School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan, China.
School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, China.
Water Environ Res. 2020 Feb;92(2):302-309. doi: 10.1002/wer.1250. Epub 2019 Oct 16.
A reduction in the use of aluminum (Al)-based flocculants in the treatment of drinking water is considered essential for human health reasons. In this study, a novel composite flocculant, made of carboxymethylpullulan-AlCl , is evaluated in a lab-scale, jar test system for the flocculation of kaolin. The results showed that the coagulation efficiency of carboxymethylpullulan-AlCl was more effective in reducing turbidity than the solo use of carboxymethylpullulan or AlCl . The optimum treatment conditions assessed by a response surface methodology were obtained at pH 6.50, 13.03 mg/L carboxymethylpullulan, and 94.87 mg/L AlCl . Zeta potential measurements and photometric dispersion analysis demonstrated that AlCl had a more significant influence on charge neutralization than carboxymethylpullulan, whilst carboxymethylpullulan facilitated absorption and the development of particle bridges. Thus, the composite flocculant possessed both advantages that enhanced flocculation, and decreased the dosage of AlCl , thereby reducing the potential for secondary environment pollution. When 90 mg/L carboxymethylpullulan-AlCl was added to the model kaolin suspension characterized by a turbidity of 50 nephelometric turbidity units, the zeta potential and the maximum flocculating activity were determined as -2.28 mV and 98.0%, respectively. The results provide insight into the development of an environment-friendly composite flocculant prepared from water-dissolved polysaccharide and inorganic flocculants. PRACTITIONER POINTS: A novel composite flocculant CMP-AlCl was achieved by combining CMP and AlCl for water treatment. The coagulation efficiency of CMP-AlCl was more effective in reducing turbidity than the solo use of CMP or AlCl . The flocculation efficiency and mechanism were investigated by Zeta potential analysis, surface morphology, electron microscopy, and coagulation.
出于人类健康的原因，减少在饮用水处理中使用铝（Al）基絮凝剂被认为是至关重要的。在这项研究中，评估了一种新型的复合絮凝剂，由羧甲基普鲁兰聚糖- AlCl 制成，用于高岭土的絮凝，在实验室规模的搅拌试验系统中进行。结果表明，与单独使用羧甲基普鲁兰聚糖或 AlCl 相比，羧甲基普鲁兰聚糖- AlCl 的混凝效率更有效地降低浊度。通过响应面法评估的最佳处理条件在 pH 6.50、13.03 mg/L 羧甲基普鲁兰聚糖和 94.87 mg/L AlCl 下获得。Zeta 电位测量和光散射分析表明，AlCl 对电荷中和的影响比羧甲基普鲁兰聚糖更显著，而羧甲基普鲁兰聚糖则有利于吸收和颗粒桥的发展。因此，复合絮凝剂具有增强絮凝的双重优势，降低了 AlCl 的用量，从而降低了二次环境污染的潜力。当向浊度为 50 度的高岭土模型悬浮液中添加 90 mg/L 的羧甲基普鲁兰聚糖-AlCl 时，测定了zeta 电位和最大絮凝活性，分别为-2.28 mV 和 98.0%。结果为开发由水溶性多糖和无机絮凝剂制备的环保型复合絮凝剂提供了思路。
