Analysis of pollutants removal
The determinations of pollution parameters including colour
and COD were accomplished at the beginning and at the end
of each run, in agreement with the methodology described
by APHA (2000). The percent reductions of these parameters
were calculated by the equation:
Parameter reduction ð%Þ ¼ xi xf=xf 100 being :
xi =Parameter before the biomass growth and xf= Parameter
after the biomass growth. The results of colour and COD
removal of the CCD runs were analyzed statistically through
the analysis of variance (ANOVAs) at 95% confidence interval
and response surface methodology.