Using rotifer population demographic parameters to assess impacts of the degradation products from trinitrotoluene phytoremediation

The objective of this study was to evaluate the chronic lethal and sublethal aquatic toxicity effects associated with the phytoremediation of water contaminated with 2,4,6-trinitrotoluene (TNT) by the wetland plant species Myriophyllum aquaticum (parrot feather). Rotifers (Brachionus calyciflorus) feeding on an algal species (Nannochloropsis spp.) were used as the aquatic test organisms. Continuous flow laboratory microcosms were used to quantify effects on rotifer populations from TNT and the primary degradation product aminodinitrotoluene (ADNT) during and after phytoremediation. Rotifer demographic parameters from life tables, including survivorship, fecundity, reproductive values, net reproductive rate, generation time, intrinsic growth rate, and life expectancy, were used as measures of treatment effects. High-performance liquid chromatography analyses were performed to determine nitroaromatic concentrations. Results from this study have revealed significant differences in rotifer demographic parameters between microcosms with elevated initial TNT concentrations. Significant differences in demographic parameters also existed between the microcosms that did and did not receive phytoremediation treatment and the control microcosms. Study results have indicated that TNT phytoremediation via artificial wetlands not only may clean up hazardous waste at munitions sites but also may encourage the growth of aquatic populations such as rotifers.