As global populations grow, the generation of various waste materials like fats, oils, and grease (FOG), fruit waste, and other perishable wastes increases concurrently. Disposal of these highly putrescible waste products in landfills consumes valuable landfill space. Anaerobic digestion can transform these waste materials into valuable components, including fertilizer and biogas, reducing the demand for landfill space. The current study is based on the hypothesis that incorporating high-strength organic waste into conventional wastewater sludge can enhance the production of onsite biogas at wastewater treatment plants, therefore contributing to the reduction of the plant’s energy demands from the grid. The batch anaerobic biodegradability test assays were performed for 63 days to observe the impact on the biomethane yield from adding high-strength organic waste to the wastewater sludge and to investigate the combined effects of co-digesting two different preselected high-strength organic waste streams. Additionally, physicochemical characterization was performed on different fruit waste juicing residuals to indicate which fruit wastes might increase anaerobic digestion efficiency. The highest methane yield of 243 mL/gVS and 280 mL/gVS, respectively, were obtained with two mixtures having 10% FOG as the sole substrate and 10% FOG along with 10% fruit waste. The study also assessed the siloxane concentrations present as trace contaminants in the biogas samples. An initial economic feasibility assessment of food waste co-digestion at two wastewater treatment plants in Florida was conducted using the Co-Digestion Economic Analysis Tool (CoEAT) model. Based on the laboratory results, the analysis indicated a net positive benefit of $39,472 for a medium-sized plant (10 - 30 MGD capacity) and $52,488 for a larger plant (>30 MGD capacity) after 15 years, while diverting 10 - 18 tons/day of food waste from landfills with an anticipated minimal increase in sludge volume production at food waste additions less than 10% of the digester feed as stated in the literature.
Schieber, H. (2018) Food Waste Is a Big Problem: Here’s Why. Schieber Research. https://researchci.com/food-waste-is-a-big-problem-heres-why/
Grandhi, B. and Appaiah Singh, J. (2015) What a Waste! A Study of Food Wastage Behavior in Singapore. Journal of Food Products Marketing , 22, 471-485. https://doi.org/10.1080/10454446.2014.885863
Davis, J. (2022) Food Waste in the United States. Ballard Brief. https://ballardbrief.byu.edu/issue-briefs/food-waste-in-the-united-states
United States Environmental Protection Agency (2018) National Overview: Facts and Figures on Materials, Wastes, and Recycling. EPA. https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/national-overview-facts-and-figures-materials
United States Environmental Protection Agency (2023) Quantifying Methane Emissions from Landfilled Food Waste (EPA Report No. EPA-600-R-23-064). https://www.epa.gov/system/files/documents/2023-10/food-waste-landfill-methane-10-8-23-final_508-compliant.pdf
Deer, R. (2021) Landfills: We’re Running Out of Space. RoadRunnerWM. https://www.roadrunnerwm.com/blog/landfills-were-running-out-of-space
United States Environmental Protection Agency (2023) Importance of Methane. EPA. https://www.epa.gov/gmi/importance-methane
Dioha, I., Ikeme, C.H. and Nafiu, T. (2013) Effect of Carbon to Nitrogen Ratio on Biogas Production. International Research Journal of Natural Sciences , 1, 1-10. https://www.eajournals.org/wp-content/uploads/EFFECT-OF-CARBON-TO-NITROGEN-RATIO-ON-BIOGAS-PRODUCTION.pdf
High Strength Organic Waste for Co-Digestion Guideline (2024) https://www.sawater.com.au/__data/assets/pdf_file/0006/200859/High-Strength-Organic-Waste-for-Co-digestion-Guideline.pdf
