Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Haiyan Chen,Haibo Xu,Yeyin Li,Zhibin Li,Xin Wang,Bo Jiang,Rongshun Lai,Wenbin Fan,Chuntao Xiang,Zhi Yang,Xiao Chi,Qiang Ma
Selective chlorination has been proven to be an energy-efficient and environmentally friendly method for recycling rare earth elements (REEs) from Nd-Fe-B waste. However, little attention has been paid to the in-depth study of Nd-Fe-B sludge chlorination until now. In this work, four isoconversion methods combined with an unreacted shrinkage core model were employed for the first time to investigate the kinetic behavior of the chlorination reaction between FeCl 3 and Nd-Fe-B sludge. Through thermodynamic calculations, TG-DSC, SEM-EDS, and XRD analysis, the chlorination process and phase transformation behavior of Nd-Fe-B sludge were elucidated. The results show that under optimal conditions (350 °C, FeCl 3 /RE=3:1, 2 h), the RE components in Nd-Fe-B sludge are selectively chlorinated to RECl 3 , avoiding the formation of REOCl, while the iron components primarily exist in the leaching residue as Fe 2 O 3 or FeOCl. And 97.32 % of REEs are selectively extracted into the leachate, while the iron leaching rate is only 4.02 %. Besides, the STA method is the most accurate, yielding E α-STA and A values of 75.01 kJ/mol and 2.6 × 10 6 min −1 , respectively. The reaction control mechanism was analyzed in three steps. In Step 1 (0.05 < α < 0.63) and Step 2 (0.63 < α < 0.75), the diffusion reaction mechanism controls the overall reaction, In Step 3 (0.75 < α < 0.95), the nucleation reaction takes over the control, which provides a good explanation for the change in E α-STA . However, the control step of the entire chlorination reaction is dominated by the internal diffusion process.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Yong-Yuan Chen,Xi-Wen Lan,Hao Ren,Wen-Jie Li,Jun Chen,Xin-Yu Jiang,Jin-Gang Yu
Due to the well dispersibility of graphene oxide (GO) in aqueous solution, it is very difficult to separate GO after adsorption. Therefore, various organic/inorganic molecules have been composited with GO to produce novel adsorbents with relatively lower dispersibility and better adsorption performance. The rational selection of these organic/inorganic molecules seems very important. In this work, three-dimensional (3D) (graphene oxide-N-benzyloxycarbonylglycine) GO-ZG composites were synthesized by an easy-to-operate, one-step hydrothermal method. The 3D GO-ZG composites were illustrated by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), high-resolution transmission electron microscopy (HR-TEM), powder x-ray diffraction (PXRD), Raman spectroscopy and specific surface area (SSA) analysis. The effects of GO-to-ZG mass ratio (x: y), hydrothermal reaction time, and hydrothermal reaction temperature were investigated. The adsorption properties of 3D GO-ZG x:y composites toward rare earth elements (REEs) were studied. The results showed that the composite with a GO-to-ZG mass ratio of 2:1, reaction time of 6 h, and reaction temperature of 120 ºC possessed the best adsorption performances. Further investigation of the adsorption conditions on 3D GO-ZG 2:1/6 h/120 ℃ composites toward REEs including initial solution pH value, contact time, initial REE 3+ concentration, and contact temperature was carried out. The adsorption of REEs could reach equilibrium in 60 min at room temperature. The adsorption capacities of 3D GO-ZG 2:1/6 h/120 ℃ composite for La 3+ , Yb 3+ , Nd 3+ , Er 3+ and Y 3+ were 44.56, 53.64, 45.96, 50.48 and 30.63 mg·g -1 , respectively. Ten adsorption/desorption cycles revealed that GO-ZG 2:1/6 h/120 ℃ composite possessed good stability and recoverability . The adsorption mechanism of REEs by GO-ZG 2:1/6 h/120 ℃ composite can be summarized as ion exchange, surface complexation, and electrostatic attraction. The as-prepared GO-ZG 2:1/6 h/120 ℃ composite might be used as a renewable and structurally stable adsorbent in the adsorption.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Sustainable Materials and Technologies
·
2025
·
IF 9.2
Hui Li,Ronghao Wu,Long Zhou,Zuliang Chen
In this study, a novel C-ZIF-8@Fe/REEs composite, fabricated from one-step pyrolysis using ZIF-8@Fe adsorbed with rare earth elements (REEs) as precursors was successfully used to activate peroxymonosulfate (PMS) for efficient oxidation of Bisphenol A (BPA). The as-prepared C-ZIF-8@Fe/REEs exhibited high PMS activation performance, with an BPA removal efficiency exceeding 95 % within 120 min. Characterizations revealed that the REEs introduction increased the exposure of active sites, and facilitates the electron transfer. Electron paramagnetic resonance analysis and quenching tests confirmed that both radical (·OH, ·SO 4 − ) and non-radical ( 1 O 2 , high-valent metals, and electron transfer) pathways were involved in BPA degradation. Reasonable BPA degradation pathways were proposed by analyzing the results of LC-MS and DFT calculations. Additionally, toxicity assessments demonstrated a significant reduction in the toxicity of degradation products. Finally, the synthesized composite exhibited excellent reusability and stability in real wastewater fixed column bed experiments, with the removal efficiency still be higher than 70 % after 11 h operation. These findings demonstrate that the recovery REEs from mining wastewater is an effective strategy in developing a highly efficient Fenton-like catalysts, and also highlight the promising role of using C-ZIF-8@Fe/REEs in wastewater treatment, particularly for the removal of organic contaminants.
