Turning Waste into Worth: Valorizing Urban Tree Pruning Residues for Sustainable Materials Development

High Resolution Image Download MS PowerPoint Slide Urban trees are crucial for the quality of urban environments, but their periodic pruning generates biomass that often displays management challenges. However, this biomass represents a valuable opportunity for sustainable resource utilization through its valorization. Tree pruning waste, primarily composed of lignin, cellulose, and hemicellulose, can be transformed into a wide range of chemicals and functional materials. Therefore, in this work, a valorization process for London plane tree and Bay laurel pruning wastes was proposed; first by extracting oligosaccharides, and second by extracting lignin for its application in lignin-chitosan film formulation. The results showed that between 10 and 15 g/L of xylooligosaccharides were obtained from both raw materials. The delignification yields were higher for the untreated London plane tree (70%) than for the Bay laurel (40%). It was also observed that these yields were lower in the case of pretreated solids (36–37%). After carefully analyzing the properties of the extracted lignins, the one from pretreated London plane tree was selected for film elaboration, which exhibited improved physicochemical characteristics, including thermal stability and UV resistance, suggesting their viability as eco-friendly alternatives to conventional plastics. This way, the potential of urban tree pruning residues as oligosaccharides and sustainable material sources was assessed.