Transient behavior of polymer-induced flocculation: effect of dosing mechanism
Journal
Journal of the Chinese Institute of Chemical Engineers
Journal Volume
29
Journal Issue
3
Pages
219-228
Date Issued
1998
Author(s)
Lin D.-P.
Abstract
The aggregation of dispersed colloidal particles induced by tye introduction of polymer is modeled theoretically. In particular, the effect of the dosing mechanism of polymer on the transient behavior of the system under consideration is examined. Both continuous dosing in a certain time interval and intermittent dosing mechanisms are considered. We conclude that the longer the dosing period for the former, the broader the distribution of collision efficiency E as a function of time. This is advantageous to floc formation. The distribution of E for the case of an intermittent dosing is broader than that for the case of a continuous dosing. The former yields a larger mean floc size. For a fixed amount of polymer added, a continuous dosing is superior than an impulse dosing initially. However, if the contribution of aggregation to the mean fractional surface coverage of particles is negligible, the reverse is true.The aggregation of dispersed colloidal particles induced by the introduction of polymer is modeled theoretically. In particular, the effect of the dosing mechanism of polymer on the transient behavior of the system under consideration is examined. Both continuous dosing in a certain time interval and intermittent dosing mechanisms are considered. We conclude that the longer the dosing period for the former, the broader the distribution of collision efficiency E as a function of time. This is advantageous to floc formation. The distribution of E for the case of an intermittent dosing is broader than that for the case of a continuous dosing. The former yields a larger mean floc size. For a fixed amount of polymer added, a continuous dosing is superior than an impulse dosing initially. However, if the contribution of aggregation to the mean fractional surface coverage of particles is negligible, the reverse is true.
Type
journal article