Degradation Efficiency And Mechanism On Catalytic Ozonation By Nano-copper Oxide For The Removal Of Nitrobenzene In Aqueous Solution

Now water pollution and shortage of water resources have became the world-stateproblem. More and more people take attention to more pollutions. Nitrobenzene is atoxic chemical which could cause serious pollution of the environment and endangerhuman body health. its poor biodegradability makes it difficult to control. Thisexperiment has compounded three kinds of forms of nanometer copper oxide catalysts.The three catalysts view the nitrobenzene as target organisms to remove. The paperstudy the influence of some common factors, such as the amount of catalyst, initialconcentration of nitrobenzene, different ozone dosage, pH, temperature, commoninorganic cations and anions, humic acid etc., on explaining the mechanism, and discusswater molecules and ozone molecules in the nano-copper oxide adsorption problemwith density functional theory.（1） Three different nano-copper oxide patterns, plates, sheets and powdered, wereprepared and their catalytic activity was compared. After characterizing the copperoxide with XRD, SEM, BET and other methods, found that three kinds of copper oxidenanoparticles of various shapes belong to the same structure. Plates, sheets of copperoxide particle size are about100nm, powdered one is about50nm.They are uniform insize, a relatively high degree of crystalline. Experiments show that the flacknano-copper oxide has the highest activity in catalyzed ozonation system.（2） It was found that the effect of ozonation alone is obviously not as good as copperoxide catalytic ozonation in the degradation of nitrobenzene. Increasing the amount ofcatalyst and ozone, pH, temperature and initial concentration of nitrobenzene willimprove the catalytic activity, promote the decomposition of nitrobenzene. The effectsof general ions (Ca²⁺, Mg²⁺, Cl^-, SO₄^2-, CO₃^2-, HCO₃^-) in water on the efficiency ofnitrobenzene were in the different processes.（3） It shows that the addition of nano-CuO results in a large number of ozonetransferring to the water through ozone transformation experiment, and promotes thedecomposition of ozone so that the last remaining amount is reduced. With the increasein the amount invested tert-butanol—the HO·radical scavenger shows that the twosystems have followed HO·radical mechanism. the addition of nano-CuO also can improve the mineralization of nitrobenzene.（4） This paper also use density functional software to analyze the water moleculesadsorbed on the surface of the copper oxide and found that the density of states ofadsorbed water molecules have become more continuous. Ozone absorption experimentis carried out on the surface of the adsorbed water. The results showed that the surfaceof the copper oxide catalytic ozonation mechanism is HO·radical mechanism.