Magnetic titanium/carbon nanotube nanocomposite catalyst for oxidative degradation of Bisphenol A from high saline polycarbonate plant effluent using catalytic wet peroxide oxidation
In this study, a magnetic titanium nanotube/carbon nanotube nanocomposite (magnetite TNT@CNT nanocomposite)
was developed and its efficiency was evaluated towards oxidative degradation of Bisphenol A (BPA)
from high saline polycarbonate plant wastewater (PCW) using catalytic wet peroxide oxidation (CWPO). The
characterization of the nanocomposite was performed using XRD, SEM, BET surface area, FT-IR, and VSM
analysis. The effects of operating conditions, including solution pH, H2O2 dosage, reaction temperature and
catalyst loading, were optimized in the CWPO process for degradation of BPA in the PCW. In the best obtained
experimental condition, at pH of 6.30, H2O2 dosage of 2.5 g/L, temperature of 70 °C and 100 mg/L of catalyst
dosage, CWPO process exhibits the best catalytic performance with the complete BPA degradation, 68.78% of
COD removal and 47.14% of TOC reduction for PCW being obtained. The role of hydroxyl radicals in the
reaction mechanism was shown by indirect analysis i.e. tert Butanol (tBuOH) scavenging experiment. Under the
optimum experimental conditions, the stability and reusability of the nanocomposite was demonstrated with
slight decline (< 10% reduction) in the CWPO after four consecutive runs in terms of its catalytic activity. The
fate of organic pollutants in the treated PCW by CWPO was identified by qualitative GC/MS analysis. The
biodegradability of the treated PCW increased during the CWPO process with a 4-fold increase of the BOD5/COD ratio being obtained, namely from 0.1 (indicating non-biodegradability) to 0.43 (showing biodegradability by
means of biological treatment) and AOS and COS were increased to 2.26 and 3.08, respectively. Overall, the
CWPO process with magnetite TNT/CNT nanocomposite, due to the simple and easy in-situ catalyst recovery/
separation and good catalytic activity, can be considered as a promising destructive technology for industrial
wastewater treatment.
