Particle Aggregation and Sedimentation in a Continuous Flow, Gravity-Driven System

摘要CTS-9422962 为了更好地理解超微粒子的基本物理过程并为模型化提供数据基础，提出在相对理想化的条件下对超微粒子的聚集和沉降进行实验研究。 具体目标是在实验室系统中进行流动可视化，分析和建模控制重力引起的聚集的基本参数，并表征在静态环境系统中的延迟凝结和随后的聚集形态。 所提出的静态反应器装置允许重力驱动的聚集动力学的真实的时间观察，同时测量颗粒/聚集体的尺寸、速度和形状。 剪切流，布朗扩散，沉降，水化学，和颗粒表面特性对聚集的影响将进行研究。 实验结果将被引入一个适用于自然和工程系统的模型。 该项目将提高对自然地表水和地下水环境中发生的重力驱动聚集和沉积的基本理解，包括化学循环，颗粒动力学和污染物赎回。 ***

ABSTRACT CTS-9422962 It is proposed to experimentally investigate supermicron particle aggregation and sedimentation in relatively idealized conditions, in order to better understand the basic physical processes and provide a data base for modeling. The specific objectives are to conduct flow visualization in a laboratory system, analyze and model the fundamental parameters controlling gravity induced aggregation, and characterize retarded coagulation and subsequent aggregate morphology in quiescent environmental systems. The proposed quiescent reactor apparatus allows for real time observation of gravity-driven aggregation dynamics, with simultaneous measurements of particle/aggregate size, velocity and shape. The effects of shear flow, Brownian diffusion, sedimentation, aqueous chemistry, and particle surface characteristics on aggregation will be investigated. The experimental results will be introduced in a model applicable to natural and engineered systems. The project will improve basic understanding of gravity-driven aggregation and sedimentation occurring in natural surface- and ground water environments, including chemical cycling, particulate dynamics, and contaminant redemption. ***