Molecular simulation of the ion exchange behavior of Cu2+, Cd2+ and Pb2+ ions on different zeolites exchanged with sodium

In this research, the molecular dynamics simulation of separating metal ions from water at 298 K using LAMMPS software for LTA, FAU, LTN, THO, NAT and EDI zeolites and electrolyte solutions containing Cu2+, Cd2+ and Pb2+ individually and in pairs of ions have been studied. Among the single ions, the lowest ion exchange rate was Pb2+ and the highest was Cd2+, as well as the adsorption rate and ion exchange, which was directly related to the size of zeolite cavities. The FAU zeolite with the largest cavity diameter had the fastest adsorption rate. The LTA structure with the adsorption of 69% of cadmium and FAU with 46% adsorption had the highest and lowest ion exchange rate. Furthermore, the highest ion displacement in different types of zeolites was related to copper ion due to its low weight. In two cations electrolytes solutions, all the structures tended to adsorb cadmium ion EDI structures with 100% cadmium adsorption and 85% copper, FAU with 78% cadmium adsorption and 40% copper have been shown the highest and lowest selectivity and uptake of cadmium relative to copper, respectively. In addition, for electrolyte containing cadmium and lead, EDI structure with 100% cadmium adsorption against 60% lead and THO structure with 70% cadmium adsorption versus 38% lead had the highest and lowest selectivity for cadmium. In copper-leaded electrolytes, copper was superior to selected. EDI adsorbed 100% copper versus 60% lead, and FAU had a 40% copper uptake, compared to 65% lead.