Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
J Environ Sci (China). 2017 Jan;51:214-221. doi: 10.1016/j.jes.2016.06.015. Epub 2016 Jul 14.
The objective of this study was to investigate the effect of different Al species and chitosan (CS) dosages on coagulation performance, floc characteristics (floc sizes, strength and regrowth ability and fractal dimension) and membrane resistance in a coagulation-ultrafiltration hybrid process. Results showed that different Al species combined with humic acid in diverse ways. Al had better removal efficiency, as determined by UV and dissolved organic carbon, which could be further improved by the addition of CS. In addition, the optimal dosage of different Al species was determined to be 4.0mg/L with the CS concentration of 1.0mg/L, by orthogonal coagulation experiments. Combining Al/Al/Al with CS resulted in larger flocs, higher recovery, and higher fractal dimension values corresponding to denser flocs; in particular, the floc size at the steady state stage was four times larger than that obtained with Al species coagulants alone. The results of ultrafiltration experiments indicated that the external fouling percentage was significantly higher than that of internal fouling, at around 85% and 15%, respectively. In addition, the total membrane resistance was significantly decreased due to CS addition.
本研究旨在探讨不同 Al 物种和壳聚糖 (CS) 剂量对混凝-超滤混合过程中的混凝性能、絮体特性（絮体大小、强度和再生能力及分形维数）和膜阻力的影响。结果表明，不同的 Al 物种以不同的方式与腐殖酸结合。通过紫外和溶解有机碳的测定，Al 的去除效率更高，而添加 CS 可以进一步提高去除效率。此外，通过正交混凝实验确定，在 CS 浓度为 1.0mg/L 时，不同 Al 物种的最佳剂量为 4.0mg/L。Al/Al/Al 与 CS 结合后形成的絮体更大，回收率更高，分形维数值更高，表明絮体更密实；特别是稳定阶段的絮体大小是单独使用 Al 物种混凝剂时的四倍。超滤实验结果表明，外部污染百分比明显高于内部污染，分别约为 85%和 15%。此外，由于 CS 的添加，总膜阻力显著降低。
