3.2.1. Adsorption of 2-chlorophenol
Preliminary adsorption experiments revealed that in the
absence of TiO
, no noticeable change in 2-CP concentration
occurred during a 30-min experimental period. Adsorption of 2-CP
using all synthesised N-doped TiO
2
was evaluated, and the highest
concentrations of adsorbed 2-CP on different types of TiO
2
surfaces
were determined. Results of this experiment are shown in
Fig. 7. The contact time to reach equilibrium was approximately
5minforun-dopedTiO
2
, TiO
2
/TEN and TiO
/urea. Roughly, 20 min
was required for TiO
2
2
/DEA to reach equilibrium. Equilibrium concentrations
of 2-CP in aqueous solution after treatment with all
four types of N-doped TiO
were not significantly different. In all
cases, Degussa P-25 TiO
2
2
powder provided the highest adsorption
of 2-CP onto the titania surface owing to its highest surface area,
55 m
2
/g compared to a range of 9–12 m
2
/g for other types of Ndoped
TiO
. The adsorbed 2-CP under equilibrium conditions using
N-doped TiO
2
2
ranged from 7 to 9 mg 2-CP/g TiO
or approximately
28% removals.
2
2