Multifaceted Pollutant Removal by Salicornia brachiata: A Phytoremediation Approach

The increasing discharge of nutrient and metal-laden effluents into saline environments demands sustainable remediation strategies. This study evaluated the phytoremediation potential of Salicornia brachiata, a halophytic plant, under hydroponic conditions using varying concentrations of three macronutrients-nitrate (NO₃^-), phosphate (PO₄^3-), and calcium (Ca²⁺)-and three heavy metals-lead (Pb²⁺), chromium (Cr⁶⁺), and copper (Cu²⁺). The plant exhibited high removal efficiencies across all treatments, with Pb²⁺ and Cr⁶⁺ reaching nearly 99% removal within two days, while macronutrient removal showed a steady, time-dependent increase over the 14-day period. Several biochemical parameters, including proline content and antioxidant enzyme activities (catalase, superoxide dismutase, peroxidase, polyphenol oxidase), were significantly affected by treatments, with most showing dose-dependent responses to heavy metal exposure, indicating strong biochemical resilience. Fourier transform infrared spectroscopy revealed pollutant-specific structural shifts and identified -OH, -NH, and -COO^- groups as key binding sites. The study quantifies the removal efficiency of S. brachiata for both nutrients and metals and provides mechanistic insight into its ionic stress response and binding pathways. These findings establish S. brachiata as a viable candidate for integrated phytoremediation in saline, contaminated water systems.