The Experts below are selected from a list of 1767 Experts worldwide ranked by ideXlab platform
Jun Huang - One of the best experts on this subject based on the ideXlab platform.
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A mini-review on Mechanochemical Treatment of contaminated soil: From laboratory to large-scale
2018Co-Authors: Giovanni Cagnetta, Jun HuangAbstract:In recent years, the destruction of (persistent) organic pollutants and the immobilization of heavy metals and radioactive nuclides in contaminated matrices by Mechanochemical Treatment have been proved. Several studies demonstrate a remarkable versatility of the high energy ball milling technology in the detoxification of contaminated soil, a primary issue that demand rapid and adequate solutions. In the present mini-review, scientific and technological aspects of polluted soil Mechanochemical Treatment are discussed. In addition, an economic feasibility study is performed, employing technical and cost data obtained by constructors. It corroborates the competitiveness of the Mechanochemical Treatment as potential cleaning technology.
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Mechanochemical mineralization of “very persistent” fluorocarbon surfactants ‒ 6:2 fluorotelomer sulfonate (6:2FTS) as an example
Scientific reports, 2017Co-Authors: Giovanni Cagnetta, Kunlun Zhang, Jun HuangAbstract:Fluorinated organic chemicals have a wide variety of industrial and consumer applications. For long time perfluorooctane sulfonate and perfluorooctanoic acid have been used as precursors for manufacture of such chemicals. However, these C8 chain compounds have been demonstrated to be toxic, persistent, and bioaccumulative, thus inducing their phase-out. Currently, C6 telomer based fluorocarbon surfactants are considered better alternatives to C8 products because of their low bioaccumulability. But, their high persistency suggests that in the near future their concentrations will increase in the environment and in industrial waste. Being a solid state non-thermal technology, Mechanochemical Treatment is a good candidate for the destruction of emerging C6 fluorotelomers in solid waste. In the present study, 6:2 fluorotelomer sulfonate is effectively destroyed (~100%) in rapid manner (
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Mechanochemical mineralization of very persistent fluorocarbon surfactants 6 2 fluorotelomer sulfonate 6 2fts as an example
Scientific Reports, 2017Co-Authors: Giovanni Cagnetta, Kunlun Zhang, Jun HuangAbstract:Fluorinated organic chemicals have a wide variety of industrial and consumer applications. For long time perfluorooctane sulfonate and perfluorooctanoic acid have been used as precursors for manufacture of such chemicals. However, these C8 chain compounds have been demonstrated to be toxic, persistent, and bioaccumulative, thus inducing their phase-out. Currently, C6 telomer based fluorocarbon surfactants are considered better alternatives to C8 products because of their low bioaccumulability. But, their high persistency suggests that in the near future their concentrations will increase in the environment and in industrial waste. Being a solid state non-thermal technology, Mechanochemical Treatment is a good candidate for the destruction of emerging C6 fluorotelomers in solid waste. In the present study, 6:2 fluorotelomer sulfonate is effectively destroyed (~100%) in rapid manner (<1 h) by high energy ball milling with KOH. Stoichiometric fluoride formation confirms its entire mineralization, assuring that no toxic by-products are generated. Reaction mechanism and kinetics indicate that effective mineralization of the perfluorinated moiety is obtained thanks to a rapid CF2 “flake-off” process through radical mechanism.
Giovanni Cagnetta - One of the best experts on this subject based on the ideXlab platform.
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A mini-review on Mechanochemical Treatment of contaminated soil: From laboratory to large-scale
2018Co-Authors: Giovanni Cagnetta, Jun HuangAbstract:In recent years, the destruction of (persistent) organic pollutants and the immobilization of heavy metals and radioactive nuclides in contaminated matrices by Mechanochemical Treatment have been proved. Several studies demonstrate a remarkable versatility of the high energy ball milling technology in the detoxification of contaminated soil, a primary issue that demand rapid and adequate solutions. In the present mini-review, scientific and technological aspects of polluted soil Mechanochemical Treatment are discussed. In addition, an economic feasibility study is performed, employing technical and cost data obtained by constructors. It corroborates the competitiveness of the Mechanochemical Treatment as potential cleaning technology.
