Eco-friendly particleboard production from coconut waste valorization.

Reusing agro-industrial waste does not only help to mitigate environmental impact but also enables valorization through the development of new products. The aim is to enhance the physical and mechanical properties of particleboard panels produced with Eucalyptus wood and different proportions of waste products-coconut fiber (Cocos nucifera L.). Physical properties (density, water absorption, and thickness swelling) and mechanical properties (static bending and internal bond resistance) were assessed, and panels reinforced with coconut fiber showed the best qualities with higher density, greater dimensional stability, and less water absorption. Static bending resistance and internal bond resistance also increased significantly. This demonstrated the potential of achieving compatible characteristics for civil construction and furniture production through the inclusion of waste material. The impact of this research is obtained from the utilization of an important agro-industrial residue in the manufacture of permanent composites.

Translocation factor of heavy metals by elephant grass grown with varying concentrations of landfill leachate.

The aim of this study is to obtain the translocation factor by application of landfill leachate (LL) diluted in public irrigation water (IW). Pennisetum purpureum Schum (elephant grass) was cultivated for 83 days in an experimental water reuse unit. The present work was developed at the Experimental Water Reuse Unit (UERA), on the UFERSA campus in Mossoró, RN, Brazil. Plot irrigation was based on water balance and crop evapotranspiration (ETc). The concentration in the plant tissue (root and leaf) of the following heavy metals was measured to determine the respective translocation factors: manganese (Mn), zinc (Zn), copper (Cu), nickel (Ni), cadmium (Cd), and lead (Pb). The experiment was set up in a randomized block design with five treatments (T1, plots irrigated only with IW; T2, 50% of LL dose plus IW; T3, 100% of LL dose plus IW; T4, 150% of LL dose plus IW; and T5, 200% of LL dose plus IW) and five replications. All treatments received LL plus IW depth of 491.02 mm for 83 days of P. purpureum cultivation. The data obtained were submitted to multivariate analysis plus the nonparametric Kruskal-Wallis test to compare the means. Pennisetum purpureum showed a potential to accumulate metals in its tissues, mainly Mn, Zn, and Cu. The treatments that most favored the extraction of these metals were T2 and T5; in this sense, P. purpureum was not efficient in translocating heavy metals, since the translocation factor observed in all treatments was below 1.0, indicating that the species used extract heavy metals from soil solution and keeps in yours roots. This suggests planting P. purpureum may not be a viable option to remediate environments highly contaminated with heavy metals.

Physical-mechanical properties of wood panel composites produced with Qualea sp. sawdust and recycled polypropylene.

Adhesive-free wood-plastic composite panels made with lignocellulosic wastes, and recycled plastics can be a sustainable option for generating useful "green" products. The present work assessed the physical-mechanical properties of adhesive-free panels produced with Qualea sp. sawdust and recycled polypropylene (PP). Discarded PP packaging was used. The packages were washed and ground with a laboratory knife mill until particle size of 10 to 14 mesh. Qualea sp. sawdust was sieved to select particle size of 14 to 30 mesh. Four experimental treatments were assessed by varying the percentages of PP and sawdust, as follows, 60 and 40%, 70 and 30%, 80 and 20%, and 90 and 10%, in an entirely randomized design with 3 panels per treatment, totaling 12 panels. The mats were hot-pressed at 180 °C during 20 min, the first 10 min under pressure of 1.0 MPa and the remaining 10 min at 42 MPa. Physical-mechanical properties of the panels were obtained as follows: density, moisture content, water absorption, thickness swelling, moduli of elasticity and rupture, and Rockwell hardness. In general, an increase of the percentage of PP provided higher dimensional stability to the panels, but there was no significant influence on mechanical strength.