stream of the industrial site. Mercury is a highly toxically heavy metal. Mercury, on the other hand, is a highly toxically heavy metal. Mercury spillage is hazardous for it destroys the tissue, lungs, brain, and can affect the nervous systems and kidneys, causing some diseases. Therefore, removing Hg (II) from drinking water, aqueous solutions is essential in wastewater treatment and hydrometallurgical. A diverse process has been suggested to eliminate Hg (II) ions from wastewater. The adsorption method is used as a low-cost, efficient, and effective technique for removing toxically heavy metals from wastewater. Researchers have turned to inexpensive adsorbents such as vegetable wastes. This study aimed to remove Hg (II) ions from wastewater by using ground rice grains as adsorbents. The suitability of different isotherm and kinetic models for the adsorption process was researched. It was determined that the Langmuir isotherm best describes the adsorption equilibrium process, and the pseudo-second-order kinetic model is the most suitable model for adsorption. As a result of the analysis of thermodynamic parameters, it was concluded that the adsorption mechanism proceeds spontaneously and has an endothermic character. The data obtained show that rice grains can be considered a cheap, practical, and effective adsorbent for Hg (II) adsorption from wastewater.