It can be observed
that initial small concentration increases of H
2
2
O
could enhance
the rate of AO7 removal; however, when increased above 5 mM,
the rate of AO7 removal did not improve further and even
decreased slightly (the value of k
AO7
2
of the reaction reduced from
0.515 to 0.495 min
1
upon increasing the H
2
O
content from
5 mM to 10 mM). This decrease in k
AO7
2
at high concentrations of
H
2
O
was mainly caused by the scavenging effect of excessive
H
2
O
2
2
to
OH [31]. Thus, the use of higher amounts of H
can lead
to a lower H
2
O
2
utilization efficiency (Fig. 7, X
). Conversely, a
higher H
2
O
2
2
O
2
consumption index (X
2
O
2
H2O2
and (b) rate constant for H
). (C
cat
=2gL
H2O2
1
= 5 mM,
T =50C and pH 3).
utilization efficiency can be achieved by reducing
the concentration.