“…Heavy metals in water are a severe environmental problem that directly affects human health even at very low concentrations; most of them are considered persistent, nonbiodegradable, and toxic, and must be removed; hence, an enormous amount of research into how to clean water at a lower cost and with less energy is needed. Many methods have been used to remove metals from water, such as ion exchange, chemical precipitation, filtration, electrolytic processes, solvent extraction, adsorption, and biosorption [ 1 , 2 , 3 , 4 , 5 ]. Adsorption is one of the most popular methods due to its simplicity, low cost, efficiency, the regeneration capacity of the adsorbent, no sludge generation, and simple recovery; however, some adsorption mechanisms are still not fully understood [ 3 , 6 , 7 , 8 ].…”