Exploring the Phytoremediation Capacity of Portulace oleracea Naphthalene Aromatic  Hydrocarbon Contaminants:A Physiological and Biochemical Study

Abstract

Aromatic hydrocarbons have detrimental effects on the animals and plants in affected habitats. Oxidative stress induced by aromatic hydrocarbons leads to the accumulation of reactive oxygen species, resulting in peroxidation of membrane lipids, DNA/RNA damage, tissue damage, and metabolic disorders. Naphthalene is one of the 16 priority hydrocarbons and falls under this category. Plant remediation is an effective method for removing naphthalene from polluted environments. Phytoremediation, a green technology, utilizes plants to enhance the degradation or removal of organic and inorganic pollutants. This study aimed to assess the impact of naphthalene on the physiological and biochemical characteristics of purslane, as well as its potential to absorb naphthalene. Four concentrations of naphthalene (0,15, 30, and 60 mg/l) were selected for the experiments. In addition a control treatment without plant containing 60mg/L of naphthalene was applied. Each treatment had four replications which were conducted using 20 hydroponic containers. The findings revealed that naphthalene reduced stem and root weights, soluble protein, and the content of photosynthetic pigments, while increasing malondialdehyde and hydrogen peroxide. However, the purslane plant demonstrated the ability to withstand naphthalene-induced stress by increasing the activities of enzymes, such as catalase, superoxide dismutase, ascorbate peroxidase, and glutathione S-transferase, as well as proline amino acid. The data obtained from Raman spectroscopy indicated that purslane could effectively absorb naphthalene. In conclusion, purslane exhibited significant potential for naphthalene phytoremediation.