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

Articles in Press

Document Type : Research Article- En

Authors

W. Asrat ¹

K. Purushottam Kolhe ²

¹ Department of Mechanical Engineering, School of Mechanical, Chemical and Materials Engineering at Adama Science and Technology University, Adama, Ethiopia

² Department of Mechanical Engineering, Sinhgad College of Engineering, Vadgaon (BK.), Pune-411041, Pune University, India

https://doi.org/10.22067/jam.2025.92821.1363

Abstract

This research seeks to determine the highest possible yield by integrating wastewater treatment plant sludge with food waste from plate scraps at Adama Science and Technology University (ASTU) in Ethiopia. Feedstock characterization and biogas co-generation were done on different Plate Scrap (PS), Wastewater Treatment Plant Sludge (WTPS), and 100 ml cow manure combination ratios. The feedstocks were evaluated for their TS and MC before combination, and TS, VS, TDS, COD, BOD, and pH after combination. This experiment was done in two rounds using three water baths and twenty-seven Batch Reactors (BR) with 2.5 L volume each. In the first round, eighteen reactors were used, and nine were used in the second experiment. Triplicate testing was used to evaluate the feedstock sample characteristics and to run the experiment. The reactors were operated for thirty-five days at a hydraulic retention time and a temperature of 50 °C. The daily biogas yield using the water displacement method, total biogas yield, and methane composition were measured and reported. Three sub-reactors were considered to find the average biogas yield of individual reactors. A notable increase in both daily and total biogas yield was observed with the reactor composition of 75% PS Injera (PSI) flat bread and 25% WTPS. The daily maximum and the average biogas yields were 220 mL and 810 mL, with the TS of 55,066 mg L^-1 and the VS of 51,000 mg L^-1. The maximum methane inside the produced biogas was 68%, from PSI75% and WTPS25%. This combination also showed the highest biogas yield.

Keywords

Anaerobic Digestion (AD)

Biogas yield

Co-generation

PS

WTPS

Subjects

• Sustainability and Circular Bioeconomy, and Environmental Resilience

---

Authors retain the copyright. This is an open access article distributed under Creative Commons Attribution 4.0 International License (CC BY 4.0)

