Study On Degradation Of P-chloroaniline By Homogeneous Photocatalytic Oxidation

The residual chemicals and intermediates in non-ferrous metals mining,beneficiation and metallurgy activities have brought heavy pressure to the surrounding ecological environment.Aniline aerofloat,an organic flotation agent,is easy to decompose into aniline compounds with obvious toxicity in the presence of acid and alkal.P-Chloroaniline?PCA?is one of the representative persistent organic pollutants.Sunlight,Fe²⁺ and Fe³⁺ are easy to obtain.Solid sodium persulfate?SPS?and sodium percarbonate?SPC?are safe and efficient.They have a wide application prospects.This paper takes PCA as the research object and discusses the effects of major factors(such as initial p H,SPS concentration,SPC concentration,Fe²⁺ and Fe³⁺ concentration,anion type and concentration)on the removal of PCA in the simulated sunlight / iron(Fe²⁺,Fe³⁺)/ SPS and SPC system.The main active oxygen radicals in the system were detected by radical scavenging experiment.The main research contents and conclusions are as follows:In the simulated sunlight / iron ions(Fe²⁺,Fe³⁺)/ SPS system,when Fe²⁺ activates SPS,the removal effect of PCA is the best;when the concentration of SPS is increased,the removal effect of PCA is enhanced;the initial p H and NO3-have little effect on the removal effect of PCA;HCO3-and high concentrations of Fe²⁺,Fe³⁺,SO42-significantly inhibit the removal of PCA;When Fe²⁺ activated SPS,Cl-slightly promoted the removal of PCA in the system,while when Fe³⁺ activated SPS,high concentration Cl-inhibited the removal of PCA in the system.The removal effect of PCA in the two systems is mainly combined by HO· and SO4·-.In the simulated sunlight / iron ion(Fe²⁺,Fe³⁺)/ SPC system,Fe²⁺ activated SPC has the best effect on the removal of PCA;HCO3-and high concentration SPC are not conducive to the removal of PCA;NO3-has no obvious effect on the removal of PCA;HO· and O2·-work together on the removal of PCA,in which HO· is the dominant free radical.When Fe²⁺ activates SPC,the removal effect of PCA in the system is weakened when the p H is increased;the high concentration of Fe²⁺ significantly inhibits the removal of PCA;Cl-and SO42-have little effect on the removal effect of PCA.When Fe³⁺ activates SPC,the initial p H of the solution has little effect on the removal of PCA;increasing the concentration of Fe³⁺ is beneficial to the removal of PCA;high concentrations of Cl-and SO42-suppress the removal of PCA in the system.In summary,sunlight and iron ions(Fe²⁺,Fe³⁺)co-activated peroxides?SPS,SPC?system is a method for efficient removal of organic matter,which has broad application prospects and deserves our attention.