Health & Environmental Research Online (HERO)


Inorganic Mercury Salts (2)


12,165 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Unique phenotypes in the sperm of the earthworm Eudrilus eugeniae for assessing radiation hazards

Authors: Yesudhason, BV; Jegathambigai, J; Thangasamy, PA; Lakshmanan, DD; Selvan Christyraj, JR; Sathya Balasingh Thangapandi, EJ; Krishnan, M; Sivasubramaniam, S (In Press) Environmental Monitoring and Assessment. HERO ID: 1337640

[Less] The earthworm, Eudrilus eugeniae is a segmented worm. It has two pairs of testes whose cells are highly . . . [More] The earthworm, Eudrilus eugeniae is a segmented worm. It has two pairs of testes whose cells are highly proliferative. It was found that the earthworm, which is irradiated with X-ray, shows the following phenotypic changes in its sperm: fragmented acrosome in the head, break in the tail, and the appearance of zigzag sperm tail. Sperm morphology can be used as a tool to study radiation hazards in local areas. These three phenotypes were not observed in the sperm of worms exposed to different concentration of toxic chemicals such as sodium arsenate, lead acetate, and mercuric chloride. In contrast, exposure of worms to ethidium bromide caused fragmented acrosome in the head of their sperm cells.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Mercury distribution and speciation in biochar particles reacted with contaminated sediment up to 1030 days: A synchrotron-based study

Authors: Liu, P; Ptacek, CJ; Blowes, DW; Finfrock, YZ (2019) Science of the Total Environment 662:915-922. HERO ID: 5020489

[Less] A previous long-term microcosm experiment showed mercury (Hg) in the aqueous phase of contaminated sediment . . . [More] A previous long-term microcosm experiment showed mercury (Hg) in the aqueous phase of contaminated sediment was effectively stabilized through the addition of biochar. The present study focuses on the application of synchrotron-related methods to evaluate the distribution and speciation of Hg in the biochar particles reacted for 235, 387, and 1030 days. The study provided more information on Hg stabilization mechanisms in addition to the information obtained by the previous studies. Confocal micro-X-ray fluorescence imaging (CMXRFI) and micro-X-ray fluorescence (micro-XRF) maps show that mercury co-exists with S, Cu, Fe, Mn, and Zn on the surface and inside the particles of biochar. Extended X-ray absorption fine structure (EXAFS) modeling shows that Hg is in an oxide form on the surface of an iron (hydro)oxide particle from fresh sediment and in Hg-sulfide forms in biochar samples. S X-ray absorption near-edge structure (XANES) analyses show that sulfide is present within the biochar particles. After amendment with biochars, a fraction of the Hg originally present in unstable forms (dissolvable, HgO, colloidal, nano, etc.) in the sediment was likely stabilized as less soluble Hg-sulfide phases on the surface or within the biochar particle. These results suggest Hg accumulation by the biochar particles renders it less potential for transport and bioavailability.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Impact of dissolved organic matter on mercury and methylmercury sorption to activated carbon in soils: implications for remediation

Authors: Schwartz, GE; Sanders, JP; Mcburney, AM; Brown, SS; Ghosh, U; Gilmour, CC (2019) Environmental Science: Processes & Impacts 21:485-496. HERO ID: 5020428

[Less] Activated carbon (AC) amendments have shown promise in reducing inorganic mercury (Hg(ii) complexes, . . . [More] Activated carbon (AC) amendments have shown promise in reducing inorganic mercury (Hg(ii) complexes, "Hg") and methylmercury (MeHg) risk in contaminated soils. However, the effectiveness of AC in Hg and MeHg immobilization has varied among studies, suggesting that site biogeochemistry might dictate efficacy. In this study, we examined the effect of dissolved organic matter (DOM) on MeHg and Hg sorption to AC. We evaluated the impact of Suwannee River Humic Acid (SRHA) on sorption to AC directly using an isotherm approach and in a soil/AC mixture using slurry microcosms. Aqueous sorption coefficients to AC (log KAC) for Hg-SRHA and MeHg-SRHA complexes were one to two orders of magnitude lower (Hg-SRHA = 4.53, MeHgSRHA = 4.35) than those for chloride complexes (HgCl2 = 6.55, MeHgCl = 4.90) and more closely resembled the log KAC of SRHA (3.64). In anoxic, sulfidic soil slurries, the KAC for sulfide species appeared stronger than for chloride or SRHA species for both Hg and MeHg. AC significantly reduced porewater concentrations of both ambient MeHg and a fresh Me199Hg spike, and the addition of up to 60 mg L-1 SRHA did not reduce sorption to AC. The AC also reduced ambient Hg and 201Hg porewater concentrations, but as SRHA concentration increased, the magnitude of solid phase sorption decreased. Speciation modeling revealed that SRHA may have impacted Hg distribution to the solid phase by reducing HgS precipitation. This study highlights the need for site-specific evaluation of AC efficacy and the value in developing biogeochemical models of AC performance for Hg control.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Rapid pre-concentration of mercury in solids and water for isotopic analysis

