In this study, a unique polystyrene sulfonic acid (PSSA) has been synthesized by chemical recycling of waste expanded polystyrene used for fridge packing. Polystyrene sulfonic acid has been used for the preparation of polystyrene composites with silicon dioxide in three percentages 5%, 10%, and 20%. FT-IR, 1H-NMR, and 13C-NMR spectroscopic analysis of the obtained materials confirmed their structure. Scanning electron microscopy (SEM) was used to examine the surface morphology of the prepared materials. The crystallinity of the polymer composite was observed through XRD (X-ray diffraction) techniques, and its thermal stability with thermogravimetry (TG) processes was studied. Furthermore, polystyrene sulfonic acid and its composites with silicon dioxide were used as solid adsorbents for decontaminating organic dye-contaminated water. PSSA/Silicon dioxide composites could regenerate the methylene blue MB for a maximum of four cycles without losing their adsorption efficiency.