CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Xiangxing Xu,Xianzhou Ning,Faqin Dong,Xiaoyong Yang,Wei Zhang,Bin Ye,Zhiguo Yang,Guoqiang Zhao,Chuan Zeng,Yushan Yang
In this paper, we present a productive low-temperature fabrication of Cs-hollandite ceramics by adding Bi 2 O 3 as a sintering aid to achieve high cesium retention. The effects of Bi 2 O 3 addition on the phase composition, crystal structure and aqueous stability of the stoichiometric Ba 0.9 Cs 0.3 Cr 2.1 Ti 5.9 O 16 ceramic waste form were investigated. It was found that adding Bi 2 O 3 can effectively reduce the sintering temperature and promote densification of Cs-containing hollandite products. The Cs-hollandite ceramic with 2 wt% Bi 2 O 3 sintered at 1000 °C showed a single phase with > 98 % cesium retention, which was ∼ 200 °C lower and ∼ 11 % retention rate higher than those of reported Cs-bearing hollandite. Moreover, the leached sample remained stable tetragonal structure, the LR Cs was in the order of 10 -3 g·m - 2 ·d -1 after 28 days and the leaching indexes > 8, exhibiting good aqueous stability. This route can be considered as a promising solution to prevent cesium loss for incorporating the cesium waste in ceramic hosts.
研究领域:
材料科学
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核废料管理
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2016
·
IF 3.926
Tao Bao,Pingxiu Tang,Deying Kong,Zhenkun Mao,Zilin Chen
Covalent-organic frameworks (COFs) are attractive materials for their fascinating properties, such as rigid structures, exceptional thermal stabilities, low densities, and permanent porosity with specific surface areas, which indicate potential for application in chromatography similar to related metal-organic frameworks (MOFs). However, the utilization of COFs in analytical chemistry is far behind as compared to that of the MOFs due to the challenging work of their immobilization. Here, we have successfully demonstrated the growth of the boron COF-5 on the inner wall of the fused silica capillary by a developed polydopamine-supported method. Combined with the layer-by-layer strategy, multilayer COF-5-coated capillary was obtained. The formation of COF-5 on polydopamine-coated substrate has been confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction. A novel stationary phase of COF-5 was developed on the basis of successful growth of COF-5 on polydopamine for open-tubular capillary electrochromatography (OT-CEC). Baseline separation of neutral, acidic and basic analytes was achieved on multilayer COF-5-coated capillary column. The fabricated capillary columns showed high column efficiency (154,060 plates/m for methylbenzene), excellent stability and repeatability. The precision (relative standard deviation (RSD), n = 3) of retention time, peak height, and peak area for tested neutral compounds were in the range of 1.2–1.3%, 1.8–4.2%, and 0.9–2.4%, respectively. To the best of our knowledge, it was the first demonstration that COF-5 was developed as a novel stationary phase.
研究领域:
分析化学
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材料科学
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DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2018
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IF 3.141
Guocai Wang,Shigui Tang,Fei Cao,Hongli Wu,Honghua Jia,Ping Wei,Pingkai Ouyang
During the lactide producing process, volatile impurities, such as lactic acid and its dimer, are simultaneously distilled out with lactide. To remove these impurities, many post-treatments were needed. Herein, we present a novel approach to obtain high purity lactide by adding high-boiling-point alcohols to immobilize these volatile impurities. A series of high-boiling-point alcohols were screened and pentaerythritol was found to be the best immobilization reagent. When the molar ratio of lactic acid’s carboxylic group and pentaerythritol’s hydroxyl group was 15:1, lactide with 99% GC purity was directly distilled out and no traces of lactic acid and its dimer were detected. The results of HPLC-MS revealed that the distillation residues were esters of pentaerythritol with lactic acid or its oligomer. This indicated that volatile impurities were immobilized in distillation residues. The distillation residues were reused for 4 runs, and the purities of lactide were all over 98%.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2025
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IF 5.4
Linyu Guo,Wei Qian,Ren-kou Xu
