Study On PMS Advanced Oxidative Ex-situ Remediation Of 2,4-DCP Contaminated Soil And Its Follow-up Wastewater Treatment

In the soil survey,high concentration of 2,4-dichlorophenol?2,4-DCP?have been detected in soil.It poses a serious threat to human health and environmental safety due to the high toxicity of 2,4-DCP,the soil contaminated by it needs to be quickly remedied.Ex-situ chemical oxidation has been widely used and studied in the remediation of organic contaminated soils due to its advantages of high operability,wide range of applications and short treatment cycle.As an emerging oxidant,peroxymonosulfate?PMS?is highly oxidizing and can react with water to generate hydroxyl radicals?HO^·?,and can also be more easily activated by transition metals to produce sulfate radicals(SO₄^·-)and HO^·.Based on the above studies,the paper used PMS ex-situ oxidation to remedy 2,4-DCP contaminated soil.In addition,due to the need for further treatment of the 2,4-DCP wastewater generated during the remediation process,the advanced oxidation system composed of the synthesized FeCo₂O₄ nanoparticles and PMS was used to degrade the 2,4-DCP in the aqueous solution.In the process of used PMS to remedy 2,4-DCP-contaminated soil,PMS can effectively remedied the contaminated soil by measured the concentration of contaminant in the soil after the reaction.After 8h reaction time,the degradation efficiency of 2,4-DCP of 151 mg kg^-1 in soil reached 93.1%.Through the PMS dose,reaction temperature and soil-water ratio and other factors.The results showed that 10mM PMS concentration,20°C reaction temperature and 1:1 soil-water ratio were the best reaction conditions for the reaction system.In addition,HO^·plays a major role in the reaction system.By studied the effect of Cl^-?HCO₃^-and HA on the reaction system,Cl^-has a smaller inhibitory effect on the degradation of contaminant,HCO₃^-has a greater inhibitory effect on the degradation of contaminant,HA has almost no effect on it.In the study of 2,4-DCP of aqueous was degraded by FeCo₂O₄/PMS reaction system,the synthesized FeCo₂O₄ nanoparticles were characterized by XRD,TEM,XPS,nitrogen adsorption-desorption isotherms and magnetization curves.The results showed that FeCo₂O₄ nanoparticles are composed of Fe³⁺,Co²⁺,Co³⁺,and O^2-,and have a very good spinel structure and good magnetic properties.In the degradation experiment,the FeCo₂O₄/PMS reaction system enabled the degradation rate of 2,4-DCP of 100 mg L^-1 to reach 95.8%in 90 minute.The optimal reaction conditions were as follows:FeCo₂O₄=0.06 g L^-1,PMS=4 mM,pH=7.0.During the reaction,SO₄^·-and HO^·are the main types of free radicals.In addition,FeCo₂O₄ nanoparticles have good stability,reusability and environmental friendliness.Through the above studies,new solution has been provided for the remediation of2,4-DCP contaminated soil,and an efficient method has been found for the subsequent treatment of 2,4-DCP wastewater.