Experimental Study of Co-digestion of Wastewater Treatment Plant Sludge and Plate Scrap to Increase Biogas Yield

Co-digestion of Wastewater Treatment Plant Sludge and Plate Scrap to Increase Biogas Yield

Abstract

This study aims to find the maximum yield of biogas by combining wastewater treatment plant sludge (WTPS) and plate scraps (PS) from Adama Science and Technology University (ASTU) student canteen. Feedstock characterization and biogas co-generation were performed using different Combinations of Plate Scrap, Wastewater Treatment Plant Sludge, and cow manure in varying ratios. The individual feedstocks were evaluated for their Total solid (TS) and Moisture content (MC) before the prepared feedstock combination, and also measured combined TS, VS, Total dissolved solid (TDS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), and P^H   after combination of all feedstock. These experiments were conducted in two rounds using three water baths and twenty-seven Batch Reactors (BR) with a 2.5 L volume each. These experiments were conducted in Adama Science and Technology University, Chemical Engineering Department at Adama, Ethiopia, to identify the biogas potential of the above-stated feedstocks. The experimental results noted that the maximum daily and total biogas yields were obtained on a composition ratio of 75% PS and 25% WTPS reactors. The daily maximum and average biogas yields were 220 and 810 ml, respectively.  The average methane composition produced inside biogas was 57 %. The results of a combination of 75% PSI and 25% WTPS have shown the highest biogas yield