Journal of Environmental Sciences
·
2022
·
IF 6.796
Ning Wang,Hao Lu,Bo Liu,Tai Xiong,Jianping Li,Hualin Wang,Qiang Yang
An eddy deep leaching technology was developed in this paper to address the challenge of treating heavy metal contaminants in industrial mining areas. The desorption effect of As, Cd, Sb and Pb was investigated utilizing chemical leaching and physical eddy techniques. It was found that the heavy metals concentration increased with decreasing particle size. The highest proportion of Cd in the form distribution of soil was in the bound to iron and manganese oxides, while the maximum proportion of As, Sb and Pb were in the residual. The optimal solid-liquid ratio of the hydrocyclone was 1:20, and the corresponding separation efficiency and flow rate were 84.7% and 1.76 m 3 /hr, respectively. The grade efficiency of soil particle separation increases with particle size and exceeds 99% for particles above 1,000 µm. Leaching experiments have revealed that oxalic acid (OA) and a combination of oxalic acid and EDTA (OAPE) were more efficient than citric acid (CA) and a combination of citric acid and EDTA (CAPE) for the desorption of heavy metals, respectively. The comparison of OAPE and eddy leaching found that the latter improved the desorption efficiency by 9.4%, 7.5%, 7.2% and 7.8% for As, Cd, Sb and Pb compared to the former, respectively. The results demonstrated that the eddy leaching technique could further enhance the desorption efficiency of heavy metals. It is expected to provide technical support for soil remediation with reduced usage of leaching agents.
研究领域:
环境科学
·
土壤修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Zuowei Liu,Qinghua Tian,Xueyi Guo,Yasong Huang,Zhipeng Xu
Traditional gallium electrowinning suffers from low current efficiency and high specific energy consumption due to the inevitable hydrogen evolution reaction. In order to inhibit hydrogen evolution reaction and alleviate the concentration polarization, the pulse cyclone electrowinning process was proposed and developed to enhance diffusion and convection. During the pulse current off time, the ion concentration in the cathode diffusion layer can be effectively restored, while forced convection accelerates this process. Electrochemical experiments using a rotating disk electrode have preliminarily confirmed that pulsed electrodeposition can accelerate nucleation and improve current efficiency. Pilot experiments were conducted using an industrial gallium electrolyte to further validate the feasibility of the pulse cyclone electrowinning process. Under the following conditions: current density of 2000 A/m 2 , duty ratio of 50%, frequency of 10 Hz, and circulation flow of 400 L/h, the current efficiency and specific energy consumption were determined to be 69.21% and 7836 kWh/t, respectively. Compared to the traditional electrowinning process at the same average current density, pulse cyclone electrowinning exhibited a significant increase in current efficiency and a reduction in specific energy consumption by 52.28% and 31.57%, respectively. Overall, this study confirmed the feasibility of pulse cyclone electrowinning coupling pulse current and forced convection, which can also be applied to other electrodeposition processes to achieve higher current efficiency and lower energy consumption.
研究领域:
冶金工程
·
电化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Liang Ma,Xiaoxu Duan,Jiwei Wu,Jianping Li,Lv Peng,Liwang Wang,Lingyu Xiao
Boiler flue gas in the chemical industry contains SO 2 and nitrogen oxides (NO x ). These flue gases not only pollute the environment, but also seriously endanger human health. In this work, we studied the process of jet atomization and swirl enhancement. Then we constructed a miniaturized hydrojet cyclone. After that, we proposed a new type of flue gas purification technology to achieve integrated and efficient desulfurization and denitrification. All studies were based on combining the liquid jet field with the three-dimensional swirl field to increase the mass transfer area of the gas and liquid phases. The industrial sideline test results showed that the gas purification efficiency increased with the increase of inlet velocity and absorption liquid flow rate, Efficiency is always above 80%. Increasing the concentration of activator could significantly improve the desulfurization efficiency by 27%. Increasing the concentration of oxidant was beneficial to denitrification, and the maximum denitrification efficiency of methyldiethanolamine (MDEA) was 98.2%. Overall, this technology can not only help enterprises save maintenance and treatment costs, but also protect the environment by avoiding the harm caused by flue gas pollution.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
·
2022
·
IF 7.34
