An Insight into the Anaerobic Co-digestion of Municipal Solid Waste and Food Waste: Influence of Co-substrate Mixture Ratio and Substrate to Inoculum Ratio on Biogas Production
- 106 Downloads
The unbalanced nutrients of municipal solid waste (MSW), particularly high carbon contents, were regarded as a major limiting factor to anaerobic digestion process. In this study, the addition of MSW in food waste (FW) feedstock to have a balanced C/N ratio was studied. Different co-substrate mixtures with C/N ratio of 20 to 40 were subjected to anaerobic batch experiment at lab scale, under mesophilic conditions. The biogas production decreased with the increase in C/N ratio due to insufficient availability of organic nitrogen for anaerobic microbial growth. Specific biogas and methane yields were observed to be 827 and 474.44 mL g−1VS, respectively, with volatile solids (VS) reduction rate of 88%, at C/N ratio of 20. Furthermore, the effect of the substrate to inoculum (S/I) ratio on digester performance was also studied. The biogas production decreased with the increase in S/I ratio due to the formation of more volatile fatty acids (VFAs) which led to decrease in pH and accumulated unionized ammonia-N. Specific biogas and methane yields were recorded to be 655 and 410.20 mL g−1VS, with 64% rate of biodegradability at S/I ratio of 0.5. Kinetics and statistics study showed that the higher S/I ratio could lead to VFA accumulation and result in low methane yield.
KeywordsAnaerobic co-digestion Municipal solid waste Food waste Biogas production C/N ratio
This study received funding from the National “Twelfth Five-Year” plan for Science and Technology Support (2014BAC24BO1-02) and the National “Twelfth-Five Year” plan for Science and Technology Support (2015BAD21B03).
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflicts of interest.
- 1.Tanimu, M. I., Ghazi, T. I. M., Harun, R. M., & Idris, A. (2014). Effect of carbon to nitrogen ratio of food waste on biogas methane production in a batch mesophilic anaerobic digester. International Journal of Innovation, Management and Technology, 5, 116.Google Scholar
- 2.Lebiocka, M., & Piotrowicz, A. (2012). Co-digestion of sewage sludge and organic fraction of municipal solid waste. A comparison between laboratory and technical scales. Environment Protection Engineering, 38, 157–162.Google Scholar
- 5.Sreekrishnan, T., Kohli, S., & Rana, V. (2004). Enhancement of biogas production from solid substrates using different techniques - A Review. Bioresource Technology, 95, 1–10.Google Scholar
- 7.Chen, X., Pang, Y., Zou, D., Yuan, H., Liu, Y., Zhu, B., & Li, X. (2014). Optimizing acidogenic process for achieving high biomethane yield from anaerobic co-digestion of food waste and rice straw using response surface methodology. Journal of Biobased Materials and Bioenergy, 8(5), 512–518.CrossRefGoogle Scholar
- 14.Martínez, M., Driller, L., Chamy, R., Schuch, W., Nogueira, M., & Fraser, P. (2016). In biogas potential of residues generated by the tomato processing industry under different substrate and inoculum conditions. XIV International Symposium on Processing Tomato, 1159, 151–158.Google Scholar
- 16.APHA, A. W., (1998). American Public Health Association/American Water Works Association/Water Environment Federation, Washington DC.Google Scholar
- 17.Van Soest, P. V., Robertson, J., & Lewis, B. (1991). Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. Journal of Dairy Science, 74(10), 3583–3597.Google Scholar
- 20.De Mes, T., Stams, A., Reith, J., Zeeman, G., (2003). Methane production by anaerobic digestion of wastewater and solid wastes. Bio-Methane Bio-Hydrogen, 58–102.Google Scholar
- 23.Heo, N. H., Park, S. C., & Kang, H. (2004). Effects of mixture ratio and hydraulic retention time on singlestage anaerobic co-digestion of food waste and waste activated sludge. Journal of Environmental Science and Health, Part A Environmental Science, 39, 1739–1756.Google Scholar
- 30.Jaffar, M., Pang, Y., Yuan, H., Zou, D., Liu, Y., Zhu, B., Korai, R. M., & Li, X. (2016). Wheat straw pretreatment with KOH for enhancing biomethane production and fertilizer value in anaerobic digestion. Chinese Journal of Chemical Engineering, 24, 404–409.Google Scholar
- 31.Li, H., Guo, X., Cao, F., & Wang, Y. (2014). Process evolution of dry anaerobic co-digestion of cattle manure with kitchen waste. Chemical and Biochemical Engineering Quarterly, 28, 161–166.Google Scholar
- 33.Yoon, Y. M., Kim, S. H., Shin, K. S., & Kim, C. H. (2014). Effects of substrate to inoculum ratio on the biochemical methane potential of piggery slaughterhouse wastes. Asian-Australasian Journal of Animal Sciences, 27, 600.Google Scholar
- 38.Fernandez, B., Porrier, P., & Chamy, R. (2001). Effect of inoculum-substrate ratio on the start-up of solid waste anaerobic digesters. Water Science and Technology, 44, 103–108.Google Scholar