ACS Applied Materials & Interfaces
·
2014
·
IF 5.9
Zhi Chen,Zanyong Zhuang,Qing Cao,Xiaohong Pan,Xiong Guan,Zhang Lin
The mechanism of the interaction between nano-Mg(OH)2 adsorbent and uranyl in water was studied. At trace levels, the uranyl is adsorbed as a monolayer on nano-Mg(OH)2, and occupied a small proportion of the adsorption sites. As the uranyl concentration crosses over a threshold, continuous increase of adsorption capacity takes place. It indicates that, by taking the pre-adsorbed uranyl as the nucleation centers, the additional uranyl crystallizes and forms U-rich nanocrystals well-scattered on the surface of nano-Mg(OH)2. A strategy of inducing fast crystal growth of nano-Mg(OH)2 to micrometer-sized Na2Mg(CO3)2 enables the desorption and enrichment of uranyl. The recycling and reuse of nano-Mg(OH)2 can be achieved simultaneously. The finding in this work provides fundamental understanding of the efficient usage of nano-Mg(OH)2 in practical applications.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
Journal of the Australian Ceramic Society
·
2019
·Vol. 56
·期 2
·795-801
·
IF 0.692
Zhang Tao,Wei Yaowu,Chen Junfeng,Li Nan
In spite of the advantages of CaO refractories, such as high refractoriness, potential to produce pure steel molten, and high alkaline corrosion resistance, their application has been limited due to its poor hydration resistance. Introducing additives to improve the hydration resistance of lime is a novel method. The influences of Mg(OH) 2 and sintering temperatures on the sintering and hydration resistance of CaO aggregates that were produced by thermal decomposition were investigated in this paper. The purpose of this work was to produce high-purity CaO raw material with high density, low porosity, well grain growth, and good hydration resistance economically. The sintered samples were characterized by bulk density, apparent porosity, surface appearance, and microstructure. The results indicated that (1) Mg(OH) 2 promoted the grain growth of CaO, reduced the apparent porosity, and improved the density of the specimens. The hydration resistance of the samples was increased. (2) Increasing the sintering temperature improved the hydration resistance of the specimens obviously in the experiment. (3) Grain size of CaO was more uniform with the increment of Mg(OH) 2 content, and the density of the compacts was improved.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2013
·
IF 5.008
Chaoran Li,Zanyong Zhuang,Feng Huang,Zhicheng Wu,Yangping Hong,Zhang Lin
Treatment of wastewater containing low-concentration yet highly-expensive rare earth elements (REEs) is one of the vital issues in the REEs separation and refining industry. In this work, the interaction and related mechanism between self-supported flowerlike nano-Mg(OH)2 and low-concentration REEs wastewater were investigated. More than 99% REEs were successfully taken up by nano-Mg(OH)2. Further analysis revealed that the REEs could be collected on the surface of Mg(OH)2 as metal hydroxide nanoparticles (<5 nm). An ion-exchange model was proposed as a critical factor for both guaranteeing the reaction speed and maintaining the self-supported structure of the materials. In addition, a method was developed to further separate the immobilized REEs and the residual magnesium hydroxide by varying the solution pH. In a pilot-scale experiment, the REEs from practical wastewater were immobilized effectively at a high flow rate. We anticipate this work can provide a good example for the recycling of valuable REEs in practical industrial applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
Frontiers in Chemistry
·
2018
·
IF 4.155
Li Yinong,Tian Chen,Liu Weizhen,Xu Si,Xu Yunyun,Cui Rongxin,Lin Zhang
