RESUMEN
Thousands of tons of residual lignocellulosic biomass are produced and discarded by agroindustries in the Amazon. These biomasses could be harnessed and used in the preparation of activated carbon, in view of the growing demand for this product with high added value, however, little is known about their characteristics, in addition to their potential as precursors of activated carbon. Therefore, the aim of this work was to evaluate the potential of four different biomasses in the preparation and quality of activated carbon. Residues from the processing of the fruits of acai, babassu, Brazil nut, and oil palm were collected, characterized, carbonized, physically activated with CO2, and characterized. The contents of the total extractives, insoluble lignin, minerals, holocellulose, and elemental (CHNS-O) were analyzed. The surface area and surface morphology were determined from the AC produced, and adsorption tests for methylene blue and phenol were performed. The four biomasses showed potential for use in the preparation of CA; the residues presented high contents of lignin (21.83-55.76%) and carbon (46.49-53.79%). AC were predominantly microporous, although small mesopores could be observed. The AC had a surface area of 569.65-1101.26 m2 g-1, a high methylene blue (93-390 mg g-1), and phenol (159-595 mg g-1) adsorption capacities. Babassu-AC stood out compared to the AC of the other analyzed biomasses, reaching the best results.
RESUMEN
Urban forestry generates a huge amount of waste worldwide, resulting from the processes of pruning and suppression. Disposal in landfills reduces the useful life of these facilities and forgoes the possibility of generating income from the waste. This study investigated the manufacture of toys as a strategy to valorize urban forestry waste. For this, physical-mechanical, chemical (extractive), color and shape characterizations were performed for three species of urban trees commonly planted in Brazil, a region of Neotropical forests. Toy prototypes were developed and manufactured from wood waste. Regarding color, all studied species showed high value of the variable b*, which refers to the blue-yellow axis. Handroanthus heptaphyllus wood had the highest values of basic density (0.706 g.cm-3) and Janka hardness (1142, 1027 and 1669 kgf.cm-2 for radial, tangential and transverse directions, respectively), and had the lowest volumetric shrinkage (11.38%). The lowest content of total extractives was measured in Handroanthus heptaphyllus, 6.33%, and the greatest content was found in Spathodea campanulata, 7.01%. The average value suggested for the toy prototypes varied between $ 3.70 and $ 13.58. The urban pruning wastes of the species studied have physical, chemical and mechanical attributes suitable for the manufacture of toys. This use has strong potential for environmental, economic and social sustainability and the toys are pedagogically accepted by adults and children.