Design of a preliminary priming treatment in Salvinia rotundifolia to improve its performance during vinasse remediation.

TABERNERO NOELIA ROMINA; CHOCOBAR PONCE SILVANA; PRADO CAROLINA DEL VALLE; ROSA MARIANA DANIELA

MONTEVIDEO

Congreso; SETAC Latin America 15th Biennial Meeting i; 2023

SETAC

During the process of obtaining bioethanol, the sugar-alcohol industry generates a residual liquid called vinasse. Physicochemical characteristics of this effluent make it a potential contaminant of water resources, so it is important to seek and implement treatments to reduce its pollutant load and high volume of production.To improve the performance of Salvinia rotundifolia during the remediation process and, in turn, obtain a more suitable effluent for subsequent uses and/or dumping, a priming treatment was carried out on S. rotundifolia using manganese sulfate at low concentrations during 24 hours. First, vinasse was treated by bioadsorption, using agro-industrial wastes, then remediation was carried out for 7 days using 1:10 diluted vinasse and the primed plants. Vinasse samples were taken at 0, 2 and 7 days and pH, conductivity, sucrose, reducing sugars and phenolic compounds was determined. In plant tissues, we proceeded to quantify the content of H2O2, phenolic compounds and malondialdehyde (MDA) in samples taken at the beginning and at the end of the phytoremediation treatment.The results showed a 50% decrease in the content of phenolic compounds in the effluent treated with plants with priming, compared to the effluent treated with plants without priming. However, this effect was not observed in the levels of reducing sugars and sucrose. Regarding the plants, although macroscopic signs of damage were not observed, the content of hydrogen peroxide and MDA showed significant increases on day 7.Based on the results obtained, we can conclude that priming with Mn improved the performance of the plant, favoring the reduction of phenolic compounds present in the vinasse, which could be related to a stimulation of Mn-peroxidase. Likewise, it cannot be ruled out that Mn has stimulated both endogenous mechanisms of the plant and the activity of other microorganisms present in the rhizosphere. The stress indicator parameters showed that oxidative processes were activated in the plant, which could harm the remediation process in the long term. For this reason, more studies are necessary to adjust the Mn dose, the incubation time and the addition of some factor that favors the antioxidant mechanisms of the plant.