Activation Of Persulfate Over Synthetic Iron Bearing Mineral Materials For Typical Organic Pollutants Degradation

With the development of social economy,people's living standards improved,however,the environmental problems come along.In the process of industrialization,exploiting and utilizing natural resources unreasonably result in the deterioration of environment and threaten to human health directly.Since water environment is one of the natural environment that we depend on,more and more environmental researchers devoted their research on water pollution control.So far,water pollution control methods include physical method,chemical method and biological method,etc.Although the traditional water control methods can improve the water environment in degree,there are still some problems such as low efficiency,high energy consumption and high cost.In recent years,persulfate activation based advanced oxidation processes become a hot spot.The main active oxygen species is sulfate radical,which has high redox potential and can degrade organic contaminants efficiently.The activation methods ofpersulfate include heat activation,photochemical activation,base activation,and transition metal activation,etc.However,these methods have some shortcomings.This paper focuses on the devlepment of more green and efficient persulate activation method,and studies the degradation of organic pollution by two natural iron-based activated persulfate as well as the degradation pathways and actvition mechanism.Firstly,we demonstrated that the Aletai copper deposit(mainly containing FeS2)could activate persulfate and degradate atrazine efficiently.In order to futher study the degradation pathway and activation mechanism of atrazine,FeS2 was synthesized via hydrothermal method.Then we discussed the effects of different pH on degradation.Trapping experiments and electron spin resonance techniques show that the main active oxygen species are superoxide anion radical,sulfate radical and hydroxyl radical.The inermaediates of atrazine were detected by LC-MS.Finally,we demonstrate the mechanism of activation persulfate over FeS2 for degradation of atrazine.Secondly,we illustrated that the Aletai copper-nickel sulphide deposit(mainly containing CuFeS2)could activate persulfate and degradate thiamphenicol efficiently.In order to study the activation mechanismand degradation pathway of thiamphenicol,we synthesized the CuFeS2 and characterized the surface of the iron bearing mineral material before and after the reaction by XPS.ESR and trapping experiments showed that the main active oxygen species in the system were sulfate radical and hydroxyl radical.Through the calculation of Laplasse bond order,we calculated that the covalent bond,which was the most easily to break in the process of the reaction,was in agreement with the LC-MS results.In summary,the mechanism of activation over iron based minerals is deepened and provides theoretical support for natural iron based mineral materials in environmental remediation.