Assessment of Natural Zeolite Clinoptilolite for Remediation of Mercury-Contaminated Environment

Abstract

The soil at ancient roasting sites in the surroundings of the Idrija mine (Slovenia) is highly contaminated with mercury. To assess the impact of mercury on groundwater by infiltration and find an eco-friendly remediation method, the leaching of mercury from the soil containing 1347 mg Hg/kg, followed by sorption of the total leached mercury on cost-effective natural zeolite (NZ) clinoptilolite, was performed. The leaching of soil in ultrapure water of pHo = 3.00–11.46 after 24 h resulted in the total leached mercury concentration in the range 0.33–17.43 µg/L. Much higher concentrations (136.9–488.0 µg/L) were determined after the first few hours of leaching and were high above the maximum permissible level in water for human consumption. The NZ showed very good sorption of the total leached mercury, with a maximum removal efficiency of 94.2%. The leaching of mercury in presence of the NZ resulted in a significant decrease of the total leached mercury (1.9–20.3 µg/L compared to 12.8–42.2 µg/L), with removal efficiencies up to 90.5%, indicating immobilization of mercury species. The NZ has a great potential for economically viable remediation of mercury-contaminated environment. However, efforts should be made in the further study of mercury leachability to reduce the mercury concentration in water to acceptable levels.

Comparative study of the sequential methodologies for fractionation analysis of mercury in coal allonge with proximate and ultimate analysis

“…Water soluble fraction of mercury in coal was estimated by DIN test (DIN-38414-S4) provides information about the behavior of solid matrices when it comes in contact with water (Nuić et al 2022). Triplicate 5.0 g of air-dry coal samples from four seams of block-VII of the Thar coalfield were weighed in polyethylene tube.…”