Preparation Of Photo-Fenton Catalyst And Its Application To Treatment Of Nitrophenol Wastewater

A novel heterophoto-Fenton catalyst was prepared to optimize Fenton reagent for the first time. This catalyst can take full advantage of sunlight, increase the catalytic decomposition of H2O2 effectively and be recycled to avoid the second pollution to environment. Nitrophenols wastewater with the feature of strong toxicity, bioaccumulation and difficulty biochemical degradation, threat the ecological environment and human health seriously.This heterophoto-Fenton catalyst is used indegradation nitrophenols wastewater successfully and the result is satisfying. It gives a powerful technical support to treatment of wastewater for the future.The research in this paper involves there parts:In the first part of the paper, the optimal [Fe(III)-ssal]-Al2O3 catalyst was prepared by comparison with different carriers and amounts of Fe(NO3)3·9H2O and 5-sulfosalicylic acid(ssal). It was characterized by FT-IR and TEM-EDX technique.In the second part of the paper, a detailed investigation of photocatalytic degradation of 2,4-dinitrophenol (DNP),2-sec-butyl-4,6-dinitrophenol (DNBP) and 2,6-dinitro-p-cresol (DNPC) using [Fe(III)-ssal]-Al2O3 catalyst and H2O2 under solar light irradiation was carried out, the results indicate that the degradation rate is nearly 100% in reaction time.The [Fe(III)-ssal]-Al2O3 system exhibiting better photocatalytic activity than Fe(III)-Al2O3 catalyst for wastewater degradation indicates that the ligand in [Fe(III)-ssal]-Al2O3 catalyst can be regarded as a hydroquinone-like compound, which can accelerate the circle Fe3+/Fe2+. Kinetic analysis reveals that photo-Fenton-type process can be divided into the initiation phase and the fast phase, both phases can be described by a pseudo-first-order kinetic model. Increase of the initial solution concentration or decrease the reaction temperatures will decrease the pseudo-first-order rate. Activation energy are also calculated by Arrhenius equation in the different reactions.In the last part of the paper, the reuse tests indicate that the reproducibility [Fe(III)-ssal]-Al2O3 catalyst is stable, it realizes both economic benefits and environmental benefits. Real dinitrophenols wastewater was also investigated using [Fe(Ⅲ)-ssal]-Al2O3 catalyst and H2O2 under solar light irradiation and satisfying results were obtained. The color and COD removal is 98.6% and 75.6%, respectively. Therefore, the preparation and application of heterophoto-Fenton catalyst give a new way to degrade organic pollutants under sunlight.