Study On Oxidative Degradation Of Nitrobenzene In Aqueous Solution With Microwave-Enhanced Fenton Process

The oxidative degradation of Nitrobenzene in aqueous solution with Microwave-enhanced Fenton system was studied systematically.The degradation of Nitrobenzene with Fe²⁺/H₂O₂ and Fe³⁺/H₂O₂ system was studied first. The influence of Microwave Power, Microwave radiation time, H₂O₂ amount, Fe²⁺ and Fe³⁺ amount, pH and initial concentration of Nitrobenzene were discussed. The results showed that there's certain optimal range for Fe²⁺, Fe³⁺ amount and pH, while the degradation rate of Nitrobenzene rises up with the increase of Microwave Power, Microwave radiation time and H₂O₂ amount, but this trend slows down if certain threshold is surpassed. Taking the cost factors into consideration, the optimal condition were chosen as below: Microwave power 100W, Microwave radiation time 4min, concentration of H₂O₂ 4.5mmol·L-1, M[H₂O₂]/M[Fe²⁺]=25 , M[H₂O₂]/M[Fe³⁺]=15, pH 3. At the optimal condition, the degradation rate of Nitrobenzene with the initial concentration of 80 mg·L-1 can reach 98.1%, the residual concentration is less than 2 mg·L-1, the national primary discharge standard.In the Fe³⁺/H₂O₂ case orthogonal test was performed. The importance of main factors are in sequence as: H₂O₂ amount >pH>Microwave power> M[H₂O₂]/M[Fe³⁺]>Microwave radiation time.The oxidative degradation of Nitrobenzene with Microwave-enhanced Hydroquinone-Fenton system was studied. It was concluded that the addition of Hydroquinone can accelerate the reaction drastically. The degradation rate of Nitrobenzene is in proportion to the amount of Hydroquinone in certain range. The influence of Microwave radiation time, pH and H₂O₂ amount are investigated, the optimal parameters are chosen as: concentration of Hydroquinone 0.5mg·L-1, concentration of Fe³⁺3×10-4mol·L-1, Microwave power 25W, Microwave radiation time 280s, concentration of H₂O₂ 4.5mmol·L-1, pH3.The oxidative degradation of Nitrobenzene with Microwave-enhanced Humic acid-Fenton system was studied. The results showed that the addition of Humic acid accelerates the reaction, and this system has higher efficiency in neutral pH. Influence of different parameters was studied, the optimal conditions...