Nano-Mg(OH)2 is attracting great attention as adsorbent for pre-concentration and recovery of rare earth elements (REEs) from low-concentration solution, due to its superior removal efficiency for REEs and environmental friendliness. However, the nanoparticles also cause some severe problems during application, including aggregation, blockage in fixed-bed column, as well as the difficulties in separation and reuse. Herein, in order to avoid the mentioned problems, a carbon cloth (CC) supported nano-Mg(OH)2 (nano-Mg(OH)2@CC) was synthesized by electrodeposition. The X-ray diffraction and scanning electron microscopy analysis demonstrated that the interlaced nano-sheet of Mg(OH)2 grew firmly and uniformly on the surface of carbon cloth fibers. Batch adsorption experiments of Eu(III) indicated that the nano-Mg(OH)2@CC composite maintained the excellent adsorption performance of nano-Mg(OH)2 toward Eu(III). After adsorption, the Eu containing composite was calcined under nitrogen atmosphere. The content of Eu2O3 in the calcined material was as high as 99.66%. Fixed-bed column experiments indicated that no blockage for Mg(OH)2@CC composite was observed during the treatment, while the complete blockage of occurred to nano-Mg(OH)2 at an effluent volume of 240 mL. Moreover, the removal efficiency of Mg(OH)2@CC was still higher than 90% until 4,200 mL of effluent volume. This work provides a promising method for feasible application of nanoadsorbents in fixed-bed process to recycle low-concentration REEs from wastewater.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
·
2023
·
IF 3.5
Hongming Zhang,Fangyuan Si,Jiawei Dou,Mingxuan Li,Long Wu,Tian Xie,Lanming Zhao,Chuyuan Huang,Xianfeng Chen
Experiments on the flame propagation of starch dust explosion with the participation of ultrafine Mg(OH) 2 in a vertical duct were conducted to reveal the inerting evolution of explosion processes. Combining the dynamic behaviors of flame propagation, the formation law of gaseous combustion products , and the heat dissipation features of solid inert particles, the inerting mechanism of explosion flame propagation is discussed. Results indicate that the ultrafine of Mg(OH) 2 powders can cause the agglomeration of suspended dust clouds, which makes the flame combustion reaction zone fragmented and forms multiple small flame regions. The flame reaction zone presents non-homogeneous insufficient combustion, which leads to the obstruction of the explosion flame propagation process and the obvious pulsation propagation phenomenon. As the proportion of ultrafine Mg(OH) 2 increases, flame speed, flame luminescence intensity, flame temperature and deflagration pressure all show different degrees of inerting behavior. The addition of ultrafine Mg(OH) 2 not only causes partial inerting on the explosion flame, but also the heat dissipation of solid inert particles affects the acceleration of its propagation. The explosion flame propagation is inhibited by the synergistic effect of inert gas-solid phase, which attenuates the risk of starch explosion. The gas-solid synergistic inerting mechanism of starch explosion flame propagation by ultrafine Mg(OH) 2 is further revealed.
研究领域:
安全工程
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
Science China-Chemistry
·
2010
·Vol. 53
·期 7
·1497-1501
·
IF 0
Ma Hong,Nie Xin,Cai JiaYing,Chen Chen,Gao Jin,Miao Hong,Xu Jie
The catalytic oxidation of biomass-derived polyhydroxyl compounds provides an efficient and green route for biomass resource utility. Gold nanocrystals supported on Mg(OH) 2 were synthesized by sol-immobilization method, characterized by XRD, TEM, UV-vis DRS, and tested in the selective oxidation of 1,2-propanediol to lactic acid. The gold particle size and the ratio of Au to 1,2-propanediol strongly influenced the catalytic activity. Over Au/Mg(OH) 2 with the majority of gold particles concentrated in 14–18 nm, excellent catalytic performance with 94.4% conversion and 89.3% selectivity to lactic acid has been achieved under 0.3 MPa O 2 at 60 °C for 6 h.
