Grenda Kinga, Gamelas José A F, Arnold Julien, Cayre Olivier J, Rasteiro Maria G
Chemical Engineering Department, CIEPQPF, University of Coimbra Pólo II, Rua Sílvio Lima 3030-790 Coimbra Portugal
Aqua+Tech Specialities SA Chemin du Chalet-du-Bac 4, Avully 1237 Geneva Switzerland.
RSC Adv. 2019 Oct 29;9(60):34814-34826. doi: 10.1039/c9ra05757a. eCollection 2019 Oct 28.
Modification of cellulosic-rich materials such as wood waste and production of cellulose-based polyelectrolytes (PELs) presents several advantages for a variety of applications, when compared to the utilization of synthetic PELs, due to the nature, availability, high biodegradability and low or no toxicity of cellulosic materials. Moreover, valorization of the cellulosic waste itself to provide end products with higher added value is also an important aspect. In the present work, the objective was to evaluate the possibility of cationizing more complex and heterogeneous chemical pulps, obtained from wood waste, with different cellulose purity and a relatively high lignin content (up to 4.5%). A two-step reaction (with sodium periodate and Girard's reagent T) was employed and a range of cellulose-based cationic polyelectrolytes were produced with different degrees of substitution. The final products were characterized by several analytical techniques and the bio-PELs with the highest and the lowest substitution degree by cationic groups were evaluated in a new application, as flocculants in the decoloration of model effluents, bentonite having been used as an inorganic aid. Also, possible mechanisms of flocculation were discussed and the results compared with those of a synthetic flocculant, often used in these treatments, cationic polyacrylamide. Lignocellulosic-PELs proved to be very favorable eco-friendly flocculation agents for the decoloration of dye-containing waters with potential application in several industries.
与合成聚电解质相比，由于纤维素材料的性质、可得性、高生物降解性以及低毒性或无毒性，对富含纤维素的材料（如木材废料）进行改性并生产纤维素基聚电解质（PELs）在各种应用中具有诸多优势。此外，将纤维素废料本身转化为具有更高附加值的最终产品也是一个重要方面。在本研究中，目标是评估用不同纤维素纯度和相对较高木质素含量（高达4.5%）的木材废料制得的更复杂且多相的化学纸浆进行阳离子化的可能性。采用了两步反应（用过碘酸钠和吉拉德试剂T），制备了一系列具有不同取代度的纤维素基阳离子聚电解质。通过多种分析技术对最终产品进行了表征，并在一种新应用中评估了阳离子基团取代度最高和最低的生物聚电解质，即在模拟废水脱色中作为絮凝剂，膨润土用作无机助剂。此外，还讨论了可能的絮凝机制，并将结果与这些处理中常用的合成絮凝剂阳离子聚丙烯酰胺的结果进行了比较。木质纤维素聚电解质被证明是用于含染料水脱色的非常有利的环保型絮凝剂，在多个行业具有潜在应用价值。
