Leiva Williams H, Toro Norman, Robles Pedro, Quezada Gonzalo R, Salazar Iván, Jeldres Ricardo
Facultad de Ingeniería, Arquitectura y Diseño, Universidad San Sebastián, Concepción 4030000, Chile.
Faculty of Engineering and Architecture, Universidad Arturo Prat, Iquique 1100000, Chile.
Polymers (Basel). 2024 May 20;16(10):1441. doi: 10.3390/polym16101441.
High-molecular-weight anionic polyacrylamide was used to analyze the effect of kaolin on the structure of particle aggregates formed in freshwater and seawater. Batch flocculation experiments were performed to determine the size of the flocculated aggregates over time by using focused beam reflectance measurements. Sedimentation tests were performed to analyze the settling rate of the solid-liquid interface and the turbidity of the supernatant. Subsequently, a model that relates the hindered settling rate to the aggregate size was used to determine the mass fractal dimension (Df). Flocculation kinetics revealed that greater amounts of kaolin generated larger aggregates because of its lamellar morphology. The maximum size was between 10 and 20 s of flocculation under all conditions. However, the presence of kaolin reduced the settling rate. The fractal dimension decreased with the increase in the kaolin content, resulting in the formation of irregular and porous aggregates. By contrast, factors such as the flocculation time, water quality, and quartz size had limited influences on the fractal dimension. Seawater produced a clearer supernatant because of its higher ionic strength and precoagulation of particles. Notably, the harmful effect of clays in seawater was reduced.
采用高分子量阴离子聚丙烯酰胺分析高岭土对淡水和海水中形成的颗粒聚集体结构的影响。通过聚焦光束反射测量进行间歇絮凝实验，以确定絮凝聚集体随时间的尺寸。进行沉降试验以分析固液界面的沉降速率和上清液的浊度。随后，使用将受阻沉降速率与聚集体尺寸相关联的模型来确定质量分形维数（Df）。絮凝动力学表明，由于高岭土的层状形态，更多量的高岭土会产生更大的聚集体。在所有条件下，最大尺寸出现在絮凝10至20秒之间。然而，高岭土的存在降低了沉降速率。分形维数随高岭土含量的增加而降低，导致形成不规则和多孔的聚集体。相比之下，絮凝时间、水质和石英尺寸等因素对分形维数的影响有限。由于海水具有较高的离子强度和颗粒的预凝聚作用，其产生的上清液更清澈。值得注意的是，海水中粘土的有害影响降低了。
