Preparation Of Modified Titanium Based DSA Electrode And Study On The Treatment Of Oily Wastewater

At present, many domestic oilfields have entered the stage of high water cut stage, in order to enhance the oil recovery rate; we generally use secondary or tertiary recovery methods. The oil-fields will produce a lot of wastewater in the production process; the component in oily wastewater is very complex, which will bring enormous damage to ecological environment. At the same time, sulfate reducing bacteria, iron bacteria and saprophytic bacteria will cause corrosion and blockage to the water pipeline. Traditional physical and chemical method, biological method, chemical method, and so on, the oil-removing effect is not good, and the cost is high, therefore, it is very important to find a new way of oily sewage treatment. In recent years, we pay more attention to the rising advanced oxidation technology, as a kind of advanced oxidation; electro catalytic oxidation will produce free radicals in electrolysis process and removal pollutants by strong oxidation of free radicals to kill the bacteria in water effectively.The subject prepared Titanium modified DSA electrode by sol gel method. The morphology of the surface coating was studied by scanning electron microscopy(SEM). The electrode surface elemental composition and elements of the atomic ratio were analyzed by X-ray energy spectrometer(EDS). The crystal structure of the electrode coating was analyzed by X-ray diffraction(XRD) determination. The results shows that the doping of rare earth can refine the grain size and increase the specific surface area of the coating, and improve the catalytic activity of the electrode. Treatment of oily wastewater by Ti/RuO2-IrO2 electrode,Ti/IrO2-Ta2O5 electrode and Ti/IrO2-Ta2O5-SnO2 electrode prepared, choose the best anode material, Then investigated the optimal operating parameters of removing oil the by single factor experiments, including pH value, electrode distance, current density, water temperature and electrolysis time; draw a conclusion as follows: using the best anode material Ti/IrO2-Ta2O5-SnO2 electrode as anode, the titanium electrode of the same size as the cathode electrode. Under the conditions: the spacing is 15 mm, the current density is 30mA/cm2, pH value is 3, the temperature is 30 DEG C, the electrolysis time is 60 min, the oil removal rate reached 93.9%, And the orthogonal experiment was used to verify the results. Determination of the composition of wastewater before and after treatment by gas chromatography, It is presumed that the degradation process is: the total petroleum hydrocarbons in sewage is gradually transformed from large molecular substances into small molecules, or CO2; At last,investigate Ti/IrO2-Ta2O5-SnO2 electrode’s bactericidal effect for sulfate reducing bacteria,iron bacteria and saprophytic bacteria, Draw the conclusion the optimal process conditions are:the space between electrodes is 20 mm, current density is 20mA/cm2, pH value is 5,electrolytic time 30 min. Under this condition, three bacteria sterilization rate respectively reach 99.35%, 99.33%, 99.31%.