Amine-Cross-Linked Lignin-Based Polymer: Modification, Characterization, and Flocculating Performance in Humic Acid Coagulation

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• 作者：Ruihua Li ; Baoyu Gao ; Shenglei Sun ; Qinyan Yue ; Meng Li ; Xudan Yang ; Wuchang Song ; Ruibao Jia
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2015
• 出版时间：December 7, 2015
• 年：2015
• 卷：3
• 期：12
• 页码：3253-3261
• 全文大小：649K
• ISSN：2168-0485

文摘

In this study, a lignin-based flocculant (LNF) was synthesized by grafting amine groups into alkali lignin containing papermaking sludge. Characterization of LNF, such as FTIR, zeta potential, cationic degree, viscosity, and molecular weight, showed that the product was a cationic polymer with high solubility. LNF was used with aluminum sulfate (AS) and polyaluminum chloride (PAC) in humic acid coagulation to demonstrate its efficiency. Coagulation behavior and floc properties of LNF+PAC and LNF+AS dual-coagulant were comparatively evaluated. Results showed that the coagulation aid effect of LNF was independent of aluminum species. Addition of LNF could enhance humic acid removal efficiency and floc properties including size, strength, and fractal dimension significantly. The effect of solution pH on coagulation processes was also studied. Dual-coagulants showed the same variation trend as that of aluminum-based coagulants but enhanced coagulation performance during the investigative pH range. Flocs formed at pH 9 and pH 5 achieved maximum floc size in AS and PAC coagulation systems, respectively. Fractal dimension was relatively high at pH 7鈥? due to the sweeping effect of aluminum hydrolysates. Overall, LNF brought in charge neutralization and absorption bridging effect and played a positive role in coagulation processes.