Iron/aluminum (Fe/Al) oxides and fulvic acid (FA) are omnipresent in nature, and their interaction determines the migration and immobilization of copper (Cu). In this study, we provide new insights into the understanding of the differential mechanisms for Cu(II) immobilization at the interaction interfaces of Fe/Al oxides with FA. The immobilization behaviors and mechanisms of Cu(II) at the Fe/Al oxides-FA interaction interfaces were elucidated under different coexistence levels of 3 wt% and 5 wt% FA, and at solution pH of 4.0 −6.0 based on batch adsorption experiments, liquid-phase Cu(II) species assessment by Cu ion-selective electrodes, the surface charge analysis by zeta potential measurement and potentiometric titration, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The results showed that the Cu(II) adsorption capacity at the Fe/Al oxide-FA interaction interfaces followed: amorphous (Am)·Fe > goethite > Am·Al > gibbsite. Fe oxides showed greater Cu(II) immobilization capacity and affinity than Al oxides. The concentration of Cu(II) complexed with FA in the liquid phase followed: goethite > Am·Fe and gibbsite > Am·Al, which showed that the strong adsorption of FA by the oxides resulted in a lower concentration of Cu(II) complexed with FA in the liquid phase (FA adsorption followed: Am·Fe > Am·Al > goethite > gibbsite). The free Cu 2 + decreased with the increase of FA coexistence. BET and surface charge analyses showed that the larger specific surface area, less positive charge and higher binding sites and higher FA adsorption capacity of Am·Fe and goethite contributed to their greater Cu(II) immobilization capacity. ATR-FTIR and XPS analyses revealed the abundance of surface reactive hydroxyl and oxygen vacancy defects of Am·Fe and goethite significantly promoted their Cu(II) immobilization compared with Al oxides. Principal component analysis revealed that surface reactive hydroxyl and oxygen vacancy defects dominated the differences in surface charge and Cu(II) immobilization, and quantified their contributions.
研究领域:
环境科学
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化学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Weifang Zhang,Lianyang Huang,LingLing Zhuang,Jiahong Pan,Kun Li,Yu Luo,Chunshan Wu,Menglu Zhang,Chunli Wang
While mechanochemical reactions have garnered attention for their broad applicability and readily attainable operational conditions, their utilization in wastewater purification, particularly for the treatment of chromium-containing effluents, remains limited. In this study, we present a novel mechanism for ball milling-mediated reduction and immobilization of hexavalent chromium, achieving removal efficiencies of up to 93.7% over a pH range of 2.0 to 10.0. This mechanism advocates for the concurrent effect of mechanical force to facilitate the reduction of Cr(VI) to its stable surface form (Cr(III)), and the precipitation of BaCrO 4 , thereby immobilizing the chromium species. Density functional theory calculations demonstrate that oxygen vacancies can efficiently adsorb Cr(VI), thereby imparting electrons to it, consequently facilitating reduction processes. This study provides novel insights into metal ion-contaminated wastewater treatment and the role of naturally generated mechanical forces on the redox processes of chromium species.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
Journal of Environmental Sciences
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2023
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IF 6.9
Hanbing Meng,Shiwen Hu,Zebin Hong,Wenting Chi,Guojun Chen,Kuan Cheng,Qi Wang,Tongxu Liu,Fangbai Li,Kexue Liu,Yang Yang
Zero-valent iron (ZVI) is a promising material for the remediation of Cd-contaminated paddy soils. However, the effects of ZVI added during flooding or drainage processes on cadmium (Cd) retention remain unclear. Herein, Cd-contaminated paddy soil was incubated for 40 days of flooding and then for 15 days of drainage, and the underlying mechanisms of Cd immobilization coupled with Fe/S/N redox processes were investigated. The addition of ZVI to the flooding process was more conducive to Cd immobilization. Less potential available Cd was detected by adding ZVI before flooding, which may be due to the increase in paddy soil pH and newly formed secondary Fe minerals. Moreover, the reductive dissolution of Fe minerals promoted the release of soil colloids, thereby increasing significantly the surface sites and causing Cd immobilization. Additionally, the addition of ZVI before flooding played a vital role in Cd retention after soil drainage. In contrast, the addition of ZVI in the drainage phase was not conducive to Cd retention, which might be due to the rapid decrease in soil pH that inhibited Cd adsorption and further immobilization on soil surfaces. The findings of this study demonstrated that Cd availability in paddy soil was largely reduced by adding ZVI during the flooding period and provide a novel insight into the mechanisms of ZVI remediation in Cd-contaminated paddy soils.
