University of São Paulo’s e-book explains how to reuse waste from urban tree pruning

Did you know that it is possible to manufacture furniture and toys from the waste of pruning trees in the city? And what diverse design businesses are emerging from sustainable products? In order to expand knowledge about the reuse of branches and trunks, the Institute of Technological Research (IPT) and the Faculty of Architecture and Urbanism (FAU) of USP joined forces in 2021 to think about ways to add value to this waste and one of the results part of this partnership is the publication of the e-book Waste from urban pruning: how to reuse it? The publication is available free of charge for download, just make a brief registration at this link .

The rapprochement between the FAU and the IPT began in 2020 with the approval of a research project submitted by researchers to the Superintendence of Environmental Management (SGA) at USP, called Valorization of woody residues from tree management: contribution to management for the sustainability at the Armando Salles de Oliveira Campus of the University of São Paulo .

Both institutions sought alternative uses for waste from urban tree pruning with greater added value and generation of environmental services. In this process, the IPT would carry out projects that rely on accumulated knowledge about wood, urban forests and solid waste treatment and the FAU would develop projects in which it applies its experience in teaching, research and extension.

At that time, IPT already had the first results of the training project Technical solutions for waste management from urban trees in Bertioga/SP , which were presented at the 13th International Seminar of the Nucleus of Research in Architecture and Urbanism Technology (Nutau) at USP .

“Based on the development of project activities on the USP campus, prior knowledge of IPT’s involvement with the topic and knowing its competence related to the area of ​​characterization tests and identification of wood properties, the coordinating team invited IPT to a meeting. Then there was the realization of common interests and the effective approximation of the teams”, explains Cyntia Santos Malaguti de Sousa, professor of the Department of Architecture Technology at FAU. Once executed, the project was awarded and Jornal da USP produced a text about the work carried out on the university campus .
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Explaining the process

The development of an e-book by IPT and FAU was one of the ideas that emerged during discussions between the two teams during the partnership. The publication launched now brings researchers and professors reflections on the subject and presents options to overcome the challenges related to the management of pruning residues, helping managers of urban afforestation at different scales.

“The e-book was conceived as a step-by-step guide to reusing pruning residues and shows that it is first necessary to have a minimal knowledge of the trees in the area of ​​interest, which can be the afforestation of a municipality, a neighborhood, a park, a condominium or another defined territory”, explains the researcher and project manager at IPT, Caroline Almeida Souza.

In this work, it is necessary to quantify the average physical and gravimetric composition of the pruning residues: this determination makes it possible to carry out studies on the application of treatment technologies, reuse and recycling of materials, thus reducing the waste of a noble material and its disposal in landfills.

Another step is the technological characterization of the analyzed tree species, through physical and mechanical tests carried out on samples of pruning residues. The characterization is important in indicating the potential use of wood from these residues for structural purposes and in the manufacture of furniture and small wooden objects.

The stages were put into practice by the teams during the pilot project carried out in the coastal city of Bertioga and the e-book brings a series of examples of the reuse of waste collected during its execution, with information on the species in technical sheets containing a summary of their features and potential uses.
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Model for Brazilian cities

“The e-book’s main audience are Brazilian municipalities that can be inspired by the methodology built with Bertioga and conclude that using waste from urban pruning in a more intelligent and sustainable way is not an impossible goal to achieve. Professionals who use wood to develop products, such as artisans and designers, may also be interested in the publication,” explains Souza. Electric power concessionaires have also taken an interest in the study, aiming at a better destination for the pruning carried out by them and their outsourced companies.

The numbers raised in the work corroborate the importance of the correct disposal of waste: the City Hall of São Paulo estimates that it collects from 3.5 to 4 thousand tons of waste from tree pruning per month – that is, the annual volume can reach almost 50 thousand tons of branches and trunks. The coastal city of Bertioga, in the State of São Paulo, generates 180 tons of pruning waste per month, which totals just over two thousand tons per year – that is, the numbers show that the amount of this type of waste is significant , whether for a large or small municipality.

“We hope that the publication helps to remember that the waste generated by urban pruning must be recognized as a noble material of great importance, which can be used properly, closing a more sustainable cycle and avoiding landfills as a final destination”, completes the researcher of the Territorial Planning, Water Resources, Sanitation and Forests Section of the IPT, Giuliana Del Nero Velasco.

The partnership between IPT and FAU should continue with the expansion of the field of action and development of university research and extension projects that have greater breadth and impact, and the intention of the University researchers is to raise funds in development agencies and consolidate partnerships with other public and private institutions.

“Right now, there is an ongoing project (2022-2025), in which IPT technicians also participate, which has scientific and financial support from the CNPq call, entitled Prototyping in product design: experimental production processes with urban tree residues” , explains FAU professor Tomás Queiroz Ferreira Barata.

This project’s main objective is to promote experimentation and the development of product prototypes using local forest-based materials, associating conventional woodworking processes and subtractive Digital Fabrication (FD) technologies. Participants therefore hope to define technological routes and identify the best potential for using wood from urban pruning in products and components.