Xiaoyue Zhang,Xiujun Wang,Xiaoli Ren,Qingqing Tang,Shenwen Fang,Ming Duan
Air flotation cyclone is a potentially efficient method to improve the treatment efficiency of heavy oil produced water in offshore fields. For its practical application, it is of great significance to develop a flocculant that can flocculate air bubbles and oil droplets together to form oil aerated flocs. In this paper, a novel flocculant capable of rapidly forming oil aerated flocs was prepared and the formation conditions and mechanism of oil aerated flocs were investigated. Firstly, copolymer (PDAMPE-NH) was synthesized by free radical solution copolymerization of N-(3-dimethylaminopropyl) methacrylamide (DPM), diallylamine (DAA) and block polyether macromonomer (PEP) as the monomers . Then, the molecular weight of PDAMPE-NH was increased by using polyethylene glycol diacrylate (PEG-DA) as a chain extender. Finally, the target flocculant DA was obtained by protonating the tertiary amine group in the copolymer with formic acid . The protonated tertiary amine group in DA can capture oil droplets, and the polyether group in DA can capture air bubbles. When the DA dosage was 500 mg/L and bubble size was in range of 20 μm to100 μm, the oil aerated flocs were formed, and the oil content of heavy oil produced water reduced from 7250 mg/L to less than 100 mg/L within 90 s. Microscopic observation found that there were three stages for oil aerated flocs formation and the formation of oil-coated bubbles was the key step. The reported results can provide a reference for the fast treatment of heavy oil produced water in offshore fields.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2014
·
IF 3.828
Yichen Zong,Shuiqing Li,Fang Niu,Qiang Yao
The titania supported palladium nano catalysts (Pd/TiO 2 ) are synthesized in one-step using a premixed stagnation swirl flame (SSF) with ultra-fine spray system. This novel SSF method, with features of short residence time and fast quenching, produces nanosized (<2.5 nm) palladium particles being well dispersed on the 7–8 nm TiO 2 particle surface, with an overall specific surface area of 210–220 m 2 /g. The X-ray photoelectron spectroscopy (XPS) results indicate that the collected palladium particles are a mixture of both Pd and PdO, whereas the TiO 2 support is mainly in anatase phase by X-ray diffraction (XRD). A revised population balance model (PBM) by incorporating coagulation, sintering and scavenging of the binary system (Pd and TiO 2 ) is developed to explain the in situ doping mechanism of Pd/TiO 2 composites in the flame domain. Then, we use the synthesized nano catalyst to conduct the catalytic combustion of methane under 5–15% Pd loadings. It exhibits more excellent activity than those in the literature under identical temperatures. The T 20 , as 20% methane conversion temperature, can reduce to as low as 293 °C at 15% Pd loading. It is because that the Pd/TiO 2 catalysts made from the stagnation flame show a good dispersion of size-controlled palladium on TiO 2 which may not be accessible by wet-chemistry and even other flame synthesis routes.
研究领域:
材料化学
·
环境催化
·
纳米材料
·
能源工程
·
燃烧科学
✓ 已验证
DOI
高影响因子
JOURNAL OF AEROSOL SCIENCE
·
2019
·
IF 2.24
Jili Wei,Yihua Ren,Yiyang Zhang,Baolu Shi,Shuiqing Li
This work examines the effect of temperature-time history on the flame synthesis of titania nanoparticles using a specially designed swirl-stabilized tubular burner with two kinds of precursor feeding modes, the tangential inlet and the central jet inlet. When the Damköhler number is less than unity, a rapidly mixed type tubular flame is well-formed, which is chosen to be the condition for flame synthesis. The ex situ characterization of the synthesized TiO 2 nanoparticles shows that the particle samples from the tangential inlet feeding mode are mainly anatase (up to 84.3%) with a mean primary particle size of 13.0 ± 3.2 nm, whereas those from the central jet inlet feeding mode are large polydisperse rutile (up to 74%) nanoparticles with a mean size of 16.9 ± 8.8 nm. The significant differences in particle size and crystal phase are attributed to the varied temperature-time histories of two feeding modes, as the residence time of nanoparticles in high-temperature zone of the central jet inlet mode is much longer with larger variation than that of the tangential inlet feeding mode. Finally, the well-dispersed Pd/TiO 2 nanocatalysts are generated by elaborately feeding palladium acetate through the central jet inlet and titanium tetraisopropoxide through the tangential inlets, respectively, to better match the temperature-time histories with the decomposition properties of two different precursors. The study demonstrates the potential of this swirl-stabilized burner for producing tailored single- and multi-component nanomaterials for a variety of applications.
