this process is Titanium Dioxide (TiO2) . This research aims at the investigations for the modification of TiO2/Bentonite (TB) catalysts for attaining more economical saving and degradation stabilization conditions. To achieve this goal, the Bentonite and TiO2 photocatalyst was synthesized by a co-precipitation procedure, and its catalytic activity on Para Nitro-Toluene (PNT) degradation was examined. The designed TB photocatalyst is made of 5, 10 and 20 % of TB. A suspension reactor and the spectrophotometry was applied for specifying the extent of the degradation. Characterization of modified catalyst was conducted by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and energy dispersive X-ray (EDX). The results highlight that with increasing TiO2 percent, degradation rate augmented, and the highest degradation was attained for TB 20% at 59%. However, Under the same conditions, for pure TiO2, the degradation rate is 64%, but with more TiO2 consumption and time. Finally, in order to further confirm the extent of the degradation, chemical oxygen demand (COD) test was performed on the TA20 sample. The results showed that about 53% of PNT has been converted to minerals.