JOM
·
2020
·Vol. 72
·期 9
·3179-3185
·
IF 2.054
Wang Xun,Jiao Fen,Qin Wenqing,Li Zihan,Wang Na,Liu Wei,Yang Congren
Waste printed circuit boards (WPCBs) are an essential component in electronic waste (e-waste), and contain a number of valuable metals (e.g., Cu, Sn) as well as non-metal resources (e.g., brominated epoxy resin). Currently, most of the non-metals are disposed of in landfills, causing environmental problems. In this study, a combination of pyrolysis and physical separation is proposed to recover valuable resources, including both metals and non-metals, from WPCBs. The WPCBs were pyrolyzed at 700°C under a nitrogen atmosphere. Pyrolysis oil and gas can be reused as fuel for the pyrolysis of WPCBs. Metals like copper, tin, and iron in the pyrolysis residues were separated by selective crushing, sieving, gravity separation, and magnetic separation. Finally, rich copper (Cu 82.21%, Sn 1.47%), rich tin (Cu 53.20%, Sn 13.43%), rich iron (Fe > 63%), and non-metal products were obtained, and the total recoveries of copper, tin, and iron were 95%, 86%, and 76%, respectively.
研究领域:
环境科学
·
资源循环利用
·
冶金工程
·
固体废物处理
·
清洁生产技术
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Huaxia Li,Wencui Chai,Yijun Cao,Shichong Yang
Surface pretreatment on minerals prior to flotation was proved to increase the selectivity of separation process. Organic acid pretreatment of low-grade diasporic-bauxite was conducted, and the effects of oxalic acid on bauxite flotation were investigated in this work. The oxalic acid pretreatment mechanisms were studied by adsorption measurements, zeta potential testing, XPS analysis, and ICP analysis. The flotation results showed that the oxalic acid treatment could significantly improve Al 2 O 3 recovery from 75.39% to 81.88% and decrease SiO 2 recovery from 53.26% to 47.30%. The adsorption capacity of diaspore for sodium oleate (NaOL) increased by 8.50%, while that of kaolinite decreased by 11.72%. XPS analysis revealed that oxalic acid treatment improved the relative contents of unsaturated Al at diaspore surface beneficial to the adsorption of NaOL. While the relative content of Al at kaolinite surface was decreased due to the Al dissolution revealed by ICP results. Zeta potential analysis indicated that oxalic acid changed the surface property of minerals favorable for the selective adsorption of NaOL on diaspore surface rather than kaolinite surface. These findings provided a promising direction for surface pretreatment of low-grade bauxite using oxalic acid for the improvement of the flotation desilication.
研究领域:
矿物加工工程
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表面化学
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资源综合利用
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浮选化学
·
冶金工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2018
·
IF 2.829
Yueyun Fang,Qizhang Huang,Pengyi Liu,Jifu Shi,Gang Xu
This study demonstrated high-efficient dye adsorption for wastewater using MoS 2 -glue sponge as an easy-separative and regenerative adsorbent. Flower-like molybdenum disulfide (MoS 2 ) nanopowders with rich polar edge sites were firstly synthesized by a facile one-pot hydrothermal method . Chemical and morphological features of MoS 2 nanoflowers were then examined by XRD , XPS , SEM and TEM . Afterwards, different concentrations of the MoS 2 -glue sponges with easy separability were successfully fabricated by a convenient two-step dip-coating method. The adsorption performance was estimated by the removal of Rhodamine B (RhB) dyes. The results proved that the maximum adsorption capacity of MoS 2 -glue sponge was 127.39 mg RhB/g product in 60 min. The RhB uptake behaviors can be well described by the Sips isotherm model and pseudo-second-order kinetic model , indicating a multilayer and chemical adsorption process. The adsorption mechanism proposed that the zwitterionic RhB molecules in aqueous solution would aggregate on the surface of negative charged MoS 2 in a head-to-tail way through electrostatic interaction . Furthermore, RhB dyes could desorb easily from MoS 2 -glue sponges when changing the polarity of solvent and the reusability experiment showed that the MoS 2 -3% glue sponge could be reused for 15 times with above 85.8% of the adsorption capacity retained. Thus, the novel MoS 2 -glue sponge is considered as a competitive adsorbent for treatment of dyestuff waste water.
