Treatment sample Contact time with H2O2 min pH H2O2 added (%of sludge weight)
O* O --- 8.04 0
P P1 P3 60 180 7.97 8.09 55
R R1 R3 60 180 3.34 3.32 5 5
Q Q1Q3 60 180 2.02 2.06 55

*O= control (no treatment); P = addition ofH2O2 alone; R= classic Fenton’s treatment; Q = proposed modified Fenton’s treatment.
Table 3: Experimental design with treatments and values of pH and added H2O2.