A batch test was done to study the effect of anaerobic mono-digestion of sludge and pretreatment on the 
sludge properties like viscosity and total organic carbon removal. After the Biome thane potential test of the first 
and second sets ended, samples of an aerobically digested sludge were analyzed for TOC removal. Set one and set 
two ended after 22 days. Set 1 shows that the best TOC removal was caused for the concentration of 11% for the 
pretreated and blank reactors and it was 33.92% and 27.25% respectively. The minimum removal ratio occurred at 
16% concentration for the pretreated and blank reactors. Set 2 shows that the best TOC removal was caused for the 
reactor at a pre-treatment temperature of 180℃ and it was 35.83% and which was higher than the removal of the 
blank reactor which was 27.50%. The maximum biogas produced was 2475 ml at 11% TS with an improvement of 
55.56% and in terms of TOC removed, it was 189.19 mLbiogas/gTOCremoved. In set 2, The maximum Biogas 
produced was 3645 ml at 11% TS with an improvement of 60.57% and pretreatment temperature of 180℃ and in 
terms of TOC removed, it was 169.53 mLbiogas/gTOCremoved. Sludge viscosity is enhanced after thermal 
pretreatment and improved the mixing of the high solid sludge