2.3 Sludge pre-treatment
The feedstocks were subjected to combined microwave and hydrogen
peroxide treatment. The sludge was initially heated at 80 °C by
microwave irradiation at 660 W for 2 minutes to curtail catalase
activity in the microbial fraction of MWAS; catalase breaks down
H2O2 into water and molecular oxygen
inhibiting the oxidative effect of pre-treatment 24.
Followed by, the addition of hydrogen peroxide (1% w/w
H2O2/TS) at room temperature with
constant mixing. The sludge was again microwave irradiated at 660W for 3
minutes in a laboratory-scale microwave oven, with an intermittent break
to avoid water evaporation. The treated and untreated mixed sludge
samples were inoculated with 10% DS making up to an operating volume of
500 ml.