Heterocycles, including imidazole derivatives, are important chemicals due to their structural similarity to active natural molecules. This study explored the utilization of phenylimidazole ...derivatives for mercury removal from aqueous solutions. Three derivatives were tested, including one harboring a sulfhydryl functional group, thus offering distinct mercury-binding capabilities. Mercury binding experiments revealed modest mercury binding by two derivatives. However, extraordinary efficiency of mercury binding by the sulfhydryl-bearing compound was demonstrated through a reduction in mercury concentrations in pure water by 43-fold in just 15 min and decreasing below the analytical detection limit with prolonged exposure (30 min). Moreover, the ultra-efficiency of mercury binding was demonstrated by a capability to reduce mercury concentrations even in highly contaminated environmental water sample by a factor exceeding 1200-fold in 20 h, using minimal amounts of the compound. This phenylimidazole derivative exhibited comparable efficiency in binding mercury from authentic environmental water samples, hinting at practical applications for real-world remediation efforts. Kinetic investigations showed a pseudo-first order reaction with a rate constant of 0.26 min
−1
and half-life of 2.69 min that governs mercury binding to this phenylimidazole derivative. These findings underscore the potential of the sulfhydryl-containing phenylimidazole derivative, as swift and effective binding material for aqueous mercury removal. Its rapid action, coupled with binding efficiency, suggests a promising material for addressing mercury contamination in highly contaminated environmental water samples.
Mercury (Hg/TOC) spikes from eight Permian–Triassic boundary (PTB) sections in this study display patterns similar to each other across the so-called extinction interval as well as strong variation ...in sedimentation rates from section to section. Mercury may have been originated from the synchronous magmatism of the Siberian Traps Large Igneous Province (STLIP).
At the GSSP in Meishan, China, Hg/TOC peaks were observed in the latest Permian mass extinction interval (LPME) and Early Triassic mass extinctions (ETME). The successions at Hovea-3 (Australia), Ursula Creek (Canada), Idrijca (Slovenia), Rizvanuša (Croatia) exhibit Hg/TOC peaks at the LPME and PTB. The Rizvanuša section displays one peak at the ETME horizon, Zal and Abadeh (Iran) successions at the LPME and ETME horizons, while Misci/Seres (Tyrol/Italy) section shows an enrichment at the LPME. The largest Hg/TOC peaks at the LPME, PTB and ETME are, perhaps, linked to the beginning of stage 2 (extrusive hiatus) of the Siberian Traps LIP. The meaning of the Hg/TOC spike between the LPME event and the PTB in seven of these sections is fuzzy.
In the δ202Hg (MDF) vs Δ201Hg (MIF) cross plot, the majority of samples from the extinction interval appear within the volcanic-emission box and a few samples plot in the sediment/soil/peat box. Hg-isotope signatures resulted from mixing processes of volcanic and normal marine sediment Hg, generating four horizontal trends whose Δ201Hg shows negligible to no variation. Less terrigenous-Hg influx was noticed in the sections closer to the STLIP (Rizvanuša, Idrijca and Seres/Misci, all in Europe) in which Δ201Hg (MIF) is close to zero. Marked influence occurs in sections far distant from the STLIP (Meishan, Ursula Creek and Hovea-3) that exhibit negative Δ201Hg (MIF). The two sections from Iran, at intermediate distance from the STLIP, exhibit the highest, positive Δ201Hg values (Abadeh section) and the lowest, negative Δ201Hg values (Zal section). A Δ199Hg (MIF) vs Hg (n·ng−1) cross plot suggests that volcanic Hg has been contaminated by normal marine source-Hg influx in these sections helping to shape two major curved trends.
The negative C-isotope excursions and Hg/TOC enrichments in the studied sections are nearly coeval and this supports the hypothesis of synchronism between the Permian–Triassic transition biotic crises (LPME and ETME) and the start of the stage 2 of the Siberian Traps (sill-intrusion style of magmatism).
•Hg/TOC pathways across the extinction interval from eight PTB sections are similar.•Hg/TOC peaks at LPME, PTB and ETME are linked to stage 2 of Siberian Traps volcanism.•In δ202Hg vs Δ201Hg plot samples from the extinction interval plot in the volcanic box•Low terrigenous-Hg influx is noticed in sections closer to the STLIP.•High terrigenous-Hg influence occurs in sections far distant the STLIP.
