Quantitative Model of Coagulation with Inorganic Polymer Flocculant PACl: Application of the PCNM

In this paper, a quantitative model of coagulation with inorganic polymer flocculants (IPFs) was investigated, using polyauminum chloride (PACl) as an example. Application of a modified precipitation charge-neutralization model (M-PCNM) was examined and discussed, including variation of dose, pH, and B value on the resulting coagulation diagram. The model was modified by using measured Al fractions as model inputs. The experimental results show that there exists a remarkable difference in coagulation with various PACl formulations in accordance with the different species being preformed. This indicates that the assumption of all the surface species consisting of the same aluminum hydroxide solids is not correct, and some modification of the PCNM is therefore needed. By invoking different final hydroxide precipitates, the M-PCNM can be used quite well to predict the general behavior of coagulation with IPF-PACl.