Characterization of biosolids and potential use in the production of seedlings of Schinus terebinthifolia Raddi

ABSTRACT This study aimed to technically, chemically and biologically characterize the biosolids from the Sewage Treatment Plant (STP) of Alegria, Rio de Janeiro, Brazil, and infer about their aptitude as a substrate component for the seedlings production of Anadenanthera macrocarpa (Benth.) Brenan. Significant samples of biosolid were collected and submitted to chemical and biological analysis in a specialized laboratory, according to the specifications of the current Brazilian law (CONAMA Resolution nº 375/2006). In the forest nursery, four different formulations of substrate, composed by different volumetric proportions of commercial substrate (CS) and biosolids (BIO) were tested, consisting of the following treatments: T1 (100% SC + 0% BIO); T2: (75% SC + 25% BIO); T3: (50% SC + 50% BIO); e T4: (0% SC + 100% BIO). The experimental design was CRD, each of the four treatments having four replications of eighteen seedlings. The biosolid met the legal specifications concerning its composition. Fifty days after sowing, shoot height and stem diameter were measured. It was observed, for both characteristics, that seedling growth was directly proportional to the concentration of sewage sludge in the substrate. Finally, the Alegria ETE’s biosolid attends the legislation and shows a technically viable alternative for the production of angico vermelho seedlings.