Preparation Of Bipyridine Coordination Compounds And Their Catalytic Properties In Dye Degradadation

Dye wastewater decolorization methods include physical coagulation flocculation,adsorption, membrane separation, biological degradation and chemical methods,which mainly contain chlorine oxidation, ozone oxidation, catalytic oxidation,electrochemical degradation and so on. Biological enzymes produced by microorganism are the key active substance that catalyzes dyes decoloration in the biological degradation, but they usually easily lose catalytic activities. Limited by their harsh use conditions, study and application of biomimetic catalysts is full of potentiality. Metal organic complexes are widely used in catalytic field due to their structural diversity and good catalytic property. What’s more, some complexes have similar catalytic activity structure element with the biological enzymes. So it’s significant to research Biological-enzymal coordination complexes using in dyes decolorization.In this paper 1,4-(di-4-pyridyl)methoxy benzene and 1,4-(di-4-pyridyl)methoxy benzene(C18H16O2N2) were synthesized, then they were used as the ligands respectively coordinated with CuCl2, CoCl2 and MnCl2 to form corresponded complexes CoCl2 L.1.5H2 O,(MnCl2)2L.1.5H2 O and CuCl2 L.1.5H2 O. The structures were characterized by 1H NMR, IR and EA.Some effects on the catalytic activity such as catalyst dosage, pH and emperature were studied in detail. What’s more, we also aplied the complexes in some different dyes decolorizations. As it was imagined, we got the optimal bleaching process:the system contains 30 m L 100mg/L dye solution, 14 mL 1mol/L buffer solution(Na2CO3/NaHCO3, pH=9~10), 56 mL distilled water, 20 m L 3% hydrogen peroxidesolution, 10 mg CoCl2L.1.5H2O(30mg(MnCl2)2L.1.5H2 O or 60 mg CuCl2L.1.5H2O)and decolorized at room temperature.The decolorization rate is up to 90%.In the fourth part, we studied the catalytic mechanism of the decolorization process.By controlling pH of the system and camparing the decolorization rate of two conditions that additon or non-additon of the hydroxyl free radical trapping agent(DMSO) in the system, it concluded the hydroperoxyl anions decomposited by hydrogen peroxide played a key role in this decolorization process. At last, the analysis of the products was carried out by using organic carbon content and liquid chromatography-mass spectrometry, the possible decomposition products ware speculated.