光电催化氧化处理高含氯采油废水的研究

Photoelectrocatalytic Degradation of Oilfield Wastewater with High Content of Chlorine

以高压汞灯为光源,考察了在光催化、电氧化、光电催化及光电催化/H2O2体系中降解实际油田采油废水的效率.研究了实际高含氯采油废水在TiO2悬浮态光电催化反应器中的降解动力学.结果表明,在相同的槽电压和反应时间下,光电催化体系降解有机污染物的效率均高于电化学氧化和光催化,而且在电氧化和光电催化氧化体系中均检测到有一定量的活性氯产生,从而可以提高有机污染物的降解效率.光电催化/H2O2体系中由于在紫外光的照射下H2O2分解为大量的.OH从而使得降解效率在短时间内大大提高.同时详细研究了采油废水的初始ρ(CODCr),槽电压和溶液pH等对光电催化降解的影响.

The photoelectrocatalytic degradation of oilfield wastewater containing high content of chlorine was studied in TiO2 aqueous suspensions. The effect of different degradation technologies, such as photocatalysis, electro-oxidation, photoelectrocatalysis and photoelectrocatalysis/H2O2, on the CODe, removal efficiency of oilfield wastewater was compared. The results showed that CODCr removal efficiency of photoelectrocatalysis was much higher than photocatalysis and electro-oxidation alone. It is also interesting to note that a certain amount of active chlorine was produced and had an obvious enhancement effect on both electro-oxidation and photoelectroeatalytic degradation of oilfield wastewater. The CODCr removal efficiency of photoelectrocatalysis/H2O2 was the highest, and much of organic pollutants were completely mineralized in a short period in that H2O2 can easily Rroduce ·OH radical under UV irradiation. The effects of various operating conditions, such as initial concentration of wastewater, applied cell voltage and initial pH, were also investigated in detail. It was shown that the degradation efficiency of oilfield wastewater would be comparatively low when initial concentration of CODCr is too high or too low, and that the degradation efficiency increased with the increase of applied cell voltage or the decrease of initial pH of the wastewater.