Equilibria and kinetics of copper sorption and its effects on flocculation of colloidal oxide particles

A comprehensive experimental and modeling study of metal sorption by colloidal oxide particles, and its effects on particle flocculation behavior, is carried out in this research. The primary objective of this work is to obtain a fundamental understanding of the influence of metal sorption on surface charge, electrophoretic mobility, and flocculation behavior of inorganic colloidal particles in natural and treatment systems. These goals are addressed by (i) experimentally studying the equilibrium and dynamics of copper uptake by ferric oxide and silica particles, under various surface and solution chemistries, and (ii) adopting an extensive sorption modeling approach based on surface complexation concepts to predict copper sorption and its effects on the surface electrostatic potential of the oxide colloids. Changes in the size distribution of the colloids are experimentally studied to better understand floe formation and breakage during copper sorption.