两性絮凝剂EPPCX的制备及对Pb^(2+)作用机理研究

Preparation of an Amphoteric Polymer Flocculant EPPCX and its Pb^(2+) Removal Mechanism

以聚酰胺多胺(PPC)-2,3-环氧丙基三甲基氯化铵(ETA)接枝共聚物(EPPC)、NaOH和CS_2为原料,在乙醇为溶剂条件下合成一种两性絮凝剂阳离子聚酰胺黄原酸钠(EPPCX)。通过FT-IR、13C-NMR、紫外光谱对产物结构进行表征。考察了絮凝剂投加量、温度、不同阴离子对Pb^(2+)去除率的影响;测定了絮体的Zeta电位、分形维数、采用扫描电镜观察了絮体的形貌。结果表明,处理25 mg·L^(-1) Pb^(2+)模拟废水时,EPPCX投加量为110.75 mg·L^(-1),Pb^(2+)的去除率达到97.2%。温度为35℃时,去除效果最好,阴离子的存在对Pb^(2+)的去除起到促进作用。絮凝过程中ζ电位的变化,表明絮凝过程主要以电荷作用为主,通过分形维数测定表明絮体具有密实的聚集结构。通过絮体形貌的变化,表明絮体有明显的堆积层次,形成絮体密实。

Cationic polyamide xanthogenate(EPPCX)as an amphoteric flocculant was prepared with polyaminamide-2,3-epoxypropyltrimethl ammonium chloride copolymer,carbon disulfide and sodium hydroxide in ethanol.The chemical structure of the product was characterized by infrared spectroscopy,nuclear magnetic resonance and ultravoilet spectroscopy.Effects of EPPCX dosage,temperature and anion on Pb2+removal from wastewater were investigated.Meanwhile,zeta potential of flocs was determined,and the flocs were investigated by scanning electron microscopy.The result shows that Pb2+removal is97.2%when the EPPCX dosage is110.75mgL1.The maximum Pb2+removal is achieved at35℃,which can be promoted by anions.Zeta potential results indicate that flocculation is controlled by charge neutralization.Fractal dimension shows the highest value under optimal flocculant dosage conditions,which indicates that the flocs have compact aggregated structure.The flocs morphology show leveled accumulation structure which further confirms the results.