Phytoremediation Technique for Heavy Metal Removal from Wastewater: Eco-Friendly Wastewater Treatment

Global industrialization and urbanization have accelerated the release of hazardous substances, particularly heavy metals, into aquatic environments, posing serious threats to environmental and public health owing to their persistence and bioaccumulation. Phytoremediation has emerged as a promising, eco-friendly, and cost-effective strategy for treating heavy-metal contaminated wastewater. This study evaluated the phytoremediation potential of two aquatic macrophytes water hyacinth (WH) ( Eichhornia crassipes ) and water lettuce (WL) ( Pistia stratiotes ), in addition to their mixture, for removing heavy metals from industrial and drainage wastewater under mesocosm tank conditions. Over a 2 months period, metal removal efficiencies ranged from 10.93% to 85.90% for zinc (Zn), 14.03% to 67.95% for manganese (Mn), 11.62% to 45.00% for copper (Cu), and 8.39% to 27.58% for nickel (Ni), depending on treatment setup. The study further highlights the critical role of total suspended solids (TSSs) in heavy metal dynamics, with a significant proportion of Ni and Mn found adsorbed onto TSS rather than directly accumulated by the aquatic plants. In addition, translocation factor (TF) values revealed metal-specific behaviors, with Cu and Mn exhibiting higher TF values (up to 2.50 and 3.15, respectively), while Ni and Zn exhibited lower TF values (0.28–0.38 and 0.15–0.16, respectively). Overall, the results provide compelling evidence for the application of WH and WL, individually and in combination, as viable nature-based solutions for the removal of heavy metals from wastewater. These findings support the integration of phytoremediation into broader water management frameworks, offering a sustainable approach for water reuse and pollution mitigation.