Design And Application Research Of Wastewater Degradation Reactor Based On Three-dimensional Electrode Method

With the development of industrial technology,the pollution problems caused by various kinds of wastewater have become increasingly serious,causing great harm to the environment and human health.In recent years,the three-dimensional electrode method has gained the attention of many researchers as an environmentally friendly and pollution-free wastewater treatment technology.However,the traditional three-dimensional electrode reactor has the disadvantages of low current efficiency and high energy consumption,which limits its industrial application.Aiming at these problems,a three-dimensional electrode reactor with high efficiency and low energy consumption was designed and applied to the degradation of two different types of dye wastewater in this paper.Firstly,the three-dimensional electrode reactor was designed from three aspects:electrode material,reactor structure and power supply mode.The results show that the best reactor was a cylindrical electrolytic cell with a rod-shaped Ti/Ru O₂-Ir O₂ anode and a barrel-shaped graphite cathode,with the anode as the center and the cathode was arranged around the anode,the particle electrode was filled with a mixture of activated carbon and glass beads with a mass ratio of 2:1,the pulse power supply was adopted with a pulse duty cycle of 0.4 and a pulse period of 15 s.The three-dimensional electrode reactor was used for electrolysis of malachite green（MG）simulated dye wastewater,the removal rates of MG and COD reached 96.2%and 80.5%after 150 min,respectively.Compared with the conventional three-dimensional electrode reactor,the wastewater degradation effect and current efficiency were significantly improved,the energy consumption was greatly reduced.The stability of the reactor was verified by performing20 consecutive cycles of degradation experiments on MG simulated dye wastewater.By studying the effects of electrolysis voltage,initial p H,electrolyte Na₂SO₄concentration,aeration rate,and electrolysis time on the degradation effect of MG simulated dye wastewater,and combined with orthogonal experiments,the optimal operating conditions of three-dimensional electrolysis of MG wastewater were determined as electrolysis voltage 15 V,electrolyte concentration 0.10 mol/L,initial p H=5,aeration rate 0.5 L/min,and electrolysis time 140 min.Under those conditions,the removal rates of MG and COD reached 95.6%and 80.3%,respectively.Then,the degradation pathway of MG was explored by UV-Vis absorption spectroscopy and GC-MS.The three-dimensional electrode reactor was further applied to the treatment of methylene blue（MB）simulated dye wastewater.The optimal operating conditions were determined by single factor experiments and orthogonal experiments as electrolysis voltage 15 V,electrolyte concentration 0.050 mol/L,initial p H=5,aeration rate 0.6L/min,and electrolysis time 140 min.Under those conditions,the removal rates of MB and COD reached 92.7%and 81.3%,respectively,which showed that the reactor was suitable for the treatment of different types of dye wastewater.Finally,the degradation mechanism of MB was preliminarily discussed by UV-Vis absorption spectroscopy.