Characterization and evaluation of the life cycle of energy use from drying bed sludge. (15th January 2023)

• Record Type: Journal Article
• Authors: Moni Silva, Ana Paula; Barros, Regina Mambeli; Silva Lora, Electo Eduardo; Díaz Flórez, Carlos Andrés; Silva dos Santos, Ivan Felipe; Cassia Crispim, Adriele Maria de; Grillo Renó, Maria Luiza
• Is Part Of: Energy. Volume 263:Part B(2023)
• Publication Date: 2023-01-15
• Subjects: Drying bed sludge -- Life cycle assessment -- Energy conversion -- Biogas; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2022.125630
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: This study sought to characterize sludge digested in Upflow Anaerobic Sludge Blanket (UASB) reactors during the drainage process of Drying Bed Sludge (DBS) to conduct a Life Cycle Assessment (LCA) for different DBS disposal scenarios. In addition, the potential recovered energy from the waste material was verified when submitted to Anaerobic Digestion (AD) or when combusted through simulation software SimaPro®. Laboratory analyses were conducted with the collected samples from a wastewater treatment plant in Itajubá, Minas Gerais, Brazil. The calorific value, ashes generated from the burning process, and methane production were conducted in two experiments for a qualitative and quantitative evaluation of the biogas generated. The scenarios included DBS disposal in landfills and ditches, DBS biodigestion, and combustion. The methane yield generated by DBS resulted in a lower value compared to DBS produced by the UASB reactor disposal system. The LCA results show that the impact category pertaining to global warming is indeed influenced for all scenarios, almost entirely comprised of biogas emissions coming from the drying bed waste. Heavy metal emissions may occur during combustion, which may impact human toxicity. Under the scenario in which DBS undergoes biodigestion, the pollutants include nitrogen oxide, sulfur monoxide, and carbon monoxide. Graphical abstract: Image 1 Highlights: Methane production and the energy recovery from anaerobic sludge were evaluated. Life Cycle analysis was conducted using data obtained in laboratory tests. Sludge incineration presented a higher energy generation than anaerobic digestion. Incineration showed the best results for all impacts, except human toxicity.