研究领域:
环境科学
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材料科学
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纳米技术
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化学工程
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水污染控制
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Xiujuan Zhao,Yangyang Luo,Peixin Tan,Mingxian Liu,Changren Zhou
A high-performance oil-water separation device that built by environment-friendly materials is a promising strategy to solve water pollution problem. In this study, we developed an oil-water separation system with chitin/halloysite nanotubes (C/HNTs) composites. C/HNTs were crosslinked by epichlorohydrin and freeze-dried, then a porous sponge was formed. The C/HNTs sponge was modified to be hydrophobic via immersing into bromohexadecane ethanol solution. The surface structure, mechanical properties, microstructure, oil absorption and oil-water separation ability of the C/HNTs sponge were investigated. The addition of HNTs significantly increased the compressive strength of chitin sponge without influence on porous structure . IR spectra indicated the successful coating of bromohexadecane on the C/HNTs sponge surface, which enabled the hydrophobicity and lipophilicity of this construct. The inside construct of the C/HNTs sponges were full of interconnected pores, and the pore size ranged from 250 to 500 μm. The absorption capability for various oil and grease were measured, including methylbenzene, sunflower seed oil , carbon dichloride, n-hexane, chloroform and acetone. It is found that the total amount of chloroform absorbed by a C/HNTs sponge was ~11.23 times of the sponge's weight, and the absorption for hexane was ~3.94 times of the sponge's weight. The sponge also exhibited an excellent oil-water separation ability with as high as 98.7% separation efficiency. All the results suggested that the chitin/HNTs sponges with improved mechanical property would have a great potential in oil-water separation.
研究领域:
材料科学
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环境工程
·
高分子化学
·
纳米复合材料
·
分离技术
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2019
·
IF 6.395
Duchao Zhang,Hongbin Ling,Tianzu Yang,Weifeng Liu,Lin Chen
Electric arc furnace (EAF) dust is a hazardous waste material containing valuable elements, such as zinc (Zn) and iron (Fe), as well as other environmentally harmful elements. In the conventional process, the existence of zinc ferrite (ZnFe 2 O 4 ) in EAF dust results in a low recovery ratio of zinc and can induce high energy consumption or difficulties utilizing iron resources. In this article, a hydrothermal reduction method in a NaOH system is proposed to recover Zn selectively from EAF dust. First, when pure ZnFe 2 O 4 was used as the input material to test the feasibility of the new method, 70% Zn leaching efficiencies and the isolation of Fe in the residue through the formation of ferroferric oxide (Fe 3 O 4 ) were achieved at the optimal conditions of 260 °C, 6 M [NaOH], 10 g/L [C 6 H 12 O 6 ] n and 50 mL/g of L/S. Second, a leaching process of EAF dust was proposed using the following two procedures: (i) first leaching under normal pressure to dissolve zinc oxide (ZnO); and (ii) second leaching of the first leach residue under hydrothermal reduction conditions to dissolve ZnFe 2 O 4 . The leach liquor from the second step was recycled to the first step. Under optimum conditions, the leaching efficiencies of Zn during the first and second leaching were 66.4% and 69.3%, respectively. The total Zn leaching efficiency was calculated to be 89.7%, producing Zn-impregnated leach solution and a leach residue rich in Fe (up to 39.4 wt%) that are suitable as resources for a steel-making plant. However, this process also has its shortcomings owning to larger liquid-solid ratio in the leaching process. Overall, the study technically provides an alternative approach to improve the recycling of zinc and iron and effectively reduce environmental risks from EAF dust.
研究领域:
环境工程
·
冶金工程
·
资源循环利用
·
清洁生产技术
·
工业废物处理
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 17
·
IF 1.866
Ruiqing Hu,Yuping Pi,Na Wang,Qian Zhang,Jinqi Feng,Weilin Xu,Xia Dong,Dujin Wang,Hongjun Yang
Biodegradable polymers have received increased attention due to their potential application in the medicine and food industries; in particular, poly(lactic acid) (PLA) is a primary biopolymer because of its excellent biocompatibility and absorbability features. In this study, a porous PLA membrane was fabricated by phase separation using water microdroplets produced by an ultrasonic atomizer as a coagulation bath. The formation of S-type clusters was attributed to the slow exchange rate between solvent and coagulant, which provided time for the movement of polymer molecules. The effect of preparation conditions on the structure of S-type clusters, including polymer concentration in solution and ambient temperature was investigated. The PLA porous membrane prepared from water micro-droplets with different morphology compared with the sample fabricated from distilled water has potential application in fields of tissue engineering and artificial organ generation. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43355.