The investigation of Idrija, one of the oldest mining areas in Slovenia, is an on-going field of geochemical research. Over 500years of Hg mining and ore processing resulted in widespread ...contamination, especially in soil. Past investigations showed that soil in the Idrija surroundings is seriously contaminated on a regional scale (160km2 area), mainly due to aerial emissions from an ore roasting plant in the past. This study focuses on the soil from the urban area of Idrija (3km2). Following a sampling model grid, which was developed for collection of 9 soil samples per km2, 45 sampling sites were selected and sampled. Concentrations of 10 potentially harmful elements (As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Zn) were determined using aqua regia digestion. Soil samples were taken from two different depths (0–10cm and 10–20cm) in order to distinguish between possible different element sources. The results showed that only Hg concentrations were extremely high in comparison to element concentrations reported in other areas around the world, and national guidelines for soil contamination. Mercury ranges from 8 to 1210mg/kg with a median of 60mg/kg in topsoil and from 7 to 1550mg/kg, with a median of 50mg/kg in subsoil. Spatial analysis show that high Hg concentrations occur near the identified Hg sources (rocks containing Hg ore, Hg ore residue dumps and old roasting sites). High Hg concentrations cause concern, because the soil in Idrija area is often used for vegetable gardening.
•Systematic soil sampling was performed to investigate element contents•Determination of PHE concentrations in the urban soil of Idrija•Urban soil in Idrija is critically polluted with mercury•PHE, except Hg, are within representative background soil concentrations
Soil degradation is a major environmental problem in many parts of the world, including Slovenia. The spatially distributed WATEM/SEDEM model can be used to identify the most critical parts of the ...catchment with regard to soil erosion. Five Slovenian (Central Europe) catchments with inhomogeneous topography, land use, geological conditions, hydro-meteorological properties and sizes (catchment areas between 1 and 2000 km²) were modeled with calibrated parameters, while the WATEM/SEDEM model was calibrated with an automatic parameter estimation procedure, which is model independent. Both direct and indirect information regarding sediment yields, including turbidity measurements, daily suspended sediment concentration observations and bed load observations, were used for the WATEM/SEDEM model’s calibration. A detailed rainfall erosivity (R) factor map, which was constructed from 5-min rainfall data from 31 pluviographic meteorological stations, was used as one of the inputs for the WATEM/SEDEM model. The calculated mean annual soil loss was between 0.3 and 7.4 t/ha/year, and the sediment delivery ratio (SDR) ranged from 0.07 to 0.22 for 5 modeled catchments. The results indicate that the SDR decreases with increasing catchment area; however, the ratio between the average sediment yield and mean soil erosion obviously depends on many other factors, e.g., topography, climatic and geological conditions. The parcel trap efficiency parameter for forests had the greatest influence on the WATEM/SEDEM model’s outputs in all five case studies.
The influence of geomorphological factors to Hg contamination of the Idrijca River alluvial sediments because of the historical mining and ore roasting activities has been studied. Main source of Hg ...in alluvial sediments was dumping of ore roasting residues and mining waste into the river channel and its erosion downstream. The position of the material in relation to the geomorphological properties is highly related with its Hg content. Floodplains were found to be the most contaminated geomorphological units (mean Hg content 335
mg/kg), with Hg concentration rapidly dropping in the first terrace (155
mg/kg). The least contaminated material was found in the higher terraces (3.8
mg/kg). Sampling upstream Idrija (average Hg content is 22.1
mg/kg) shows that not only mine and ore roasting plant increased Hg levels in alluvial deposits but also contaminated sites upstream Idrija contribute to Hg contamination. Geochemical background for alluvial sediments for this area is estimated to be 0.75
mg/kg. Downstream Idrija, 9 hotspots were determined where highly contaminated material is actively eroded and carries a high risk of further contamination of the Soča River and northern Adriatic Sea ecosystems.
► Hg contamination of alluvial sediment because of mining tradition in Idrija. ► High rate of contamination, up to 2000
mg/kg, enrichment factors up to 15,000. ► Floodplain most contaminated geomorphological unit. ► Exponential decrease of contamination in relation to the distance from the source. ► Geochemical background for Hg in alluvial sediments estimated to 0.75
mg/kg.
The distribution and transport of Hg and other elements were studied in aquatic systems draining contaminated ancient Hg ore roasting sites Pšenk and Frbejžene trate in Idrija surroundings. Hg ...concentrations in sediments at the studied roasting site areas were found extremely high, ranging from 18 to 1240mg/kg (average 387mg/kg) in the <0.063mm grain-size fraction, and from 48 to 1080 (average 456mg/kg) in the <0.125mm fraction. Further downstream along the Padarjeva grapa Stream, which drains both contaminated areas, Hg concentrations were 330–2040 (average 721mg/kg; for <0.125mm) and 380–840 (average 531mg/kg; for <0.04mm). Increased Hg concentrations were found in the Idrijca River sediments downstream of the Padarjeva grapa Stream confluence. The results of our investigation have proved that Hg-loaded materials are not only still present at the roasting sites, but are intensively eroded and transported downstream during high waters. Consequently they have significant influence on the Idrijca River sediment contamination. Delivery of Hg contaminants from historically contaminated roasting sites via Padarjeva grapa Stream during heavy rainfalls was most intense during operation of the roasting sites, but remains an ongoing issue.
•Stream sediments are highly contaminated with Hg.•Strong effect of ancient Hg ore roasting sites on the Idrijca River sediment contamination•Delivery of Hg by storm waters from ancient roasting sites is an ongoing issue.
