Influence of initial concentration of chlorpyrifos in aquatic environment on removal by softstem bullrush (Scirpus tabernaemontani Gmel.)

This work focused on the influence of initial concentration on toxicity and removal potential of chlorpyrifos by Scirpus tabernaemontani under laboratory greenhouse conditions. An increased sensitivity and reduced removal rate to chlorpyrifos were observed with increasing chlorpyrifos concentration. At initial concentrations of 0, 1 and 2 mg·L⁻¹, the relative growth rates (RGRs) of S. tabernaemontani was not significantly different. In contrast, in the presence of 4, 8 and 16 mg·L⁻¹ chlorpyrifos the RGRs were significantly inhibited. A negative relationship was found between RGR and initial concentration on day 20 after incubation. The removal kinetics constant of chlorpyrifos in solution was decreased with increasing initial concentration. Half-life of chlorpyrifos was shortened with plants. S. tabernaemontani was able to uptake chlorpyrifos and transfer it to its above ground tissues. S. Tabernaemontani can efficiently accelerated removal of chlorpyrifos from water and may ultimately serve as phytoremediation agents in the natural environment.