Study On Catalytic Performance Of Schwertmannite In The Degradation Of Nitrobenzene

In this paper,a systematic research on the schwertmannites catalyzed hydrogen peroxide degradation of nitrobenzene wastewater.Schwertmannite,naturally exists in acid mine drainage,plays an important role in the adsorption and migration of heavy metals.Nitrobenzene is widely used in medicine,dyes,explosives and other fields.Nitrobenzene wastewater is a typical persistent organic pollutants in aromatic hydrocarbons,which is very stable in water and difficult to deal with.Few reference has been reported that schwertmannite could be act as a heterogeneous catalyst in the Fenton-like reaction to degrade organic contaminants.This is the first study to investigate the degradation of nitrobenzene through hydrogen peroxide oxidation catalyzed by schwertmannnite produces highly reactive hydroxyl radical,system to study the effects of mineral catalytic properties,reaction process in various influence factors and nitrobenzene degradation mechanism.The research outcomes were listed as follows.1.The artificial synthesis of schwertmannite were characterized by measuring the XRD,SEM,TEM,BET,FT-IR,TG,etal.The results showed that the minerals morphology were spherical with poor crystallinity,and the diameter of about 1000 nm.2.The catalytic activity and the control experiments were evaluated in view of the effect of various conditions: catalyst dosage,initial hydrogen peroxide concentration,initial pH value,and concentration of nitrobenzene in schwertmannite/hydrogen peroxide Fenton-like reaction.The results showed that the 50 mg/L nitrobenzene could be achieved 92.5% in 30 min at initial pH value of 3,the concentration of hydrogen peroxide(500 mg/L),schwertmannite(1 g/L)conditions,which indicated that the catalyst was a kind of efficient Fenton catalyst.3.The stability and reuse of the catalyst also examined.The results showed that the catalyst retained almost its high catalytic activity and stability after 5 consecutive runs.Through the investigation of the common anions and small molecules acid in nature,the results showed that the application of the mineral was high effective halotolerant,acid catalystan.4.The determination of hydrogen peroxide in the course of consumption,the leaching of iron ion and TOC removal also tested,and adding free radical quenching agent showed that the mechanism of catalytic oxidation was radical mechanism.In addition,nitrophenols were the main transformation products detected by liquid chromatography and mass spectrometric(LC/MS),and accordingly put forward nitrobenzene degradation pathway.