Using waste to treat waste: elemental mercury removal from flue gas by coal gasification slag

Regulating Mn-O bond strength by different loading methods to promote elemental mercury removal over brookite TiO2 supported MnOX

The Arctic is undergoing rapid environmental change, with sea-ice loss altering key exchanges among the cryosphere, atmosphere, and biosphere. During spring, atmospheric mercury and ozone depletion events (AMDEs and ODEs) drive rapid declines in gaseous elemental mercury (Hg0) and ozone (O3), promoting mercury deposition to snow, ice, and marine ecosystems. Despite three decades of research, AMDEs have been documented almost exclusively at coastal land-based stations, leaving their occurrence and mechanisms over oceanic sea-ice poorly constrained. To address this gap, we conducted a research cruise in the Arctic marginal ice zone to study the connections between sea-ice and atmospheric Hg chemistry. We measured atmospheric Hg0, reactive gaseous Hg (RGM), and O3 along the cruise track, identifying the simultaneous occurrences of AMDEs and ODEs. Air mass back-trajectory analysis combined with sea-ice images from satellite remote sensing revealed that these depletion events occurred exclusively when air masses originated from over sea-ice and were near its surface. Our findings confirm that Arctic sea-ice plays a pivotal role in initiating AMDEs observed in the marginal ice zone, driven by halogen release from the sea-ice surface. This study advances understanding of the interplay between sea-ice dynamics and atmospheric chemistry, with important implications for Hg deposition in polar ecosystems and the consequences for human and wildlife health, given the potential impacts of a rapidly changing Arctic.

Workers in artisanal and small-scale gold mining (ASGM) are exposed to metals and metalloids (referred to here as "metals") while mixing milled ore and elemental mercury to produce a gold-mercury amalgam. Although concentrations of metals in surface waters near ASGM activities have been described, little is known about concentrations of metals in the water-ore-mercury slurry with which workers have extensive dermal contact. We sought to characterize those concentrations. Water samples (n = 76) were collected from amalgamation basins and milled ore washing ponds at 13 ASGM sites in Western Kenya. Samples were filtered and metals in the filtrate and metals retained on filters were analyzed for trace elements by inductively coupled plasma mass spectrometry (ICP-MS). Based upon the volume filtered and ICP-MS results, total metal concentrations in the original samples (pre-filtration), were calculated. Concentrations of metals in the amalgamation basins were high. The median concentrations of arsenic (240.23µg/L), chromium (312.97µg/L) and total mercury (3.52µg/L) all exceeded Kenya's drinking water standard by several fold. Only 3.38% of arsenic, 0.28% of chromium, 40.51% of manganese, 0.22% of mercury and 0.01% of lead mass were in filtrate, with the remainder of the metal mass retained on filters. Concentrations of arsenic, chromium, manganese and lead to which ASGM workers are exposed in the amalgamation process were approximately 5-100-fold higher concentrations than reported in prior studies of metals in surface waters near ASGM sites. These findings should be useful in assessments of exposure and health risk of the many thousands ASGM workers who amalgamate milled ore. The high concentrations of As, Mn and Hg put at risk the health of children who live near or work at ASGM sites. Policy measures and changes in occupational practices are urgently needed to reduce Hg use in ASGM and to protect individuals from metals present in milled ore.

Enhanced elemental mercury removal using modified natural zeolites: a study on activation methods and adsorption stability

What influences Hg uptake and movement in tree rings?

Corrigendum to “Removal of elemental mercury from coal-fired flue gas by vanadium diselenide”. [Fuel 412 (2026) 138162

Atmospheric mercury depletion events (AMDEs) are a unique phenomenon in polar mercury cycling, involving intense atmospheric mercury oxidation and deposition that amplify marine mercury sinks. The Southern Ocean, a critical hotspot for environmental mercury exposure, exhibits AMDEs whose characteristics and distribution patterns remain unclear. This study presents the observational dataset of atmospheric gaseous elemental mercury (GEM) across the circum-Antarctic Southern Ocean. We observed pronounced summertime AMDEs that drove high spatial heterogeneity in circumpolar GEM distribution. By combining Generalized Additive Models (GAM) simulations with multi-platform observational evidence, we demonstrate that the Antarctic continental outflow largely shapes the circumpolar distribution of summertime AMDEs, concentrating these events within the convergence zones of katabatic winds. This work highlights the critical role of land-sea coupling effects in Antarctic atmospheric chemistry, and underscores the need to systematically assess the implications of these processes for mercury bioavailability across Southern Ocean ecosystems.

