sample by measuring their absorbance at 260 nm (A260). The
results shown in Fig. 1 describe the effectiveness of PAC with two
other coagulants, aluminum sulfate (AS) and ferric chloride (FC). It
was found that PAC is an effective coagulant because the removal
efficiency is higher than the two other coagulants used. PAC also
showed comparatively higher removal efficiency even at a low
dosage compared with FC. These results were obtained because
PAC has large molecular weight, and therefore, it produces a huge
amount of aluminum hydroxides which is the origin of the
flocks.
In addition, the alkali consumption of PAC was small compared
with AS and FC. From these results, it can be said that PAC is a
suitable coagulant for the removal of HA.