研究领域:
生物材料学
·
高分子科学
·
组织工程
·
再生医学
·
纳米结构制备
·
相变动力学
✓ 已验证
DOI
高影响因子
DESALINATION
·
2021
·
IF 9.501
Lihua Zhao,Zhiyu Liu,Faizal Soyekwo,Changkun Liu,Yunxia Hu,Qingshan Jason Niu
Sludge thickening from sewage treatment plants is an essential step in reducing the sludge volume and processing cost of the subsequent treatment. Forward osmosis (FO) technology is one of the research endeavors used in the field of membrane separation and feed solution concentration. However, the traditional used single-skinned FO membranes encounter the problems of serious internal concentration polarization (ICP) and fouling phenomenon within porous substrates . A novel double-skinned FO membrane was proposed in this study in order to enhance the anti-fouling performance and mitigate the ICP phenomenon. Single-skinned FO membrane using the same substrate was also fabricated. Results demonstrated that the double-skinned FO membrane significantly reduced ICP and exhibited higher flux when using draw solutions with high concentrations as compared to the single-skinned FO membrane. Furthermore, the double-skinned FO membrane demonstrated reasonably high-water flux (11.6 LMH), whereas zero flux was recorded from the single-skinned FO membrane when using the feed solution that contained 15.0 g/L organic foulants in the fouling tests. At last, the double-skinned FO membrane exhibited superior anti-fouling properties and much higher flux than that of single-skinned FO membrane operated under both modes during the long-term sludge thickening process, indicating the great potential of the double-skinned FO membrane to deal with the high-water-content sewage sludge in the water treatment process.
研究领域:
环境工程
·
膜科学与技术
·
水处理
·
分离科学
·
环境功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Tingliang Xie,Minxuan Chen,Cong Xu,Jing Chen
Microextractors are known to provide high mass transfer rates for the extraction and separation of rare-earth elements (REEs). High-throughput microextractors are essential for industrial-scale production of REEs, but few practical studies have been conducted to date. In this work, a chaotic advection microextractor, i.e., a three-stage microextractor, was designed and demonstrated to extract Pr(III) and Ce(III) efficiently from nitric acid media at high throughputs by using 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (P507) and sulfonated kerosene as an extraction agent and a diluent, respectively. Flow visualization experiments showed that the dispersed phase could be effectively broken into small droplets owing to vortex and recirculation flows. Microextraction experiments performed under optimal extraction conditions indicated that at low throughputs, the concentration ratio D , extraction efficiency E , and separation factor β decreased with an increase in the throughput, whereas at high throughputs, D , E , and β increased with an increase in the throughput. An extraction efficiency close to that of co-current balanced extraction was successfully achieved, even at a high total throughput of 100 mL/min and a rather short residence time of 0.029 s. Thus, the chaotic advection microextractor features a high throughput and high extraction efficiency, which are appropriate for the high-efficiency extraction and separation of REEs.
研究领域:
化学工程
·
分离科学
·
稀土冶金
·
微流控技术
·
过程强化
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2014
·
IF 2.269
Jianxiu Liu,Dafeng Zhang,Xipeng Pu,Daoyou Dong,Peiqing Cai,Hyo Jin Seo
Magnetically separable Zn 1− x Cd x S/γ-Fe 2 O 3 ( x =0–1) photocatalysts were synthesized by a one-step combustion method. The structures, morphologies, absorbance, optical and photocatalytic properties of the samples were studied by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy , ultraviolet–visible spectrophotometry and photoluminescence . The experimental results show that the formation of hexagonal Zn 1− x Cd x S and γ-Fe 2 O 3 and the combination of them were one-pot achieved. The Cd 2+ content has a significant influence on the absorbance of visible light and fluorescence properties. The magnetic properties of samples ensure the magnetic separation by using a magnet. CdS/γ-Fe 2 O 3 shows the best photocatalytic performance compared with other samples, ascribed to its small energy band gap and matching energy band structure between CdS and γ-Fe 2 O 3 . Moreover, no obvious deterioration was observed in the stability tests.
