Bentonite was used as a coagulant aid to investigate the effect of
particles in order to clarify the role of CaCO3 on coagulation of HA
using PAC. PAC coagulated both positively charged CaCO3 and
negatively charged bentonite suspended in distilled water. CaCO3
added into HA solution coagulated with PAC formed large
flocks
and precipitated rapidly. On the other hand,
flocculation did not
occur for bentonite in the existing HA, and therefore, no