Mercury mining in Idrija has profoundly changed environmental conditions in the Idrijca River basin. Impacts of mining-related activities on the river system and its ichthyofauna from circa 1490 ...until World War I were analysed. Literature and archival sources were both studied. Heavy water pollution with mercury and its components, the floating of wood using splash dams in order to create artificial flood waves, fishing and stocking of non-indigenous fish species were the factors identified contributing to major impacts on ichthyofauna. Fish statistics make clear that after four centuries of mercury production ichthyofauna in the Idrijca was by no means the most industrially affected one in Carniola and that there were huge differences among various sections of the Idrijca and its tributaries. We presented the history of fish hatcheries operating from 1876 onward in order to reduce the damage inflicted by mercury mining and related activities and reviewed its impacts on hybridization between marble and brown trout. Introduction of non-native fish was the major threat for the ichthyofauna in comparison to the other mentioned impacts of mercury mining, conducted over long periods but with comparably minor consequences for the survival of the native ichthyofauna.
Results obtained by a laboratory flux measurement system (LFMS) focused on investigating the kinetics of the mercury emission flux (MEF) from contaminated soils of the Idrija Hg-mine region, Slovenia ...are presented. Representative soil samples with respect to total Hg concentrations (4–417 μg g−1) and land cover (forest, meadow and alluvial soil) alongside the River Idrijca were analysed to determine the variation in MEF versus distance from the source, regulating three major environmental parameters comprising soil temperature, soil moisture and solar radiation. MEFs ranged from less than 2 to 530 ng m−2 h−1, with the highest emissions from contaminated alluvial soils and soils near the mining district in the town of Idrija. A significant decrease of MEF was then observed with increasing distance from these sites. The results revealed a strong positive effect of all three parameters investigated on momentum MEF. The light-induced flux was shown to be independent of the soil temperature, while the soil aqueous phase seems to be responsible for recharging the pool of mercury in the soil available for both the light- and thermally-induced flux. The overall flux response to simulated environmental conditions depends greatly on the form of Hg in the soil. Higher activation energies are required for the overall process to occur in soils where insoluble cinnabar prevails compared to soils where more mobile Hg forms and forms available for transformation processes are dominant.
In the town of Idrija, Slovenia, the world's second largest mercury mine was active for 500 years and about 37,000 tons of mercury has been lost in the environment. Mercury is still drained from ...soil, riverbed and floodplains and transported with the Idrijca and Soča Rivers to the Gulf of Trieste. A part of inorganic mercury is methylated either in the river system, or later in the coastal area, and, due to its bioaccumulation and biomagnification represents potential danger to human health. A 1-D aquatic model MeRiMod was used to simulate hydrodynamics and sediment transport in the river system from Idrija to the Soča River mouth. Transport of particle bound and dissolved mercury as well as potential net methylation of mercury in the river system was simulated. The simulation of an observed flood wave with 20-year recurrence period was performed in order to validate the model. Methylation was simulated at lower discharges, as higher methylation rates occur in such conditions. The measurement data and the MeRiMod model were also used to establish a historical mercury mass balance of the Idrijca and Soča Rivers catchment. Sediment core data from the Gulf of Trieste and the measured concentrations from floodplains were used to verify and calibrate the model. Simulations of different high discharges were performed as most of the transport of particulate mercury occurs within flood wave conditions. Compared to the measurements, the results of the model showed an agreement within an order of magnitude, for the transport of total mercury mostly within a factor of 4, and for the methylation within a factor of 5. However, proper trends of the phenomena were obtained by simulations. The combination of modelling and measurements has resulted in some interesting conclusions about the phenomenon of the transport and transformations of mercury in the observed river system.
Five centuries of mining and processing of mercury ore in the Idrija area have resulted in widespread contamination of different environmental compartments. Environmental impacts on a regional and ...local scale, caused by atmospheric emissions from the Idrija ore roasting plant, were established in the investigations of mercury spatial distribution in soil and attic dust in 160 km
2
area. Very high values were determined in the Idrijca River valley, and they decrease exponentially with the distance from Idrija. Mercury concentrations in attic dust are higher than in surrounding soils and the attic dust/soil ratio changes with distance. Measurements of mercury in the air confirmed widespread dispersion of mercury and showed highly elevated mercury concentrations around roasting plant and mine ventilation shaft. Beside, systematic monitoring of mercury contents in the stream sediments has demonstrated that huge amounts of mercury are stored in areas where ancient overbank sediments were deposited, and there was no decrease in mercury concentration in active sediments during the last 15 years. Recently, interesting and extremely polluted locations of historical small-scale roasting sites in the Idrija surroundings were discovered. Ongoing geochemical study aims to determine the extreme pollution and significance of these sites for wider contamination of soils and aquatic systems. Presented studies have shown that Hg mining in Idrija caused intense pollution of local and regional environment including the aquatic systems in the Gulf of Trieste, which is seen as the final sink of a major part of the Hg stored in soils and river sediments in the Idrija area.
PDF