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Mechanochemical mineralization of “very persistent” fluorocarbon surfactants ‒ 6:2 fluorotelomer sulfonate (6:2FTS) as an example
Scientific reports, 2017Co-Authors: Giovanni Cagnetta, Kunlun Zhang, Jun HuangAbstract:Fluorinated organic chemicals have a wide variety of industrial and consumer applications. For long time perfluorooctane sulfonate and perfluorooctanoic acid have been used as precursors for manufacture of such chemicals. However, these C8 chain compounds have been demonstrated to be toxic, persistent, and bioaccumulative, thus inducing their phase-out. Currently, C6 telomer based fluorocarbon surfactants are considered better alternatives to C8 products because of their low bioaccumulability. But, their high persistency suggests that in the near future their concentrations will increase in the environment and in industrial waste. Being a solid state non-thermal technology, Mechanochemical Treatment is a good candidate for the destruction of emerging C6 fluorotelomers in solid waste. In the present study, 6:2 fluorotelomer sulfonate is effectively destroyed (~100%) in rapid manner (
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Mechanochemical mineralization of very persistent fluorocarbon surfactants 6 2 fluorotelomer sulfonate 6 2fts as an example
Scientific Reports, 2017Co-Authors: Giovanni Cagnetta, Kunlun Zhang, Jun HuangAbstract:Fluorinated organic chemicals have a wide variety of industrial and consumer applications. For long time perfluorooctane sulfonate and perfluorooctanoic acid have been used as precursors for manufacture of such chemicals. However, these C8 chain compounds have been demonstrated to be toxic, persistent, and bioaccumulative, thus inducing their phase-out. Currently, C6 telomer based fluorocarbon surfactants are considered better alternatives to C8 products because of their low bioaccumulability. But, their high persistency suggests that in the near future their concentrations will increase in the environment and in industrial waste. Being a solid state non-thermal technology, Mechanochemical Treatment is a good candidate for the destruction of emerging C6 fluorotelomers in solid waste. In the present study, 6:2 fluorotelomer sulfonate is effectively destroyed (~100%) in rapid manner (<1 h) by high energy ball milling with KOH. Stoichiometric fluoride formation confirms its entire mineralization, assuring that no toxic by-products are generated. Reaction mechanism and kinetics indicate that effective mineralization of the perfluorinated moiety is obtained thanks to a rapid CF2 “flake-off” process through radical mechanism.
Kunlun Zhang - One of the best experts on this subject based on the ideXlab platform.
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Mechanochemical mineralization of “very persistent” fluorocarbon surfactants ‒ 6:2 fluorotelomer sulfonate (6:2FTS) as an example
Scientific reports, 2017Co-Authors: Giovanni Cagnetta, Kunlun Zhang, Jun HuangAbstract:Fluorinated organic chemicals have a wide variety of industrial and consumer applications. For long time perfluorooctane sulfonate and perfluorooctanoic acid have been used as precursors for manufacture of such chemicals. However, these C8 chain compounds have been demonstrated to be toxic, persistent, and bioaccumulative, thus inducing their phase-out. Currently, C6 telomer based fluorocarbon surfactants are considered better alternatives to C8 products because of their low bioaccumulability. But, their high persistency suggests that in the near future their concentrations will increase in the environment and in industrial waste. Being a solid state non-thermal technology, Mechanochemical Treatment is a good candidate for the destruction of emerging C6 fluorotelomers in solid waste. In the present study, 6:2 fluorotelomer sulfonate is effectively destroyed (~100%) in rapid manner (
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Mechanochemical mineralization of very persistent fluorocarbon surfactants 6 2 fluorotelomer sulfonate 6 2fts as an example
Scientific Reports, 2017Co-Authors: Giovanni Cagnetta, Kunlun Zhang, Jun HuangAbstract:Fluorinated organic chemicals have a wide variety of industrial and consumer applications. For long time perfluorooctane sulfonate and perfluorooctanoic acid have been used as precursors for manufacture of such chemicals. However, these C8 chain compounds have been demonstrated to be toxic, persistent, and bioaccumulative, thus inducing their phase-out. Currently, C6 telomer based fluorocarbon surfactants are considered better alternatives to C8 products because of their low bioaccumulability. But, their high persistency suggests that in the near future their concentrations will increase in the environment and in industrial waste. Being a solid state non-thermal technology, Mechanochemical Treatment is a good candidate for the destruction of emerging C6 fluorotelomers in solid waste. In the present study, 6:2 fluorotelomer sulfonate is effectively destroyed (~100%) in rapid manner (<1 h) by high energy ball milling with KOH. Stoichiometric fluoride formation confirms its entire mineralization, assuring that no toxic by-products are generated. Reaction mechanism and kinetics indicate that effective mineralization of the perfluorinated moiety is obtained thanks to a rapid CF2 “flake-off” process through radical mechanism.