研究领域:
环境科学
·
材料科学
·
化学工程
·
环境污染控制
·
催化化学
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
HYDROMETALLURGY
·
2020
·
IF 3.338
Fujian Li,Zhong Xiao,Jingyao Zeng,Jinqing Chen,Xiaoqi Sun
Ionic liquid (IL) based on tetraheptylammonium cooking oil (TC) was used for the first time to recovery rare earth elements (REEs) from leaching liquor of ion-adsorbed-type rare earths ores. Firstly, extraction performances of tetraheptylammonium oleate (TO) and tetraheptylammonium linoleate (TL) type ILs were investigated. It was shown that these ILs had good extraction performances, such as short equilibrium time less than 1 min, good extraction capacity of 0.225 mol/L and high stripping efficiency of 99%. Additionally, REEs extraction occurred in the solutions with high acidity (pH = 0.24) because the cation (C 7 H 15 ) 4 N + of TO and TL could form a strong amine salt with hydrogen ion to decrease acidity of the feed solution. Also, an ion association mechanism of REEs extraction was proposed by FT-IR spectra, 1 H NMR investigation and slope analysis method. Secondly, TC was synthesized in water bath by mixing tetraheptylammonium bromide with saponified peanut oil. Then, comparative study of commercial extractants showed that TC had the highest REEs recovery yield of 100% from the leaching liquor. The sustainability, biocompatibility and non-toxicity, as well as simple synthesis route and well extraction performances make these cooking oil based ILs promising for REEs recovery from the leaching liquor.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Xinmiao Xu,Zhenjun Zhang,Xiulan Weng,Zuliang Chen
Extracting rare earth elements (REEs) from wastewater is crucial for saving the environment, sustainable use of natural resources and economic growth. Reported here is a simple, low cost and one-step synthesis of Fe nanoparticles (FeNPs) based on two plant extracts having the ability to recover REEs. The synthesis of FeNPs using Excoecaria cochinchinensis leaves extract (Ec-FeNPs) exhibited high selectivity for heavy rare earth due to unique biomolecules, achieving separation coefficients (K d ) of 3.16 × 10 3 –4.04 × 10 6 mL/g and recovery efficiencies ranging from 71.7 to 100 %. Conversely, the synthesis of FeNPs using Pinus massoniana lamb extract (PML-FeNPs) revealed poorer REE recovery efficiencies of 7.2–86.7 %. To understand the differences between Ec-FeNPs and PML-FeNPs in terms of selectivity and efficiency, LC-QTOF-MS served to analyze the biomolecules differences of two plant extracts. In addition, various types of characterization were carried out to identify the different functional groups encapsulated on the surface of FeNPs. These results reveal the source of the difference in the selectivity of Ec-FeNPs and PML-FeNPs for REEs. Furthermore, during DFT calculations, it was found that biomolecules with varying affinities for the surface of FeNPs interact with each other, leading to the formation of structures that exhibit high reactivity towards REEs. Finally, incorporating Spearman correlation analysis demonstrates that the selective removal efficiency of REEs was closely linked to surface complexation, ion exchange, and electrostatic adsorption. Consequently, this work strongly highlights the potential for the practical application of novel adsorbents in this field.
