Enhancing acid orange II degradation in ozonation processes with CaFe2O4 nanoparticles as a heterogeneous catalyst
Lương Thị Quỳnh Nga, , , , , , Sep-2023, In: RSC Advances, 13, p. 28753-28766
, Overview
Abstract:
This study used CaFe2O4 nanoparticles as a catalyst for ozonation processes to degrade Acid Orange II
(AOII) in aqueous solution. The study compared heterogeneous catalytic ozonation (CaFe2O4/O3) with
ozone treatment alone (O3) at different pH values (3–11), catalyst dosages (0.25–2.0 g L−1
), and initial
AOII concentrations (100–500 mg L−1
). The O3 alone and CaFe2O4/O3 systems nearly completely
removed AOII's color. In the first 5 min, O3 alone had a color removal efficiency of 75.66%, rising to 92%
in 10 min, whereas the CaFe2O4/O3 system had 81.49%, 94%, and 98% after 5, 10, and 20 min,
respectively. The O3 and CaFe2O4/O3 systems degrade TOC most efficiently at pH 9 and better with
1.0 g per L CaFe2O4. TOC removal effectiveness reduced from 85% to 62% when the initial AOII
concentration increased from 100 to 500 mg L−1
. The study of degradation kinetics reveals a pseudofirst-order reaction mechanism significantly as the solution pH increased from 3 to 9. Compared to the
O3 alone system, the CaFe2O4/O3 system has higher k values. At pH 9, the k value for the CaFe2O4/O3
system is 1.83 times higher than that of the O3 alone system. Moreover, increasing AOII concentration
from 100 mg L−1 to 500 mg L−1 subsequently caused a decline in the k values. The experimental data
match pseudo-first-order kinetics, as shown by R2 values of 0.95–0.99. AOII degradation involves
absorption, ozone activation, and reactive species production based on the existence of CaO and FeO in
the CaFe2O4 nanocatalyst. This catalyst can be effectively recycled multiple times.
Pages (from-to) | 28753-28766 |
Journal | RSC Advances |
Volume | 13 |
Publication status | Published - Sep-2023 |
ISBN | 2046-2069 |