The Study Of Construction And Treatment Performance On The Dye Wastewater Of The Three-Dimensional Electrode Reactor

Dye wastewater is difficult to treat with high concentration, big toxicityand poor biochemical characteristics. Electrochemical technology can be effective treatment of dye wastewater for fast reaction rate, high efficiency, easy operation and environment friendly. Now, in order to further improve the reaction efficiency and reduce the energy consumption of electrochemical water treatment technology, the development of new electrode materials, construction of new electrochemical reactor become one of the important direction in the field of electrochemical research. This paper is aimed at the preparation of a new type of anode material and particle electrode material which is used to build a new type of three-dimensional electrode system, in order to treat dye wastewater with high efficiency and low energy consumption.In this paper, the CNTs-Sb-SnO₂/Ti electrode was prepared by sol-gel-thermal decomposition method. The electro-catalytic oxidation performanceof electrode was analyzed and CNTs doped quantity was optimized through degradation experiments of congo red.The micrograph and electrochemical properties of the modified electrode was characterized by SEM, electrochemical impedance spectroscope?EIS? and polarization curvetechniques. The stability of the electrode was investigate through accelerated life test. Then, via high temperature sintering technology the sludge ceramsite as particle electrode carrier was prepared with excess sludge and auxiliary materials as raw materialsand the preparation conditions was optimized.Sb-SnO₂ particle electrodewas preparedby Sb-SnO₂ on the carrier andits surface morphology and phase structure was investigated by means of SEM and XRD.Finally,with the anode and particle electrode prepared, a three-dimensional electrode system was established to explore the its effectiveness and energy consumptionof the dye wastewater treatmentThe results indicate that the optimal dopant amount of CNTs is 2.0g/L and the modified electrode holds higher electro-catalytic activity so that the congo red removal rate increases by 14.7% using the CNTs modified electrode compared with the unmodified electrode under the same reaction conditions. Meanwhile micropore structure appearsand roughness increases on the surface of modified electrodes leading to larger specific surface area of electrode. Furthermore, the modified electrodes exhibit higher oxygen evolution potential and lower charge transfer resistance.Additionally, accelerated life tests reveal that the modified electrode has better electro-cataulytic stability while the service life increases by 27 h.The optimal preparation conditions for particle electrode carrier is that montmorillonite content is 30%, the sludge content is 70%, preheat temperature is 400 ?, preheating time is 30 min, sintering temperature o is 1100 ? and the sintering time is 60 min. SEM, EDS and XRD show that Sb- SnO₂ has been loaded on the particle electrode carrier.In the three-dimensional electrode system established,with cell voltage of15 V, Na2SO4 concentration of 0.1 mol/L, the reaction time of 180 min, the congo red wastewaterinitial concentration of 150 mg/L, the congo red removal rate can reach 99.3%, COD removal rate is 90%, energy consumption is 49.5k Wh/t. compared with the two-dimensional electrode system its congo red removal rate Increased by 14.3% and COD removal rate increased by 46.3%, but the energy consumption reduces by39.8 k Wh/t. Furthemore, in the three-dimensional electrode system,the degradation mechanism of Congo red is that,firstly, conjugation structure is damaged leading to higher removal rate of dye wastewater; then, benzene ring and some chromophore was damaged leading to higher COD removal rate of dye wastewater.