Anaerobic digestion (AD) is a biological process that occurs in the limited presence of oxygen. This process involves various difficulties during the operation, such as acidification and increased concentration of volatile fatty acids, which can inhibit methane production. Therefore, in this work, the impact of biochar on the co-digestion of untreated sludge and residual biomass under mesophilic conditions was studied. For the production of biochar, the gasification process was used at different temperatures: 759 °C (BL), 798 °C (BM), and 888 °C (BH). This biochar was added in concentrations of 0 g/L, 3.33 g/L, and 6.67 g/L at the beginning of the co-digestion process. The results showed that a concentration of 6.67 g/L with BH biochar increased the PBM by 18% compared to the control sample and reduced the chemical oxygen demand (COD) by 88%. In addition, there was a reduction of volatile fatty acids (VFA) of 42.75%. Furthermore, FTIR analysis demonstrated that biochar has appropriate functional groups for this process. These data suggest a good interaction of biochar with the mixture of sludge and municipal waste, indicating that biochar can improve the anaerobic co-digestion of untreated sludge and municipal waste.

Los residuos sólidos orgánicos son una materia prima con potencial para producir energía y materiales de medio y alto valor agregado. Los residuos orgánicos incluyen biomasa residual de actividades agrícolas y ganaderas que pueden promover una economía circular y el desarrollo de la sostenibilidad en diferentes áreas. Este proyecto tiene como objetivo la carbonización de residuos agroindustriales para su aplicación en suelos de regiones agrícolas. Esto podría ayudar a mejorar las propiedades fisicoquímicas del suelo. En este documento se presentó un resumen de los avances en la identificación de biomasa disponible. Este estudio se centró en la región de Azuero ya que se ha informado que los suelos de esta región están degradados. Como parte de los resultados anteriores, se identificaron ocho residuos con potencial de carbonización. Se aplicaron encuestas a productores agroindustriales y se utilizaron bases de datos nacionales para calcular la cantidad de residuos no utilizados para cultivos específicos. Los resultados para residuos de arroz y maíz se presentan en este documento. Se identificó que el residuo de arroz en los distritos de Tonosí, Pedasí y Pocrí fue de aproximadamente 52140 toneladas, 11984 toneladas y 3727 toneladas, respectivamente. Para el residuo de maíz, los distritos de Los Santos, Pocrí y Las Tablas generaron alrededor de 14045 toneladas, 12406 toneladas y 12264 toneladas, respectivamente. Por lo tanto, la cantidad de biomasa generada en la región podría representar una oportunidad para su implementación en diferentes actividades, incluida la carbonización, para mejorar la calidad de las áreas agrícolas.

Acid fermentation for the generation of mediumchain fatty acids (MCFA) through mixed culture is an alternative that has a high potentital for high-value biomaterials production. It has been studied with greater concurrence in recent years, obtaining promising results in the pharmaceutical industry and biorefineries. This has created a circular economy by using biomass from distilleries, livestock waste, food waste, and organic sludge. Therefore, this research aims to evaluate the state of the art of producing medium-chain fatty acids from biomass. During this acid fermentation process, electron donors are needed to promote chain elongation pathways, such as β-reverse oxidation, fatty acid synthesis, or other pathways, such as maintaining a high intracellular concentration of acetyl-Coenzyme A. On the other hand, emphasis is made on improved processes to produced medium-chain fatty acids, such as microbial electrolysis, metabolic engineering techniques, the use of new enzymes, and the effect of various carbon sources to increase microbial activity. The results were compared to control samples achieving higher MCFA concentration. The use of biomass for the generation of MCFA for chemical and pharmaceutical products, as well as for biorefining, is an innovative and constantly advancing application.

Water contamination by heavy metals is a major global concern resulting from anthropogenic activities and natural geological processes. Their removal and recovery are important for protecting water resources and addressing the depletion of critical metals. This study evaluated wild sugarcane (WSC) biochar as an adsorbent for Cu²⁺ and Zn²⁺ removal from aqueous media, providing a potential valorization pathway for this biomass. WSC biochars were produced at airflow rates of 8, 12, 16, and 20 L min⁻¹ and characterized by Fourier-transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction. Cu²⁺ and Zn²⁺ adsorption data were analyzed using the Langmuir, Freundlich, and Temkin isotherm models. The characterization results indicated the presence of oxygen-, carbon-, and hydrogen-containing surface functional groups that may contribute to metal adsorption. Under the investigated batch conditions, BP12 achieved removal efficiencies of approximately 70–90% for Cu²⁺ and 83–94% for Zn²⁺. For BP12, the Langmuir expression yielded an apparent maximum Cu²⁺ adsorption capacity of 42.3 mg g⁻¹, while Zn²⁺ uptake reached 26.9 mg g⁻¹ and was best described by the Freundlich expression among the models evaluated; the Langmuir model did not converge for Zn²⁺. These results demonstrate the potential of WSC biochar for Cu²⁺ and Zn²⁺ removal from aqueous media and support the valorization of wild-sugarcane biomass as a minimally processed adsorbent.