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Preparation and Characterization of Multi-layer Poly(arylene sulfide sulfone) Nanofibers Membranes for Liquid Filtration

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Chinese Journal of Polymer Science 2019年第12期37卷 1248-1256,I0006页

作者： Zhen-Yan Liu Zhi-Mei Wei Xiao-Jun Wang Gang Zhang Sheng-Ru Long Jie Yang College of Polymer Science and Engineering Sichuan UniversityChengdu 610065China Analytical&Testing Center Sichuan UniversityChengdu 610064China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengdu 610065China

Owing to the excellent filtration performance and low energy cost,polymeric nanofibers microfiltration(MF)membranes have attracted increasing attentions.Poly(arylene sulfide sulfone)(PASS),as one of the structurally modified polymers based on poly-(phenylene sulfide)(PPS),has been selected as the raw material to fabricate nanofibers MF membranes via electrospun techniques.The effects of PASS solution and the electrospinning processing parameters on the structural morphology of nanofibers were investigated in detail.The average diameter of PASS nanofibers was(296±46)nm under the optimal condition:polymer concentration of 0.27 g·m L^–1 PASS/DMI,applied voltage of 20 kV,and speed of collector drum of 300 r·min^–1.And then the multi-layer PASS nanofibers MF membranes were fabricated from cold-pressing the optimized PASS nanofibers(as-prepared PASS nanofibers)membrane.The morphology,porosity,pore size,mechanical properties,and surface wettability of the multi-layer PASS nanofibers MF membranes could be tuned by the layers of as-prepared nanofibers membrane.The results demonstrated that the membrane with 6 layers(marked as PASS-6)exhibited the smallest porosity,smallest pore size,highest mechanical property,and best surface wettability.Meanwhile,the multi-layer PASS nanofibers MF membranes showed that the rejection ratio gradually increased,while the pure water flux decreased with increasing membranes thickness.The PASS-6 membrane exhibited large water flux of 747.76 L·m^–2·h^–1 and high separation efficiency of 99.9%to 0.2μm particles,making it a promising candidate for microfilter.

关键词： Poly(arylene sulfide sulfone) Electrospinning Nanofibers membranes Microfiltration

Simultaneous removal of hydrogen sulfide and volatile organic sulfur compounds in off-gas mixture from a wastewater treatment plant using a two-stage bio-trickling filter system

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Frontiers of Environmental Science & Engineering 2019年第4期13卷 153-165页

作者： Shihao Sun Tipei Jia Kaiqi Chen Yongzhen Peng Liang Zhang National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology and Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering Beijing University of TechnologyBeijing 100124China

Simultaneous removal of hydrogen sulfide (H2S) and volatile organic sulfur compounds (VOSCs) in off-gas mixture from a wastewater treatment plant (WWTP) is difficult due to the occasional inhibitory effects of H2S on VOSC degradation. In this study, a two-stage bio-trickling filter (BTF) system was developed to treat off-gas mixture from a real WWTP facility. At an empty bed retention time of 40 s, removal efficiencies of H2S, methanethiol, dimethyl sulfide, and dimethyl disulfide were 90.1, 88.4, 85.8 and 61.8%, respectively. Furthermore, the effect of lifting load shock on system performance was investigated and results indicated that removal of both H2S and VOSCs was slightly affected. Illumina Miseq sequencing revealed that the microbial community of first-stage BTF contained high abundance of H2S-affinity genera including Acidithiobacillus (51.43%), Metallibacterium (25.35%), and Thionomas (8.08%). Analysis of mechanism demonstrated that first stage of BTF removed 86.1% of H2S, mitigating the suppression on VOSC degradation in second stage of BTF. Overall, the twostage BTF system, an innovative bioprocess, can simultaneously remove H2S and VOSC.

关键词： Odor Two-stage bio-trickling filter process Bio-trickling filter Hydrogen sulfide Volatile organic sulfur compound

Hydrogen sulfide inhibits ethylene-induced petiole abscission in tomato(Solanum lycopersicum L.)

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Horticulture Research 2020年第1期7卷 2611-2621页

作者： Danmei Liu Jianing Li Zhuowen Li Yanxi Pei College of Life Science Shanxi UniversityTaiyuan 030006China Shanxi Key Laboratory for Research and Development of Regional Plants Taiyuan 030006China

Abscission is a dynamic physiological process that is ubiquitous in plants and can also be an essential agronomic trait in crops,thus attracting attention from plant growers and breeders.In general,the process of plant organ abscission can be divided into four steps,among which the step to obtain the competence to respond to abscission signals(step 2)is the most complex;however,the molecular mechanism underlying this process remains unclear.In this study,we found that hydrogen sulfide(H_(2)S)inhibited the abscission of the tomato petiole in a dose-dependent manner,and the abscission of the petiole was accelerated when an H_(2)S scavenger was applied.Further enzymatic activity and gene expression analyses showed that H_(2)S suppressed the activity of enzymes capable of modifying the cell wall by inhibiting the usual upregulation of the transcription of the corresponding genes during the abscission process but not by affecting the activities of these enzymes by direct posttranslational modification.H_(2)S treatment upregulated the expression levels of SlIAA3 and SlIAA4 but downregulated the transcription of ILR-L3 and ILR-L4 in the earlier stages of the abscission process,indicating that H_(2)S probably functioned in the second step of the abscission process by preventing the abscission zone cells from obtaining the competence to respond to abscission signals by modulating the content of the bioactive-free auxin in these cells.Moreover,similar H_(2)S inhibitory effects were also demonstrated in the process of floral organ abscission and anther dehiscence in other plant species,suggesting a ubiquitous role for H_(2)S in cell separation processes.