研究领域:
化学工程
·
环境科学
·
催化科学
✓ 已验证
产品关联
DOI
APPLIED ENERGY
·
2020
·
IF 8.848
J. Yan,Z.H. Pan,C.Y. Zhao
Thermochemical heat storage uses a reversible chemical reaction to store thermal energy. This thermal energy storage method has high energy density and allows long-term thermal energy storage. MgO/Mg(OH) 2 is a promising reversible reaction for thermochemical heat storage systems. The performance of this reversible reaction inside a reactor plays a key role in its practical applications. The direct type heat transfer reactor is a novel design compared with an indirect powder bed reactor. It allows the gaseous heat transfer fluid to flow through the powder in order to break the heat transfer limitation from the heat exchanger between the MgO/Mg(OH) 2 powder and the heat transfer fluid. In this study, we evaluated the performance of a direct type MgO/Mg(OH) 2 reactor under various operating conditions. Parametric analyses indicated that the heat output is limited by the reaction rate rather than the heat transfer efficiency. Results also showed the best bed thickness in order to achieve the highest temperature output. Material characterization indicated that the MgO/Mg(OH) 2 particles did not agglomerate with each other after 15 heat charging and discharging cycles.
研究领域:
能源科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2018
·Vol. 5
·期 11
·2570-2578
·
IF 6.087
Xinwen Ou,Xueming Liu,Weizhen Liu,Wencong Rong,Jingyuan Li,Zhang Lin
The surface defects of adsorbents are generally considered to be the active sites for adsorbates, and the adsorption behaviors of a variety of pollutants in wastewater are strongly influenced by the surface defects of the adsorbents. With simple chemical and structural properties, nano-Mg(OH)2 exhibits a high adsorption affinity and selectivity to heavy metals from wastewater. The insight into the surface complex structures of heavy metals on the Mg(OH)2 surface is fundamental for both the mechanism and application of defective adsorbents in wastewater treatment. In this study, the impact of surface defects of Mg(OH)2 nanoplates on the structure, energy, and adsorption amounts of toxic heavy metal oxyanions (HAsO42− and CrO42−) was investigated by combining the first-principles calculations and batch experiments. The first-principles calculations illustrated that the heavy metal oxyanions can be steadily incorporated into the surface defects to form inner-sphere complexes. The incorporated heavy metal oxyanions have strong charge–charge and chemical bonding interactions with the surface defect sites, which are much stronger than the hydrogen bonding interactions with the surface OH sites. Moreover, the adsorption affinity of surface defects towards heavy metal oxyanions is stronger than that towards other oxyanions (e.g. SO42− and NO3−), indicating the high adsorption selectivity of heavy metal oxyanions over other oxyanions. Batch adsorption experiments verified that the adsorption of defect-rich Mg(OH)2 adsorbents towards heavy metal ions, e.g., As(V) and Cr(VI), was favorable even under the condition of low concentration (mg L−1 level). These findings reveal the significance of surface defects of Mg(OH)2 for extracting As(V) and Cr(VI) from low-concentration solutions. The proposed strategy of surface defect-fabrication should provide a useful insight into designing effective adsorbents for the selective extraction of heavy metal oxyanions at low concentration.
研究领域:
环境科学
·
材料科学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2012
·Vol. 4
·期 7
·2423-2430
·
IF 5.914
Qing Cao,Feng Huang,Zanyong Zhuang,Zhang Lin
This work aims at the investigation of nano-Mg(OH)2 as a promising adsorbent for uranium recovery from water. Systematic analysis including the uranium adsorption isotherm, the kinetics and the thermodynamics of adsorption of low concentrations of uranyl tricarbonate (0.1–20 mg L−1) by nano-Mg(OH)2 was carried out. The results showed a spontaneous and exothermic uranium adsorption process by Mg(OH)2, which could be well described with pseudo second order kinetics. Surface site calculation and zeta potential measurement further demonstrated that UO2(CO3)34− was a monolayer adsorbed onto nano-Mg(OH)2 by electrostatic forces. Accordingly, the adsorption behavior met the conditions of the Langmuir isotherm. Moreover, in most of the reported literature, nano-Mg(OH)2 had a higher UO2(CO3)34− adsorption affinity b, which implied a higher adsorption amount at equilibrium in a dilute adsorbate system. The significance of the adsorption affinity b for choosing and designing adsorbents with respect to low concentration of resources/pollutants treatment has also been assessed.
