Effect Of Magnetic Field Strengthening And Catalyst Modification On Fenton Reaction Treatment Of Phenol-containing Wastewater

With the rapid development of industry,phenolic substances are widely used in various industries.A large amount of phenol-containing wastewater will pollute all kinds of freshwater basins,including groundwater,and threaten the survival of living things on Earth.Due to the poor biodegradability of phenolic wastewater,advanced oxidation methods are currently used.The Fenton method is an advanced oxidation technology widely used in recent years.It has the advantages of strong oxidizing ability,convenient operation,rapid reaction,mild reaction conditions and strong reaction characteristics.However,the conventional Fenton method has problems such as low catalyst utilization rate,narrow pH application range,and high processing cost.It is reported that the magnetic field has a significant effect on free radicals.The magnetically strengthened Fenton reaction can improve the defects of the traditional Fenton method to some extent.In addition,the surface modified modified catalyst has better degradation effect than the unmodified catalyst.Stability,it can be speculated that the use of modified catalytic materials in the strong magnetic field strengthening Fenton system can improve the system's ability to oxidize pollutants.In this paper,the prepared wastewater of hydroquinone simulated wastewater is used as the target wastewater.Three kinds of traditional catalytic materials?FeSO₄ powder,reduced iron powder,Fe₃O₄ particles?are subjected to univariate factor experiments,orthogonal experiments and magnetization experiments.The optimal reaction conditions of the system are:pH 3,H₂O₂ dosage is 1.0mL,FeSO₄·7H₂O dosage is 100mg,reaction time is 10min;pH is 3,H₂O₂ dosage is 0.35mL,Fe is added simply.The amount was 80 mg,the reaction time was 30 min;the pH was 3,the dosage of H₂O₂ was 0.6 mL,the dosage of Fe₃O₄ was 180 mg,and the reaction time was 30 min.The optimum magnetic induction intensities of the three catalysts were 20.92mT,20.92mT and 12.53mT,respectively.The strengthening effect of the magnetic field on Fe₃O₄ was the most obvious.The nano-Fe₃O₄ particles were prepared and modified by TMAH and EDTA.The effect and stability of the catalyst before and after modification were investigated.The application of actual wastewater can be known.After the modification of nano-Fe₃O₄ by TMAH and EDTA,the size of particle is between 10-15nm,the agglomeration phenomenon is reduced and the dispersibility is improved.The optimum condition parameters of the Fenton-like system composed of the modified catalyst are pH 3.5,the dosage of the modified catalyst is 150 mg,the dosage of H₂O₂ is 0.5 mL,and the reaction time is The optimal magnetic induction intensity of the five catalysts is 12.53mT,and the magnetic field strengthening effect of 5#Fe₃O₄ is the best.After 8 cycles of use,the cycle stability is the highest;the overall removal efficiency of the treatment of actual wastewater is 5#Fe₃O₄ after magnetic>Fe₃O₄ magnetic>5#Fe₃O₄ magnetic front?1#Fe₃O₄>Fe₃O₄ magnetic front,indicating that the particle size reduction and modification and magnetic field strengthening achieve double strengthening effect on this type of Fenton system.In addition,after 5#Fe₃O₄ is used for 6 times,the removal rate is still above 60%,and the cycle stability is also the highest.The magnetically enhanced Fenton system composed of 5# modified catalyst breaks through the limitations of the traditional Fenton method,such as narrow pH range,low catalyst utilization rate and unrecoverable,which provides theoretical basis and guiding direction for Fenton combination technology research.