关键词： inhibited sulfide attracting

A method for observing tridimensional morphology of sulfide inclusions by non-aqueous solution electrolytic etching

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Journal of Iron and Steel Research(International) 2019年第3期26卷 275-284页

作者： Dong Zhang Ping Shen Jian-bo Xie Jin-min An Zong-ze Huang Jian-xun Fu State Key Laboratory of Advanced Special Steel Shanghai Key Laboratory of Advanced Ferrous Metallurgy School of Materials Science and Engineering Shanghai University Shanghai 200072 China State Key Laboratory of Development and Application Technology of Automotive Steel (Baosteel Group) Shanghai 20190 China

Three-dimensional investigation of sulfides is required in order to improve the mechanical properties of steel by controlling the sulfides in the steel.A method including its principles and device is introduced for the investigation of threedimensional morphology of sulfides.The method is suitable for gear steel,free cutting steel,non-quenched steel,tempered steel(ws≥0.02 wt.%),etc.The influences of current density,time,and temperature on the exposure degree of sulfide inclusions were investigated by using 16MnCrS5 steel.The best parameters of electrolytic etching of sulfur steel,as found by experimentation,are as follows:current density,37.5-52.5 mA/cm2;time,30-35 min;and temperature,—10 to 0℃.Under these conditions,the three-dimensional morphology of sulfide inclusions in sulfur-bearing steel can be exposed effectively.

关键词： sulfide Non-aqueous electrolyte Electrolytic etching Three-dimensional morphology

Structural and optical properties of nanostructured copper sulfide semiconductor synthesized in an industrial mill

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Frontiers of Chemical Science and Engineering 2019年第1期13卷 164-170页

作者： Marcela Achimovicova Erika Dutkova Erika Tothova Zdenka Bujnakova Jaroslav Briancin Satoshi Kitazono Institute of Mineral and Waste Processing Waste Disposal and Geomechanics Clausthal University of Technology Clausthal 38678 Germany Institute of Geotechnics Slovak Academy of Sciences Kosice 04001 Slovakia Nakase Refinery Nihon Seiko Co. Ltd. Yabu-shi Hyogo 667-1111 Japan

Chalcogenide nanostructured semiconductor, copper sulfide (CuS) was prepared from copper and sulfur powders in stoichiometric ratio by a simple, fast, and convenient one-step mechanochemical synthesis after 40 min of milling in an industrial eccentric vibratory mill. The kinetics of the mechanochemical synthesis and the influence of the physical properties of two Cu powder precursor types on the kinetics were studied. The crystal structure, physical properties, and morphology of the product were characterized by X-ray diffraction (XRD), the specific surface area measurements, particle size distribution and scanning electron microscopy. The XRD analysis confirmed the hexagonal crystal structure of the product-CuS (covellite) with the average size of the crystallites 11 nm. The scanning electron microscopy analysis has revealed that the agglomerated grains have a plate-like structure composed of CuS nanoparticles. The thermal analysis was performed to investigate the thermal stability of the mechanochemically synthesized CuS. The optical properties were studied using UV-Vis and photoluminescence spectroscopy. The determined optical band gap energy 1.80 eV responds to the value of the bulk CuS, because of agglomerated nanoparticles. In addition, a mechanism of CuS mechanochemical reaction was proposed, and the verification of CuS commercial production was performed.

关键词： copper sulfide industrial mechanochemical synthesis thermal analysis optical properties

Evaluation of spontaneous combustion tendency of sulfide ore heap based on nonlinear parameters

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Journal of Central South University 2017年第10期24卷 2431-2437页

作者：潘伟吴超李孜军伍智伟杨月平 School of Resources and Safety Engineering Central South University School of Nuclear Resources Engineering University of South China

To explore a new evaluation method for spontaneous combustion tendency of different areas in sulfide ore heap, ore samples from a pyrite mine in China were taken as experimental materials, and the temperature variations of the measuring points of simulated ore heap were measured. Combined with wavelet transform and nonlinear parameters extraction, a new method for spontaneous combustion tendency of different areas in sulfide ore heap based on nonlinear parameters was proposed and its reliability was verified by field test. The results indicate that temperature field evolution of the simulated ore heap presents significant spatial difference during self-heating process. Area with the maximum increasing extent of temperature in sulfide ore heap changes notably with the proceeding of self-heating reaction. Self-heating of sulfide ore heap is a chaotic evolution process, which means that it is feasible to evaluate spontaneous combustion tendency of different areas by nonlinear analysis method. There is a relatively strong correlation between the maximum Lyapunov exponent and spontaneous combustion tendency with the correlation coefficient of 0.9792. Furthermore, the sort of the maximum Lyapunov exponent is consistent with that of spontaneous combustion tendency. Therefore, spontaneous combustion tendency of different areas in sulfide ore heap can be evaluated by means of the maximum Lyapunov exponent method.