研究领域:
土壤科学
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环境修复
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产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
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2022
·
IF 11.072
Changsong Zhao,Yongpeng Wang,Mengxi Cheng,Hailing Zhang,Yuanyou Yang,Ning Liu,Jiali Liao
Column reactors and batch experiments were conducted to investigate the performance and mechanism of uranium (U) immobilization enhanced by extracellular polymeric substances (EPS) from anaerobic granular sludge (ANGS). Successful remediation of anoxic U-contaminated groundwater was achieved using ANGS-inoculated column reactors (all higher than 98% of U removal rate for the three columns at hydraulic retention time of 72-h), and parameters (hydraulic retention time, nitrate content, the type and content of the external carbon sources) influenced the reactor performance. 306-day column studies implied the enhanced U immobilization by EPS, where EPS acted as energy source, electron donors and U reservoir with a contribution of 3.5–6.8% to total U removal by ANGS. Results in 26-h batch experiments further demonstrated that U immobilization performance of ANGS could be promoted (6.4–22%) by EPS through adsorption and reduction. EPS induced the precipitation of U(VI) and U(IV) particulates, and amino and carboxyl groups were the main functional groups for EPS binding with U. Complexation was confirmed between humic acids in EPS and U. The interaction mechanisms between U and EPS were directly evidenced to involve complexation, induced particulate formation and reduction.
研究领域:
环境科学
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微生物学
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DOI
高影响因子
Materials Today Communications
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2025
·
IF 4.5
Cheng Jianfeng,Zong Zihua,Dong Yanhui,Xie Jingli,Cao Shengfei,Zhang Qi,Peng Liyuan,Jiang Qiao
Geopolymers prepared from recycled fly ash have emerged as sustainable and effective solutions for the solidification of radioactive wastewater. In this study, fly ash-based geopolymers with varying 137 Cs concentrations are prepared, and their solidification effects as well as the compressive strength, porosity, microstructure, and leaching behavior after solidification are investigated. The results indicate the uniform incorporation of Cs into the prepared fly ash-based geopolymers. As the concentration of Cs in the geopolymers increases, the compressive strength decreases and porosity increases; however, the chemical structure remains almost unchanged. These observations are attributed to the electrostatic interaction between Cs + ions and the negatively charged [SiO 4 ] 4− and [AlO 4 ] 5− ions in the geopolymers. Moreover, the geopolymers exhibited lower leaching rates and cumulative leaching fractions in both deionized water and Beishan groundwater; the leaching rate and cumulative leaching fraction of 137 Cs in fly ash-based geopolymers were lower than the Chinese national standards. Further, the Cs solidification performances of the prepared geopolymers and traditional cement on real radioactive wastewater were compared. The fly ash-based geopolymers demonstrated a superior performance than traditional cement, making them a promising material for radioactive wastewater treatment. This study offers new insights into reducing radioactive waste and makes a substantial contribution to the knowledge of nuclear waste solidification processes employing fly ash-based geopolymers.
研究领域:
材料科学
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环境科学
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核废料管理
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2024
·
IF 7.4
Chengwei Huang,Shanke Liu,Xu Bao,Jialing Xu,Xuanyu Cai,Chao Liang,Lijun Yu
Phytoremediation is an effective technology for the removal of heavy metals (HMs) from contaminated soils. However, improper post-treatment of hyperaccumulators can lead to secondary environmental hazards. This study explores the application of supercritical water gasification (SCWG) for the treatment of Cu-enriched hyperaccumulator Elsholtzia splendens ( ES ), with the dual aims of H 2 production and HM immobilization. SCWG process yielded a maximum H 2 output of 16.68 mol/kg after 20 min, demonstrating its potential for waste valorization. Within the temperature range of 500–650°C, the migration and transformation mechanisms of HMs were investigated through detailed biochar characterization. The results demonstrate that SCWG significantly reduces the leaching rate of Cu from 25.18 % to below 0.08 %, with over 99 % of HMs being immobilized in the resultant biochar. Furthermore, higher temperatures and prolonged residence times were found to promote the complexation of HMs with inorganic components in the biochar, resulting in their transformation into stable F4 fractions. Then, HMs in liquid products and solid residues were evaluated in terms of Nemerow index and potential ecological risk. The results indicated that the pollution risks of liquid products were safe while the original hyperaccumulators showed high risk, underscoring the promise of SCWG as an effective method for the concurrent production of H 2 -rich syngas and the immobilization of HMs.
