Ricinus communis as a phytoremediator of soil mineral oil: morphoanatomical and physiological traits

Abstract

Rapid growth in the oil industry has been accompanied concomitant increases in risks of spills or leaks triggered by natural or anthropogenic causes that cause soil changes and plant damage. Bio-scavenging and phytoremediation plants are important tools for identifying pollutants and mitigating environmental damage. The objective of this study was to evaluate the phytoremediation potential of Ricinus communis cultivated in soils contaminated with mineral oil, and to determine the possible visual, anatomical and physiological effects. R. communis seeds were pre-germinated in individual pots containing Red Latosol contaminated with Lubrax Essential SL (15W-40) mineral oil at concentrations of 0 (control), 5, 10, and 15 g kg^-1. After exposure to treatments, emergency evaluations were performed, and after 45 days of cultivation, visual, morphoanatomical, physiological and oil removal effects were evaluated. There was no difference in emergence showed between treatments. Visual effects were characterized by necrosis and chlorosis formation in R. communis, evidenced on the 45th day of cultivation in all treatments tested, followed by parenchymal tissue alterations with collapsed cell formation and damage to photosynthesis with increasing doses. We found that R. communis removed up to 81% of hydrocarbons in soils, classifying it as potential phytoremediator of contaminated soils. The strong correlation between the variables suggests that R. communis can be used as an indicator of pollutant action.

Keywords: Castor bean; Correlogram; Hydrocarbons; Phytoremediation; Pollution.