Authors: Janssen, SE; Lepak, RF; Tate, MT; Ogorek, JM; Dewild, JF; Babiarz, CL; Hurley, JP; Krabbenhoft, DP (2019) Analytica Chimica Acta 1054:95-103. HERO ID: 5020554

[Less] The precise quantification of mercury (Hg) stable isotope compositions in low concentration or dilute . . . [More] The precise quantification of mercury (Hg) stable isotope compositions in low concentration or dilute samples poses analytical challenges due to Hg mass limitations. Common Hg pre-concentration procedures require extended processing times, making rapid Hg stable isotope measurements challenging. Here we present a modified pre-concentration method that combines commonly used Hg reduction and gold trap amalgamation followed by semi-rapid thermal desorption (less than 1 h) and chemical trapping. This custom designed system was demonstrated to perform adequately on multiple trapping matrices including a new bromine monochloride (BrCl) wet oxidant trap (40% 3HNO3:BrCl), capable of trapping consistently in 2 mL volume over a wide range of Hg masses (5-200 ng). The procedure was also shown to work effectively on natural matrices, waters and sediments, producing comparable isotope results to the direct digestion analyses. Here, we present a method that can effectively triple sample throughput in comparison to traditional procedures, and also access lower concentration matrices without compromising the accuracy or precision of Hg isotope measurements.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Chronic exposure to inorganic mercury alters stress responses in male prairie voles (Microtus ochrogaster)

Authors: Soto, M; Lewis, R; Curtis, JT (2019) Hormones and Behavior 109:53-55. HERO ID: 5020770

[Less] Male, but not female, prairie voles that experience chronic exposure to inorganic mercury display aberrant . . . [More] Male, but not female, prairie voles that experience chronic exposure to inorganic mercury display aberrant social behavior - avoiding unfamiliar conspecifics rather than approaching them. The mechanisms that underlie such behavioral changes are unknown, but likely involve the hypothalamus-pituitary-adrenal (HPA) axis. We tested this hypothesis by providing voles of both sexes with mercury chloride in their drinking water for ten weeks and then staging same-sex dyadic encounters after which plasma was assayed for corticosterone as an index of HPA activity. Consistent with sex-specific behavioral responses previously reported, mercury-treated males had lower plasma corticosterone after social encounters than did similarly-treated females or males that consumed normal drinking water. The results suggest that mercury-treated males may be less inclined toward social engagement with conspecifics due to reduced HPA activity.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Promoter Effects of Functional Groups of Hydroxide-Conductive Membranes on Advanced CO2 Electroreduction to Formate

Authors: Wang, M; Preston, N; Xu, N; Wei, Y; Liu, Y; Qiao, J (2019) ACS Applied Materials & Interfaces 11:6881-6889. HERO ID: 5020560

