engleski

Comparative study of mercury(II) removal onto natural and iron-modified zeolite

This paper compares the sorption abilities of natural (NZ) and iron-modified zeolite (FeZ) for removal of mercury(II) ions from aqueous solutions. The influence of pH, initial concentration, solid/liquid ratio and contact time on the sorption efficiency of both sorbent materials was investigated. At the optimal pH=2, the maximum amount of sorbed mercury(II) on the NZ was 0.28 mmol/g and 0.54 mmol/g on the FeZ. It has been observed that a minimum contact time of 600 minutes is required to achieve the maximum sorption capacity for both sorbents. The results showed that the FeZ has a better sorption ability compared to the NZ. The leaching of mercury from saturated sorbents was examined according to the standard leaching method DIN 38414. In a wide pH range, 4.01≤pH≤11.08, the leaching of mercury(II) was observed in the amount of only 0.28 %–0.78 % from NZ and 0.07 %–0.51 % from FeZ. At extreme pH conditions, pH≤3.02 and pH≥12.05, leaching of mercury(II) in an amount of 4–7 % occurs on both sorbents. In conclusion, both sorbent materials could be used for remediation purposes but modification significantly improves the sorption properties of zeolite.

natural zeolite, iron-modified zeolite, mercury(II), sorption, leaching

This paper has been financially supported by the bilateral Croatian-Slovenian project “Natural modified sorbents as materials for remediation of mercury contaminated environment” (2020-2023) and the research programmes “Groundwater and Geochemistry (P1- 0020)” and “Mineral Resources (P1-0025)” carried out by the Geological Survey of Slovenia.