Torben R Jensen - One of the best experts on this subject based on the ideXlab platform.
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synthesis and thermal stability of perovskite alkali metal strontium borohydrides
Dalton Transactions, 2016Co-Authors: Kasper T. Møller, Radovan Cerný, Pascal Schouwink, Morten B Ley, Torben R JensenAbstract:Three new perovskite-type bimetallic alkali metal strontium borohydride compounds, α-MSr(BH4)3 (M = K, Rb, Cs), have been synthesized and investigated by in situ synchrotron radiation powder X-ray diffraction, thermal analysis combined with mass spectrometry and Sievert's measurements. The bimetallic borohydrides were synthesized via an addition reaction between Sr(BH4)2 and MBH4 (M = K, Rb, Cs) by Mechanochemical Treatment. The Sr(BH4)2–NaBH4 system, which was treated in a similar manner, did not undergo reaction. All three α-MSr(BH4)3 compounds crystallize in the orthorhombic crystal system at room temperature: KSr(BH4)3 (P21cn), a = 7.8967(6), b = 8.2953(7), and c = 11.508(1) A (V = 753.82(12) A3). RbSr(BH4)3 (Pbn21), a = 8.0835(3), b = 8.3341(4), and c = 11.6600(5) A (V = 785.52(6) A3). CsSr(BH4)3 (P22121), a = 8.2068(9), b = 8.1793(9), and c = 6.0761(4) A (V = 407.87(7) A3). All three compounds are perovskite-type 3D framework structures built from distorted [Sr(BH4)6] octahedra. High-temperature polymorphs are identified to form at 258, 220 and 150 °C for MSr(BH4)3, M = K, Rb and Cs, respectively. The new compounds are thermally stable and decompose at T > 360 °C into SrB6, SrH2 and MBH4 (M = K, Rb, Cs).
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a composite of complex and chemical hydrides yields the first al based amidoborane with improved hydrogen storage properties
Chemistry: A European Journal, 2015Co-Authors: Iurii Dovgaliuk, Torben R Jensen, Lars H. Jepsen, Damir A Safin, Zbigniew łodziana, Vadim Dyadkin, Michel Devillers, Yaroslav FilinchukAbstract:The first Al-based amidoborane Na[Al(NH2 BH3 )4 ] was obtained through a Mechanochemical Treatment of the NaAlH4 -4 AB (AB=NH3 BH3 ) composite releasing 4.5 wt % of pure hydrogen. The same amidoborane was also produced upon heating the composite at 70 °C. The crystal structure of Na[Al(NH2 BH3 )4 ], elucidated from synchrotron X-ray powder diffraction and confirmed by DFT calculations, contains the previously unknown tetrahedral ion [Al(NH2 BH3 )4 ](-) , with every NH2 BH3 (-) ligand coordinated to aluminum through nitrogen atoms. Combination of complex and chemical hydrides in the same compound was possible due to both the lower stability of the AlH bonds compared to the BH ones in borohydride, and due to the strong Lewis acidity of Al(3+) . According to the thermogravimetric analysis-differential scanning calorimetry-mass spectrometry (TGA-DSC-MS) studies, Na[Al(NH2 BH3 )4 ] releases in two steps 9 wt % of pure hydrogen. As a result of this decomposition, which was also supported by volumetric studies, the formation of NaBH4 and amorphous product(s) of the surmised composition AlN4 B3 H(0-3.6) were observed. Furthermore, volumetric experiments have also shown that the final residue can reversibly absorb about 27 % of the released hydrogen at 250 °C and p(H2 )=150 bar. Hydrogen re-absorption does not regenerate neither Na[Al(NH2 BH3 )4 ] nor starting materials, NaAlH4 and AB, but rather occurs within amorphous product(s). Detailed studies of the latter one(s) can open an avenue for a new family of reversible hydrogen storage materials. Finally, the NaAlH4 -4 AB composite might become a starting point towards a new series of aluminum-based tetraamidoboranes with improved hydrogen storage properties such as hydrogen storage density, hydrogen purity, and reversibility.