[Less] The electrochemical reduction of CO2 at ambient conditions provides a latent solution of turning waste . . . [More] The electrochemical reduction of CO2 at ambient conditions provides a latent solution of turning waste greenhouse gases into commodity chemicals or fuels; however, a satisfactory ion-conducting membrane for maximizing the performance of a CO2 electrolyzer has not been developed. Here, we report the synthesis of a sequence of hydroxide-conductive polymer membranes, which are based on polymer composites of poly(vinyl alcohol)/Guar hydroxypropyltrimonium chloride, for use in CO2 electrolysis. The effect of different membrane functional groups, including thiophene, hydroxybenzyl, and dimethyloctanal, on the efficiency and selectivity of CO2 electroreduction to formate is thoroughly evaluated. The membrane incorporating thiophene groups exhibits the highest Faradaic efficiency of 71.5% at an applied potential of -1.64 V versus saturated calomel electrode (SCE) for formate. In comparison, membranes containing hydroxybenzyl and dimethyloctanal groups produced lower efficiencies of 67.6 and 68.6%, respectively, whereas the commercial Nafion 212 membrane was only 57.6% efficient. The improved efficiency and selectivity of membranes containing thiophene groups are attributed to a significantly increased hydroxide conductivity (0.105 S cm-1), excellent physicochemical properties, and the simultaneous attenuation of formate product crossover.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Photolysis of chloral hydrate in water with 254 nm ultraviolet: Kinetics, influencing factors, mechanisms, and products

Authors: Gan, Y; Ma, S; Guo, X; Chen, B; Jassby, D (2019) HERO ID: 5020703

[Less] Chloral hydrate (CH) is a common disinfection by-product found in treated water, and its effective control . . . [More] Chloral hydrate (CH) is a common disinfection by-product found in treated water, and its effective control is important to human health. This study evaluated the effects of some environmental factors (e.g., pH, CH dosage, typical ions) and operational variables (e.g., lamp power, irradiation time) on CH photolysis efficiency via low-pressure mercury lamp-induced ultraviolet (LPUV) at 254 nm. The results demonstrated that the photolysis rate increased significantly with increasing pH from 7.0 to 10.5 and lamp power from 6 to 12 W. Meanwhile, the presence of nitrate, iodide, or free chlorine facilitated CH photolysis, whereas the existence of natural organic matter hindered the process. Together, these factors may help explain varying CH photolysis in different types of waters: seawater > ultrapure water > tap water > lake water. In addition, the initial CH dosage also played an important role, with higher CH being degraded more slowly. Mechanistically, although no catalyst or oxidant was added, CH photolysis was to some extent inhibited by a hydroxyl radical quencher, tert-butyl alcohol, suggesting that indirect photolysis was also responsible for CH loss. In terms of reaction products, the CH photolysis yielded primarily chloride ions and carbon dioxide, thus supporting mineralization as the key pathway. The results may help better understand the control of CH in water using UV.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Mn3O4 with different morphologies tuned through one-step electrochemical method for high-performance lithium-ion batteries anode

Authors: Yang, Y; Huang, X; Xiang, Y; Chen, Shu; Guo, Lei; Leng, S; Shi, Wei (2019) HERO ID: 5020968

[Less] A simple, green, efficient, and controllable electrochemical potential perturbation method has been . . . [More] A simple, green, efficient, and controllable electrochemical potential perturbation method has been developed to synthesize Mn3O4 nanomaterials. No toxic or explosive chemicals are used during the fabrication process. Taking pure Mn metal as the working electrode and 2 M KCl aqueous solution as the electrolyte solution, the Mn3O4 products with rod-like, spherical-like and mixed structures can be obtained through cyclic voltammetry technology under rapid scan rates of 5, 200 and 50 V s(-1) within a potential range of -2.0 to 2.0 V (vs Saturated calomel electrode, SCE), respectively. Rapid and repeated redox treatment of Mn metal surface accompanying intense oxygen and hydrogen evolution will lead to the dispersion of Mn metal and the formation of the Mn3O4 nanomaterials. The lithium-ion storage behaviors of these as-fabricated Mn3O4 nanomaterials have been studied contrastively, showing that the spherical-like Mn3O4-S nanoparticles with the highest Li-ion chemical diffusion coefficient display the best cycling stability and rate capability. As a consequence, it shows an excellent specific capacity of up to 780 mAh g(-1) after 250 cycles a high rate of 1000 mA g(-1) and a good rate capability of 895, 798, 722, 683, 601 and 530 mAh g(-1) at current densities of 200, 500, 800, 1000, 1500 and 2000 mA g(-1), respectively. This work is of importance for energy storage as it provides a new and efficient electrochemical way for the fabrication of anode materials for the next-generation LIBs with outstanding electrochemical performances. (C) 2018 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Identification of pigments in the Annunciation sculptural group (Cordoba, Spain) by micro-Raman spectroscopy

