Parameter P1 P2 Optimum Condition Aeration F1 93.993 94.581 1(aeration) Humidity (ml) F2 0.999 0.949 1 Glucose (gr) F3 1.452 1.404 0.01 Bacteria (ml) F4 1.112 1.062 0.02 Composting (gr) F5 0.053 ----- 0.01 Temp.(0C) F6 0.281 ----- 35 Salt (gr) F7 0.000 ----- 0.01 Urea (gr) F8 1.206 1.157 0.01 Other error 0.904 0.847 ------ Oil removal percent in optimum conditions 64.4%

Table 7: The effect percent of each factor (P1), effect percent of more important parameters (P2) and optimum conditions for set 1, determined by the analysis of variance (ANOVA).