Poisoning from mercury has the potential to affect multiple organ systems and can be fatal in some circumstances. We present a case of a patient who had both ingested and inhaled elemental mercury resulting in deposits in his pulmonary and gastrointestinal systems. The patient was admitted to the intensive care unit (ICU) as a precautionary measure but did not require any organ support. The patient was treated with chelation therapy guided by the UK National Poisons Information Service (NPIS) and was discharged from ICU after having a prophylactic appendicectomy due to mercury deposition. This case presented several challenges logistically as there was a need to follow expert guidance with regards to personal protective equipment (PPE) and waste disposal, alongside the clinical requirements.

Abstract Elemental mercury (Hg0) is a pervasive pollutant of global concern. Recent research shows that global Hg0 emissions are significantly underestimated, but the additional sources contributing to this gap are unclear. Here, we demonstrate that chemolithoautotrophic microorganisms, such as sulfur-oxidizing and iron-oxidizing bacteria that are ubiquitous in diverse environments, utilize mercury sulfide (HgS) nanoparticles to support growth while releasing substantial amounts of Hg0. Unlike dissolved Hg(II) species, HgS nanoparticles (HgSNP) are internalized into bacterial cells through an adenosine triphosphate (ATP)-independent, highly energy-efficient process. This enhanced internalization leads to rapid metabolism of HgSNP via sulfur-oxidation, as well as the subsequent reduction of the released Hg(II) to Hg0 mediated by the mer operon, superoxide, or cytochrome c. Our modeling results show that the annual emission flux of Hg° from this previously unrecognized source can reach 272.44 ± 134.99 tons, equivalent to that of geogenic Hg0 emissions and matching that of the fourth largest anthropogenic source, cement production.

ABSTRACT Source separation of municipal solid waste (MSW) is advocated as a sustainable strategy to mitigate pollution from waste-to-energy facilities, yet quantitative, field-based evidence of its impact on mercury (Hg) emissions remains scarce. Here, we investigate the effects of Beijing’s city-wide mandatory waste sorting policy, implemented in 2020, by conducting a comparative study at a representative incinerator before (2019) and after (2021) its enactment. The policy drove a profound 67.7% reduction in the Hg input load to the incinerator, primarily by diverting high-Hg components from the waste stream. This source-level change cascaded through the system, resulting in a dramatic 82% decrease in total Hg emissions from the stack (from 1.35 ± 0.6 to 0.24 ± 0.05 μg/m3). Counterintuitively, the relative abundance of oxidized mercury (Hg2 +) in the final flue gas dropped from 45.5% to 28%. We attribute this to a powerful synergistic mechanism: increased chlorine from a higher proportion of plastics in the sorted waste enhanced the in-furnace and catalytic oxidation of elemental mercury (Hg0), which was then captured with exceptional efficiency by the plant’s advanced air pollution control system. This work provides the first field-scale validation that front-end policy intervention is a highly effective tool for controlling industrial Hg emissions, demonstrating a direct link between public policy and the operational performance of pollution control technologies. Implications: Controlling mercury emissions from municipal solid waste incineration is a significant global environmental challenge, often reliant on expensive end-of-pipe technologies. Our study provides crucial mechanistic evidence demonstrating that waste classification policy is not merely a waste management strategy, but a direct and effective chemical pre-treatment for pollution control. We reveal that by altering waste composition at the source, specifically the chlorine content, mandatory waste sorting fundamentally shifts mercury’s chemical transformation pathways during incineration. This process promotes the oxidation of difficult-to-capture elemental mercury (Hg0) into water-soluble divalent mercury (Hg2 +), which is much more easily removed by existing air pollution control systems. This finding establishes a clear synergistic link between environmental policy and engineering reality: policy can chemically enhance the effectiveness of pollution control technology. Our mercury mass balance and Sankey diagram provide a quantitative model that validates this synergy. Consequently, this research offers a compelling, scientifically-backed rationale for policymakers to implement and enforce stringent waste classification programs as a direct, proactive, and cost-effective strategy for mercury emission reduction. It bridges the gap between policy goals and chemical processes, offering a new paradigm for integrated waste management that simultaneously advances sustainability and protects public health.

