Photoelectrocatalytic Degradation Of Copper Cyanide Complexes

Heavy metal wastewater pollution from electroplating and metallurgical industry is becoming more and more serious. Generally, the heavy metals in the wastewater existed in the metal-cyanides complexes, which can not be efficiently removed by conventional methods. In this study, copper cyanide complexes were selected as the treated target. Efforts were made to efficiently treat the copper cyanide complexes with the recovery of heavy metals.Firstly, Bi2MoO6 film was deposited onto ITO substrate from a complex solution by dip-coating method and TiO2 nanotubes electrode was fabricated by anodic oxidation method in fluorine-containing organic solution and then modified, which were used as different anodes to degrade copper cyanide complexes. Simultaneously, the liberated heavy metal ions were recovered by electrodeposition process at cathode. The oxidation and reduction processes were investigated in details.This paper mainly contained the following three parts:1. Copper cyanide complexes was selected as the target pollutants, with Bi2MoO6 electrode as anode, the photoelectric catalytic oxidation was studied. The main influence factors were investigated. The results showed that in the presence of EDTA or K4P2O7, the photoelectric catalytic oxidation was promoted. Simultaneous, copper was mainly electrodeposited on cathode instead of that onto anode.-OH radicals were not the key role in the photoelectric catalytic oxidation process.2. TiO2 nanotubes electrode was fabricated by anodic oxidation method in fluorine-containing organic solution and used as anode. The photoelectric catalytic oxidation was studied as well as the influence factors. The results showed that at 2.0 V, the photoelectric catalytic oxidation was best. In the presence of EDTA, the photoelectric catalytic oxidation was promoted. Simultaneous, copper was most electrodeposited on cathode.3. Graphene film and graphene quantum dots were formed on the surface of TiO2 nanotubes electrode, respetively. The results showed that the photoelechemcal performance of the electrode was all improved. With these electrodes as anode, the photoelectric catalytic oxidation was studied in degradation of copper cyanides.