Nanoscale Research Letters
·
2015
·Vol. 10
·期 1
·1-9
·
IF 2.779
Qi Yun,Jiang Meng,Cui Yuan-Lu,Zhao Lin,Zhou Xia
Pb(II) is a representative heavy metal in industrial wastewater, which may frequently cause serious hazard to living organisms. In this study, comparative studies between alginate nanoparticles (AN) and quercetin-decorated alginate nanoparticles (Q-AN) were investigated for Pb(II) ion adsorption. Characterization of AN and Q-AN were analysed by transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffractometer (XRD), and thermogravimetric analysis (TG-DTG-DSC). The main operating conditions such as pH, initial concentration of Pb(II), and co-existing metal ions were also investigated using a batch experiment. AN and Q-AN, with a diameter of 95.06 and 58.23 nm, were constituted by many small primary nanoparticles. It revealed that when initial concentration of Pb(II) is between 250 and 1250 mg L −1 , the adsorption rate and equilibrium adsorption were increased with the increase of pH from 2 to 7. The maximum adsorption capacities of 147.02 and 140.37 mg L −1 were achieved by AN and Q-AN, respectively, with 0.2 g adsorbents in 1000 mg L −1 Pb(II) at pH 7. The adsorption rate of Pb(II) was little influenced by the co-existing metal ions, such as Mn(II), Co(II), and Cd(II). Desorption experiments showed that Q-AN possessed a higher desorption rate than AN, which were 90.07 and 83.26 %, respectively. AN and Q-AN would probably be applied as adsorbents to remove Pb(II) and then recover it from wastewater for the advantages of simple preparation, high adsorption capacity, and recyclability.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
WATER AIR AND SOIL POLLUTION
·
2017
·Vol. 228
·期 9
·1-16
·
IF 1.702
Shu Yuehong,Huang Renlong,Wei Xiangyu,Liu Lingling,Jia Zhenzhen
Different from direct application of free nanoparticles (NPs) in water treatment, a composite material is used to reduce the release and potential toxic effects of NPs with maintained adsorption capacity and kinetics. Novel monolithic composites with TiO 2 NPs incorporated into the walls of macroporous cryogels were synthesized and evaluated for material characteristics and their efficiency for removal of Pb(II) from aqueous solution in batch test and continuous mode. The uniformly distributed 6% TiO 2 -cryogel is shown to be optimal for minimizing TiO 2 NP losses while maximizing Pb(II) removal. Under (25.0 ± 0.1) °C with the initial Pb(II) concentration of 10 mg/l, TiO 2 -cryogels exhibit excellent adsorption characteristic for Pb(II) removal with adsorption capacity up to 23.27 mg/g TiO 2 , which is even a little higher than that of TiO 2 NPs (21.58 mg/g TiO 2 ), and the results fit well with Langmuir–Freundlich isotherm. Both adsorbents work well in higher pH range with the highest removal rate at pH 6 for TiO 2 -cryogel, and the adsorption mechanism might be strong chemical interaction. Pseudo-second-order process can better describe the adsorption process rather than pseudo-first-order for both adsorbents. The external mass transfer process of Pb(II) on TiO 2 NPs is much faster than that on TiO 2 -cryogel, and the ultimate equilibrium time is about the same (3 h) on both adsorbents. The synthesized composites could also withstand a continuous treatment, and the effect of competing and co-existing constituents such as Cd 2+ , SO 4
2− and dissolved organic matter (DOM) is almost negligible. The composite design with small particles embedded into cryogels is proved to successfully keep the adsorption activity of TiO 2 NPs and prevent them from releasing into the environment in engineering practice.
研究领域:
环境工程
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水处理
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纳米技术
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材料科学
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2022
·
IF 10.723
Weifeng Xu,Xiang Liu,Kewen Tang
A novel bi-functional β-cyclodextrin polymer (CD@TCT@PEI) was synthesized for the removal of hydroquinone and Pb(II) from wastewater. The structure and adsorption performance of CD@TCT@PEI towards hydroquinone and Pb(II) were studied comprehensively. Both of the adsorption processes fit the pseudo-second-order kinetic model well. The adsorption isotherms of hydroquinone and Pb(II) could be described well by Langmuir isotherm model, and the maximum adsorption capacities of hydroquinone and Pb(II) are 364.86 and 113.52 mg g −1 , respectively. The adsorption of hydroquinone and Pb(II) on CD@TCT@PEI is an exothermic and spontaneous process. The adsorbed CD@TCT@PEI could be regenerated easily, and can still maintain high adsorption performance after 5 cycles. The electrostatic interaction and coordination interaction account for the adsorption of Pb(II), and inclusion of cyclodextrin and hydrogen-bond interaction are responsible for hydroquinone adsorption. This study provides some insights to design an adsorbent that can simultaneously remove heavy metal ions and organic micropollutants from wastewater.
