2.7. Removal of phenol compounds
Studies in removal of phenol and p-chlorophenol were performed
at 25 C with laccase-immobilized particles in phosphate
buffer (0.1 M, pH 6.0) with shaking at 100 rpm. In each set of the
experiment, 3.0 mg of the immobilized laccase was added into
10 ml reaction medium with 2 mM phenol and p-chlorophenol,
with incubation time lasting for 12 h. Before reaction initiation,
the solution of buffer and phenols was saturated with oxygen by
vigorously shaking for 15 min. The percentage of phenol and
p-chlorophenol removal was determined at different intervals by
separating the upper solution with magnetism, and then the residual
concentration of phenol and p-chlorophenol was determined
using a UV–vis spectrophotometer at 270 nm and 279 nm, respectively
(Wu and Yu, 2006). To determine how carrier adsorption affected removal efficiency of phenol and p-chlorophenol, the heatdenatured
immobilized enzyme was used in place of the intact
immobilized laccase under the same experimental condition.