Authors: Cosano, D; Esquivel, D; Costa, CM; Jiménez-Sanchidrián, C; Ruiz, JR (2019) HERO ID: 5020483

[Less] A highly flexible method based on micro-Raman spectroscopy was used to examine pigment traces on an . . . [More] A highly flexible method based on micro-Raman spectroscopy was used to examine pigment traces on an Annunciation sculpture group dating from the late Middle Ages. The group comprises a statue of the Archangel Gabriel and another of the Virgin Mary. Both are currently housed in the Archaeological Museum of Cordoba, southern Spain. Information about the pigment palette used by the artists of the time to decorate religious limestone sculptures was for the first time obtained. The pigments found included vermilion (HgS), hematite (α-Fe2O3), azurite [Cu3(CO3)2(OH)2], cerussite (PbCO3) and anatase (TiO2). None was directly applied to the sculptures; rather, the limestone was coated with a primer containing calcium carbonate (possibly chalk or half-chalk). The polychromy on both sculptures, which was originally applied in the XV century and seriously damaged in the XVIII, had been treated with an ochre-coloured priming layer of gypsum to make it more uniform and optically similar to the underlying stone.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Environmental Mercury Chemistry - In Silico

Authors: Asaduzzaman, A; Riccardi, D; Afaneh, AT; Cooper, SJ; Smith, JC; Wang, F; Parks, JM; Schreckenbach, G (2019) Accounts of Chemical Research 52:379-388. HERO ID: 5020485

[Less] Mercury (Hg) is a global environmental contaminant. Major anthropogenic sources of Hg emission include . . . [More] Mercury (Hg) is a global environmental contaminant. Major anthropogenic sources of Hg emission include gold mining and the burning of fossil fuels. Once deposited in aquatic environments, Hg can undergo redox reactions, form complexes with ligands, and adsorb onto particles. It can also be methylated by microorganisms. Mercury, especially its methylated form methylmercury, can be taken up by organisms, where it bioaccumulates and biomagnifies in the food chain, leading to detrimental effects on ecosystem and human health. In support of the recently enforced Minamata Convention on Mercury, a legally binding international convention aimed at reducing the anthropogenic emission of-and human exposure to-Hg, its global biogeochemical cycle must be understood. Thus, a detailed understanding of the molecular-level interactions of Hg is crucial. The ongoing rapid development of hardware and methods has brought computational chemistry to a point that it can usefully inform environmental science. This is particularly true for Hg, which is difficult to handle experimentally due to its ultratrace concentrations in the environment and its toxicity. The current account provides a synopsis of the application of computational chemistry to filling several major knowledge gaps in environmental Hg chemistry that have not been adequately addressed experimentally. Environmental Hg chemistry requires defining the factors that determine the relative affinities of different ligands for Hg species, as they are critical for understanding its speciation, transformation and bioaccumulation in the environment. Formation constants and the nature of bonding have been determined computationally for environmentally relevant Hg(II) complexes such as chlorides, hydroxides, sulfides and selenides, in various physical phases. Quantum chemistry has been used to determine the driving forces behind the speciation of Hg with hydrochalcogenide and halide ligands. Of particular importance is the detailed characterization of solvation effects. Indeed, the aqueous phase reverses trends in affinities found computationally in the gas phase. Computation has also been used to investigate complexes of methylmercury with (seleno)amino acids, providing a molecular-level understanding of the toxicological antagonism between Hg and selenium (Se). Furthermore, evidence is emerging that ice surfaces play an important role in Hg transport and transformation in polar and alpine regions. Therefore, the diffusion of Hg and its ions through an idealized ice surface has been characterized. Microorganisms are major players in environmental mercury cycling. Some methylate inorganic Hg species, whereas others demethylate methylmercury. Quantum chemistry has been used to investigate catalytic mechanisms of enzymatic Hg methylation and demethylation. The complex interplay between the myriad chemical reactions and transport properties both in and outside microbial cells determines net biogeochemical cycling. Prospects for scaling up molecular work to obtain a mechanistic understanding of Hg cycling with comprehensive multiscale biogeochemical modeling are also discussed.