研究领域:
环境科学
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材料科学
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Xiya Yang,Lingyuan Chen,Dong Ren,Shixing Wang,Zhaogang Ren
An O -hydroxyphenyl thiourea-modified chitosan ( OTCS ) with excellent Pb(II) adsorption performance and selectivity was prepared as an adsorbent. The structure and morphology of the adsorbent were systematically investigated by SEM, BET, FTIR, EDX , zeta-potential measurements, XPS and XRD. The impacts of the initial Pb(II) concentration, reaction time, temperature, pH value, and coexisting ions were explored. At pH 7 and 303 K, the maximal adsorption capacity of OTCS for Pb(II) was 208.33 mg/g, which was greater than those of other adsorbing materials reported in the literature. The metal ion adsorption kinetics and isotherm models were found to obey pseudo-second-order kinetics and the Langmuir isothermal model, indicating that the adsorption process was monolayer chemisorption. The adsorption process could proceed spontaneously, and the thermodynamic results revealed that the adsorption mechanism was an endothermic reaction. The ion exchange and chelation between the sulfur, nitrogen and oxygen groups on the adsorbent and lead ions endowed the material with excellent adsorption properties. Significantly, OTCS showed excellent selectivity toward Pb(II). Therefore, the adsorbent OTCS is expected to promote the wider application of chitosan in the adsorption of Pb(II).
研究领域:
环境科学
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材料科学
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高影响因子
Membranes
·
2023
·Vol. 13
·期 7
·651
·
IF 4.2
Lu Liu,Hongyang Ma,Madani Khan,Benjamin S. Hsiao
To achieve high throughput, low-pressure drops, and high adsorption capacity of Cr(VI) and Pb(II) in industrial wastewater treatment, cellulose membranes containing cationic and anionic groups were fabricated, respectively. In this process, cost-effective cotton fabrics were oxidized using sodium periodate, followed by quaternary ammonium or sulfonation modifications. The chemical composition, surface morphology, and thermal and mechanical properties of the cellulose membranes were investigated by ATR-FTIR, solid-state NMR, SEM, TGA, and tensile experiments. Quaternary ammonium, aldehyde, and sulfonate groups were distributed on the cationic/anionic cellulose fibers as adsorption sites, which issue remarkable adsorption capability to the cellulose membranes. The highly toxic Cr(VI) and Pb(II) ions were used to challenge the adsorption capacity of the cationic and anionic cellulose membranes, respectively. The maximum adsorption capacities of Cr(VI) and Pb(II) ions were 61.7 and 63.7 mg/g, respectively, suggested by Langmuir isotherms, kinetics, and thermodynamics in the static experiments. The dynamic adsorption capability of cationic cellulose membranes against Cr(VI) ions was determined and compared with that of commercially available anionic-exchange membranes. Spiral wound filtration cartridges were fabricated by cationic and anionic cellulose membranes, respectively, and were used to adsorb Cr(VI) and Pb(II) from lab-made wastewater, respectively. The cationic cellulose cartridge can purify 4.4 L of wastewater containing 1.0 mg/L of Cr(VI) ions with a 100% removal ratio, while the pressure drop was retained at 246 Pa. Similarly, the anionic cellulose cartridge exhibited even more impressive adsorption capability; the removal ratio against Pb(II) was 99% when 8.6 L of 1.0 mg/L of Pb(II) ions containing wastewater was treated, and the pressure drop was retained at 234 Pa. A composite cartridge fabricated by the integration of cationic and anionic cellulose membranes was successfully employed to purify the wastewater containing Cr(VI) and Pb(II) simultaneously. The possible adsorption mechanism was proposed, and the recycling ability of the cellulose membranes was also discussed.Keywords:cationic/anionic cellulose membrane;oxidation;adsorption;heavy metal ions;wastewater treatment
研究领域:
环境科学
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材料科学
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化学工程
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PubMed
高影响因子
Materials
·
2023
·Vol. 16
·期 23
·7290
·
IF 3.4
Qi Xu,Yan Yan,Yazhou Jiao,Jinxiong Wu,Xiuling Yan,Xintai Su