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tailoring the properties of ammine metal borohydrides for solid state hydrogen storage
Chemsuschem, 2015Co-Authors: Lars H. Jepsen, Yaroslav Filinchuk, Flemming Besenbacher, Torben R JensenAbstract:A series of halide-free ammine manganese borohydrides, Mn(BH4)2·nNH3, n=1, 2, 3, and 6, a new bimetallic compound Li2Mn(BH4)4·6NH3, and the first ammine metal borohydride solid solution Mg1xMnx(BH4)2·6NH3 are presented. Four new crystal structures have been determined by synchrotron radiation powder X-ray diffraction and the thermal decomposition is systematically investigated for all the new compounds. The solid-gas reaction between Mn(BH4)2 and NH3 provides Mn(BH4)2·6NH3. The number of NH3 per Mn has been varied by Mechanochemical Treatment of Mn(BH4)2·6NH3-Mn(BH4)2 mixtures giving rise to increased hydrogen purity for n/m1 for M(BH4)m·nNH3. The structures of Mg(BH4)2·3NH3 and Li2Mg(BH4)4·6NH3 have been revisited and new structural models are presented. Finally, we demonstrate that ammonia destabilizes metal borohydrides with low electronegativity of the metal (cp ~1.6) are generally stabilized.
Renjie Chen - One of the best experts on this subject based on the ideXlab platform.
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a green and effective room temperature recycling process of lifepo4 cathode materials for lithium ion batteries
Waste Management, 2019Co-Authors: Yifan Bian, Ersha Fan, Xiaoxiao Zhang, Qing Xue, Ying Yao, Renjie ChenAbstract:Abstract Nowadays LiFePO4 cathode develops rapidly for its advantages of long life span, low cost and non-toxicity, especially in electrical vehicle markets. Because of its stable olivine structure, LiFePO4 is difficult to be recycled by the conventional hydrometallurgical processes as for LiCoO2 or LiNixCoyMnzO2. Pyrometallurgical processes consume much energy and release toxic gases. Herein, an effective room-temperature process based on the Mechanochemical Treatment is proposed to extract metals from LiFePO4. Spent LiFePO4 is co-grinded with low-cost citric acid agent in a ball mill. After grinding, the mixture is dissolved in deionized water and filtrated. With addition of H2O2, the extraction efficiency of Li reaches as high as 99.35%. Conversely, Fe is hardly extracted with a low extraction efficiency of only 3.86%, indicating a selective recovery of valuable Li element. In addition, when H2O is used instead of H2O2, the Mechanochemical reaction changes and the extraction efficiencies of Li and Fe at optimal conditions reach 97.82% and 95.62%, respectively. The Fe impurity is removed as Fe(OH)3 precipitation by adding NaOH, and Li is recycled as Li2CO3 after reaction with saturated Na2CO3 at 95 °C. This simple and easily-operated process has little negative impact on the environment and has great potential in industrial applications.
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Selective Recovery of Li and Fe from Spent Lithium-Ion Batteries by an Environmentally Friendly Mechanochemical Approach
2018Co-Authors: Ersha Fan, Xiaoxiao Zhang, Yifan Bian, Qing Xue, Renjie ChenAbstract:Recycling of spent LiFePO4 batteries has drawn recent attention relating to recovering their high contents of rare elements and negating potential negative environmental effects of their disposal. However, the stable crystal structure of LiFePO4 materials has prevented the development of a recycling process with high selectivity and extraction efficiency. We report the selective extraction of Fe and Li from spent LiFePO4 batteries via an environmentally friendly Mechanochemical process with oxalic acid. With the use of a Mechanochemical Treatment and water leaching, the Li extraction efficiency can be improved to 99%. Furthermore, 94% of Fe can be simultaneously recovered as FeC2O4·2H2O. To understand the reaction mechanism and determine the optimum reaction conditions, we investigated various parameters, including the LiFePO4 to oxalic acid mass ratio, rotation speed, milling time, and ball-to-powder mass ratio. Moreover, metal ions from the water leaching process were recovered by chemical precipitation. This study provides an efficient and selective process for recovery of valuable metals from spent LiFePO4 materials