Moreover, the effects of the degree of deacetylation in
chitin and chitosan on SRDW adsorption at 0.5% (w/v) and
1.0% (w/v) dosage under acidic conditions are shown in Table
1. Chitin (48%DD) and chitosan (90%DD), at a dosage
of 0.5% (w/v), removed 64 and 82% of the SRDW, while the
system pH of chitin and chitosan was 1.90 and 2.47, respectively.
Furthermore, the SRDW was removed by 82 and 85%
chitin (48%DD) and chitosan (90%DD), at a dosage of 1.0%
(w/v), respectively, while the system pH of chitin and chitosan
was 2.06 and 6.43, respectively. In addition, chitin had
only 48% amine groups, while chitosan had 90%. Therefore,
chitosan at a dosage of 1.0% could adsorb more SRDW than
chitin and the initial pH changed from 2.11 to 6.43, whereas
chitosan at a dosage of 0.5% slightly changed the initial pH
from 2.11 to 2.47. This result indicated that the increase of
SRDW adsorption under acidic conditions was followed by
the increase of amine groups in the chitosan polymer.