研究领域:
材料化学
·
光催化
·
纳米材料
·
环境功能材料
·
无机合成
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Jishu Han,Fangxu Dai,Ying Liu,Ruiyang Zhao,Lei Wang,Shouhua Feng
The photocatalytic hydrogen production has become one of the most promising strategies to solve the energy crisis and environmental pollution. Novel CdSe/SrTiO 3 nanocomposites (average diameter ≈ 114.6 nm) with high photocatalytic activity are synthesized and used for visible light photocatalytic water splitting for hydrogen production . Through optimizing the concentration of CdSe QDs, CdSe/SrTiO 3 nanocomposites exhibit increased visible light absorption and enhanced photocatalytic hydrogen evolution efficiency compared to SrTiO 3 nanoparticles. The maximum H 2 evolution amount reaches to 3350.53 μmol in 8 h by using CdSe/SrTiO 3 -3 as catalyst. Owing to the formation of heterojunction at the interface between CdSe and SrTiO 3 , the electrochemical impedance spectrum of CdSe/SrTiO 3 -3 exhibits the smallest arc radius and the photocurrent density of CdSe/SrTiO 3 -3 reaches to 0.26 μA cm −2 . The photogenerated electrons are effectively separated and transferred and the recombination of electron-hole pairs is avoided, thus significantly improving the photocatalytic hydrogen production performance of CdSe/SrTiO 3 nanocomposites.
研究领域:
材料科学
·
物理化学
·
纳米催化
·
能源材料
·
光催化
✓ 已验证
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2019
·Vol. 33
·期 9
·e5082
·
IF 3.259
Dongmei He,Li Zeng,Guiqing Zhang,Qinggang Li,Wenjuan Guan,Zuoying Cao,Shengxi Wu
A new compound, α-aminophosphonate derivative containing pyridine ring (PPDE), was designed and synthesized as an extractant for the separation of nickel from metal impurities. Over 94.5% of Ni (II) extraction from sulfuric acid solution was achieved by using PPDE with an equilibrium pH of 4.02. Meanwhile, high separation coefficients of 23.8 for Ni to Co, 84.9 for Ni to Mn, 254.1 for Ni to Ca and 696.7 for Ni to Mg, respectively, were obtained. It was noted that PPDE exhibited an excellent regenerability, and the extraction of Ni with the recycled organic phase ranged from 92.5% to 93.9% during six circulations. The extracted nickel complex was determined as [Ni (PPDE) 2 (DNNSA − ) 2 (H 2 O) 4 ], which was supported by the data obtained from Fourier transform-infrared, UV–Vis and electrospray ionization-mass spectrometry spectra.
研究领域:
无机化学
·
湿法冶金
·
分离科学
·
配位化学
·
环境化学
·
资源回收
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 27
·47723
·
IF 2.188
Yayun Zheng,Yaofang Hu,Xing Yang,Meng Yuan,Jie Zhang,Yaodong Zhang,Jujie Luo
We synthesized novel polyurethane (PU) membranes from isophorone diisocyanate (IPDI), poly(ethylene glycol) (PEG) with a molecular weight of 2000, aminopropyl-terminated poly(dimethyl siloxane) (PDMS) with a molecular weight of 2000, and 1,4-butanediol (BDO) via a two-step polymerization. The structure of each synthesized membrane was studied through Fourier transform infrared spectroscopy and gel permeation chromatography. The effect of the thermal behavior was determined by differential scanning calorimetry and thermogravimetric analysis. The gas-permeability characteristics of the PU membranes were then tested for a single gas. The results show that the permeability of CO 2 ( P CO2 ) gradually increased with PDMS content. Among these PU membranes, PU-d (PEG/PDMS = 1:1, PEG/PDMS/IPDI/BDO = 1:3:2) showed the best P CO2 (132.6 Barrer) at 25°C and 1 bar pressure. The gas-permeability coefficients of each PU membrane at different operating temperatures were investigated, and the results show that P CO2 reached 302.6 Barrer at 65°C and 1 bar. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47723.
研究领域:
高分子材料科学
·
膜分离技术
·
气体分离
·
功能高分子
·
环境化工
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）