Water bodies are routinely exposed to a mixture of contaminants via various anthropogenic exposure mechanisms. Phytoremediation offers a low-cost nature-based solution to remove contaminants from polluted water bodies. The ability of the aquatic macrophyte, Lemna minor to accumulate both organic antibiotics, plant protection products (PPPs) and inorganic contaminants (metals), individually and in co-contaminant mixtures, was evaluated to offer new insights into its potential for phytoremediation in realistic exposure scenarios. When exposed individually, diazinon accumulated to the greatest extent in L. minor, (95.51 ± 2.13%), followed by ciprofloxacin (31.91 ± 6.07%), atrazine (13.04 ± 3.44%), trimethoprim (11.43 ± 5.77%), chromium (4.5 ± 2.74%), and cadmium (3.08 ± 1.36%) These findings highlight that accumulation by L. minor is highly compound specific. Further results revealed that contaminant co-exposure significantly (p = 0.002–0.029) influenced the uptake of selected contaminants. The presence of chromium increased cadmium uptake by a factor of 6.34, while the combination of multiple contaminants (e.g., metals, PPPs, and antibiotics) reduced uptake. Changes in uptake capacity have potential knock-on effects for environmental risk assessments, including an assessment of the potential for antibiotics to contribute to the development of antibiotic resistance. For ciprofloxacin and diazinon, phytoremediation for 72 h was sufficient to reduce the concentration of a single antibiotic below concentrations predicted to result in the development of resistance (PNEC-R) or effects to Daphnia magna. In co-contaminant mixtures a risk was identified with RQ values being a factor of 17 greater than the toxicity threshold for D. magna. Our results support the need for a more comprehensive assessment of the impact of co-contaminant mixtures on L. minor uptake capacity to optimise phytoremediation strategies for improved water quality and reduced environmental risks.
Chowdhury et al. (2026) studied this question.