Pa i ADDIS ABABA UNIVERSITY ADDIS ABABA INSTITUTE OF TECHNOLOGY (AAiT) SCHOOL OF CHEMICAL AND BIOENGINEERING ENVIRONMENTAL ENGINEERING POST GRADUATE PROGRAM M.Sc. Thesis on: Comparative Study on Biogas Production Potential of Sewage, Slaughterhouse, Fruit-Vegetable Wastes and their Co-digestion A Thesis Submitted in Partial Fulfillment of the Requirements for the Award of a Master’s Degree in Chemical Engineering under Environmental Engineering stream. By: Alemu Gizaw Wakene Advisor: Dr.Ing. Zebene Kiflie July, 2016 Addis Ababa , Ethiopia