Preparation Of Insoluble Catalytic Electrode On Stainless Steel And Its Electro-Catalysis For Degrading Of Organic Wastewater With Low Biodegradability

Electrode material is the basis for the electrochemistry, which is technology pilot of industrial development of modern electrochemical techniques. The invention of dimensionally stable anodes (DSA) on titanium is realization of the chlor-alkali industry revolution. The research of high performance electrode has become the forefront of electrochemical topics. The electro-catalytic activity of dimensionally stable anode on titanium is not high enough for other applications, and the preparation cost is expensive. The dimensionally stable anodes for the modification on titanium and insoluble anode on stainless steel and catalytic activity of the cathode material were studied. Then we study the catalytic activity of prepared electrode and catalytic mechanism in refractory organic wastewater treatment.The IrO-RuO-CeO on titanium was prepared by high temperature thermal decomposition. The experimental results show that electrodes was prepared under optimum conditions : drying temperature is 80℃, thermal decomposition temperature is 450℃, brushing times is 10-12, the oxidation time is 10 minutes. The surface of the porous electrode is the honeycomb pattern without signs of cracking. The oxygen electrode potential is 1．3 V in 0．5 M HSO solution. The catalytic performance of electrode is superior to conventional dimensionally stable anode. But the electrode preparation is complex and the cost of electrode preparation is high.The CeO-PbO on stainless steel was prepared by electrodeposition. The experimental results show that the optimum conditions for electrode preparation is that current density is 5～15 mA/cm, temperature is 60℃. The electrode structure is tetrahedral and porous with doped Ceria. The crystals of electrode have been refined and the electro-catalytic performance has been increased with the addition of rare earth element. The oxygen evolution over-potential is 2．1 V in 0．5 M HSO solution. The service life of electrode is 1,100 hours on the condition of 3 M sulfuric acid solution, the current density of 1 A/cm, and the temperature is 35℃. The anode has a higher oxygen evolution potential, long service life, low-cost advantages of preparation, particularly good catalytic activity in dyes wastewater treatment, but anode is brittleness. The CNT(carbon nanotubes)-PbO on stainless steel was prepared by composite electrodeposition. The experimental results show that the optimum conditions for electrode preparations are that current density is 5～15 mA/cm, temperature is 20℃. The electrode structure is tetrahedral and cylindrical holes were made on the electrode surface with adding carbon nanotubes grains and that changes the electrode surface. The oxygen evolution over-potential is 1．8 V in 0．5 M HSO solution. The preparation of the anode with an excellent catalyst activity and higher oxygen evolution potential is simple.A new cathode material for wastewater treatment was studied in this paper. The cathode was prepared by impulse electrodeposition on stainless steel substrate, with amorphous ingredients Ni-W-P as a carrier, doped SiC and the rare earth element. The experimental results show that the optimum conditions for electrode preparation is that current density is 10 A/dm, PH is 4．5, temperature is 65℃, duty ratio is 1:3～5, frequency range is 300～800 Hz. The cathode has high catalytic performance, surface area, effectively improving HO reaction rate on the cathode surface. The cathode has the advantage of high hardness and wear resistance.A catalytic reactor was designed and the CeO-PbO on stainless steel used as anode and stainless steel used as cathode. The results show that each module aeration chamber and the electrodes can be individually installed by modular design. The optimal parameters are that the cell voltage is 15 V, particle electrode size is 4 mm, electrode spacing is 8 mm, filler particles is 60%. The antibiotic refractory wastewater is good treated in the electro-catalytic reactor.The electro-catalytic degradation mechanism of organic matter and dynamics process were studied by electrochemical method, such as potentiodynamic polarization technique and cyclic voltammetry method. There is a characteristic potential in the electro-catalytic process. The characteristics potential has to do with hydroxyl radical and has nothing to do with organic matter concentration. The current peak increased with a rise of concentration of organic matter. The potential of electrode decreased with the increase in wastewater solution temperature. The linear relationship between temperature and potential features accords with the first order reaction principle. The electro-catalytic degradation process of organic matter was a first order reaction.