Vermicompostagem de diferentes tipos de lodo de curtume associado a cinzas

Abstract

The objective of this study was to evaluate the vermicomposting of different types of tannery sludge mixed with different types of ash, with the purpose of reuse as waste treatment technology, producing vermicompostos with high nutritional quality. For this purpose, two tannery sludges were mixed: L1 (residue referring to the general tannery industry) and L2 (tannery of the tannery industry) and ash: C1 (waste from the boiler from wood) and C2 (ash from leaves). The treatments were as follows: T1 = 25% L1 + 75% C1; T2 = 50% L1 + 50% C1; T3 = 25% L1 + 75% C2; T4 = 50% L1 + 50% C2; T5 = 25% L2 + 75% C1; T6 = 50% L2 + 50% C1; T7 = 25% L2 + 75% C2; T8 = 50% L2 + 50% C2 on a dry basis. The experimental design was completely randomized, obtaining eight treatments with three replicates. The worms (Eisenia foetida) were monitored for 45 days and substrate moisture was maintained at around 40%. The substrates were chemically characterized at the beginning and at the end of the vermicompost process. The results showed that the parameters P, Ca, Mg, Fe and pH in the treatments presented statistical differences, highlighting the vermicomposting process to provide nutrients to the plant, favoring a final destination environmentally appropriate to the sludge. The treatments with wood ash were not feasible, probably because of the high iron content. The vermicompostos presented values of Cr and pH adequate to the technical specifications of the Normative Instruction of MAPA and CONAMA Resolution. The vermicompost can be adopted as biotechnology of final destination of different types of tannery sludge mixed with leaf ash, incorporating nutritional value of agronomic quality.