Slopiecka, K., Liberti, F., Massoli, S., Bartocci, P. and Fantozzi, F. (2022) Chemical and Physical Characterization of Food Waste to Improve Its Use in Anaerobic Digestion Plants. Energy Nexus , 5, Article 100049. https://doi.org/10.1016/j.nexus.2022.100049
Salama, E.-S., Saha, S., Kurade, M.B., Dev, S., Chang, S.W. and Jeon, B.-H. (2019) Recent Trends in Anaerobic Co-Digestion: Fat, Oil, and Grease (FOG) for Enhanced Bio Methanation. Progress in Energy and Combustion Science , 70, 22-42. https://doi.org/10.1016/j.pecs.2018.08.002
Lv, Y.Y., Chang, N., Li, Y.Y. and Liu, J.Y. (2021) Anaerobic Co-Digestion of Food Waste with Municipal Solid Waste Leachate: A Review and Prospective Application with More Benefits. Resources , Conservation and Recycling , 174, 105832-105832. https://doi.org/10.1016/j.resconrec.2021.105832
Tandukar, M. and Pavlostathis, S.G. (2022) Anaerobic Co-Digestion of Municipal Sludge with Fat-Oil-Grease (FOG) Enhances the Destruction of Sludge Solids. Chemosphere , 292, Article 133530. https://doi.org/10.1016/j.chemosphere.2022.133530
Aromolaran, A., Sartaj, M. and Abdallah, M. (2023) Supplemental Sewage Scum and Organic Municipal Solid Waste Addition to the Anaerobic Digestion of Thickened Waste Activated Sludge: Biomethane Potential and Microbiome Analysis. Fermentation , 9, Article 237. https://doi.org/10.3390/fermentation9030237
Mato, F.A., Peña, M. García-Rodríguez, Y. Bermejo, M.-D. and Ángel Martín. (2021) Analysis of the Energy Flow in a Municipal Wastewater Treatment Plant Based on a Supercritical Water Oxidation Reactor Coupled to a Gas Turbine. Processes , 9, Article 1237. https://doi.org/10.3390/pr9071237
U.S. Environmental Protection Agency (2016) Anaerobic Digestion: Co-Digestion. U.S. EPA. https://archive.epa.gov/region9/organics/web/html/codigest.html
Chiu, S.L.H. and Lo, I.M.C. (2016) Reviewing the Anaerobic Digestion and Co-Digestion Process of Food Waste from the Perspectives on Biogas Production Performance and Environmental Impacts. Environmental Science and Pollution Research , 23, 24435-24450. https://doi.org/10.1007/s11356-016-7159-2
Siddique, M.N.I. and Wahid, Z.A. (2018) Achievements and Perspectives of Anaerobic Co-Digestion: A Review. Journal of Cleaner Production , 194, 359-371. https://doi.org/10.1016/j.jclepro.2018.05.155
Nghiem, L.D., Koch, K., Bolzonella, D. and Drewes, J.E. (2017) Full Scale Co-Digestion of Wastewater Sludge and Food Waste: Bottlenecks and Possibilities. Renewable and Sustainable Energy Reviews , 72, 354-362. https://doi.org/10.1016/j.rser.2017.01.062
Williams, T.R., Gupta, R., Tasser, C., Appleton, R., Puente, P., Raskin, L., Schaum, C. and Bettina, S. (2023) The Relevance of Food Waste Quality for Co-Digestion Facility Planning, Design, and Operation. The Water Research Foundation. https://www.waterrf.org/resource/relevance-food-waste-quality-co-digestion-facility-planning-design-and-operation
Labatut, R.A., Angenent, L.T. and Scott, N.R. (2014) Conventional Mesophilic VS. Thermophilic Anaerobic Digestion: A Trade-Off between Performance and Stability? Water Research , 53, 249-258. https://doi.org/10.1016/j.watres.2014.01.035
Mao, C., Feng, Y., Wang, X. and Ren, G. (2015) Review on Research Achievements of Biogas from Anaerobic Digestion. Renewable and Sustainable Energy Reviews , 45, 540-555. https://doi.org/10.1016/j.rser.2015.02.032
Nagarajan, S., Jones, R.J., Oram, L., Massanet-Nicolau, J. and Guwy, A. (2022) Intensification of Acidogenic Fermentation for the Production of Biohydrogen and Volatile Fatty Acids—A Perspective. Fermentation , 8, Article 325. https://doi.org/10.3390/fermentation8070325
Filer, J., Ding, H.H. and Chang, S. (2019) Biochemical Methane Potential (BMP) Assay Method for Anaerobic Digestion Research. Water , 11, Article 921. https://doi.org/10.3390/w11050921
