This two-part study assesses the impact of biogas inhibition on large-scale waste-to-energy anaerobic digestion (WtE-AD) plants through techno-economic and life cycle assessment approaches. The first part addresses technical and economic aspects. An anaerobic co-digestion system using vegetable waste (FVW) and meat waste (MW) was operated at laboratory scale in a semi-continuous regime with daily feeding to establish a stable process and induce programmed failures causing methanogenic inhibition, achieved by removing MW from the reactor feed and drastically reducing the protein content. Experimental data, combined with bioprocess scale-up models and cost engineering methods, were then used to evaluate the effect of inhibition periods on the profitability of large-scale WtE-AD processes. In the experimental stage, the stable process achieved a yield of 521.5 ± 21 mL CH₄ g⁻¹ volatile solids (VS) and a biogas productivity of 0.965 ± 0.04 L L⁻¹ d⁻¹ (volume of biogas generated per reactor volume per day), with no failure risk detected, as indicated by the volatile fatty acids/total alkalinity ratio (VFA/TA, mg VFA L⁻¹/mg L⁻¹) and the VFA/productivity ratio (mg VFA L⁻¹/L L⁻¹ d⁻¹), both recognized as effective early warning indicators. However, during the inhibition period, productivity decreased by 64.26 ± 11.81% due to VFA accumulation and gradual TA loss. With the progressive reintroduction of the FVW:MW management and the addition of fresh inoculum to the reaction medium, productivity recovered to 96.7 ± 1.70% of its pre-inhibition level. In WtE-AD plants processing 60 t d⁻¹ of waste, inhibition events can reduce net present value (NPV) by up to 40.2% (from 0.98 M USD to 0.55 M USD) if occurring once per year. Increasing plant capacity (200 t d⁻¹), combined with higher revenues from waste management fees (99.5 USD t⁻¹) and favorable electricity markets allowing higher selling prices (up to 0.23 USD kWh⁻¹), can enhance resilience and offset inhibition impacts without significantly compromising profitability. These findings provide policymakers and industry stakeholders with key insights into the economic drivers influencing the competitiveness and sustainability of WtE-AD systems.

Los residuos de alimentos (FW) son materiales desechados en las cadenas de producción, suministro y distribución de productos destinados al consumo humano. La digestión anaeróbica (DA) se ha consolidado como una práctica clave dentro de la economía circular, transformando estos residuos en biogás y fertilizantes orgánicos. Para evaluar la viabilidad de diferentes sustratos en procesos de DA, se utiliza ampliamente la metodología del potencial bioquímico de metano (BMP). Sin embargo, los resultados de BMP pueden variar significativamente debido a las condiciones experimentales y la heterogeneidad de los residuos. Este estudio presenta una revisión bibliométrica y sistemática de la literatura publicada entre 2019 y 2024 sobre el uso de BMP en la valorización de FW, analizando las variaciones en las metodologías y los factores que afectan los resultados experimentales. De un total de 497 estudios identificados, 34 fueron seleccionados para un análisis detallado. Los hallazgos ofrecen una visión integral de las tendencias actuales en la investigación, subrayando la necesidad de estandarizar metodologías y condiciones experimentales para obtener resultados más consistentes y replicables. Además, se identifican barreras y oportunidades para optimizar la eficiencia y sostenibilidad de los procesos de DA, con implicaciones para investigaciones futuras y su implementación a gran escala en la gestión de residuos.

The Santa Catarina River (SCR) is considered an urban forest within the Monterrey Metropolitan Area (MMA); however, the impacts of contaminants detected in this system on local fauna remain largely unknown. These contaminants include heavy metals, organic pollutants, and medical residues originating from stormwater runoff and clandestine discharges. This study evaluated the temporal stability of toxicity at the study site using the macroinvertebrate Chironomus plumosus as bioindicator determining the differential susceptibility of four anatomical structures (mentum, pecten epipharyngis, mandibles, and antennae). A Chi-square test confirmed the temporal stability of mentum deformities (28-48 %) across the sampling dates ( = 5.30, p = 0.151), indicating chronic and constant exposure. However, an Analysis of Variance (ANOVA) revealed highly significant differences in vulnerability among structures (F = 64.85, p < 0.001). The pecten epipharyngis exhibited the highest damage frequency (91.2 %), significantly exceeding the mentum (43.8 %), whereas the mandibles (7.0 %) and antennae (6.5 %) were the most conserved structures. Although the mentum is a reliable indicator, the pecten epipharyngis appears to exhibit a greater response to environmental stress, suggesting it as a more sensitive biomarker. It is recommended to adopt a multi-structural approach in future biomonitoring programs and to conduct tissue-level toxicological analyses to validate these findings.