The global water crisis is a complex issue that affects millions of people worldwide. According to the United Nations, over 2 billion people lack access to safe drinking water, and water-borne diseases are a leading cause of death in many developing countries. On the other hand, pollution contributes to this crisis worldwide and the sources of water pollution are diverse and widespread. Industrial activities, such as mining and manufacturingManufacturing, release toxic chemicals and heavy metals into waterways. According to the above, the efficiency of a composite material made from autoclaved cellular concrete and industrial jarosite wasteJarosite waste in adsorbing Cr(III) from synthetic solutions has been investigated. This study aimed to valorize toxic jarosite waste and provide an innovative solution for remediating waters contaminated with heavy metals. The material was prepared by mixing silica sand, cement, lime, aluminumAluminum, gypsum, and jarosite, then autoclaving at 190 °C for 12 h. The resulting material was characterized and tested for Cr(III)Chromium adsorption adsorptionAdsorption capacity. Preliminary result showed that jarosite-free samples achieved 64.2% adsorption at pH 7 and 30 °C. Adding jarosite improved adsorption, with 84.1% achieved at 0.10% jarosite content. This study highlights the potential of this composite material for heavy metal removal from contaminated waters, with optimal conditions identified at pH 7 and 30 °C. The findings suggest a promising solution for waterWater remediation remediationRemediation while valorizing toxic jarosite wasteJarosite waste.