The most common types of anaerobic digesters for solid wastes have been compared based on biological and technical performance and reliability. Batch systems have the most simple designs and are the least expensive solid waste digesters. They have high potential for application in developing countries. Two-stage systems are the most complex and most expensive systems. Their greatest advantage lies in the equalisation of the organic loading rate in the first stage, allowing a more constant feeding rate of the methanogenic second stage. Two-stage systems with biomass accumulation devices in the second stage display a larger resistance toward toxicants and inhibiting substances such as ammonia. However, the large majority of industrial applications use one-stage systems and these are evenly split between "dry" systems (wastes are digested as received) and "wet" systems (wastes are slurried to about 12% total solids). Regarding biological performance, this study compares the different digester systems in terms of organic loading rates and biogas yields considering differences in input waste composition. As a whole, "dry" designs have proven reliable due to their higher biomass concentration, controlled feeding and spatial niches. Moreover, from a technical viewpoint the "dry" systems are more robust and flexible than "wet' systems.
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Environ Res
January 2025
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China. Electronic address:
The resource utilization of municipal solid waste incineration fly ash (MSWI FA) has been widely concerned at present. The chlorine removal from MSWI FA is of great significance for controlling environmental risk and improving materials properties in the process of its resource utilization. This work specifically proposes to divide the chlorine in MSWI FA into inorganic chloride and organic chloride.
View Article and Find Full Text PDFWaste Manag
January 2025
Department of Mathematics, University of Padova, Via Trieste, 63, Padova, 35121, Italy; Augmented Intelligence Center, Fondazione Bruno Kessler (FBK), Via Santa Croce, 77, Trento, 38122, Italy; Department of Information Engineering and Computer Science, University of Trento, Via Sommarive, 9, Povo, 38123, Italy.
We explore the application of machine learning (ML) techniques to forecast door-to-door waste collection, addressing the challenges in municipal solid waste (MSW) management. ML models offer a promising solution to optimize waste collection operations, especially amid growing urban populations and evolving waste generation rates. Leveraging comprehensive data from a northeastern Italian municipality, including various waste types, our study investigates ML algorithms' efficacy in predicting household waste collection requirements.
View Article and Find Full Text PDFWaste Manag
January 2025
BioEngine Research Team on Green Process Engineering and Biorefineries, Chemical Engineering Department, Université Laval, Pavillon Adrien-Pouliot 1065, av. de la Médecine, Québec, Québec, Canada; CentrEau, Centre de recherche sur l'eau, Université Laval, 1065 Avenue de la Médecine, Québec, QC, G1V 0A6, Canada. Electronic address:
Despite advances in anaerobic digestion (AD), full-scale implementation faces significant challenges, particularly during the start-up phase, where inoculum selection is crucial. This study examines the impact of inoculum choice on the operational and economic performance of thermophilic digesters during the start-up phase. Methanogenic reactors R3 and R4 were inoculated with digested sludge (DiS) and diluted sewage sludge (DSS), respectively, and fed with hydrolyzed source-sorted organic fraction of municipal solid waste (SS-OFMSW) and thickened sewage sludge, which were processed in R1 and R2, serving as acidogenic reactors.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
LAQV@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal.
Polyethylene terephthalate (PET) has been widely used in plastic products, leading to massive PET waste accumulation in ecosystems worldwide. Efforts to find greener processes for dealing with post-consumer PET waste led to the discovery of PET-degrading enzymes such as PETase (PETase). studies have provided valuable contributions to this field, shedding light on the catalytic mechanisms and substrate interactions in many PET hydrolase enzymes.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
School of Civil Engineering and Transportation, Northeast Forestry University, Harbin 150040, China.
Given the current construction waste accumulation problem, to utilize the resource of red brick solid waste, construction waste red brick was used as a concrete coarse aggregate combined with polypropylene fiber to prepare PPF (polypropylene fiber)-reinforced recycled brick aggregate concrete. Through a cube compression test, axial compression test, and four-point bending test of 15 groups of specimens, the influences of the aggregate replacement rate of recycled brick and the PPF volume on the mechanical properties of recycled brick aggregate concrete reinforced by PPF were studied, and a strength parameter calculation formula was constructed and modified based on the above. Finally, combined with a life cycle assessment (LCA), the carbon emissions of raw materials were analyzed and evaluated.
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