(277e) Degradation of P-nitrophenol Using Microwave Assisted Bimetallic Nano Zero Valent Iron and Copper Composite Activated Sodium Percarbonate

This study explored the capability of microwave assisted (MA) nano zero valent iron-copper composite (nZVI-Cu) activated sodium percarbonate (SPC) system for the degradation of p-nitrophenol in aqueous solution. The key parameters like microwave power, SPC concentration, initial p-nitrophenol concentration and nZVI-Cu dosages were investigated. The achieved results elucidated the higher degradation efficiency of p-nitrophenol in the MA/SPC/nZVI-Cu system as compared to MA/SPC, MA/nZVI, MA/nZVCu and SPC/nZVI-Cu systems. A complete removal of p-nitrophenol was observed in a reaction time of 120 min at the SPC concentration of 0.7g/L, nZVI-Cu dosage of 20 mg/L, p-nitrophenol concentration of 80 mg/L and initial pH of 7. Total organic carbon and chemical oxygen demand removal rates on optimum conditions in the same interval of time were 60 and 90% respectively. Hydroxyl radicals were identified as dominant generated radicals in the system by using radical scavengers. P-nitrophenol degradation followed pseudo first order kinetic model. The main intermediate products of p-nitrophenol were 2-chlorohydroquinine, p-chlorophenol, hydroquinone, and catechol. The p-nitrophenol degradation pathway was proposed accordingly.

Keywords

P-nitrophenol, Sodium percarbonate, Microwave assisted, Nano zero valent iron-copper composite, Degradation pathway.