Study of the metal ion adsorption capacity of palygorskite by computer simulation

Abstract

Palygorskite is a magnesium-rich aluminosilicate clay mineral with a unique chain-layered structure. This structure gives palygorskite a large specific surface area and interesting physical properties. Many researchers have investigated the applications of palygorskite in various fields, including heavy metal adsorption, petroleum and chemical industries, building materials, medicine, and agriculture. In this study, molecular dynamics simulations were used to explore the heavy metal adsorption ability of palygorskite. The results showed that polyacrylic acid (PAA) had a heavy metal adsorption ability. In terms of the ability of the substrate to adsorb Pb2+, Ni2+, and Cr3+, palygorskite (attapulgite, ATP) was more effective than SiO2 or clay. Based on this study, the same phenomenon reported in the literature was confirmed, and it was demonstrated that molecular dynamics could properly simulate the filtration of heavy metal ions in water using novel materials. Moreover, H+ ions were found to play an essential role in assisting PAA/ATP in capturing heavy metal ions. Using this method, we were able to observe the details of heavy-ion adsorption.