In this study, our goal was to create ZnS nanoparticles (ZSN's) and use them to remove different heavy metals, such as iron and phosphate, from aqueous solutions. A sol-gel process was used to create ZnS nanoparticles, which is a quick and effective way to produce vast quantities of nanoscale ZnS. XRD, IR, UV-vis DRS, BET, and TEM techniques were used to analyze the surface properties and material structure of ZnS. The adsorption capacity of the ZnS (ZSN's) was assessed by several experiments. To determine the ideal conditions for iron and phosphate removal, the pH solution effects (2–10), contact time (10–180 min), adsorbent dosage (20–200 mg), and beginning iron and phosphate concentration (10–200 mg/l) on the capacity of adsorption were examined. Results indicated a high iron and phosphate removal at pH 10 after 120 min with an adsorbent dosage of 10 mg. Iron and phosphate followed the Langmuir isotherm in their adsorption, with maximal adsorption capacities of 23.3 and 31.3 mg/g, respectively. Kinetics data were expressed in a pseudo-second-order mode with R2 values of 0.96 and 0.99 for iron and phosphate. The real samples showed a removal efficiency of 92.2% for iron and 86.5% for phosphate.