Optimization of Parameters Responsible for the Rate of Gas Generation Through Mixed Anaerobic Digestion

A key source of renewable energy, biogas (methane) was generated in the anaerobic mixed digestion of floral waste along with the combinations of other substrates. The present study has focused on the treatment of floral waste by anaerobic mix digestion along with co wastes named as canteen waste (CW), dairy waste (DW), and yard waste (YW) by using cow dung (CW) and sewage sludge (SS)as an inoculum. The concept of mixed digestion is used in this work by using different substrates with the main substrate as floral waste. The substrates are added with co substrates in a ratio of 2:1. Three types of comparative studies are carried out by making different combinations of substrates by keeping floral waste common in every combination. Different parameters responsible for the quantity of methane gas resulting from anaerobic digestion are optimized using design expert software's response surface methodology (RSM). A specially designed laboratory-scale model is used which is attached with a biogas analyser to continuously measure and analyse the generated biogas. A total of 45 experiments were carried out on the predicted conditions for different combinations. Parameters such as pH, temperature, and food to microorganism ratio have been chosen as independent variables. Daily biogas generation and cumulative biogas generation were recorded. COD removal efficiency recorded after eight days was in the range of 75–85%. Good interactions have been occurred among the independent variables chosen for the generation of biogas. Highest results were observed at optimum conditions (with pH = 7.2, F/M ratio = 2, T = 37°C). The cumulative biogas yield resulting from an experiment was 7.2L/kg VS. The average VS removal of 62–73% and TS removal of 45–55 % were recorded.

---

Opracowanie rekordu ze środków MNiSW, umowa nr POPUL/SP/0154/2024/02 w ramach programu "Społeczna odpowiedzialność nauki II" - moduł: Popularyzacja nauki (2025).