Estudio del potencial de producción de biogás mediante digestión anaerobia de residuos sólidos orgánicos generados en el barrio El Paraiso, Ciudad Bolívar, Bogotá, Colombia

Abstract

Solid waste management in Bogotá faces challenges due to the saturation of the Doña Juana landfill, where the organic fraction accounts for over 50% of incoming waste. In the El Paraíso neighborhood—located in UPZ 67 within the Lucero sector of Ciudad Bolívar—improper waste disposal exacerbates environmental issues, leading to the proliferation of disease vectors, foul odors, and leachate that contaminates nearby water sources, such as the Tunjuelo River. Against this backdrop, the potential for biogas production via the anaerobic digestion of organic solid waste (OSW) generated in the El Paraíso neighborhood (Ciudad Bolívar, Bogotá) was investigated. The methodology involved collecting and characterizing the OSW (used as the substrate) and employing sludge from the El Salitre Wastewater Treatment Plant as the inoculum. Tests were conducted in laboratory-scale batch reactors, and biogas production was quantified using the volumetric displacement method. The experimental design evaluated anaerobic digestion using three types of inoculum: primary sludge, secondary sludge, and digested sludge. In Test No. 1, digested sludge demonstrated the best operational performance, achieving a specific yield of 0.0906 NL/g VS and maintaining pH levels between 6.8 and 7.6; this was followed by primary sludge (0.0498 NL/g VS) and secondary sludge (0.0235 NL/g VS). In Test No. 2, primary sludge exhibited acidification, with pH values ​​ranging from 5.2 to 5.4, indicating lower process stability. Furthermore, the results suggest that prolonged sludge storage between tests negatively affected biogas production yields. Finally, the capture system utilizing an NaOH solution did not allow for reliable quantification of the methane produced. It is concluded that the organic solid wastes evaluated show potential for biogas production via anaerobic digestion. However, process performance depends on inoculum stability, the inoculum-to-substrate ratio, and pH control, while methane quantification requires specific analytical methods to reliably determine biogas composition.