experimental results which indicated the occurrence of parti-The paper examines the behavior of particle detachment in deep cle detachment and the dependence of particle detachment bed filtration and the dependence of particle detachment on sevon particle size.
eral filtration operating parameters. Theoretical analysis was car-
The reason for particle detachment in filtration was exried out by considering the balance of various relevant interaction plained either as a result of the flow shear forces overcoming forces. Based on the results, experiments were conducted to study the attachment forces (4) or instabilities caused by arriving the effect of particle size, filter grain size, and headloss gradient particles (5). Even without a consensus on this problem, it on particle detachment in deep bed filtration. In one set of experiwas generally believed that increases in interstitial velocity ments, the filter was operated at constant filtration rate in order due to the build up of deposit was instrumental in particle to build up the headloss across the filter bed continuously. In the other set of experiments, the filter in operation was allowed to detachment. Mints (8) described particle detachment as beexperience a short period of flow shock (i.e., to be subject to a ing directly proportional to the specific deposit. Others (9, higher flow rate during this period). Both sets of experiments 10) assumed that particle detachment was directly proporconfirmed the dependence of particle detachment on particle size, tional to the product of the hydraulic gradient and the specific collector gain size, and headloss gradient (degree of filter clogging) deposit. As particles retained in a filter are subject to drag of the filter, as predicted by the analysis.