Mechanism Of Degradation Of Polychlorinated Biphenyls By Peroxymonosulfate Activated By Nano-FeSe₂

Despite the complete cessation of PCBs production in China in the 1980s,residual PCBs remain a major safety hazard due to the high toxicity,persistence and long-range mobility of PCBs.The pollution caused by properly disposed PCBs should not be underestimated.Polychlorinated biphenyls?PCBs?remaining in the environment are easily expanded step by step through the food chain and are enriched in living organisms.The“three-acting effect”is a serious threat to human health and safety.Semi-volatiles cause long-distance migration and spread to all corners of the world.It is extensive and serious and must be taken seriously.The traditional repair methods have their own drawbacks.The physical repair and treatment of the symptoms are not cured,the chemical repair is expensive,and the bioremediation cycle is long.They can not achieve the ideal repair target.It is extremely urgent to find an economic green and efficient repair technology.Compared with general chemical oxidation,advanced oxidation technology has a rapid response,wide application range and good degradation effect,which has gradually attracted the attention of researchers.Persulfate-based advanced oxidation technology is an emerging technology that has been widely used in recent years for the efficient restoration of polluted water bodies and soils.The material is used to efficiently activate monopersulfate,thereby generating sulfate radicals and hydroxyl radicals,and free radicals attack pollutants,thereby triggering a series of radical chain reactions to completely degrade pollutants.Based on the above considerations,this paper selected nano-sized diselenide iron and peroxymonosulfate to carry out this research and explored the mechanism of nano-FeSe₂-activated peroxymonosulfate degradation of polychlorinated biphenyls.The main research results have the following three aspects?1?The nano-FeSe₂ material with high ability to activate peroxymonosulfate is successfully synthesized,and its activated peroxymonosulfate can achieve rapid degradation of PCB 28.?2?The effects of nano-FeSe₂ material and peroxymonosulfate dosage were studied.The effects of pH,anion and Fe²⁺were investigated,and the key technical parameters of degradation were optimized.The free radical quenching reaction and electron paramagnetization were used.Resonance Spectrometer?EPR?,which identified hydroxyl radicals as the main type of free radicals degrading PCB 28;analyzed the degradation of PCB 28 by gas chromatography-mass spectrometry?GC-MS?;finally revealed the activation of nano-Selenide The mechanism of action of single persulfate degradation of PCB 28.?3?Two kinds of surfactants,polyoxyethylene lauryl ether and sodium dodecylbenzenesulfonate,were used for soil elution experiments to find surfactants and concentrations suitable for contaminated soil in PCBs.The Nano-FeSe2/PMS system was then used to achieve efficient removal of PCBs from soil eluents.The results of this study provide a new method for the remediation of contaminated soils in PCBs.Figure[30]Table[4]Reference[82]...