Fiber and Particle Engineering Laboratory, University of Oulu, P.O. Box 4300, FI-90014 Oulu, Finland.
Water Res. 2012 May 1;46(7):2159-66. doi: 10.1016/j.watres.2012.01.035. Epub 2012 Feb 2.
In this work, the effectiveness of a novel, combined coagulation-flocculation treatment based on alum and soluble or nanoparticular anionic derivatives of dialdehyde cellulose, ADAC, was evaluated by studying the removal of colloidal material in a model suspension containing kaolin. Four different ADACs with varying degrees of substitution, size and water solubility were synthesized by periodate oxidation and sulfonation of cellulose. The effects of ADAC dosage, solution pH and temperature on flocculation were studied by measuring residual turbidity of the settled suspension. Moreover, the charge densities, sizes, ζ-potentials and stability of the ADACs in aqueous solutions were studied. The combined treatment was effective in the removal of colloidal particles, as demonstrated by reduced residual turbidity with remarkably lower total chemical consumption compared with coagulation with alum alone. Of the ADACs, samples with lower solubility that contained cellulose nanoparticles performed better than the fully water-soluble sample. Due to the restricted pH tolerance of alum, the combined treatment was effective only at acidic conditions (pH < 5), although the ADACs were found to be stable in a much broader pH range (pH of 3 to about 9). ADACs also retained strong activity at higher temperatures (30-60 °C) and after several days of storage in aqueous solution.
在这项工作中，通过研究含有高岭土的模型悬浮液中胶体物质的去除，评估了一种基于明矾和醛基纤维素的可溶性或纳米阴离子衍生物（ADAC）的新型组合混凝-絮凝处理的效果。通过纤维素的高碘酸盐氧化和磺化合成了四种不同取代度、大小和水溶性的 ADAC。通过测量沉降悬浮液的残余浊度来研究 ADAC 用量、溶液 pH 值和温度对絮凝的影响。此外，还研究了 ADAC 在水溶液中的电荷密度、粒径、ζ 电位和稳定性。组合处理在去除胶体颗粒方面非常有效，与单独使用明矾混凝相比，残余浊度降低，总化学耗用量显著降低。在 ADAC 中，与完全水溶性样品相比，含有纤维素纳米颗粒的低水溶性样品表现更好。由于明矾的 pH 容忍度有限，因此该组合处理仅在酸性条件下（pH<5）有效，尽管 ADAC 在更宽的 pH 范围内（pH 为 3 到约 9）被发现是稳定的。ADAC 在较高温度（30-60°C）下和在水溶液中储存数天后仍保持很强的活性。
