宽pH值适应性木质素絮凝剂的制备及其对乳化含油废水的处理

Synthesis of Lignin-based Flocculants with Wide pH Adaptability and Its Treatment on Wastewater Containing Emulsified Oil

中文关键词:  木质素  阳离子  絮凝剂  乳化含油废水

Key Words:lignin  cationic  flocculant  emulsified-oil wastewater

中文摘要:

      以预水解木质素为原料，甲基丙烯酰氧乙基三甲基氯化铵（METAC）和丙烯酰胺（AM）为接枝单体，过硫酸钾（KPS）为引发剂，通过接枝聚合反应制备了阳离子型木质素三元接枝聚合物（LAM），探讨了pH值、KPS用量、METAC/木质素摩尔比、AM/木质素摩尔比等对LAM电荷密度、溶解度和接枝率的影响，并利用傅里叶变换红外光谱（FT-IR）、电荷滴定等技术对LAM的结构和性能进行表征。结果表明，在pH值为5、KPS用量为4.0 wt%、METAC/木质素摩尔比为2.5、AM/木质素摩尔比为2.5条件下制备的LAM性能最优，电荷密度为2.38 mmol/g，溶解度为8.92 g/L，METAC和AM的接枝率分别为166.2%和70.1%；与木质素接枝METAC二元聚合物相比，LAM对废水中乳化油具有优异的絮凝效果，去除率达91%以上且表现出宽pH值适应性。

Abstract:

      The cationic lignin ternary graft polymer （LAM） was prepared by radical polymerization reaction using pre-hydrolyzed lignin as raw material， ［2-（methacryloyloxy） ethyl］ trimethylammonium chloride （METAC） and acrylamide （AM） as graft monomers， and potassium persulfate （KPS） as initiator. The effects of pH value， KPS dosage， METAC/lignin molar ratio， AM/lignin molar ratio， and other conditions on the charge density， solubility， and grafting rate of LAM were investigated； the structure and properties of LAM were characterized by Fourier transform infrared spectroscopy （FT-IR）， charge titration， etc. The results showed that LAM prepared at pH value of 5， KPS dosage 4.0 wt%， METAC/lignin molar ratio 2.5， and AM/lignin molar ratio 2.5 had the optimum performance with a charge density of 2.38 mmol/g， solubility of 8.92 g/L， graft ratio of 166.2% for METAC and 70.1% for AM. Compared with the lignin-grafted METAC binary polymer， LAM showed a wide range of pH adaptability and had an excellent flocculation effect on emulsified-oil in wastewater， with removal rate of over 91%.