School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221000, China.
School of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
Int J Biol Macromol. 2020 Jun 1;152:576-583. doi: 10.1016/j.ijbiomac.2020.02.273. Epub 2020 Feb 24.
Polyacrylamide (PAM) has been used as a coagulant aid in water treatment process for past decades, but it has caused great damages to human nervous system. Developing new coagulant aid with high biological safety is urgently demanded. This study provides a natural biomacromolecule coagulant aid with good biosecurity-Enteromorpha prolifera polysaccharide (Ep). Its coagulant aid efficiency and mechanism were investigated in terms of organics removal, floc properties and membrane fouling degree. In addition, contrast experiments were conducted with PAM to evaluate its potential of industrial applications. Results showed that organics removal could be increased by 23% when 0.3 mg/L Ep was used, which exhibited comparable aid effects to PAM. Due to the bridging-sweep aid role of Ep, flocs sizes, growth rate and recovery factor reached 470 μm, 62.6 μm/min and 0.492, respectively, while only 170 μm, 14.0 μm/min and 0.326 were obtained by PAM. Additionally, flocs exhibited more porous and multi-branched structures when Ep was applied, which caused less ultrafiltration membrane fouling (eventual J/J value = 0.52). As a result, Ep could be considered as a potential substitute of PAM, since better biosecurity, higher organics removal and lower membrane fouling could be obtained simultaneously by Ep addition.
聚丙烯酰胺 (PAM) 在过去几十年中一直被用作水处理过程中的混凝助剂，但它对人类神经系统造成了极大的损害。因此，迫切需要开发具有高生物安全性的新型混凝助剂。本研究提供了一种具有良好生物安全性的天然生物大分子混凝助剂——浒苔多糖 (Ep)。从有机物去除、絮体特性和膜污染程度等方面研究了 Ep 的混凝辅助效果和机理。此外，还与 PAM 进行了对比实验，以评估其在工业应用中的潜力。结果表明，当投加 0.3mg/L 的 Ep 时，有机物去除率可提高 23%，其助凝效果可与 PAM 相媲美。由于 Ep 的架桥扫集作用，絮体粒径、增长速率和恢复系数分别达到 470μm、62.6μm/min 和 0.492，而 PAM 仅为 170μm、14.0μm/min 和 0.326。此外，当 Ep 存在时，絮体呈现出更多的多孔和多分支结构，导致超滤膜污染程度更低（最终 J/J 值为 0.52）。因此，Ep 可以作为 PAM 的潜在替代品，因为 Ep 的添加可以同时获得更好的生物安全性、更高的有机物去除率和更低的膜污染程度。
