2.4. Statistical tests
In order to investigate statistically significant differences, a
one-way between groups analysis of variance (ANOVA) at 95% significance
level was used to examine the effect of various design andoperation parameters on VFCW performance. ANOVA was applied for the comparison of effluent concentrations and areal load reduction
of each unit. Post Hoc pair comparisons were also performed
to test equal variations, using Tukey honestly significant difference
test. Homogeneity of variance tests (Levene) were bypassed, since
the number of data points for each group was the same. Statistical
analyses were performed using SPSS Statistics 17.0 for Windows.