Synthesis Characterization And Performance Evaluation Of Rare Earth-Al Polymer Heterogeneous Flocculant

At present,most oil fields in China have entered the late stage of waterflooding development,and the water content of the produced fluid exceeds 80%,which results in the production of a large amount of oil recovery wastewater.Discharge without treatment or improper treatment will cause serious pollution to the surrounding environment.Traditional wastewater treatment agents have been difficult to meet national environmental protection requirements.For such wastewater with complex components and difficult to process,the development of new flocculants is an inevitable trend.In this paper,aluminum chloride hexahydrate?Al Cl₃·6H₂O?and cerium chloride heptahydrate?Ce Cl₃·7H₂O?are used as inorganic components,acrylamide and dimethyldiallylammonium chloride are used as organic components,and the redox system of ammonium persulfate and sodium bisul-fite is used as the initiator.Under certain conditions,an inorganic-organic hybrid flocculant Al/Ce?OH?₃-CPAM was synthesized.The Characterization results show that coordination chemical bonds are formed between the inorganic and organic components,and the inorganic-organic components achieve heteropolymerization.The effects of the addition of each component and the synthesis conditions on the product were studied.The total mass fraction of the inorganic components was 20%?mass ratio Al Cl₃·6H₂O:Ce Cl₃·7H₂O=7:3?,the mass fraction of sodium hydroxide was 8%,and the total mass fraction of the organic monomer was 18%?mass ratio AM:DMDAAC=2:1?,the total mass fraction of the initiator accounts for 0.8%of the total mass of the organic monomers?molar ammonium persulfate:sodium bisulfite=1:1?,the reaction temperature is 45°C,With a reaction time of 5h,the viscosity average molecular weight of the synthesized product reached 953.3×10⁴,and the Heteropolymerization rate reached 62.3%.Al/Ce?OH?₃-CPAM flocculant has a good flocculation effect on the wastewater of the Bell Sumu 301 Combined Station in Hailar Oilfield at a dosage of 150mg/L.The degree of mineralization of wastewater has little effect on its flocculation performance,but The flocculation sedimentation has a greater effect;the results of the flocculant mechanism study of the Al/Ce?OH?₃-CPAM flocculant show that the flocculant has simultaneously the mechanisms of electric neutralization,adsorption bridging,and net capture precipitation.