紫外引发合成三元阳离子聚丙烯酰胺及其对雌酮的絮凝去除

Synthesis of a Cationic Polyacrylamide under UV Initiation and Its Flocculation in Estrone Removal

通过紫外引发聚合技术制备了具有疏水特性的三元阳离子聚丙烯酰胺,并用于典型环境雌激素雌酮(E1)的分离和去除。由丙烯酰胺(AM)、丙烯酰氧基乙基三甲基氯化铵(DAC)和丙烯酰氧基乙基二甲基苄基氯化铵(AODBAC)单体合成三元共聚物(PADA),并采用傅里叶变换红外光谱(FT-IR),核磁共振氢谱(~1H NMR)和热失重/差示扫描量热仪(TG/DSC)分别对聚合物的结构和热分解性能进行表征。FT-IR和~~1H NMR结果表明聚合物成功合成。通过引入疏水性基团(苯基),TG/DSC分析观察到PADA热稳定性能提高。在最佳条件下(p H=7,絮凝剂用量为4.0 mg/L),用高效絮凝剂PADA-3(阳离子度为40%,特性黏度为6.30 d L·g^(-1))得到最佳E1絮凝性能(E1去除率90.1%,絮凝体积18.3μm,絮凝动力学22.69×10^(-4)s^(-1))。Zeta电位和絮体尺寸分析用于探究E1去除的絮凝机理。结果表明,E1去除过程中,电中和、吸附和架桥效应占主导地位。

A ternary cationic polyacrylamide with the hydrophobic characteristic was prepared through ultraviolet(UV)-initiated polymerization technique for the estrone(E1)environmental estrogen separation and removal.The monomers of acrylamide(AM),acryloyloxyethyl-trimethyl ammonium chloride(DAC)and acryloyloxyethyl dimethylbenzyl ammonium chloride(AODBAC)were used to synthesize the ternary copolymer(PADA).Fourier transform infrared spectroscopy(FT-IR),1H nuclear magnetic resonance spectroscopy(1H NMR),thermogravimetry/differential scanning calorimetry(TG/DSC)and scanning electron microscopy(SEM)were employed to characterize the structure and thermal decomposition property of the polymers,respectively.FT-IR and 1H NMR results indicated the successful formation of the polymers.Besides,with the introduction of hydrophobic groups(phenyl group),a favorable thermal stability of the PADA was observed by TG/DSC analyses.At the optimal condition(pH=7,flocculant dosage is 4.0 mg/L),an excellent E1 flocculation performance(E1 removal rate:90.1%,floc size:18.3μm and flocculation kinetics:22.69×10-4 s-1)was acquired by using the efficient flocculant PADA-3(cationic degree is 40%,and intrinsic viscosity is 6.30 dL·g-1).The zeta potential and floc size analyses were used to analyze the possible flocculation mechanism for the E1 removal.Results indicated that the charge neutralization,adsorption and birding effects were dominant in the E1 removal progress.