4th International Conference on Data Science and Applications (ICONDATA), Yalova, Turkey, 4 - 06 July 2021, pp.9
Heavy metals are major pollutants in marine, soil, industrial and even treated wastewater. Most of the point sources of heavy metal contaminants are industrial wastewater from mining, metal processing, tanneries, pharmaceuticals, pesticides, organic chemicals, rubber and plastics, timber, and wood products. Heavy metals are transported by flowing waters and contaminated water sources downstream of the industrial site. Therefore, toxic heavy metals must be removed from wastewater before disposal. As most of the heavy metals discharged into wastewater are toxic and carcinogenic, they pose a serious threat to human health. Mercury is an extremely toxic heavy metal. Mercury spillage is extremely dangerous because it destroys brain tissue, lungs, and could degrade protein leading to toxic effects; it mainly affects the kidney and nervous systems and may cause some ailments and illnesses. In addition, mercury is a mutagen, teratogen and carcinogen that causes embryonical, cytochemical and histopathological events. Therefore, removal of mercury from aqueous solutions, especially drinking water, is very important in hydrometallurgical and wastewater treatment. Various methods have been proposed to remove Hg (II) ion from wastewater. Adsorption method is used as a low-cost, effective, and efficient technique for removing toxic heavy metals from wastewater. Researchers have turned to inexpensive adsorbents such as herbal waste. They used materials such as tea waste, sawdust, oiled coffee beans, tree ferns, chitosan, olive oil waste, orange juice waste, rice husks, algae, and dried herbs as adsorbents. In this study, it is aimed to remove Hg (II) ions from wastewater by using ground rice grains as adsorbents. The effects of contact time, pH, temperature, and initial concentration of mercury on adsorption were investigated using the batch method. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption isotherm models were examined to analyze equilibrium data. It has been determined that the Langmuir isotherm, which provides the best correlation in Hg (II) adsorption, is the isotherm model that best describes the adsorption equilibrium process. In adsorption studies examining pseudo first order kinetic model, pseudo second order kinetic model and intra-particle diffusion model; it was determined that the adsorption process was compatible with the pseudo second order kinetic model. As a result of the analysis of thermodynamic parameters, it was concluded that the adsorption process is a self-progressing and endothermic process. The data obtained show that rice grains can be used as a cheap, useful, and effective adsorbent for the adsorption of Hg (II) from wastewater.