References

1. APHA. (2005). Standard Methods for the Examination of Water and Wastewater. 21st Edition, American Public Health Association/American Water Works Association/Water Environment Federation, Washington DC.
2. Azadbakht, M., & Safieddin Ardebili, S. M. (2024). A study on generating bioelectricity from urban waste, A case study of Golestan, Iran. CIGR Journal, 26(4), 117-128
3. Azadbakht, M., Safieddin Ardebili, S. M., & Rahmani, M. (2023). Potential for the production of biofuels from agricultural waste, livestock, and slaughterhouse waste in Golestan province, Iran. Biomass Conversion and Biorefinery, 13(4), 3123-3133. https://doi.org/10.1007/s13399-021-01308-0
4. Benti, N. E., Gurmesa, G. S., Argaw, T., Aneseyee, A. B., Gunta, S., Kassahun, G. B., Aga, G. S., & Asfaw, A. A. (2021). The current status, challenges and prospects of using biomass energy in Ethiopia. Biotechnology for Biofuels, 14(1), 1-25. https://doi.org/10.1186/s13068-021-02060-3
5. Cheong, W. L., Chan, Y. J., Tiong, T. J., Chong, W. C., Kiatkittipong, W., Kiatkittipong, K., Mohamad, M., Daud, H., Suryawan, I. W. K., Sari, M. M., & Lim, J. W. (2022). Anaerobic Co-Digestion of Food Waste with Sewage Sludge: Simulation and Optimization for Maximum Biogas Production. Water (Switzerland), 14(7), 1-21. https://doi.org/10.3390/w14071075
6. Deepanraj, B., Sivasubramanian, V., & Jayaraj, S. (2017). Effect of substrate pretreatment on biogas production through anaerobic digestion of food waste. International Journal of Hydrogen Energy, 42(42), 26522-26528. https://doi.org/10.1016/j.ijhydene.2017.06.178
7. Ebner, J. H., Labatut, R. A., Lodge, J. S., Williamson, A. A., & Trabold, T. A. (2016). Anaerobic co-digestion of commercial food waste and dairy manure: Characterizing biochemical parameters and synergistic effects. Waste Management, 52, 286-294. https://doi.org/10.1016/j.wasman.2016.03.046
8. Gashaye, D. (2020). Wastewater-irrigated urban vegetable farming in Ethiopia: A review on their potential contamination and health effects. Cogent Food and Agriculture, 6(1). https://doi.org/10.1080/23311932.2020.1772629
9. GIZ. (2020). Partnership Ready Ethiopia: Water supply and wastewater treatment. 8. https://www.giz.de/en/downloads/GBN_Sector Brief_Äthiopien_Water_E_WEB.pdf
10. Haddis, A., de Geyter, A., Smets, I., & Van der Bruggen, B. (2014). Wastewater management in Ethiopian higher learning institutions: functionality, sustainability and policy context. Journal of Environmental Planning and Management, 57(3), 369-383. https://doi.org/10.1080/09640568.2012.745396
11. Indren, M., Birzer, C. H., Kidd, S. P., & Medwell, P. R. (2020). Effect of total solids content on anaerobic digestion of poultry litter with biochar. Journal of Environmental Management, 255, 109744. https://doi.org/10.1016/J.JENVMAN.2019.109744
12. Jayaraj, S., Deepanraj, B., & Velmurugan, S. (2014). Study on the Effect of pH on Biogas Production from Food Waste by Anaerobic Digestion. The International Green Energy Confrence, 5(May), 799-803. https://www.researchgate.net/publication/264545493
13. Kolhe P. (2015). Stability analysis of tractor-mounted hydraulic elevator for horticultural orchards. World Journal of Engineering, 12(5), 479-488. https://doi.org/10.1260/1708-5284.12.5.479
14. Kolhe, K. P., Lemi, D. G., & Busse, S. K. (2024). Studies of tractor maintenance and replacement strategies of Wonji Shoa Sugar Factory, Ethiopia. Journal of Agricultural Engineering, 55(1), 1552-1556. https://doi.org/10.4081/jae.2024.1552
15. Mrosso, R., Mecha, A. C., & Kiplagat, J. (2023). Characterization of kitchen and municipal organic waste for biogas production: Effect of parameters. Heliyon, 9(5), e16360. https://doi.org/10.1016/j.heliyon.2023.e16360
16. Prabhu, M. S., & Mutnuri, S. (2016). Anaerobic co-digestion of sewage sludge and food waste. Waste Management and Research, 34(4), 307-315. https://doi.org/10.1177/0734242X16628976
17. Safieddin Ardebili, S. M., & Khademalrasoul, A. (2018). An analysis of liquid-biofuel production potential from agricultural residues and animal fat (case study: Khuzestan Province). Journal of Cleaner Production, 204, 819-831. https://doi.org/10.1016/j.jclepro.2018.09.031
18. Srisowmeya, G., Chakravarthy, M., & Nandhini Devi, G. (2020). Critical considerations in two-stage anaerobic digestion of food waste– A review. Renewable and Sustainable Energy Reviews, 119, 109587. https://doi.org/10.1016/J.RSER.2019.109587
19. Wang, Z., Hu, Y., Wang, S., Wu, G., & Zhan, X. (2023). A critical review on dry anaerobic digestion of organic waste: Characteristics, operational conditions, and improvement strategies. Renewable and Sustainable Energy Reviews, 176(January), 113208. https://doi.org/10.1016/j.rser.2023.113208
20. Wang, Z., Jiang, Y., Wang, S., Zhang, Y., Hu, Y., Hu, Z. hu, Wu, G., & Zhan, X. (2020). Impact of total solids content on anaerobic co-digestion of pig manure and food waste: Insights into shifting of the methanogenic pathway. Waste Management, 114, 96-106. https://doi.org/10.1016/j.wasman.2020.06.048
21. Zaki Dizaji, H., Haroni, S., Sheikhdavoodi, M. J., Safieddin Ardebili, S. M., González Alriols, M., & Kiani, M. K. D. (2021). An investigation on the environmental impacts and energy efficiency of biogas and bioethanol production from sugarcane and sugar beet molasses: A case study. Energy Sources, Part A: Recovery, Utilization and Environmental Effects, 00(00), 1-15. https://doi.org/10.1080/15567036.2021.1898493
22. Zhao, X. F., Yuan, Y. Q., Chen, Q. K., Li, Q., Huang, Y., Wu, D., & Li, L. (2021). Effect of total solids contents on the performance of anaerobic digester treating food waste and kinetics evaluation. E3S Web of Conferences, 272, 1-8. https://doi.org/10.1051/e3sconf/202127201026