A nonintrusive digital imaging process was developed to study particle size distributions created through flocculation and sedimentation. Quantification of particle size distributions under different operating conditions can be of use in the understanding of aggregation mechanisms. This process was calibrated by measuring standardized polystyrene particles of known size and was utilized to count and measure individual kaolin clay particles as well as aggregates formed by coagulation with polyaluminum chloride and flocculation. Identification of out-of-focus flocs was automated with LabVIEW and used to remove them from the database that was analyzed. The particle diameter of the test suspension of kaolinite clay was measured to be 7.7 ± 3.8 μm and a linear relationship was obtained between turbidity and the concentration of clay particles determined by imaging. The analysis technique was applied to characterize flocs and floc particle size distribution as a function of coagulant dose. Removal of flocs by sedimentation was characterized by imaging, and the negative logarithm of the fraction of turbidity remaining after settling had a linear relationship with the logarithm of aluminum dose. The maximum floc size observed in the settled water was less than 120 μm, which was in accordance with the value predicted by a model for the capture velocity of the experimental tube settler of 0.21 mm/s.

中文翻译：

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使用图像分析表征絮凝物和絮凝物尺寸分布


开发了一种非侵入式数字成像过程来研究通过絮凝和沉降产生的颗粒尺寸分布。不同操作条件下粒度分布的量化可用于理解聚集机制。该过程通过测量已知尺寸的标准化聚苯乙烯颗粒进行校准，并用于计数和测量单个高岭土颗粒以及通过聚氯化铝凝结和絮凝形成的聚集体。使用 LabVIEW 自动识别失焦絮凝物，并将其从分析的数据库中删除。测得高岭石粘土测试悬浮液的粒径为7.7±3.8μm，通过成像测定得到浊度与粘土颗粒浓度之间的线性关系。该分析技术用于表征絮体和絮体粒径分布与混凝剂剂量的函数关系。通过成像对沉降去除絮体进行表征，沉降后剩余浊度分数的负对数与铝剂量的对数呈线性关系。沉降水中观察到的最大絮体尺寸小于120μm，这与实验管沉降器捕获速度0.21mm/s的模型预测值一致。