研究领域:
环境科学
·
材料科学
·
放射化学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED THERMAL ENGINEERING
·
2024
·
IF 6.1
Lisheng Deng,Shusen lin,Linfa Xiao,Mitsuhiro Kubota,Hongyu Huang,Jun Li,Dezhen Chen
The application of MgO/Mg(OH) 2 in heat storage technology has been limited due to slow hydration rate and easy agglomeration. In this paper, nanoporous carbon particle (NCP) as a carrier was used to prepare NCP/MgO chemical heat storage composite materials by impregnation and calcination methods, respectively. The microstructure characterization, hydration reaction, and simultaneous thermogravimetric analysis experiments were carried out on the prepared composite materials. The results showed that the internal distribution of MgO in the composite material prepared by calcination method was more uniform, and the particle size of MgO was smaller. Under the conditions of 110 ℃ hydration temperature and 57.8 kPa water vapor partial pressure, the hydration conversion ratio of the composite material prepared by calcination method after 120 min of hydration conversion ratio reached 93 %, which was 17.7 % higher than that of the impregnated composite material and 50 % higher than that of pure MgO. Under the comprehensive influence of specific surface area, pore structure, and active component particle size, compared with pure materials and impregnated composite materials, the dehydration rate of the composite material prepared by calcination method at 300 ℃ was twice that of impregnated method and 6 times that of pure MgO, and the heat storage density reached 1039kJ/kg. After 10 cycles, the heat storage density still maintained an initial state of 95.8 %. Compared with pure materials and impregnated composite materials, NCP/MgO composite materials prepared by calcination method had better heat storage performance and higher cyclic stability.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2025
·
IF 5.1
Ying Wang,Fuming Wang,Xuyang Feng,Haoyou Jiang,Hualin Zhang,Yongfang Qian,Botian Zhu,Yaping Huang,Yimin Zhu
In recent years, microbial pollution has become a serious environmental problem, and the release of microorganisms into the water environment seriously threatens human health. As environment-friendly and low-cost antibacterial agents, Mg(OH)2 nanoparticles (M-NPs) have garnered considerable attention for their small size, innocuity, no drug resistance, chemical stability and thermal stability. However, little is known about the physiological changes that bacteria undergo in the presence of M-NPs. In this work, the antibacterial mechanism of M-NPs synthesized by applying the coprecipitation method was investigated using Escherichia coli (E. coli) as a model system. The oxygen vacancies on the M-NP surface, which can produce reactive oxygen species (ROS, ·O2−, H2O2, and ·OH), were examined via O2-temperature programmed desorption (O2-TPD). Abnormality in three central metabolic pathways (energy, glucose and tricarboxylic acid cycle) induced by M-NPs was detected by analyzing the activity of respiratory chain dehydrogenase, gluconokinase (GK) and succinate dehydrogenase (SDH). The downregulated activity and gene expression levels of GK confirmed that M-NPs play an inhibitory role, and these physiological changes result in cell death. Thus, M-NPs have great potential in the field of preventing and controlling microbial pollution.
研究领域:
微生物学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY
·
2022
·
IF 7.188
J. Yan,B.W. Yang,C.Y. Zhao
Thermochemical energy storage (TCES) is a promising energy storage method because of its high energy storage density and long-term storage ability. The reactor is the most critical part of the TCES system, and the fluidized bed reactor (FBR) is a novel reactor, which is not restricted by the low effective thermal conductivity of energy storage materials. However, there is little theoretical guidance about the design and operation of the FBR for a TCES system. In this study, we investigated the performance of an FBR using MgO/Mg(OH) 2 as reaction materials by establishing a numerical model followed by experimental validation. The influence of operating parameters on the bed temperature was discussed based on numerical results. According to the sensitivity analysis, the reactor inner diameter, material mass, and inlet gas velocity were the main factors affecting the bed temperature. The optimal boundary surface temperature was analyzed, which influences the proportion of TCES in the total heat storage.
研究领域:
能源工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）