Particle Deposition and Aggregation

Particle Deposition and Aggregation: Measurement, Modelling and Simulation describes how particle deposition and aggregation can be measured, modeled, and simulated in a systematic manner. It brings together the necessary disciplines of colloid and surface chemistry, hydrodynamics, experimental methods, and computational methods to present a unified approach to this problem. The book is divided into four parts. Part I presents the theoretical principles governing deposition and aggregation phenomena, including a discussion of the forces that exist between particles and the hydrodynamic factors that control the movement of the particles and suspending fluid. Part II introduces methods for modeling the processes, first at a simple level (e.g. single particle-surface, single particle-single particle interactions in model flow conditions) and then describes the simulation protocols and computation tools which may be employed to describe more complex (multiple-particle interaction) systems. Part III summarizes the experimental methods of quantifying aggregating and depositing systems and concludes with a comparison of experimental results with those predicted using simple theoretical predictions. Part IV is largely based on illustrative examples to demonstrate the application of simulation and modeling methods to particle filtration, aggregation, and transport processes. This book should be useful to graduates working in process and environmental engineering research or industrial development at a postgraduate level, and to scientists who wish to extend their knowledge into more realistic process conditions in which the fluid hydrodynamics and other complicating factors must be accommodated.

Preface Part I: Theoretical Analysis of Deposition and Aggregation Phenomena 1 Introduction 2 Electrical Properties of Interfaces 2.1 Introduction 2.2 The electrical double layer 2.3 Electrokinetic phenomena Bibliography References 3 Surface Interaction Potentials 3.1 Introduction 3.2 Double layer interaction between macroscopic bodies 3.3 Van der Waals interaction 3.4 Non-DLVO forces 3.5 DLVO description of colloidal stability Bibliography References 4 Colloidal Hydrodynamics and Transport 4.1 Basic concepts in fluid and particle dynamics 4.2 Brownian motion and diffusion 4.3 Motion of a single sphere 4.4 Relative motion of two spheres 4.5 Concentration dependence of diffusion coefficients 4.6 Quantitative description of deposition phenomena Bibliography References Part II: Modeling and Simulation 5 Modeling of Particle Deposition onto Ideal Collectors 5.1 Rotating disc system 5.2 Stagnation-point flow 5.3 Parallel-plate channel 5.4 Spherical collector 5.5 Interaction-force boundary-layer approximation 5.6 Trajectory analysis 5.7 Representative simulations of particle deposition Bibliography References 6 Modeling of Aggregation Processes 6.1 Collisions and aggregation: the Smoluchowski approach 6.2 Collision mechanisms 6.3 Collision efficiencies 6.4 Form of aggregates 6.5 Aggregate strength and break up 6.6 Aggregate size 6.7 Flocculation by polymers Bibliography References 7 Selection of a Simulation Method 7.1 Overview of simulation protocol 7.2 Useful concepts in statistical mechanics 7.3 Monte Carlo methods 7.4 Molecular dynamics methods 7.5 Brownian dynamics methods Bibliography References 8 Implementation of Computer Simulations 8.1 Pair potential models 8.2 Periodic boundary conditions 8.3 Generating random numbers 8.4 Example: implementation of Metropolis MC simulation 8.5 Computer hardware 8.6 Visualization of simulation results 8.7 Appendices Bibliography References Part III: Experimental Methods and Model Validation Techniques 9 Experimental Techniques For Aggregation Studies 9.1 General: choice of technique 9.3 Light-scattering methods 9.4 Other optical methods 9.5 Aggregate properties Bibliography References 10 Experimental Techniques in Particle Deposition Kinetics 10.1 System requirements 10.2 Particle counting methods 10.3 Model deposition systems 10.4 Determination of experimental collision efficiencies Bibliography References 11 Theoretical Predictions Compared to Experimental Observations in Particle Deposition Kinetics 11.1 Deposition with repulsive double layers 11.2 Deposition in the presence of attractive double layers 11.3 Possible explanations for observed discrepancies in unfavorable deposition 11.4 A Semi-empirical approach for predicting collision efficiencies Bibliography References Part IV: Applications and Limitations of Predictive Modeling 12 Performance Of Packed Bed-Filters 12.1 Particle removal mechanisms 12.2 Modeling of particle removal in granular filtration 12.3 Predictions of filter performance Bibliography References 13 Transport of Colloidal Materials in Ground Water 13.1 Transport of viruses in soils and ground water 13.