Herein, we report a novel renewable pH-responsive starch-based flocculant (CIAT-ST) via etherifying 2-chloro-4,6-isopropylamino-[1,3,5]-triazine (CIAT) onto the starch backbones for decontamination and reuse of highly saline effluents. The obtained CIAT-ST shows a unique pH-sensibility and reversibility in response to a subtle pH change due to a pH-controllable surface charge density of polymer chains. The level of residual CIAT-ST in the solution can be facilely monitored by using UV–vis detection. The dye flocculation performance of CIAT-ST was evaluated by using a batch experiment. The results exhibited that the dye removal was highly dependent on the solution pH (optimal pH was 2), the flocculation equilibrium can be achieved within 5 min, and the maximum flocculation capacity of CIAT-ST for K–2BP and KN–B5 were calculated to be 2452.6 ± 23.9 and 792.7 ± 14.1 mg/g, respectively. The multiple flocculation mechanisms, including charge neutralization, bridging and charge patching, may participate in the flocculation process. Adjustment in pH-mediated hydrophilicity-hydrophobicity switch of flocculant facilitates readily recovery and then sequentially reused three times while retaining satisfying flocculation efficiency. A significant contribution was also confirmed that the highly saline effluents after flocculation and sedimentation were reused in three successive dyeing processes without sacrificing fabric quality (ΔE* < 1) due to relatively low polymer residuals, and the efficiency of salt reuse for consecutive regeneration processes could be achieved above 85%. The present work could provide alternative thoughts for the reutilization of spent flocculant and clarified saline wastewater, which is also an efficient and sustainable strategy for textile wastewater management.

在此，我们通过将 2-氯-4,6-异丙基氨基-[1,3,5]-三嗪 (CIAT) 醚化到淀粉骨架上来报告一种新型的可再生 pH 响应淀粉基絮凝剂 (CIAT-ST)，用于去污和高盐度废水的再利用。由于聚合物链的 pH 可控表面电荷密度，获得的 CIAT-ST 显示出独特的 pH 敏感性和可逆性，以响应细微的 pH 变化。溶液中残留 CIAT-ST 的水平可以通过使用 UV-vis 检测轻松监测。CIAT-ST的染料絮凝性能通过批量实验进行评价。结果表明，染料去除高度依赖于溶液的 pH 值（最佳 pH 值为 2），絮凝平衡可在 5 分钟内达到，并计算了 CIAT-ST 对 K-2BP 和 KN-B5 的最大絮凝能力为 2452.6 ± 23。分别为 9 和 792.7 ± 14.1 毫克/克。多种絮凝机制，包括电荷中和、桥接和电荷修补，都可能参与絮凝过程。调节絮凝剂的 pH 介导的亲水-疏水转换有利于容易回收，然后连续重复使用 3 次，同时保持令人满意的絮凝效率。一个重要的贡献还被证实，絮凝和沉淀后的高盐废水在三个连续的染色过程中重复使用，而不会因为相对较低的聚合物残留而牺牲织物质量 (ΔE* < 1)，并且连续再生过程中盐再利用的效率可以达到85%以上。