Técnicas de biorremediação em pequena escala de solo contaminado com resíduo oleoso vegetal.

Abstract

Population growth brought consequences for the environment, causing a significant increase in pollution. Improper disposal of hazardous wastes such as vegetable oils, due to their high degree of pollution, has concerned the scientific community. This situation has enabled the development of techniques to remediate contaminated areas. Among the known techniques, bioremediation stands out for being a technology that uses the biota to remedy contaminated areas. In view of that, this study aims at verifying the bioremediation of soils contaminated with vegetable oil wastes considering different techniques under and the soil and climate conditions of a semiarid land located in Paraiba State, Brazil. In order to carry this out, we compared the following techniques: natural attenuation (ATN), and biostimulation with (BCN) and without (BSN) the addition of nutrients. The treatment with the addition of nutrients was supplemented with urea and superphosphate, as sources of nitrogen (N) and phosphorus (P). The initial rate used for carbon, nitrogen and phosphorus was 100:10:1. The monitoring analyses carried out were: moisture rate, electrical conductivity, volatile solids, C/N ratio, respirometry, and oils and greases. After six days of experiment, the treatment with additional nutrients presented macroscopic filamentous structures, which were identified as Aspergillus niger. The natural attenuation provided a 69.37% oil removal rate, while BSN and NCB treatments reached 90.18% and 95.66%, respectively. The treatments were effective for the remediation of contaminated soils with vegetable oil wastes under the soil and climate condition of the semiarid environment chosen for this study.