研究领域:
环境科学
·
材料科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Ruize Gao,Haisen Peng,Qiongqiong He,Zhen Meng,Pengxu Xiang,Lihua Hou,Zhenyong Miao
Lithium (Li), gallium (Ga), and rare earth elements (REEs) are essential in various industries due to their wide range of applications, and extraction of rare metals from coal fly ash (CFA) has become a hot topic in recent years. This study investigates the simultaneous leaching of Li, Ga, and REEs from CFA using both inorganic and organic acids. High leaching efficiencies, exceeding 90%, were achieved for Li (90.4%), Ga (90.5%), and REEs (92.7%) with 3 M HCl leaching. The leaching efficiency of citric acid is lower, but it can achieve a leaching rate of 70–80% at low concentration (0.5 M). A novel two-stage acid leaching approach is proposed for the selective leaching of Li and Ga from CFA. In the first step, 1 M HCl leaching results in the leaching of most Li (71.12%) and a small amount of Ga (2.63%). Subsequently, 2 M HCl leaching led to the leaching of a small amount of Li (18.14%) and most of Ga (83.93%). The silicic acid gel produced during low HCl concentration leaching exhibited a stronger affinity for Ga 3+ than for Li + , with significantly higher adsorption energy for Ga (−211.554 kcal/mol) compared to that for Li (−3.481 kcal/mol). This two-stage acid leaching process ingeniously utilized H 2 SiO 3 to achieve the selective separation and leaching of Li and Ga.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Qiuting Yan,Zhenjun Zhang,Zuliang Chen
Recycling rare earth elements (REEs) from secondary sources such as mine wastewater has emerged as a sustainable economic strategy. In this study, microbial synthesized iron nanoparticles after the recovery of rare earth elements (FeNPs/REEs) have been used as an environmentally friendly material to remove arsenic from mine groundwater. The removal efficiencies of As(III) and As(V) were 94.5% and 96.0%, respectively, compared to that of As(III) (44.5%) and As(V) (66.5%) using only FeNPs. Indicated here is that the efficiency of FeNPs/REEs in removing arsenic was better than those of FeNPs. IC-AFS and XPS analysis showed that As(III) was partially oxidized to As(V) during the adsorption process via electron transfer. Electrochemical and BET indicated that FeNPs/REEs not only helped to expose more active sites but also the catalytic activity was enhanced. Meanwhile SEM-Mapping and FTIR demonstrated that arsenic was adsorbed onto the surface of FeNPs/REEs through complexation and ion exchange. Furthermore, Zeta potential analysis revealed electrostatic interactions between arsenic and FeNPs/REEs at pH = 6.0. Thus, the key physicochemical properties for the removal of As(III) and As(V) by FeNPs/REEs were statistically analyzed via Pearson correlation analysis, in order to understand the removal mechanism of arsenic involving surface complexation, oxidation, electrostatic and ion exchange. Finally, efficiency was consistently high in removing arsenic from mine groundwater using FeNPs/REEs with As (73.0%), Pb (76.0%), and Fe (36.0%). This study generates a new insight into FeNPs/REEs used in groundwater remediation.
研究领域:
环境科学
·
纳米技术
·
水处理
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
·
2022
·Vol. 38
·期 2
·449-456
·
IF 4.351
Wengang Liu,Yuchen An,Qinyuan Qu,Pengfei Li,Lixin Zhang,Chaofeng Li,Shuang Wei,Hongying Zhou,Jiubin Chen
Barium (Ba) is a major element in many geological samples (e.g. barite/witherite-rich samples) and introduces serious oxide and hydroxide interferences during the analysis of rare earth elements (REEs) by ICP-MS. Hence, eliminating Ba interference is an indispensable step for accurate ICP-MS analysis of REEs. Though ion-exchange chromatography is widely used for REE purification, the tediousness, time consumption and high cost limit the application of this purification method. In this study, we developed a rapid and reliable separation method to eliminate Ba from geological samples for the precise measurement of REEs by ICP-MS. The new method was established based on the difference in solubility between Ba and REEs in concentrated nitric acid as barium nitrate (Ba(NO3)2) is almost insoluble, in contrast to REEs. The whole separation procedure could be completed in less than two hours and only consumed 1.5 mL 15 M nitric acid. The protocol resulted in acceptable procedural blanks (below 0.02 ng mL−1), quantitative recovery (96–103%) of REEs, and limited Ba content (0.37 ± 0.14 μg mL−1, (2SD, n = 50)) in the purified solution (50 mL), in which the interference effect could be eventually eliminated by mathematical correction during the ICP-MS analysis. The method was successfully applied to four natural barite-rich samples with BaSO4 content ranging from 18.87 wt% to 42.41 wt%. Overall, this accurate and rapid method shows great potential for the precise determination of the REE content in Ba-rich samples by ICP-MS.
研究领域:
分析化学
·
地球化学
✓ 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）