Bioadsorbent Efficiency in Heavy Metal Removal from Aqueous Solutions: Adsorption Kinetics, Isotherm, and Thermodynamics

Heavy metals are major pollutants in marine, soil, industrial, and even treated wastewater. These metals are transported by flowing waters and polluted water sources downstream of the industrial site. Mercury is an extremely toxically heavy metal. Mercury, on the other hand, is an extremely toxically heavy metal. Mercury spillage is hazardous for it destroys the tissue, lungs, brain, and can affect the nervous systems and kidney, causing some diseases. Therefore, removing Hg (II) from drinking water, aqueous solutions is very important in wastewater treatment and hydrometallurgical. 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 is self-progressing and endothermic. The data obtained show that rice grains can be considered a cheap, practical, and effective adsorbent for Hg (II) adsorption from wastewater