Degradation Effect And Mechanism Of Atrazine By Activated Permonosulfate Of Ferrovanadium Concentrate

The ATZ detected in the water body seriously threatens the health and safety of humans,animals and plants,and iron-based bimetallic materials can effectively activate PMS to remove refractory pollutants.In this paper,using ferrovanadium concentrate as catalyst to activate PMS to degrade atrazine in water,and explored the characteristics of ferrovanadium concentrate through different characterization methods.Through the mass concentration of ferrovanadium concentrate,ATZ mass concentration,PMS concentration,p H value,influence factors of coexisting anions and humic acid,free radical detection,intermediate product detection and other experiments,the effect of PMS activation of ferrovanadium concentrate to degrade atrazine,reaction mechanism and the degradation product characteristics of atrazine were explored.The research contents are as follows:（1）XRD,EDS,FTIR,and XPS characterization methods were used to characterize the phase composition,morphological structure,functional groups and electron transfer characteristics of vanadium iron concentrate.It was found that ferrovanadium concentrate is mainly composed of augite,titanomagnetite and fayalite.The main metal elements were iron and vanadium.The high efficiency of PMS activation by ferrovanadium concentrate is due to the existence of electron transfer between vanadium and iron,which promotes the rapid regeneration of Fe²⁺and the generation of sulfate radical and hydroxyl radical.（2）Through the experiments on the influencing factors such as calcining temperature（100℃～500℃）,atrazine mass concentration(1 mg·L^-1～2.5 mg·L^-1),mass concentration of ferrovanadium concentrate(100 mg·L^-1～600 mg·L^-1),PMS concentration（0.1 m M～0.6 m M）,p H（3～9）and coexisting ions and humic acid（Cl^-,HNO₃^-,H₂PO₄^-,HCO₃^-,HA）,it is found that the ferrovanadium concentrate after calcining at 500℃has the best catalytic effect.Although the concentration of dissolved iron was the highest(1.02 mg·L^-1),the influence of dissolved iron was ruled out by the experiment of relative ratio.Atrazine mass concentration and the concentration of ferrovanadium concentrate,concentration of PMS had larger influence on degradation effect,The conditions with the best effect of single-factor variable condition are:atrazine mass concentration is 1 mg·L^-1,the mass concentration of ferrovanadium concentrate is 500 mg·L^-1,PMS concentration is 0.5 m M,initial p H has an impact on the degradation rate of atrazine in the ferrovanadium concentrate/PMS system,and acidic conditions are more conducive to the reaction.Cl^-and HCO₃^-in aqueous solution have inhibitory effect,while NO₃^-,H₂PO₄^-and HA have relatively small effect.（3）Through quenching experiments and electron paramagnetic resonance（EPR）detection,it was found that hydroxyl radical and sulfate radical were the main agents for the degradation of atrazine in the V-Fe/PMS system.Six intermediate products of the degradation of atrazine by V-Fe/PMS were detected by LC-MS/MS,including CAIT,CAAT,OAAT,EIT,OAIT and OOOT,and the degradation pathways were sorted out.And the removal rate of TOC was tested,and the removal rate of TOC after 60 min of reaction was 37.5%.（4）Degradation experiments were carried out on the refractory pollutants of SMX,SIX,CBZ,2,4-DCP,DCF and LVF in water.The results showed that the degradation was close to100%in the range of 10 min～40 min,which proved that the degradation of refractory pollutants by activated PMS of ferrovanadium concentrate had broad spectrum.The degradation rate of ATZ can reach 77.9%after 6 cycles of ferrovanadium concentrate regeneration reaction,which shows that the recycling performance is good.