A novel floating compound based on a plastic sphere coated with tin titanate for the removal of the herbicide fomesafen

A tin titanate (SnTiO3) composite was synthesized by hydrothermal method (TSn) then impregnated with RhB dye (TSn@RhB powders). This composite was coated on a spheric plastic support from short life daily products with floatable capability (TSn@RhB/PP). The novel composite and synthesized powder were characterized by SEM, XRD and XPS. The SEM images revealed that the powders had an average particle size of 50 nm. Phases related to rutile and SnO2 present in other tin titanates were shown by the XRD analysis. The powders and composite were evaluated in the removal of the fomesafen molecule, which is an herbicide widely used in a variety of crops, by changing the initial pollutant concentration, sorbent dosage and initial pH. The best removal percentages (92 and over 80%) were achieved by slurry and floatable composite systems, respectively, with initial concentration of 10 mg/L of this pesticide. Similarly, experiments with different initial pH and initial dosage of this contaminant (20 ppm) were conducted. Maximal adsorption percentages of 82 and 81% were reached with neutral and acid solutions, respectively. The TOC analysis demonstrated that solutions with higher initial concentration of this herbicide (20 ppm instead of 10 ppm) favored the removal process. The XPS and FTIR analysis revealed that the pollutant could be removed by the effect of electrostatic and electronic attraction between fomesafen and the TSn@RhB composite. The use of practical coating materials and this novel floatable composite as adsorbent material is a promising alternative in the remediation of contaminated agricultural water and other environmental applications.

Automated summary

A tin titanate composite was synthesized and characterized, showing promising potential for the removal of fomesafen pesticide. Higher initial concentrations of the pollutant were found to be favorable for the removal process.