Oxidation performance of Fe0/Na2S2O8 process for the treatment of landfill leachate biochemical effluent as well as activator characterization

The aim of the present work was to study the oxidation performance as well as activator characterization of Fe-0/Na2S2O8 system for the treatment of effluent from landfill leachate biochemical process. A typical persulfate (PS), Na2S2O8 was activated by zero-valent iron (Fe degrees) for the generation of the sulfate radical (SO4-center dot) to oxidize the residual pollutants in landfill leachate biochemical effluent. The effect of various variables including Na2S2O8 dosage, Fe degrees dosage, pH value, and reaction time on the oxidation efficiency were investigated. The results indicated that the pollutants can be degraded efficiently by the Fe degrees/Na2S2O8 system. Under the working conditions of 2.5 g/L Na2S2O8 dosage, 0.5 g/L Fe degrees dosage, pH 7, and 12 h reaction time, the removal rates of COD and chroma reached up to 71% and 90%, respectively. Three-dimensional excitation emission matrix fluorescence spectrum (3DEEMFS), ultraviolet-visible spectrum (UV-vis), and Fourier Transform infrared spectrum (FTIR) illustrated that the pollution level of dissolved organic matters (DOM) in the wastewater samples which had been disposed by the Fe degrees/Na2S2O8 system and the humic acids were degraded into the small molecules of fulvic acid. The micro morphology of Fe degrees was characterized using X-ray diffraction pattern (XRD), and Scanning electron microscope spectral (SEM). After reaction, it can be found a large amount of snowflake-like which contained iron oxide attached onto the surface of nano-Fe3O4