在混凝过程中使用双混凝剂可以使两种混凝剂的效益最大化。将明矾或铁盐等无机混凝剂与阳离子聚合物结合，有助于减少无机混凝剂的用量，并产生更大、更强的絮体。本研究旨在研究添加顺序对硝酸铁和阳离子聚合物性能的影响，以确定是否可以进一步增强双重混凝的优势。研究了三种不同的顺序添加:在硝酸铁之前添加聚合物；在硝酸铁之后加入聚合物；同时加入聚合物和硝酸铁。结果表明，当阳离子聚合物和无机混凝剂同时加入时，双混凝剂的性能得到了优化。根据作者的假设，添加顺序影响絮凝动力学，因为快速反应的差异- 混合持续时间、首先形成的骨料基质以及吸附顺序。这三个因素的综合作用导致絮凝指数更高，絮体颗粒表现出更高的生长速率，以及更高的抗剪切性，这是由扩展的快速混合引起的。阳离子聚合物和无机混凝剂的联合使用已被发现对处理高浊度水有效。对于在处理过程中使用阳离子聚合物和无机混凝剂的公用事业公司，在工厂的同一位置同时添加混凝剂可能会使双混凝剂性能更加有效。包括27个参考文献、表格和图表。

The use of dual coagulants in the coagulation process can maximize the benefits of both coagulants. Combining an inorganic coagulant such as alum or ferric salts with a cationic polymer helps reduce the inorganic coagulant dosage and produce larger, stronger flocs. This research studied the effect of addition sequence on the performance of ferric nitrate and a cationic polymer to ascertain whether the advantages of dual coagulation could be further enhanced. Three different sequence additions were investigated: adding the polymer before the ferric nitrate; adding the polymer after the ferric nitrate; and, adding the polymer and ferric nitrate at the same time. Results indicated that dual-coagulant performance was optimized when the cationic polymer and inorganic coagulant were added simultaneously. According to the authors' hypothesis, the addition sequence influences flocculation kinetics because of differences in rapid-mixing duration, the matrix of the aggregate first formed, and the sequence of adsorption. The combined effects of these three factors resulted in higher flocculation index values, with floc particles exhibiting a higher growth rate as well as higher resistance to shear induced by extended rapid mixing. The combined use of cationic polymers and inorganic coagulants has been found effective for treating high-turbidity waters. For utilities using cationic polymers and inorganic coagulants in their treatment process, simultaneous addition of coagulants at the same location in the plant may make dual-coagulant performance even more effective. Includes 27 references, tables, figures.