State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
Int J Biol Macromol. 2021 Jan 15;167:223-232. doi: 10.1016/j.ijbiomac.2020.11.176. Epub 2020 Nov 29.
Two laboratory-made cationic starch-based flocculants (St-CTA and St-AD) with different chain architectures were used to simultaneously remove phosphorus and turbidity from two simulated wastewaters and one actual wastewater with laboratory and pilot scales, respectively, in conjunction with FeCl. A commercial polyacrylamide (PAM) has been also tried and compared with aforementioned starch-based flocculants. The removal extents of phosphorus and turbidity increased, the required dosages of FeCl decreased, and floc properties improved after dosing each polymeric flocculant after FeCl in all tested wastewaters due to their synergistic effects. However, the three flocculants exhibited different improvement efficiencies on the treated wastewaters containing different forms of phosphorus and showed various synergistic mechanisms owing to their distinct structural features. In inorganic-phosphorus-simulated wastewater, the linear nonionic PAM with a high molecular weight had a more notable contribution than the two starch-based flocculants due to its efficient bridging flocculation effect. Given the branched-chain structure and high positive charge density of St-AD, it had a higher efficiency in treating real wastewater and organic-phosphorus-simulated wastewater than PAM and linear cationic St-CTA. These results may serve as references for the design and selection of a suitable flocculant in treating target wastewaters.
两种实验室制备的阳离子淀粉基絮凝剂（St-CTA 和 St-AD）具有不同的链结构，分别在实验室和中试规模下与 FeCl 一起用于同时去除两种模拟废水和一种实际废水的磷和浊度。还尝试了一种商业聚丙烯酰胺（PAM），并将其与上述淀粉基絮凝剂进行了比较。在所有测试的废水中，在投加 FeCl 后投加每种聚合物絮凝剂，由于协同作用，磷和浊度的去除程度增加，FeCl 的所需剂量减少，絮体性质得到改善。然而，由于结构特征的不同，这三种絮凝剂对含有不同形态磷的处理废水表现出不同的改进效率，并表现出不同的协同机制。在无机磷模拟废水中，由于其有效的桥接絮凝作用，高分子量的线性非离子 PAM 比两种淀粉基絮凝剂具有更显著的贡献。鉴于 St-AD 的支链结构和高正电荷密度，它在处理实际废水和有机磷模拟废水中比 PAM 和线性阳离子 St-CTA 具有更高的效率。这些结果可以为设计和选择处理目标废水的合适絮凝剂提供参考。