研究领域:
材料科学
·
纳米技术
·
燃烧化学
·
催化材料
·
热力学过程
·
功能纳米材料
✓ 已验证
DOI
高影响因子
Applications in Energy and Combustion Science
·
2025
·
IF 6
Meng Wang,Zunyi Luo,Chen Fu,Kunpeng Liu,Yongjun Wang,Xiaoyang Wang,Juan Yu,Sheng Meng,Man Zhang,Yi Gao
Nanofluid fuel has attracted the interest of researchers for decades due to its prominent combustion and propulsive properties. However, combustion instability is inevitable in propulsive systems, and little is known about how nanofluid fuel drive or dampen thermoacoustic oscillations of the system. A confined boron/ethanol (B/EtOH) nanofluid fuel spray swirling flame stabilized by an axisymmetric bluff body has been experimentally investigated in this work. The flame response to the varying B nanoparticles (NPs) doping concentrations was recorded and compared. 2D images and critical data were acquired using a 10 kHz repetition-rate OH* and BO 2 * chemiluminescence (CL) system, a photomultiplier tube, and a pressure transducer. Meanwhile, several analysis methods, including flame visualization, Fourier/Hilbert transforms, spectrograms, proper orthogonal decomposition (POD), extended POD (EPOD), and Rayleigh's criterion analysis, are utilized to help us understand the underlying mechanism. From the averaged images, the high-intensity region of the BO 2 *-CL appears further downstream than that of OH*-CL, resulting in a broader heat-release distribution of B/EtOH nanofluid fuel spray flames than neat EtOH ones. As the B NPs doping concentration increases, the oscillation frequency of the B/EtOH spray swirling flames remains almost unchanged, but the oscillation amplitude gradually decreases. Numerous B particles and agglomerates exhibit intense combustion when the micro-explosion phenomenon occurs. Additionally, the time-resolved pressure and heat release oscillations are out of phase and are supposed to be associated with acoustic energy dissipation. The POD and EPOD analyses reveal that the primary flame oscillations are driven by the longitudinal flame-shedding motion and the entrained reaction pockets. Meanwhile, the OH* and BO 2 * radicals exhibit different local dynamics responses to the oscillation. Based on the Rayleigh index distribution coupling the fluctuation of pressure and heat release from EtOH and B, our study provides evidence that the combustion of B NPs downstream suppresses the thermoacoustic instability of the EtOH flames.
研究领域:
燃烧科学
·
热声学
·
流体力学
·
纳米流体技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
G. Zhou,K.P. Wang,H.W. Liu,L. Wang,X.F. Xiao,D.D. Dou,Y.B. Fan
Owing to low bearing capacity and efficiency, traditional filters or adsorbents for removal of contaminants like crystal violet (CV) dye required frequent replacement. Besides, the combination of three-dimensional (3D) printing and bionics could break the constraints of traditional configuration. In this study, a novel depth-type hybrid polylactic acid (PLA)@graphene oxide (GO)/chitosan (CS) sponge filter with bionic fish-mouth structure was prepared and fabricated, assisted by 3D printing and double freeze-drying technology, according to the theories of vertical cross-step filtration and swirling flow. And GO/CS sponge and its filtering device were characterized by FITR, SEM, water adsorption and so on. Moreover, it was explained that the impact factors on dye removal mechanism, like GO content (or CS content), contact time, pH, temperature and bionic configuration. As a result, the bionic 3D filtering device demonstrated excellent removal efficiency (97.8 ± 0.5% for CV) and GO/CS sponge exhibited higher strength (74.5 ± 3.5 MPa) at the condition of GO content of 9 wt%, contact time of 46 min, pH of 8 and 35 °C, respectively. Therefore, the resulting 3D PLA@GO/CS sponge bionic filter via gravity and vortex driving provided new alternatives for effectively dye-water separation, and it showed great promise for application of biological macromolecules in adsorption.
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
Analytical Methods
·
2014
·Vol. 6
·期 23
·9348-9353
·
IF 1.938
Fei Wang,Yang Qiu,Peng-Bo Fu,Hua-Lin Wang,Yi-Tao Long
A novel method for reliable on-site characterization of aromatic compounds adsorbed on porous particles with surface enhanced Raman spectroscopy (SERS) in a dynamic adsorption-hydrocyclone separation process (DAHS) was introduced. Aromatic compounds found in printing and dyeing wastewater were adsorbed on functionalized porous alumina particles (FPAPs). The SERS-active FPAPs were prepared by decorating and growing silver nanoparticles (Ag NPs, ∼70 nm diameter) on the surface of porous alumina particles (PAPs). Samples were then characterized with a portable Raman spectrometer. SERS offers quantitative analyses of the pollutants adsorbed on the surface of FPAPs directly and the quantity of benzidine adsorbed on porous particles was 20.5 mg kg−1. It shows that the SERS-DAHS technique could be readily applied to the quantitative characterization of aromatic compounds adsorbed on SERS-active FPAPs. Furthermore, both qualitative and quantitative detection of aromatic compounds in wastewater produced on-site were readily accomplished using the SERS-DAHS method and its analytical ability compares well with GC-MS and the detection results deviating between these two techniques was less than 10%. The results demonstrate that the SERS-DAHS method is straightforward, rapid, and preferable for the real-time detection and quantitative characterization of aromatic compounds/pollutants adsorbed on porous materials.
研究领域:
环境科学
·
分析化学
·
废水处理
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）