Evaluation of the phytoremediation capacity of Lemna minor L. in crude oil spiked cultures

Phytoremediation of freshwater contaminated with crude oil is a technology that can restore damaged freshwater areas. Lemna minor is a small vascular plant that reproduces rapidly, is sensitive to a wide variety of pollutants, and is easy to culture. This study aimed to evaluate the phytoremediation capacity of L. minor in crude oil spiked cultures. Cultivation was carried out for 7 days in a greenhouse with a natural photoperiod and in nutrient solutions containing 0.5%, 1%, 2%, and 3% crude oil. Extracts were analyzed using GC/MS and synchronous UV fluorescence spectroscopy. After a week of cultivation, the fresh weight of plants in the control medium increased by 117%. The presence of crude oil up to 0.5% v/v reduced growth as much as 50% relative to the control plants. C-17/Pr and C-18/Ph ratios decreased especially in the presence of 0.5% to 2% v/v crude oil in the growth media. In 0.5% oil concentrations, both unplanted control samples and plant samples contained no 1-4 ring polycyclic aromatic hydrocarbons. However, at oil applications of 0.5% and 1%, the plant samples contained 5 ring polycyclic aromatic hydrocarbons; their intensity was approximately two times lower than that of the unplanted control samples. It can be concluded that the biodegradation potential of L. minor strongly depends on the concentration of crude oil contaminants. Finally, the phytoremediative capacity of L. minor is only suitable for cleaning of freshwater resources containing small amounts of oil contaminants.