关键词： sulfide ore heap spontaneous combustion tendency self-heating process nonlinear parameters maximum Lyapunov exponent

Direct electrochemical reduction of copper sulfide in molten borax

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International Journal of Minerals,Metallurgy and Materials 2019年第8期26卷 992-998页

作者： Levent Kartal Servet Timur Department of Metallurgical and Materials Engineering Hitit UniversityCorum 19030Turkey Department of Metallurgical and Materials Engineering Istanbul Technical UniversityIstanbul 34469Turkey

In this study,for the first time,direct copper production from copper sulfide was carried out via direct electrochemical reduction method using inexpensive and stable molten borax electrolyte.The effects of current density(100–800 mA/cm^2)and electrolysis time(15–90 min)on both the cathodic current efficiency and copper yield were systematically investigated in consideration of possible electrochemical/chemical reactions at 1200℃.The copper production yield reached 98.09%after 90 min of electrolysis at a current density of 600 mA/cm^2.Direct metal production was shown to be possible with 6 kWh/kg energy consumption at a 600 mA/cm2 current density,at which the highest current efficiency(41%)was obtained.The suggested method can also be applied to metal/alloy production from single-and mixed-metal sulfides coming from primary production and precipitated sulfides,which are produced in the mining and metallurgical industries during treatment of process solutions or wastewaters.

关键词： molten salt electrolysis electro-reduction copper extraction copper sulfide borax

Selective removal of heavy metal ions in aqueous solutions by sulfide-selector intercalated layered double hydroxide adsorbent

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Journal of Materials Science & Technology 2019年第9期35卷 1809-1816页

作者： Jing Wang Liang Zhang Tianshu Zhang Ting Du Tao Li Tianli Yue Zhonghong Li Jianlong Wang College of Food Science and Engineering Northwest A&F UniversityYangling 712100China Shaanxi Institute for Food and Drug Control Xi'an 710065China

Remaining largely under-appreciated, a majority of metal ion sorbents are limited in their target selectivity. In this work, a 3D sulfide intercalated NiFe-layered double hydroxide (NFL-S) hierarchical sorbent has been synthesized for selective heavy metal removal. The intercalation of sulfurated groups in the interlayer of the layered double hydroxide (LDH) nanosheets endows NFL-S as a selective heavy metal ion filter;the selectivity of NFL-S for heavy metals is in the order of Pb^2+> Cu^2+≥ Zn^2+> Cd^2+> Mn^2+, and NFL-S has high kd values for Pb2+(~10^6 mL/g) and Cu2+(~10^5 mL/g). Scanning electron microscopy. X-ray photoelectron spectroscopy and powder X-ray diffraction were used to analyze the composition of the as-prepared nanoadsorbent. The selective adsorption behavior was systematically studied using batch experiments, and the performance was evaluated through kinetic and isotherm studies. Moreover, the adsorption mechanism of heavy metals by NFL-S through surface complexation was also investigated, which shows great potential for water decontamination.

关键词： Layered double hydroxide nanosheets sulfide Selective adsorption Heavy metal ions

Mechanism of Mg2+ dissolution from olivine and serpentine: Implication for bioleaching of high-magnesium nickel sulfide ore at elevated pH

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International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1069-1079页

作者： Jian-zhi Sun Jian-kang Wen Bo-wei Chen Biao Wu National Engineering Laboratory of Biohydrometallurgy GRINM Group Corporation Limited

To inhibit the dissolution of Mg^2+ during the bioleaching process of high-magnesium nickel sulfide ore, the effect of major bioleaching factors on the dissolution of Mg^2+ from olivine and serpentine was investigated and kinetics studies were carried out. The results indicated that the dissolution rate-controlling steps are chemical reaction for olivine and internal diffusion for serpentine. The most influential factor on the dissolution of Mg^2+ from olivine and serpentine was temperature, followed by p H and particle size. A novel method of bioleaching at elevated pH was used in the bioleaching of Jinchuan ore. The results showed that elevated pH could significantly reduce the dissolution of Mg^2+ and acid consumption along with slightly influencing the leaching efficiencies of nickel and cobalt. A model was used to explain the leaching behaviors of high-magnesium nickel sulfide ore in different bioleaching systems. The model suggested that olivine will be depleted eventually, whereas serpentine will remain because of the difference in the rate-controlling steps. Bioleaching at elevated pH is a suitable method for treating high-magnesium nickel sulfide ores.

关键词： olivine serpentine high-magnesium nickel sulfide ore bioleaching shrinking core model elevated pH