2.6 Photoinduced degradation of 2,4-D in presence of goethite,
fluoride, and bicarbonate at natural concentrations by
H2O2 addition. Factorial experimental
design 22
The photoinduced experiments were carried out according to previous work
reported by GutiƩrrez-Zapata et al, and following the methodology
described in section 2.4. A factorial experimental design
22 was used to study the significant influence of two
experimental factors: (A) F- and (B)
HCO3- concentrations, evaluated in two
levels low (-) and high (+) which are often found in natural well waters
on the degradation of 2,4-D pesticide in presence of natural goethite
concentrations (0.3 mg L-1; 0.2 mg
L-1 of total iron) and
H2O2 (10 mg L-1) at pH
6.9. The experimental matrix is presented in table 1 and additionally,
control experiments such as dark reactions (Fenton), 2,4-D photolysis,
and sunlight H2O2-photolysis were also
performed. Results were analyzed by using variance analysis (ANOVA) and
response surface plots obtained by STATGRAPHICS centurion XVI Software.