Schnaars, K. (2012) What Every Operator Should Know about Anaerobic Digestion. https://www.wef.org/globalassets/assets-wef/direct-download-library/public/operator-essentials/wet-operator-essentials---anaerobic-digestion---dec12.pdf
Chen, Y., Cheng, J.J. and Creamer, K.S. (2008) Inhibition of Anaerobic Digestion Process: A Review. Bioresource Technology , 99, 4044-4064. https://doi.org/10.1016/j.biortech.2007.01.057
Khanal, S.K., Nindhia, T.G.T. and Nitayavardhana, S. (2019) Chapter 11-Biogas from Wastes: Processes and Applications. In: Taherzadeh, M.J., Bolton, K. and Pandey, A., Eds., Sustainable Resource Recovery and Zero Waste Approaches , Elsevier B.V., 165-174. https://doi.org/10.1016/B978-0-444-64200-4.00011-6
Karki, R., Chuenchart, W., Surendra, K.C., Shrestha, S., Raskin, L., Sung, S., Hashimoto, A. and Kumar Khanal, S. (2021) Anaerobic Co-Digestion: Current Status and Perspectives. Bioresource Technology , 330, Article 125001. https://doi.org/10.1016/j.biortech.2021.125001
Adebayo, A., Jekayinfa, S. and Linke, B. (2015) Effects of Organic Loading Rate on Biogas Yield in a Continuously Stirred Tank Reactor Experiment at Mesophilic Temperature. Current Journal of Applied Science and Technology , 11, 1-9. https://doi.org/10.9734/BJAST/2015/18040
He, X., Iasmin, M., Dean, L.O., Lappi, S.E., Ducoste, J.J. and de los Reyes III, F.L. (2011) Evidence for Fat, Oil, and Grease (FOG) Deposit Formation Mechanisms in Sewer Lines. Environmental Science & Technology , 45, 4385-4391. https://doi.org/10.1021/es2001997
Henriksson, J. (2016) Characterization of Composition of the Fat-Rich Residues from Grease Separators. Degree Project, DiVA. http://www.diva-portal.se/smash/get/diva2:944380/FULLTEXT01.pdf
Wang, L., Aziz, T.N. and de los Reyes III, F.L. (2013) Determining the Limits of Anaerobic Co-Digestion of Thickened Waste Activated Sludge with Grease Interceptor Waste. Water R esearch , 47, 3835-3844. https://doi.org/10.1016/j.watres.2013.04.003
Hao, J., de los Reyes III, F.L. and He, X. (2020) Fat, Oil, and Grease (FOG) Deposits Yield Higher Methane than FOG in Anaerobic Co-Digestion with Waste Activated Sludge. Journal of Environmental Management , 268, Article 110708. https://doi.org/10.1016/j.jenvman.2020.110708
Yusuf, H.H., Roddick, F., Jegatheesan, V., Gao, L. and Pramanik, B.K. (2023) Tackling Fat, Oil, and Grease (FOG) Build-Up in Sewers: Insights into Deposit Formation and Sustainable in-Sewer Management Techniques. Science of the Total Environment , 904, Article 166761. https://doi.org/10.1016/j.scitotenv.2023.166761
Wallace, T., Gibbons, D., O’Dwyer, M. and Curran, T.P. (2017) International Evolution of Fat, Oil and Grease (FOG) Waste Management-A Review. Journal of Environmental Management , 187, 424-435. https://doi.org/10.1016/j.jenvman.2016.11.003
Mahat, S.B., Omar, R., Man, H.C., Idris, A.I.M., Kamal, S.M.M., Idris, A. and Anuar, N.K. (2020) Influence of Substrate to Inoculum Ratio (S/I) on the Treatment Performance of Food Processing Wastewater Containing High Oil and Grease (O&G) in Batch Mode. Desalination and Water Treatment , 203, 267-278. https://doi.org/10.5004/dwt.2020.26231
Ziels, R.M., Karlsson, A., Beck, D.A.C., Ejlertsson, J., Yekta, S.S., Bjorn, A., Stensel, H.D. and Svensson, B.H. (2016) Microbial Community Adaptation Influences Long-chain Fatty Acid Conversion during Anaerobic Codigestion of Fats, Oils, and Grease with Municipal Sludge. Water Research , 103, 372-382. https://doi.org/10.1016/j.watres.2016.07.043
El Mashad, H. and Zhang, R. (2020) Biogas Energy from Organic Wastes. In: Holden, N.M., Wolfe, M.L., Ogejo, J.A. and Cummins, E.J., Eds., Introduction to Biosystems Engineering , American Society of Agricultural and Biological Engineers (ASABE) and Virginia Tech Publishing, 49-71.
