Impact of Irrigation with Wastewater on Accumulation of Heavy Metals in Phaseolus vulgaris L. and Its Remediation

Abstract

AbstractThis study investigates the effects of Spirulina platensis, Chlorella vulgaris, leaves powder of Salix alba, and ethylenediaminetetraacetic acid treatments on the biochemical and yield traits of Phaseolus plants grown under wastewater irrigation. In addition, to assess the uptake and accumulation of heavy metals into the edible plant part. Water samples were obtained from each irrigation source (fresh tap water and untreated wastewater collected from El-Rahawy drain, Giza, Egypt); the plants were treated with our treatments (3 g per kg soil) at the beginning of the experiment (mixed fully into the soil). The results observed that the irrigation of Phaseolus plants with wastewater markedly stimulated the free proline contents, total phenols, superoxide dismutase, catalase, peroxidase, polyphenol oxidase, lipid peroxidation, and abscisic acid throughout the two growth stages. Indole acetic acid, gibberellic acid, yield parameters, total soluble carbohydrate, and protein in seeds were significantly reduced. The concentrations of nickel (Ni), cadmium (Cd), lead (Pb), and cobalt (Co) in Phaseolus seeds were significantly increased beyond recommended limits set by international organizations. However, our treatments significantly reduced the contents of Ni, Cd, Pb, and Co in seeds; free proline; total phenols; superoxide dismutase; catalase; peroxidase; polyphenol oxidase; lipid peroxidation; and abscisic acid in Phaseolus plants. Moreover, indole acetic acid, gibberellic acid, all yield traits, and seed components were enhanced. This study concluded that Spirulina platensis and salix leaves powder being economically and environmentally friendly can be considered an efficient strategy to mitigate the harmful effects of wastewater on plants.