Enhanced elemental mercury removal by facile sulfurization of agrowaste chars

Saman, Norasikin; Johari, Khairiraihanna; Kong, Helen; Mohtar, Safia Syazana; Hassan, Osman; Ali, Noorhalieza; Mat, Hanapi

doi:10.1016/j.cherd.2019.02.010

Cited by 17 publications

(15 citation statements)

References 56 publications

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“…Recently, Saman et al. reviewed the updated uptake capacity of various Hg adsorbents . Thiol‐based adsorbents, which make use of the strong affinity of S and Hg, have been investigated for gaseous elemental Hg removal (e.g., sulfurized agrowaste chars, thiol‐impregnated CaCO 3 ) .…”

Section: Resultsmentioning

confidence: 99%

“…[18] Recently,S aman et al reviewed the updatedu ptake capacity of various Hg adsorbents. [19] Thiol-based adsorbents, which make use of the strong affinity of Sa nd Hg, have been investigated for gaseous elemental Hg removal (e.g.,s ulfurized agrowaste chars, thiol-impregnated CaCO 3 ). [20,21] These adsorbents are mostly complex chemical species that require harsh conditions such as ah igh temperature and the use of energy with no satisfactory recyclability and sustainability.H owever,S arkar et al [21] reported kaolin forH gr emoval from water (not from air).…”

Section: Resultsmentioning

confidence: 99%

“…The adsorption of elemental Hg vapor on kaolin (KaHg)iscompletely physisorption, unlike many other materials used previously. [19] Consequently,w ea re able to remove the absorbed Hg by heating.…”

Section: Influence Of Temperature On the Recovery Of Adsorbedhgmentioning

confidence: 99%

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Natural Kaolin: Sustainable Technology for the Instantaneous and Energy‐Neutral Recycling of Anthropogenic Mercury Emissions

et al. 2019

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Kaolin, a natural and inexpensive clay mineral, is ubiquitous in soil, dirt, and airborne particles. Amongst four commonly available clay minerals, kaolin, as a result of its layered structure, is the most efficient natural gaseous Hg adsorbent to date (Langmuir maximum adsorption capacity Qm=574.08 μg g−1 and Freundlich Qm=756.49 μg g−1). The Hg uptake proceeds by homogeneous monolayer and heterogeneous processes. Hg physisorption on kaolin occurs in the dark, yet the adsorption rate is enhanced upon irradiation. The effects of several metal complexes, salts, halides and solvents on the Hg uptake were examined. The addition of CuCl2 particles leads to a significant enhancement of the Hg uptake capacity (>30 times) within second timescales and without irradiation. The physisorption with kaolin is switched to chemisorption upon the addition of CuCl2 to kaolin. This process is entirely reversible upon the addition of Zn/Sn granules at room temperature without any added energy. However, the investment of a small amount of renewable energy can speed up the process. This technology demonstrates the facile and efficient capture and recycling of elemental Hg0 from air. A wide range of metal particles and diverse physicochemical processes, which include the microphysics of nucleation, are herein examined to explore the potential reaction mechanism by using a suite of complementary analytical techniques. These new mechanistic insights open a new era of energy‐neutral environmental remediation based on natural soil/airborne particles.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Natural Kaolin: Sustainable Technology for the Instantaneous and Energy‐Neutral Recycling of Anthropogenic Mercury Emissions

et al. 2019

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“…Besides, a new peak ranging from 282.5 to 283.5 eV (C5) indicates the formation of Si-C bonds due to the silyl groups grafting on the CF surface [61]. As shown in Figure 7d, in the high-resolution spectrum for O1s, there is one broad peak positioned at 532.2 to 533.2 eV, which could be assigned to the presence of C-OH linkages [62,63]. A slight reduction of peak intensity after silylation indicates that a reaction takes place between the silane and the OH group on the cellulose surface.…”

Section: Morphology and Properties Of Silylated Cfsmentioning

confidence: 93%

Effect of Cellulose Microfiber Silylation Procedures on the Properties and Antibacterial Activity of Polydimethylsiloxane

et al. 2020

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In this study, the liquid phase and vapor phase procedures for silylating cellulose microfibers by hexamethyldisilazane (HMDS) were compared in terms of efficiency. The influence of functionalization degree on the morphology of microfibers and their interaction with polydimethylsiloxane (PDMS) matrix has been investigated. The antibacterial properties of silylated cellulose microfibers hybridized with Ag nanoparticles, obtained by in situ chemical reduction, were also studied. Sample morphology investigations were carried out using spectroscopy and microscopy techniques (FTIR, XPS, TEM, SEM, EDS, XPS). Trimethylsilyl moieties appear on the surface of the cellulose microfibers after modification and improve the dispersibility of the microfibers, allowing strong interaction with the PDMS matrix and favoring its crosslinking density. Microfibers functionalized by the vapor phase of HMDS show smoother surfaces with higher concentrations of Si-containing groups, resulting in a more hydrophobic wetting behavior and a greater influence on the mechanical properties of the polymer. The silylated cellulose microfiber–Ag nanohybrid shows stronger antimicrobial activity towards Gram-positive and Gram-negative bacteria strains compared to that of the untreated hybrid. A PDMS composite loaded with this hybrid exhibits the ability to inhibit bacterial growth.

