Tecnossolo elaborado com resíduos urbanos e industriais: potencial para a melhoria de qualidade do solo crescimento de mudas arbóreas

Abstract

The management of construction and demolition waste (CDW) and its correct final destination has become a problem for many Brazilian municipalities. This study aimed to evaluate the use of CDW in the preparation of Technosol, which is a “tailor made” soil, here consisting of a mixture of CDW, sterile solid waste from sand and stone mining (MW), natural soil (NS) and organic compound from the remains of urban plant pruning (OC), with the purpose of improving soil quality and promoting the growth of tree species commonly used in forest recovery projects. For this purpose, samples of CDW collected in accordance with NBR 10007, in a particle size fraction of up to 2 mm, and MW were ground in a mill and agate mortar and characterized in terms of their chemical and mineralogical composition by X-ray fluorescence and X-ray diffraction. The potential of Technosol as a substrate for the growth of tree seedlings was evaluated based on the mixture of CDW “Class A” according to CONAMA Resolution 307/2002, MW, NS and OC, in the following proportions: I. 10% RCD + 42.5% RM + 42.5% SN + 5% RV, II. 20% RCD + 37.5% SM + 37.5% SN + 5% RV, and III. natural soil as control. The experiment was conducted in randomized blocks with nine treatments and three replications, using pots with a capacity of 5.5 L. The experimental treatments consisted of the interaction of two proportions of mixtures in addition to natural soil and three tree species: pioneer, Cecropia pachystachya (Embaúba), secondary, Handroanthus impetiginosus (Ipê Roxo) and climax, Copaifera langsdorffii (Copaiba). The activity of the enzymes β-glucosidase and arylsulfatase was determined in the Technosol and natural soil at the end of the experiment. During 180 days, the height of the plants and the diameter of the stem were determined at intervals of 30 days and, at the end of the experiment, the aerial part dry mass (leaves and trunk) and roots was evaluated. The Technosol constructed from the “I” mixture proved to be viable for improving soil quality, as indicated by the greater enzymatic activity compared to other soils, and for the growth of H. impetiginosus seedlings, showing the capacity to gain plant height over 180 days after planting.