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Wastewater treatment plants (WWTPs) offer a reliable source of reclaimed water for irrigation. Metal-based chemicals (i.e. coagulants) are frequently employed in wastewater treatment, and residual metal ions remain in the treated wastewater, which could result in application of these metal ions to agricultural fields and crops. This study focuses on an emerging coagulant containing lanthanum. The behavior of lanthanum reclaimed water (LaRW) towards corn growth is barely known. Thus, if we are to recycle LaRW to support corn growth, the effects of LaRW on corn growth need to be studied. Corn kernels were grown in varying lanthanum concentrations (0-5000 mg La3+/L) to establish a toxic limit of La. Upon selecting the toxic limit, corn kernels were grown with LaRW in a greenhouse setting. The production of reactive oxygen species (ROS), enzymes, proteins, and anti-ROS compounds were studied. The presence of lanthanum in water promoted biomass, radicle, and plumule growth at less than 100 mg La3+/L when compared to controls. However, increasing the concentration above 100 mg/L attenuated radicle and plumule elongation with almost no biomass development at 5000 mg/L. The decrease in radicle-plumule elongation and failure to germinate might be attributed to increased malondialdehyde and superoxide production (yet to be confirmed). The production of these compounds increases the peroxidation of polyunsaturated fatty acids, reducing seed viability. Furthermore, the superoxide scavenging enzyme is easily destroyed by O2-, reducing the growth chances of the seeds. These results provide insight into the development of LaRW guidelines to be used in corn irrigation.
Lanthanides; Wastewater reclamation; Rare earth elements; Biomass development
Vacek, Savanna, "The Effect of Lanthanides on Corn Growth" (2021). Undergraduate Research Symposium Podium Presentations. 14.