Development of sulfonated polystyrene resin-supported tungsten oxide for Pb ion sequestration.

A sulfonated polystyrene resin-supported tungsten oxide (SO-PSWO) was synthesized and evaluated for its efficiency in removing lead (Pb) from aqueous solutions. Morphology, phase purity, structural properties, thermal stability, and elemental composition of SO-PSWO, are evaluated using SEM, XRD, FTIR, TGA, and CHNS analyzers. The ICP-OES technique was utilized for quantitative measurements of the Pb ions. The influence of key parameters such as pH, adsorbent dose, contact time, metal ion concentration, temperature, and interference of competing ions on Pb removal is systematically investigated. Under optimum conditions (pH 3.5-5.5), SO-PSWO achieved a maximum Pb removal efficiency of 99.7% within one hour and demonstrated an exceptional adsorption capacity of 386 mg g, as described by the Langmuir isotherm model. Kinetic analysis revealed a pseudo-second-order mechanism, highlighting chemisorption as the predominant process. Thermodynamic studies indicated an exothermic and spontaneous adsorption behavior. With its easy synthesis, cost-effectiveness, rapid kinetics, high adsorption capacity, and superior efficiency, SO-PSWO emerges as a promising material for the remediation of Pb contamination in water treatment applications.