Plackett-Burman Fractional Factorial Design -Application to Decolorization of Treatet Distillery Wastewater

Eight parameters were screened by a three sequntial Plachet- Burman design, consisting a total of 12 experiments in the first part and eight experiment in the second and third part for their effect on decolorization efficiency of the treated distillery wastewater by a locally isolated efficient Aspergillus species. Wight parameters screened were, maltose, pH, Cell mass, NaNO3, glycerol, KH2PO4, MnSO4, and indol.In the first part of experiments indol having largest negative magnitude effect (-14.47) it was omitted from the decolorization medium. In the second design MnSO4 had the largest magnitude effect )-20.26) and was omitted from the decolorization culture medium. NaNO3 Cell mass and KH2PO4 had low magnitude effect (-0.31, -2.06 and -2.74 respectively) and were fixed at their mid point of low and high levels. The third design was carried out with three factors namely maltose concentration, glycerol and pH and their magnitude effect were -2.64, 7.05 and 0.99. The average decolorization effisincy of the three run were increased from 14.47 in the first design to 23.21 in the second design and to 45.44 in the third design.