Collin, T., Cunningham, R., Jefferson, B. and Villa, R. (2020) Characterisation and Energy Assessment of Fats, Oils and Greases (FOG) Waste at Catchment Level. Waste Management , 103, 399-406. https://doi.org/10.1016/j.wasman.2019.12.040
Salama, E.-S., Jeon, B.-H., Kurade, M.B., Patil, S.M., Usman, M., Li, X. and Lim, H. (2020) Enhanced Anaerobic Co-Digestion of Fat, Oil, and Grease by Calcium Addition: Boost of Biomethane Production and Microbial Community Shift. Bioresource Technology , 296, Article 122353. https://doi.org/10.1016/j.biortech.2019.122353
Long, J.H., Aziz, T.N., de los Reyes III, F.L. and Ducoste, J.J. (2012) Anaerobic Co-Digestion of Fat, Oil, and Grease (FOG): A Review of Gas Production and Process Limitations. Process Safety and Environmental Protection , 90, 231-245. https://doi.org/10.1016/j.psep.2011.10.001
Leong, Y.K. and Chang, J.S. (2022) Valorization of Fruit Wastes for Circular Bioeconomy: Current Advances, Challenges, and Opportunities. Bioresource Technology , 359, Article 127459. https://doi.org/10.1016/j.biortech.2022.127459
Lyu, F., Luiz, S.F., Azeredo, D.R.P., Cruz, A.G., Ajlouni, S. and Ranadheera, C.S. (2020) Apple Pomace as a Functional and Healthy Ingredient in food Products: A Review. Processes , 8, Article 319. https://doi.org/10.3390/pr8030319
Ambaye, T.G., Rene, E.R., Dupont, C., Wongrod, S. and van Hullebusch, E.D. (2020) Anaerobic Digestion of Fruit Waste Mixed with Sewage Sludge Digestate Biochar: Influence on Biomethane Production. Frontiers in Energy Research , 8, Article 31. https://doi.org/10.3389/fenrg.2020.00031
Worrell, W.A., Vesilind, P.A. and Ludwig, C. (2016) Solid Waste Engineering: A Global Perspective. Cengage Learning.
Mrosso, R., Kiplagat, J. and Mecha, A.C. (2023) Anaerobic Codigestion of Tuber Waste and Fruit Waste: Synergy and Enhanced Biogas Production. International Journal of Chemical Engineering , 2023, Article ID: 6637249. https://doi.org/10.1155/2023/6637249
Valença, R.B., dos Santos, L.A., Firmo, A.L.B., da Silva, L.C.S., de Lucena, T.V., et al . (2021) Influence of Sodium Bicarbonate (NaHCO₃) on the Methane Generation Potential of Organic Food Waste. Journal of Cleaner Production , 317, Article 128390. https://doi.org/10.1016/j.jclepro.2021.128390
Hallaji, S.M., Kuroshkarim, M. and Moussavi, S.P. (2019) Enhancing Methane Production Using Anaerobic Co-Digestion of Waste Activated Sludge with Combined Fruit Waste and Cheese Whey. BMC Biotechnology , 19, Article 13. https://doi.org/10.1186/s12896-019-0513-y
Werkneh, A.A. (2022) Biogas Impurities: Environmental and Health Implications, Removal Technologies, and Future Perspectives. Heliyon , 8, e10929. https://doi.org/10.1016/j.heliyon.2022.e10929
Vali, S.A., Moral-Vico, J., Font, X. and Sánchez, A. (2023) Adsorptive Removal of Siloxanes from Biogas: Recent Advances in Catalyst Reusability and Water Content Effect. Biomass Conversion and Biorefinery , 14, 23259–23273. https://doi.org/10.1007/s13399-023-04478-1
Lipps, W.C., Braun-Howland, E.B. and Baxter, T.E. (2023) Standard Methods for the Examination of Water and Wastewater.24th edition, APHA Press.
Muller, C., Lam, P., Lin, E., Chapman, T., Devin-Clark, D., Belknap-Williamson, J. and Krugel, S. (2010) Co-Digestion at Annacis Island WWTP: Metro Vancouver’s Path to Renewable Energy and Greenhouse Gas Emission Reductions. Proceedings of the Water Environment Federation , January 2010, 2706-2722.
United States Environmental Protection Agency (2010) Anaerobic Digestion Tools and Resources. https://19january2017snapshot.epa.gov/anaerobic-digestion/anaerobic-digestion-tools-and-resources_.html
Misheloff, R. (2024) How Much Does It Cost to Lease a Used Dump Truck? SmarterFinanceUSA. https://www.smarterfinanceusa.com/blog/cost-lease-used-dump-truck
Sharmin, S. (2023) Support for Regional Community Anaerobic Digestion for Organic Waste Diversion (Order No. 30635246). Dissertations & Theses @ Florida Atlantic University-FCLA. https://www.researchgate.net/publication/374081862_Support_for_Regional_Community_Anaerobic_Digestion_for_Organic_Waste_Diversion
Ogundare, O.J. (2020) Potential Recovery of Biogas from Citrus Auranttfolia Waste (Lime Waste). Master’s Thesis, Covenant University.
Chuchat, N. and Skolpap, W. (2015) Biogas Production from Poultry Slaughter House and Food Processing Wastes by Microwave Thermal Pretreatment. Chiang Mai Journal of Science , 42, 456-468.