研究领域:
环境科学
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能源工程
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植物学
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2023
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IF 9.8
Qihui Yu,Hao Liu,Guocheng Lv,Xin Liu,Lijuan Wang,Libing Liao
The contamination of heavy metal lead has a serious impact on the natural environment and organisms. Among various materials for lead removal, animal bone derived hydroxyapatite has received extensive attention. However, there are different opinions among researchers regarding the mechanism of lead removal by hydroxyapatite , possibly due to varying initial lead concentrations used in different studies and lack of accuracy in the study of lead removal mechanisms. In present work, we synthesized a carbon-containing hydroxyapatite (CHAP) through pyrolysis of bovine bone with excellent lead removal efficiency, and further investigated the lead removal mechanism of CHAP under high and low initial lead concentrations by combining XRD Rietveld refinement, FTIR, XPS, HRTEM etc. methods. The results showed that under low initial Pb 2+ concentration condition, the main mechanism of lead removal by CHAP was chemical precipitation (94.1 %), with small contributions of lead complexation with carbon functional groups and cation-π interactions on the amorphous carbon in CHAP, and surface adsorption on the precipitates. Under high initial Pb 2+ concentration condition, chemical precipitation remained the main mechanism (74.68 %), but the contributions of the other three mechanisms increased, and ion exchange appeared in the later stage of the removal process. This study provides new insights on the lead immobilization mechanism by CHAP at different initial Pb 2+ concentrations in water.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL MANAGEMENT
·
2020
·Vol. 65
·期 6
·818-828
·
IF 2.561
Zhou Changrui,Yuan Haiyan,Ning Chuanchuan,Li Shuailin,Xia Zhuqing,Zhu Mengmeng,Ma Qiang,Yu Wantai
Using amendments is a cost-effective method to soil cadmium (Cd) remediation, whereas knowledge about how different amendments and rates affect remediation efficiency remains limited. This study aimed to evaluate the impacts of different types and amounts of amendments on soil Cd immobilization and its uptake by plants. Biochar (BC), zeolite (ZE), humic acid (HA), superphosphate (SP), lime (L), and sodium sulfide (SS) were applied at three rates (low, medium, and high) ranging from 0.5 to 5%. The concentration of CaCl 2 -extractable Cd was considerably affected by the amendments, except HA, and the high doses achieved better immobilization effects than the low doses did. The addition of amendments decreased weak acid soluble Cd by 4.1–44.0% but slightly increased the fractions of oxidizable and residual Cd. These amendments (except BC and HA dose of 1%) decreased Cd accumulation in grains by 1.3–68.8% and (except SP) in roots by 16.3–65.5% compared with the control. The SP efficiently immobilized Cd but posed a potential soil acidification risk. Moreover, SS treatment increased the soil electrical conductivity (EC) value and restricted the growth of wheat, possibly due to high-salt stress. BC, ZE, and L exerted significant effects on the reduction in available Cd as the application rate increased. These amendments enhanced Cd immobilization mainly by changing Cd availability in soil and influencing its redistribution in different fractions in soil and root uptake by plants. This study concluded that BC-5%, ZE-1%, and L-0.5% can be used for Cd immobilization in acidic or neutral soils.
研究领域:
环境科学
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农业科学
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DOI
PubMed
高影响因子
Environmental Science and Ecotechnology
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2022
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IF 9.371
Yabo Sun,Tao Lu,Yali Pan,Menghan Shi,Dan Ding,Zhiwen Ma,Jiuyi Liu,Yupeng Yuan,Ling Fei,Yingqiang Sun
Biotreatment of acidic rare earth mining wastewater via acidophilic living organisms is a promising approach owing to their high tolerance to high concentrations of rare earth elements (REEs); however, simultaneous removal of both REEs and ammonium is generally hindered since most acidophilic organisms are positively charged. Accordingly, immobilization of acidophilic Galdieria sulphuraria ( G. sulphuraria ) by calcium alginate to improve its affinity to positively charged REEs has been used for simultaneous bioremoval of REEs and ammonium. The results indicate that 97.19%, 96.19%, and 98.87% of La, Y, and Sm, respectively, are removed by G. sulphuraria beads (GS-BDs). The adsorption of REEs by calcium alginate beads (BDs) and GS-BDs is well fitted by both pseudo first-order (PFO) and pseudo second-order (PSO) kinetic models, implying that adsorption of REEs involves both physical adsorption caused by affinity of functional groups such as –COO– and –OH and chemical adsorption based on ion exchange of Ca 2+ with REEs. Notably, GS-BDs exhibit high tolerance to La, Y, and Sm with maximum removal efficiencies of 97.9%, 96.6%, and 99.1%, respectively. Furthermore, the ammonium removal efficiency of GS-BDs is higher than that of free G. sulphuraria cells at an initial ammonium concentration of 100 mg L −1 , while the efficiency decreases when initial concentration of ammonium is higher than 150 mg L −1 . Last, small size of GS-BDs favors ammonium removal because of their lower mass transfer resistance. This study achieves simultaneous removal of REEs and ammonium from acidic mining drainage, providing a potential strategy for biotreatment of REE tailing wastewater.
研究领域:
环境科学
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微生物学
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DOI
高影响因子
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