Estudo de viabilidade de fitorremediação de sulfentrazone (boral 500) por plectranthus neochilus (boldo gamba) em meio aquoso

Abstract

Modern agriculture is strictly dependent on the use of pesticides to maintain its level of productivity. However, it is known that most of these products may have adverse effects on the environment, such as affecting non-target organisms and promoting contamination of both soil and aquatic environment. The dynamics of pesticides in the environment are dependent on different mechanisms that influence their fate after application and their half-life. Sulfentrazone is a pesticide widely used in a variety of crops and acts by inhibiting the protoporphyrinogen oxidase enzyme and, consequently, inhibiting the synthesis of chlorophyll. The dissipation of this herbicide in the environment, as well as its toxicity in rotational crops are problems that affect non-target organisms, which brings the need to find alternatives to reverse this situation. Phytoremediation is an alternative for cleaning contaminated sites that uses the natural physiological processes of plants as a way of collecting pollutants. This feature has become popular because it is environmentally friendly, easy to apply in situ, low cost and can be used in a variety of contaminants. Thus, studies to identify plants that are capable of performing phytoremediation of pesticides are essential for this technology to be applied efficiently. The plectranthus neochilus (boldo gambá) is a species that presents a known potential to phytoremediate herbicide in aqueous medium and because of this, was selected for the study. Considering the above, the objective of this work was: 1) to evaluate the potential phytoremediator of the opossum boldo for the sulfentrazone herbicide; 1) to evaluate the phytoremediation potential of the plectranthus neochilus for the sulfentrazone herbicide; and for this purpose 2) to develop and validate a method of analysis for this herbicide by HPLC-DAD and 3) an extraction method using the SPE English solid phase extraction technique with C18 sorbent. The methods developed proved to be efficient, reliable, with good repeatability for the determination of the compound of interest in the matrix used. In the phytoremediation assay, p. neochilus was placed in aqueous solution containing sulfentrazone (10.30 mg/L) for 32 days at room temperature. Samples were collected for analysis every eight days of culture. There was a reduction in concentration and marked tolerance at high doses of the compound. The results evidenced the potential of plectranthus neochilus as water remediation plant contaminated by sulfentrazone in aqueous matrix.