Usman, M., Salama, E.-S., Arif, M., Jeon, B.-H. and Li, X. (2020) Determination of the Inhibitory Concentration Level of Fat, Oil, and Grease (FOG) towards Bacterial and Archaeal Communities in Anaerobic Digestion. Renewable and Sustainable Energy Reviews , 131, Article 110032. https://doi.org/10.1016/j.rser.2020.110032
Abdallah, M., Greige, S., Beyenal, H., Harb, M. and Wazne, M. (2022) Investigating Microbial Dynamics and Potential Advantages of Anaerobic Co-Digestion of Cheese Whey and Poultry Slaughterhouse Wastewaters. Scientific Reports , 12, Article No. 10529. https://doi.org/10.1038/s41598-022-14425-1
Xue, S., Zhao, N., Song, J. and Wang, X. (2019) Interactive Effects of Chemical Composition of Food Waste During Anaerobic Co-Digestion under Thermophilic Temperature. Sustainability , 11, Article 2933. https://doi.org/10.3390/su11102933
Kim, N.-K., Lee, S.-H., Kim, Y. and Park, H.-D. (2022) Current Understanding and Perspectives in Anaerobic Digestion Based on Genome-Resolved Metagenomic Approaches. Bioresource Technology , 344, Article 126350. https://doi.org/10.1016/j.biortech.2021.126350
Sethi, R. (2018) Biogas Production from Organic Waste, Meat, and Fog by Anaerobic Digestion and Ultimate Sludge Digestibility. Master’s Thesis, Florida Atlantic University.
Sun, M., Shi, Z., Zhang, C., Zhang, Y., Zhang, S. and Luo, G. (2022) Novel Long-Chain Fatty Acid (LCFA)-Degrading Bacteria and Pathways in Anaerobic Digestion Promoted by Hydrochar as Revealed by Genome-Centric Metatranscriptomics Analysis. Applied and Environmental Microbiology , 88, e01042-e01022. https://doi.org/10.1128/aem.01042-22
Azarmanesh, R., Zarghami Qaretapeh, M., Hasani Zonoozi, M., Ghiasinejad, H. and Zhang, Y. (2023) Anaerobic Co-Digestion of Sewage Sludge with Other Organic Wastes: A Comprehensive Review Focusing on Selection Criteria, Operational Conditions, and Microbiology. Chemical Engineering Journal Advances , 14, Article 100453. https://doi.org/10.1016/j.ceja.2023.100453
Czubaszek, R., Wysocka-Czubaszek, A. and Tyborowski, R. (2022) Methane Production Potential from Apple Pomace, Cabbage Leaves, Pumpkin Residue, and Walnut husks. Applied Sciences , 12, Article 6128. https://doi.org/10.3390/app12126128
Zhang, L., Peng, B., Wang, L. and Wang, Q. (2022) Potential of Anaerobic Co-Digestion of Acidic Fruit Processing Waste and Waste-Activated Sludge for Biogas Production. Green Processing and Synthesis , 11, 1013-1025. https://doi.org/10.1515/gps-2022-0089
Zhang, Z., Qi, H., Ren, N., Li, Y., Gao, D. and Kannan, K. (2010) Survey of Cyclic and Linear Siloxanes in Sediment from the Songhua River and in Sewage Sludge from Wastewater Treatment Plants, Northeastern China. Archives of Environmental Contamination and Toxicology , 60, 204-211. https://doi.org/10.1007/s00244-010-9619-x
Wang, J., Liao, L., Wang, L. and Wang, L. (2022) Influence of Sampling Methods and Storage Condition on Volatile Methyl Siloxanes Quantification in Biogas. Biomass and Bioenergy , 158, Article 106347. https://doi.org/10.1016/j.biombioe.2022.106347
Ruiling, G., Shikun, C. and Zifu, L. (2017) Research Progress of Siloxane Removal from Biogas. International Journal of Agricultural and Biological Engineering , 10, 30-39.
Noshadi, I., Kanjilal, B., Jafari, T., Moharreri, E., Khakpash, N., Jiang, T. and Suib, S. L. (2016) Hydrophobic Mesoporous Adsorbent Based on Cyclic Amine-Divinylbenzene Copolymer for Highly Efficient Siloxane Removal. RSC Advances , 6, 77310-77320. https://doi.org/10.1039/C6RA11382F
Ellacuriaga, M., González, R. and Gómez, X. (2024) Feasibility of Coupling Hydrogen and Methane Production in WWTP: Simulation of Sludge and Food Wastes Co-Digestion. Energy Nexus , 14, Article 100285. https://doi.org/10.1016/j.nexus.2024.100285