Environmental pollution has been widely considered by researchers, especially the heavy metals damage to the human and ecological environment is irreversible. Adsorption is an important method to remove heavy metal ions from the environment. In this paper, humic acid (HA) was functionalized by the improved Hummers method, and its adsorption capacity for Pb(II) was studied. The results of scanning electron microscope (SEM), X-ray diffraction (XRD), Roman, and Brunauer-Emmett-Teller (BET) showed that the thickness of irregular particles decreases to a layered structure during the transformation process. In addition, X-ray photoelectron spectroscopic (XPS) and Fourier transform infrared spectra (FT-IR) spectra showed that the surface of oxidized-biochar (OBC) was rich in reactive oxygen species, which was conducive to the formation of coordination bonds with Pb(II). Further adsorption experiments showed that it was a spontaneous monolayer chemisorption. The results of the DFT calculation showed that -COOH had the lowest adsorption energy for Pb(II), and it was easier to form stable chemical bonds than -OH, -C=O, and -C-O-C-. Because those oxygen-containing functional groups not only can promote electrostatic attraction but also are more favorable for forming a covalent bond with Pb(II). This study had guiding significance for the deep modification and application of weathered coal as a heavy metal ion adsorbent or cation exchanger.Keywords:HA;adsorption;lead;complexation
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Journal of Chemistry
·
2024
·Vol. 2024
·期 1
·2510050
·
IF 2.8
Baoqiang Zhang,Bo Zhao,Longfei Xia,Yingying Sun,Tianqing Chen,Hailan Shi
In order to explore a medium material for the efficient treatment of Pb(II) pollutants in groundwater, in this paper, mudstone is selected as the medium material, and the morphological structure of the mudstone is characterizes via X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analyses to study the feasibility of the mudstone adsorbing Pb(II) ions. Then, static adsorption experiments are carried out to investigate the removal effect of mudstone on Pb(II) in aqueous solutions under different conditions and to determine the optimal adsorption conditions. Finally, the results are fitted and analyzed using a thermodynamic model to explore the adsorption mechanism of the mudstone. The main results of this study are as follows. The main mineral composition of the mudstone used in the experiments includes CaCO 3 , SiO 2 , CaAl 2 O 4 ·10H 2 O, and CaFe 4 O 7 . The specific surface area of the mudstone is as high as 23.027 m 2 ·g −1 , the pore size is 9.145 nm, and its surface structure is rough, with pores and fissures developed. The pore space and adsorption capacity of the mudstone were enhanced. When 1 g·L −1 of mudstone was added, the pH value of the solution was 6, the reaction time was 60 min, and the initial concentration of Pb(II) was 30 mg·L −1 . The removal efficiency of Pb reached 84.5%, and the adsorption amount was 25.352 mg·g −1 . For the removal of Pb(II) from the aqueous solution by the mudstone under different concentrations of Pb(II), the reaction was in accordance with the Langmuir adsorption isotherm model, and the maximum adsorption amount reached 54.975 mg·g −1 . The relationship between the removal of Pb(II) and the reaction time was in accordance with the pseudo-second-order rate model. The results of this study suggest that mudstone can be used for the removal of Pb(II) from aqueous media.
研究领域:
环境科学
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地质学
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水污染治理
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
·
IF 12.2
Bokun Chang,Zixuan Huang,Xiaodong Yang,Tianhuan Yang,Xianhui Fang,Xianbao Zhong,Wei Ding,Gang Cao,Yajun Yang,Feinan Hu,Chenyang Xu,Ling Qiu,Jialong Lv,Wei Du
To investigate the adsorption effects of aged microplastics (MPs) on Pb(II) and their co-transport properties in homogeneous (quartz sand) and heterogeneous (quartz sand with apple branches biochar) porous media, we explored the co-transport of UV-irradiated aged MPs and coexisting Pb(II) along with their interaction mechanisms. The UV aging process increased the binding sites and electronegativity of the aged MPs' surface, enhancing its adsorption capacity for Pb(II). Aged MPs significantly improved Pb(II) transport through homogeneous media , while Pb(II) hindered the transport of aged MPs by reducing electrostatic repulsion between these particles and the quartz sand. When biochar, with its loose and porous structure, was used as a porous medium, it effectively inhibited the transport capacity of both contaminants. In addition, since the aged MPs cannot penetrate the column, a portion of Pb(II) adsorbed by the aged MPs will be co-deposited with the aged MPs, hindering Pb(II) transport to a greater extent. The transport experiments were simulated and interpreted using two-point kinetic modeling and the DLVO theory. The study results elucidate disparities in the capacity of MPs and aged MPs to transport Pb(II), underscoring the potential of biochar application as an effective strategy to impede the dispersion of composite environmental pollutants.
