Beschreibung:
The ability of Ludwigia octovalvis to tolerate toxicity and to degrade total petroleum hydrocarbons (TPHs) from petroleum sludge was investigated in this study. After 30 days of treatment, a different number of L. octovalvis (6, 9, and 12 plants) was exposed to 30 kg petroleum sludge. Two treatments with and without plants were tested to investigate if there is an effect of plant number on the removal of total petroleum hydrocarbon in sludge. Results revealed that exposure to real crude petroleum sludge had negative impact with toxicity ranging from 55% to 85% withered plants after 30 days in all plant numbers. Relative growth rate (RGR) analysis showed that the increase of plant number during treatment positively affected the RGR achieving the highest TPH removal efficiency of 45.2% in treatment with six plants. Scanning electron microscopic (SEM) analysis shows that petroleum sludge exposure altered the morphology of plant’s root (thickening the cell walls) with higher increasing of C percentage as compared to stem confirming that C uptake was more concentrated in the root part