Phytoremediation of Pyrene by the Aquatic Plant Azolla pinnata.

The current study tested the ability of the aquatic plant Azolla pinnata to remove the pyrene and determine the effect of Pyrene on the pigments (chlorophyll a, b, and carotenoids) and antioxidant parameters (CAT, SOD, MDA and, ROS) in the plant. The plant was exposed to different concentrations of Pyrene (1,5,10,15,25, and 50 mg/l) for 14 days. The results showed that the high removal rate of pyrene reached 99% for 25 and 50 mg/l of pyrene on the 14th day of the experiment, while the lowest removal rate was 42.1% for 1 mg/l on the third day. The results showed the lowest values of total chlorophyll, chlorophyll a and carotenoids were 0.55, 0.25, and 0.433 μg/g recorded at 50 ppm respectively. While chlorophyll b recorded a low value of 0.32 μg/g at 25 mg/l, the highest concentration of these pigments was registered in the control group. Also, the results showed a gradual increase in antioxidant values compared to the control group, recording the highest values of 0.2873 and 1.04 U/g at 50 ppm and the lowest value of CAT and SOD at 5ppm, compared to the control group. Also, the study recorded a gradual increase in ROS and MDA values with increasing concentrations of pyrene, the highest value was 1.6367 and 14.4433 µmole/g for ROS and MDA at (50ppm), whereas the lowest value was recorded at 5 ppm compared to the control group. Statistical analysis at (p˂0.05) showed significant differences between all the interactions. [ABSTRACT FROM AUTHOR]