日光/Fenton法处理油田废水的机理

摘要

The effect of disposing the oil wastewater in Liaohe Oilfield by sunlight/Fenton method was studied in this paper,and the reason why the sunlight/Fenton method was better than the common Fenton method was analyzed.The wastewater mainly contains benzene and alkane compounds.Effect of sunlight/Fenton method on oil field wastewater treatment in Liaohe was relat-ed to height of the water layer.The removal rate of aqueous COD decreased when the height of the water layer increased,and the penetration ability of sunlight to this oilfield wastewater was about 1 m.When the height of wastewater was about 40 cm, COD of wastewater reduced from 430 to 63.2 mg·L-1 after treatment of oil wastewater by sunlight/Fenton method.It is proved that the form of the poly ferric compounds generated in the system by using the UV-Vis spectroscopy,infrared spectros-copy (FTIR)and X-ray diffraction method (XRD)is the same as the poly ferric compounds generated by the common Fenton system.At the same time,the transformation processes of benzene and alkanes were studied by UV-Vis spectroscopy which in-dicated that the transformation processes of alkanes in sunlight/Fenton were as same as the common Fenton method;enzene could be converted into photosensitive molecules activated by hydroxyl radical in sunlight/Fenton system.Thus,the sensitivities of the aromatic intermediates are the reason why the sunlight/Fenton method is more efficient than the common Fenton method.%研究了日光/Fenton法对辽河油田采油废水处理效果,并分析了日光/Fenton法好于普通Fenton法的原因.辽河油田采油废水主要含有苯类和烷烃类化合物,日光/Fenton法对辽河油田采油废水处理效果与废水水层高度相关,水层高度升高,COD去除率降低,日光对本油田废水的穿透能力在1 m左右.废水水层高度为40 cm左右时,采油废水经日光/Fenton法处理后,COD由430降至63.2 mg·L-1.通过紫外可见光谱法、红外光谱法(FTIR)及X射线衍射法证明了利用日光/Fenton法处理辽河油田采油废水时体系中有聚铁生成,聚铁的形态与普通Fenton体系生成的聚铁基本相同.同时利用紫外光谱法研究了苯类及烷烃类的转化方式,结果表明:烷烃类在日光/Fenton和Fenton体系中的转化方式基本相同;而苯类在日光/Fenton体系中的羟自由基作用下转化成具有光敏性的物质.芳香族中间产物的光敏性是日光/Fenton法比普通Fenton法高效的原因.