## 1 Introduction  
The study of the formation of water in a medium is a very important area of research. The study of the formation of water in a medium is a very important area of research. ## 1 Introduction  
The global shortage of potable water is a pressing issue, impacting a substantial segment of the world's population, not only in food supply chains or their industrial activities but directly on global health and economy [1]. Human activities, including mining, agriculture, industrial processes, climate change, population growth, and detrimental societal practices, further aggravate this problem through water pollution [2; 3; 4; 5]. Water pollution arises from diverse substances, including physical contaminants like sediments, suspended particles, and abnormal temperature fluctuations. Additionally, biological, radiological, petroleum-based, and chemical contaminants, such as pesticides, solvents, fertilizers, pharmaceutical waste, and heavy metals, contribute to water pollution. Many of these pollutants reach the water through industrial pipes; drainage systems in communities, towns, and large cities; and through poor disposal habits for liquid, solid or gaseous waste. There is also contamination from leaks, poor care in pesticide and fertilizer application protocols, and activities on ships and in industry, especially mining, which has little control over its operations. In general, water pollution seriously affects vital organs of the human body and the nervous system and causes various types of cancer, cardiovascular diseases, among other conditions [6; 7; 8; 9]. Among all the pollutants mentioned above, arsenic and chromium pose significant risks, causing irreversible harm to human health and the environment. Chromium exposure is linked to cancer and neurological damage, whereas arsenic increases the risk of cardiovascular disease, kidney problems, and cancer. The presence of these metals in potable water can have catastrophic consequences, particularly for vulnerable communities reliant on contaminated water sources, due to the lack of attention to the way in which various industrial activities and public and private drainage are carried out [10; 11]. Therefore, it is essential to implement measures to protect and conserve water resources, reduce pollution, and ensure access to safe and healthy water. Currently, removing arsenic and chromium from contaminated water involves various methods based on biological, chemical, and physical techniques. Among the biological methods, phytoremediation uses plants to absorb water contaminants, while bioremediation employs microorganisms to degrade pollutants [12; 13; 14; 15]. Also, the production of biochar through the conversion of plant biomass could be a viable option for As adsorption. However, this process is typically carried out at elevated temperatures [16; 17]. Alternatively, chemical methods, including precipitation, involve introducing chemical reagents to form insoluble compounds with arsenic and chromium ions, which are subsequently removed through sedimentation [18]. In some cases, combustible coal may have arsenic content that is released during such combustion, and leaching studies with ferric chloride have been carried out to remove such As content, which show the clear affinity of Fe for As [19]. On the other hand, removal of Cr(VI) was possible with the synthesis of a compound that combines NiFeMn-layered double hydroxide and Ti3C2 TX MXene into gelatin via a cross-linking reaction [20]. However, all of the above processes can be expensive, and there is no verification that the waste generated is inert. Similarly, other researchers have synthesized magnetic nanoparticles based on nickel-iron supported on graphene oxide for the removal of Cr(III) contained in water, achieving, according to the authors, the preliminary removal of 17 mg/g of Cr(III) ions dissolved in water [21]. Conversely, ion exchange utilizes resins with elements that exchange ions, effectively retaining contaminants [22; 23].