Construction Of A New Fenton-like System And Its Application In “Three Chemical Properties” Treatment Of Oily Sludge

Oily sludge will be produced in oil exploitation,storage and transportation,refining and other aspects,and its composition is very complex.If only a single mechanical separation method is used to treat the sludge,it is difficult to achieve the expected treatment effect.Because Fenton reaction has the advantages of fast response and wide application range,it has received extensive attention in the fields of sewage treatment.However,the Fenton reaction can only show strong performance under strong acid conditions,and it is easy to produce a large amount of iron sludge after the reaction,which limits its industrial application.Based on this,a heterogeneous Fenton-like catalytic system with high catalytic performance under neutral conditions was developed and applied to the demulsification study of oily sludge to realize the"resource,harmless and reduction"treatment of oily sludge.The specific research contents are as follows:(1)Determination of full component composition of original oily sludge,including determination of oil,water and sludge in sludge.The results show that the solid content is7.40%,the oil content is 6.33%,and the water content is 86.32%.Then each phase in the three phases was determined,including the concentration of anions and cations in the water phase,the content of four components in the oil phase and the mineral composition in the mud phase.(2)A series of mesoporous alumina catalysts doped with different metals(Cu-?-Al₂O₃,Mn-?-Al₂O₃,Ni-?-Al₂O₃,Cu/Mn-?-Al₂O₃,Cu/Ni-?-Al₂O₃)were synthesized by evaporation-induced self-assembly.The structures of the catalysts were characterized by XRD,IR,SEM,BET and XPS.The results show that the original mesoporous structure of?-Al₂O₃ is still maintained after active metal doping.The active metal is in the form of low valence state of Cu⁺,Mn²⁺and Ni²⁺,and the bonding mode of M-O-Al,which is doped in the?-Al₂O₃lattice structure of spinel structure.(3)Different metal-doped mesoporous alumina catalysts were combined with H₂O₂ to form a heterogeneous Fenton-like system to treat oily sludge macroscopically.When p H is 7,the dosage of catalyst is 3.0 g/L,the concentration of hydrogen peroxide is 0.8 mol/L,and the reaction temperature is 30?,the Fenton-like system composed of Cu/Mn-?-Al₂O₃ and H₂O₂has the best effect on the treatment of oily sludge.The liquid content of oily sludge decreased from 86.32%to 63.7%,and the COD content decreased by 76.5%,and the recovery of oils reached 36.33%.This is attributed to the synergistic effect between the bimetal catalysts.After modulation,the emulsion is easy to separate,the oil products are easy to recover,and the harmful substances are reduced,which realizes the"reduction,harmless and resource"treatment of oily sludge.(4)Through the analysis of micro-surface interface properties such as solid particle size,three-phase contact angle,oil-water interfacial tension and emulsion Zeta potential,it is found that after treatment,the oil-water interfacial tension and contact angle increase,the Zeta potential decreases,and the solid particle size decreases,which reduces the emulsification degree of oily sludge,which is beneficial to the separation of oily sludge.Based on this,the stability and demulsification mechanism of the emulsified structure of oily sludge and the oxidation mechanism of Fenton-like system on the surface interface of oily sludge were discussed in detail.The mechanism study shows that the·OH produced by the new Fenton-like system breaks the spatial structure of the emulsion interface membrane,destroys the steric hindrance between the membrane and the membrane,and reduces the stability of the emulsion,thus realizing the demulsification separation of the emulsion.