Removal of As(III)/As(V) from aqueous solution using newly developed thiosalicylic acid coated magnetite [TSA@Fe3O4] nanoparticles.

The aim of this study was to develop an affordable adsorption methodology for removal of As(III)/As(V) from contaminated water. Herein, novel adsorbent TSA@Fe3O4 nanoparticles (NPs) were synthesized by decorating thiosalicylic acid (TSA) on magnetite nanoparticles (Fe3O4 NPs) and employed for removal of As(III)/As(V) species from artificially contaminated natural water systems. TSA@Fe3O4 NPs demonstrated excellent adsorption efficiency (AE) and 98% of As(V) and 93% of As(III) was removed at optimized experimental conditions. The adsorption kinetic and equilibrium isotherm studies were conducted preferentially for As(III) adsorption. Adsorption followed the pseudo-second-order kinetic (R2 = 99%) and adsorption data fitted well in Langmuir isotherm model (R2 = 99%) and maximum adsorption capacity (Qmax = 34.1 mg/g) was calculated for 5 mg/L of As(III) by using 10 mg of TSA@Fe3O4 NPs. The effect of pH, contact time, adsorption dosages, and competitive anions was also examined to identify optimum experimental conditions. The adsorbent was characterized by advanced instrumental techniques to investigate the physicochemical properties and stability of NPs. To comprehend the interactions of As(III) species with adsorbent NPs, NPs were analyzed using XPS and Raman spectroscopy techniques. Both the techniques confirmed that As(III) and As(V) species present simultaneously on adsorbent surface. The TSA@Fe3O4 was regenerated using 0.1 M NaOH. The findings of this study suggested that TSA@Fe3O4 NPs could be considered a potential adsorbent for effective remediation of As(III) and As(V) from contaminated natural water systems.