The waste water in oil production in Liaohe Oilfield is treated by Fenton method. It is proved by using UV-Vis spectroscopy

infrared spectroscopy (FTIR) and X-ray diffraction method (XRD) that the poly ferric compounds are generated in the system. The Ferron-complexation timed spectrophotomctric method is used to confirm the species distribution of the newly-formed ferric. At the same time

the process research of Fenton's oxidation and flocculation are studied. The results show that Fenton method has a dual function of oxidation and flocculation

and both of them have synergistic effect. The dual function makes the efficiency higher than that of the separate poly ferric flocculation

and also far greater than separate oxidation of itself.