In this paper,we studied the degradation of Rhodamie B(RhB)by use of K2FeO4.The degradation efficiency of RhB was determined as a function of pH,reaction time,initial concentration of K2FeO4.Acid condition,especially pH 2.0 is preferred.Higher degradation efficiency was achieved when the initial of K2FeO4 to RhB was 2∶1.After 50 ml of 100 mg·l-1 RhB solution was oxidized by K2FeO4 for 5 min,the decolourisation rate of RhB reached up to 55.64% and CODCr reduced 24.55%.Fluorescence spectrum analysis and GC-MS analysis indicated that RhB was initially oxidized to RhB·OH-and then underwent ring cleavage to small molecules.

A novel technology for the preparation of lead dioxide(PbO_2) electrode was studied.The test by XRD,SEM and AAS indicated that this electrode had high activity in electrolysis as well as excellent corrosion resistance.The mechanism and process conditions of nitrobenzene degradation using the PbO_2 electrode were further studied.Compared to the graphite electrode,the PbO_2 electrode had an obviously higher COD_Cr removal rate of 65% after 5 hours of electrolysis.During electrolysis progress,the surface of PbO_2 anode is easy to generate hydroxyl radical due to high oxygen over-voltage of PbO_2 anode.The best applicable conditions of PbO_2 anode for nitrobenzene mass electrolysis are: nitrobenzene mass concentration 501.5 mg/L,electrode gap 3 cm,and solution pH 7.The results showed that the PbO_2 electrode had obvious superiority in COD_Cr removal,especially in the system with phosphate or chloride.But the nitrobenzene cannot be completely oxidized in the electrolysis process,due to the reduction action of the cathode.

The reactions of dimethyl sulfide (DMS) with hydroxyl radical(·OH) in aqueous phase is studied by the Laser flash photolysis technique. Through the studies of the influence of pH and oxygen on the oxidation of DMS, we compared the difference of this reaction in aqueous and gas phases, therefore, lifetimes of DMS toward aqueous phase destruction via reactions with ?OH was assessed. The experiment results show that, at pH6-9,·OH reacts with DMS to form ·DMSOH radical, which increasingly reacts with another DMS molecule to form (DMS)2+. The decay of (DMS)2+ ion is greatly influenced by the pH and its reaction with oxygen is immeasurably slow.