Effect of Biological Pretreatment on Anaerobic Sewage Sludge Digestion: Using Growth Media for Methanogenic Bacteria and Kinetic Studies for Biogas Yield

Abstract

The valorization of sewage sludge, a by-product of wastewater treatment by anaerobic digestion (AD), is getting more attention as a result of the advantages it provides for the environment and economy. The current investigation is an experiment performed in a lab setting using a batch-operated anaerobic digestion reactor with a mesophilic temperature of 35°C. This study examined the generation of experimental biogas and biodegradability .The effect of pretreatment by methanogenic bacteria growth medium on anaerobic digestion of sewage sludge was studied on three different concentrations of growth media, a control, and a low, medium and high concentration of culture medium, with cumulative biogas production of 610N ml /gVS added, 750 N ml /gVS added, 900 N ml /gVS added, 10 N ml /gVS added, respectively, with biodegradability rate of 52.16%, 56.5%, 74.04%, 28.70% respectively. Biogas production was enhanced at a medium concentration of culture medium and inhibited at a high concentration during anaerobic digestion of sewage sludge. Additionally, a theoretical biogas estimate was evaluated using four kinetic models (Logistic function, Modified Gompertz, Transference function, and First order); which were utilized to match the experimental biogas generation process involving the anaerobic digestion of untreated and pretreated sewage sludge by various concentrations of growth media of methanogenic bacteria . The kinetic findings demonstrated that both models, Modified Gompertz and Logistic function, were useful for predicting biogas output and matched experimental biogas production.