Avaluació de la biodegradació de fibres tèxtils amb polièster mitjançant Tenebrio molitor: efectes sobre les larves i caracterització del frass

Abstract

This study evaluates the biodegradation of polyester-based textile fibers (PET) by Tenebrio molitor larvae, aiming to assess their capacity to transform textile residues and the quality of the resulting frass. Frass, defined as the organic residue excreted by the larvae, can have potential applications as a biofertilizer or soil amendment due to its nutrient content. The research is framed within the context of circular economy and sustainable management of textile waste, a sector facing major challenges due to its high production rates and the poor recyclability of polyester. Four textile types (P100, P65, P60L, and P12) were tested under different chemical pretreatments (acidic and basic) and compared with a control group fed with oat bran. Results show that the tested fabrics did not provide a nutritionally viable substrate, with survival, pupation, and biomass production markedly lower than in the control. The acidic pretreatment caused a strong mass reduction in P12, mainly due to physical fragmentation rather than actual biodegradation. The obtained frass showed homogeneous organic matter content and high nitrogen concentration, but with low bioavailability, resulting in a limited fertilizing potential. Overall, this work highlights both the potential and the current limitations of this biotechnological approach, emphasizing the need to optimize experimental conditions and include nutrient-rich co-substrates to enhance efficiency.

Este trabajo evalúa la biodegradación de fibras textiles con contenido en poliéster (PET) mediante larvas de Tenebrio molitor, con el objetivo de analizar su capacidad de transformación del residuo y la calidad del frass obtenido. El frass, entendido como el residuo excretado por las larvas, puede tener aplicaciones como enmienda orgánica por su contenido en nutrientes. El estudio se enmarca en el contexto de la economía circular y la gestión sostenible de los residuos textiles, un sector altamente problemático por su elevada producción y la dificultad de reciclaje del poliéster. Se ensayaron cuatro tipos de tejidos (P100, P65, P60L y P12) sometidos a pretratamientos químicos (ácido y básico) y comparados con un control alimentado con avena. Los resultados muestran que los tejidos no proporcionaron una fuente nutricional asimilable, con supervivencia, pupación y producción de biomasa muy inferiores al control. El pretratamiento ácido provocó una pérdida de masa notable en el tejido P12, atribuible principalmente a una fragmentación física más que a una biodegradación efectiva. El frass obtenido presentó valores homogéneos de materia orgánica y contenidos elevados de nitrógeno, aunque con baja biodisponibilidad y, por tanto, con valor fertilizante limitado. En conjunto, el trabajo evidencia el potencial y las limitaciones de esta estrategia biotecnológica, y subraya la necesidad de optimizar las condiciones experimentales e incorporar co-sustratos nutritivos para mejorar su eficiencia.

This study evaluates the biodegradation of polyester-based textile fibers (PET) by Tenebrio molitor larvae, aiming to assess their capacity to transform textile residues and the quality of the resulting frass. Frass, defined as the organic residue excreted by the larvae, can have potential applications as a biofertilizer or soil amendment due to its nutrient content. The research is framed within the context of circular economy and sustainable management of textile waste, a sector facing major challenges due to its high production rates and the poor recyclability of polyester. Four textile types (P100, P65, P60L, and P12) were tested under different chemical pretreatments (acidic and basic) and compared with a control group fed with oat bran. Results show that the tested fabrics did not provide a nutritionally viable substrate, with survival, pupation, and biomass production markedly lower than in the control. The acidic pretreatment caused a strong mass reduction in P12, mainly due to physical fragmentation rather than actual biodegradation. The obtained frass showed homogeneous organic matter content and high nitrogen concentration, but with low bioavailability, resulting in a limited fertilizing potential. Overall, this work highlights both the potential and the current limitations of this biotechnological approach, emphasizing the need to optimize experimental conditions and include nutrient-rich co-substrates to enhance efficiency.

Objectius de Desenvolupament Sostenible::13 - Acció per al Clima

Objectius de Desenvolupament Sostenible::13 - Acció per al Clima