Using Spirulina platensis as a natural biocoagulant for polystyrene removal from aqueous medium: performance, optimization, and modeling

Sci Rep. 2024 Jan 30;14(1):2506. doi: 10.1038/s41598-024-53123-y.

Abstract

Microplastics (MPs) are newly recognized contaminants that result from the breakdown of plastics released into aquatic environments. This study focuses on the elimination of polystyrene (PS) using S. platensis, a natural biocoagulant, from aqueous solutions. The research investigated several crucial variables, including the initial level of PS ranging from 100 to 900 mg L-1, pH levels from 4 to 10, the contact time of 20-40 min, and doses of S. platensis ranging from 50 to 250 mg L-1. The analysis of the data revealed that the quadratic model offered the best fit for the experimental results. In the present study, we utilized S. platensis as a novel natural biocoagulant to effectively eliminate PS from aqueous solutions. Process optimization was performed using a Box-Behnken design (BBD). The best-fitting model for the data was the quadratic model. The results displayed that the highest elimination of PS (81%) was occurred at a pH of 4, with a contact time of 30 min, a dose of S. platensis at 250 mg L-1, and a PS concentration of 500 mg L-1. These findings show that S. platensis has a significant effect on removing PS from the aquatic environment. Algae can serve as a convenient and eco-friendly method, replacing chemical coagulants, to effectively remove MPs from the aquatic environment.

MeSH terms

  • Plastics / metabolism
  • Polystyrenes / metabolism
  • Spirulina* / metabolism
  • Water Pollutants, Chemical* / analysis

Substances

  • Polystyrenes
  • Plastics
  • Water Pollutants, Chemical

Supplementary concepts

  • Arthrospira platensis