Study On The Synthesis Of NFP Modified Cationic Polyacrylamide And Its Flocculation Performance For Oily Wastewater

At present,the discharge and leakage of industrial oily wastewater increase rapidly with the rapid development of petroleum industry.Oily wastewater is volatile which will damage the ecological environment and cause serious pollution to the soil,water resources and air.Therefore,the harmless treatment of oily wastewater is faced with challenges.The composition of oily wastewater is complex.Including high concentration of dispersed oil,grease and suspended particles.The treatment methods for oily wastewater mainly include physical method,physical chemical method,biological method,chemical method,etc.The chemical flocculation method,with the advantages of economic applicability,simple operation and good treatment effect,has shown its unique advantages in the treatment of oily wastewater.Hydrophobically modified polyacrylamide has excellent treatment effect in flocculation process due to its hydrophobic association behavior and bridging ability.In this thesis,acrylamide(AM)was used as the main monomer,and cationic monomer acryloyloxyethyl-trimethylammonium chloride(DAC)and hydrophobic monomer N-(2,2,2-trifluoroacetyl)-2-propene(NFP)were introduced to synthesize P(AM-DAC-NFP)by aqueous solution polymerization.And the Flocculence of P(AM-DAC-NFP)was studied.(1)Synthesis of NDAET-12:NDAET-12 was synthesized by acylation of ethyl trifluoroacetate(TFAE)and N,N-dimethylethylenediamine.NDAET-12,a fluorinated quaternary ammonium salt,was synthesized by quaternization of NDAET and dodecane bromide.It can be used as surfactant to solubilize hydrophobic monomers.The structure of NDAET and NDAET-12 was characterized by FTIR,13CNMR and 1HNMR.The effects of(NDAET):n(Bromododecane),reaction time,reaction temperature and solvent dosage on the yield of NDAET-12 were investigated.The synthesis parameters of NDAET-12 were optimized by orthogonal experiment.The critical micelle concentration of NDAET-12 is 0.8 g/L,?CMC=25.15 mN/m.(2)Synthesis of NFP:NFP was synthesized by acylation of trifluoroacetic anhydride(TFAA)and AM,which was used as the hydrophobic monomer for the synthesis of cationic hydrophobically associating polyacrylamide.The structure of NFP was characterized by FTIR,13CNMR and 1HNMR.The effects of n(AM):n(TFAA),reaction time,reaction temperature and the amount of triethylamine on the yield of NFP were investigated.The synthesis parameters of NFP were optimized by response surface methodology.(3)Synthesis of P(AM-DAC-NFP):P(AM-DAC-NFP)was synthesized by aqueous solution polymerization with AM,DAC and NFP as polymerization monomers.Ammonium persulfate(APS),sodiumbisulfite(SBS)and Azobis(2-methylpropylimi)dihydrochloride(AAPH)as composite initiators.It was used as an organic polymer flocculant to purify oily wastewater.The structure of P(AM-DAC-NFP)was characterized by FTIR,XRD and EDS.The morphology of P(AM-DAC-NFP)was analyzed by SEM.The apparent viscosity of P(AM-DAC),P(AM-DAC-NFP)and P(AM-DAC-NFP)solutions with different concentrations weremeasured.The effects of cationic monomer,initiator type,total monomer concentration,n(AM):n(DAC),reaction temperature,dosage of initiator APS-SBS,dosage of initiator AAPH and reaction time on the intrinsic viscosity of P(AM-DAC-NFP)were investigated.The synthesis parameters of P(AM-DAC-NFP)were optimized by response surface methodology.(4)The produced water from Yanchang Jingbian oilfield in Shaanxi Province is taken as the flocculation object.In this thesis,P(AM-DAC-NFP),P(AM-DAC),commercial PAM and polyaluminium chloride(PAC)were used to prepare inorganic organic composite high molecular flocculant.The effects of PAC dosage,inorganic high molecular flocculant dosage,pH on the permeability and oil content of supernatant were studied,and the flocculation performance of the composite flocculant was evaluated.