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“…However, the high cost of activated carbon makes this technology economically unfavorable. In order to meet the demand of low-cost adsorbents for high-efficiency removal of mercury, many efforts have been made in developing sorbents from industrial and agricultural waste materials, such as biomass, fly ash, and petroleum coke. − Emphasis is also given to prepare regenerable sorbents with high mercury removal efficiency, such as cerium-doped activated carbon, activated carbon consisting of ZnS nanoparticles, and selenide-decorated metal foams. − High-sulfur petroleum coke is a byproduct of refining of heavy crude oil. Although coke has a high carbon content, the high sulfur content hinders its use in many fields, such as a fuel, anode, and electrode .…”

Section: Introductionmentioning

confidence: 99%

Impact of Nonoxidized Sulfur Species on Elemental Mercury Removal by SO₂ Activated Petroleum Cokes

et al. 2020

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High-sulfur petroleum coke is potentially one of the most promising materials for developing efficient and low-cost sorbents for Hg0 removal from flue gas. In this study, three distinct SO2-activated high-sulfur petroleum cokes were prepared at 650–850 °C via different sulfurization protocols, including SO2-impregnated petroleum coke (PC-S), SO2-impregnated coke produced with an additional reductive heat-treatment process in N2 (PC-NS), and SO2-impregnated coke prepared with the presence of SO2 in the gas during the cooling process (PC-SC). The SO2-activated cokes were characterized with nitrogen adsorption/desorption measurements, X-ray photoelectron spectroscopy, thermogravimetric analysis, and their mercury removal performances were investigated in a fixed-bed reactor at 80–200 °C with an initial mercury concentration of 35–120 μg/m3. To explore the influence of nonoxidized sulfur species on Hg0 removal, particular focus was given to the comparison of the reduced sulfur, sulfide sulfur, and elemental sulfur formed during different sulfurization processes, as well as the consequent differences in Hg0 adsorption characteristics. It found that the sulfur incorporated into the carbon matrix of PC-S by interaction with SO2 at 650 °C was dominantly organic sulfide. Thermal treatment in N2 at 800 °C led to an addition of reduced sulfur in PC-NS. An increment of 0.74 at. % elemental sulfur was observed in PC-SC after exposure to SO2 during the cooling step. The Hg0 adsorption capacity of PC-SC at low temperatures was significantly enhanced, yielding a mercury capacity of 622 μg/g at 80 °C. However, elemental sulfur suffered from severe temperature sensitivity for mercury binding. The sample PC-NS which contained more reduced sulfur showed the highest Hg0 adsorption capacity at elevated temperatures above 160 °C. Furthermore, the increment in inlet mercury concentration would lead to higher adsorption capacities and faster adsorption rates. According to the R L obtained from Langmuir isotherms, the Hg0 adsorption reactivity can be arranged as follows: PC-NS > PC-S > PC-SC. The mercury temperature-programmed desorption results suggested that sulfur species not only had an effect on Hg0 adsorption capacity but also played an essential role in the thermal stability of the adsorbed mercury compounds. Mercury was principally associated with elemental sulfur in the form of metacinnabar and combined with thermal-stable organic sulfide in cinnabar or organomercuric compounds Hg–SR.

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Enhanced elemental mercury removal by facile sulfurization of agrowaste chars

Cited by 17 publications

References 56 publications

Natural Kaolin: Sustainable Technology for the Instantaneous and Energy‐Neutral Recycling of Anthropogenic Mercury Emissions

Natural Kaolin: Sustainable Technology for the Instantaneous and Energy‐Neutral Recycling of Anthropogenic Mercury Emissions

Effect of Cellulose Microfiber Silylation Procedures on the Properties and Antibacterial Activity of Polydimethylsiloxane

Impact of Nonoxidized Sulfur Species on Elemental Mercury Removal by SO₂ Activated Petroleum Cokes

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Enhanced elemental mercury removal by facile sulfurization of agrowaste chars

Cited by 17 publications

References 56 publications

Natural Kaolin: Sustainable Technology for the Instantaneous and Energy‐Neutral Recycling of Anthropogenic Mercury Emissions

Natural Kaolin: Sustainable Technology for the Instantaneous and Energy‐Neutral Recycling of Anthropogenic Mercury Emissions

Effect of Cellulose Microfiber Silylation Procedures on the Properties and Antibacterial Activity of Polydimethylsiloxane

Impact of Nonoxidized Sulfur Species on Elemental Mercury Removal by SO2 Activated Petroleum Cokes

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Impact of Nonoxidized Sulfur Species on Elemental Mercury Removal by SO₂ Activated Petroleum Cokes