Colloid attachment
and detachment behaviors concern a wide range
of environmental contexts but have typically been mechanistically
predicted exclusive of one another despite their obvious coupling.
Furthermore, previous mechanistic prediction often addressed packed
column contexts, wherein specific forces and torques on the colloid
could not be well-constrained, preventing robust predictions. These
weaknesses were addressed through direct observation experiments under
conditions where perfect sink assumptions fail and allow calibration
of the contact between the colloid and collector. Attachment and flow
perturbation experiments in the presence of colloid–collector
attraction (favorable conditions) permitted calibration of contact
parameters without the complexity that comes with colloid–collector
repulsion (unfavorable conditions). Combining calibrated contact parameters
with discrete representative nanoscale heterogeneity, developed to
predict unfavorable attachment, provided an independent means to predict
unfavorable detachment. The result was mechanistic prediction of colloid
attachment and detachment that quantitatively agreed with experimental
observation for both ionic strength and flow perturbation results,
improving significantly upon previous qualitative prediction.