Use of mercury in mining 125years ago continues to impact waterfowl populations: Implications for current artisanal gold mining.

Recent progress on the advancements of adsorbent materials in elemental mercury removal from industrial flue gases

Natural organic matter-enhanced atmospheric Hg(0) uptake involves thiol-induced unusual electron transfer from Hg to carboxyl moiety.

CuCl2-modified SWCNTs for elemental mercury removal: Performance, mechanism and potential industrial applications

Br-doped BiOIO3 for efficient and stable photocatalytic oxidation of elemental mercury

Development of urea modified CuO pellets for elemental mercury adsorption from natural gas with H2S

Mercury emissions from acetylene hydrochlorination processes in polyvinyl chloride (PVC) production pose severe environmental risks yet remain poorly quantified due to methodological limitations in high-reactivity C2H2/HCl atmospheres. We reported an advanced operando mercury speciation platform named PVC-OHM, engineered through systematic optimization of the Ontario Hydro method (OHM), achieving simultaneous real-time detection of elemental mercury (Hg0) and divalent mercury (Hg2+) with unprecedented sensitivity (0.12 μg/m3) under industrially relevant conditions. Our mechanistic investigation reveals three dominant mercury escape pathways: (1) thermal desorption, wherein localized hotspots accelerate HgCl2 decomposition and elevate the saturated vapor pressure at carbon-mercury interface (from 0.9 to 20.3 atm), contributed to 80% of total Hg loss; (2) C2H2 driven reductive decomposition of HgCl2 catalyst at carbon-mercury interfaces, responsible for 65-78% of Hg0 emissions and (3) excess chlorine adsorption-induced desorption ([HgCl2/AC] Cl5, Eads > 0) accounting for >10% of Hg2+ emissions. Quantitative tracking demonstrates alarming mercury loss of per gram catalyst (5 wt % Hg) reached as 3.08 mg Hg0 and 9.01 mg Hg2+, directly linked to localized thermal gradients (ΔT = 250-300 °C) at reaction hotspots. This work establishes the first experimentally validated framework for mercury fate prediction in carbide-based PVC synthesis, providing actionable strategies for emission control through hotspot mitigation and coordination environment optimization.

Constant potential electrolysis (CPE) is a widely used approach for conducting organic electrosynthetic reactions, enabling the formation of desired products under prescribed thermodynamic conditions and facilitating accurate mechanistic investigations of electroorganic reactions. A stable reference electrode is essential for CPE, as it continuously monitors the working electrode potential and adjusts the applied driving force accordingly. However, developing a reference electrode that is both stable and free of toxic components, such as elemental mercury or cadmium, remains a significant challenge.Herein, we report the development of a stable reference electrode for electroorganic reactions in nitrogen-containing solvents such as N,N′-dimethylformamide (DMF) and acetonitrile. Our design is based on the widely used Ag/AgCl reference electrode, which is commonly employed in aqueous electrochemical studies. The stability of the Ag/AgCl reference electrode was systematically investigated as a function of the supporting electrolyte, chlorination method, stabilizing reagents, and the ratio of stabilizing reagent to Cl⁻ ions. The electrode's performance was evaluated using extended cyclic voltammetry and constant potential electrolysis experiments. Our results demonstrate that an optimally constructed Ag/AgCl reference electrode exhibits exceptional stability, with a potential variance of ~1 mV over 10 hours of cyclic voltammetry measurements and a deviation of ~10 µV/min in open-circuit studies.

Outstanding Performance of Chalcopyrite (CuFeS ₂ ) for Gaseous Elemental Mercury Adsorption: Mechanism, Kinetics, and Structure–Activity Relationship