Evaluating the Phytoremediation Potential of Lemna minor for Iron-Contaminated Municipal Wastewater: A Case Study from Cuttack, India

Municipal wastewater often contains high concentrations of contaminants, including heavy metals, which may cause serious consequences to aquatic ecosystems and human health. Phytoremediation using aquatic macrophytes has emerged as an environmental friendly and cost-effective approach for removing metals from contaminated water. The present study investigated the phytoremediation potential of Lemna minor in municipal wastewater containing Iron (Fe) concentrations of 0.625, 0.937, and 1.25 mgL-1 over 15 days. The physico-chemical parameters of the wastewater were analysed, and the phytoremediation performance of Lemna minor was evaluated using relative growth rate (RGR), Fe accumulation (Fe Acc), bioconcentration factor (BCF), and Fe removal efficiency (RE). The results showed that Lemna minor effectively reduced Fe concentrations across all treatments, with the highest removal efficiency of 70.31% observed at 1.25 mg L-1 after 15 days of exposure. Fe accumulation in plant tissues increased with both wastewater concentration and exposure duration, reaching a maximum value of 1.462 mg g⁻¹. High BCF with values >1 was recorded throughout the experiment, which demonstrated the strong Fe accumulation capacity of Lemna minor, while positive relative growth rates indicated that the presence of Fe in wastewater supported plant growth. Statistical analyses, including two-way ANOVA, Pearson correlation, and simple linear regression, demonstrated that Fe concentration significantly influenced Fe accumulation, RGR, and removal efficiency, highlighting the strong phytoremediation potential of Lemna minor. The findings suggest that Lemna minor can efficiently remove and accumulate Fe while maintaining healthy growth, highlighting its potential as a sustainable and low-cost phytoremediation species for the treatment of Fe-contaminated municipal wastewater.