研究领域:
环境科学
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生态学
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PubMed
高影响因子
Frontiers of Environmental Science & Engineering
·
2022
·Vol. 16
·期 8
·1-11
·
IF 6.048
Dong Lei,Xie Pin,Zhang Xin,Qiao Junlian,Rao Dandan,Sun Yuankui,Guan Xiaohong
The permanganate (Mn(VII)) oxidation has emerged as a promising technology for the remediation and treatment of the groundwater and surface water contaminated with the organic compounds. Nonetheless, only a few studies have been conducted to explore the role of the heavy metals (especially the redox-active ones) during the Mn(VII) oxidation process. In this study, taking Pb(II) as an example, its influence on the Mn(VII) decontamination performance has been extensively investigated. It was found that, with the presence of Pb(II), Mn(VII) could degrade diclofenac (DCF), 2,4-dichlorophenol, and aniline more effectively than without. For instance, over a wide pH range of 4.5–8.0, the dosing of 10 µmol/L Pb(II) accelerated the DCF removal rate from 0.006–0.25 min −1 to 0.05–0.46 min −1 with a promotion factor of 1.9–9.4. Although the UV-vis spectroscopic and high resolution transmission electron microscopy analyses suggested that Mn(VII) could react with Pb(II) to produce Mn(IV) and Pb(IV) at pH 6.0–8.0, further experiments revealed that Pb(II) did not exert its enhancing effect through promoting the generation of MnO 2 , as the reactivity of MnO 2 was poor under the employed pH range. At pH below 5.0, it was interesting to find that, a negligible amount of MnO 2 was formed in the Mn(VII)/Pb(II) system in the absence of contaminants, while once MnO 2 was generated in the presence of contaminants, it could catalyze the Pb(II) oxidation to Pb(IV) by Mn(VII). Collectively, by highlighting the conversion process of Pb(II) to Pb(IV) by either Mn(VII) or MnO 2 , the reactive Pb(III) intermediates were proposed to account for the Pb(II) enhancement effect.
研究领域:
环境科学
·
化学
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Feng Zhao,Weixia Yang,Yong Han,Xueli Luo,Wenzhi Tang,Tianli Yue,Zhonghong Li
The transformation of metal-organic frameworks (MOFs) to metal-organic gels (MOGs) is an attractive but challenging issue because they are generally regarded as the opposite, with the former being hard and the latter soft. Herein, a straightforward strategy was developed to synthesize amorphous Zr-MOG-12 by gelatinization of UiO-66-NH 2 (i.e. Zr-MOF) via a facile standing time-controlled crystallization method. The precursor ZrCl 4 obtains oxide and hydroxide bridges after standing at room temperature, which promotes the formation of [Zr 6 O 4 (OH) 4 ] 12+ clusters and induces rapid and excessive nucleation rate, and further leads to the coordination perturbation of UiO-66-NH 2 nanoparticles to achieve Zr-MOG-12. The as-prepared Zr-MOG-12 integrates the more hierarchical porous structure of gel-based soft materials and the amorphous structure of lower-coordinated active sites, which exhibits superb adsorption capacity for Pb(II) with excellent selectivity and reusability, indicating that Zr-MOG-12 is more promising to removal Pb(II) in practical water treatment . In addition, the transformation of amorphous Zr-MOG-12 to highly crystaline Zr-MOF’ has been achieved by the solvothermal reorganization using glacial acetic acid as the crystallization promoter. The novel methods proposed in this study successfully link crystalline MOF with amorphous MOG, providing new opportunities for facile preparation and transformation of MOFs and MOGs.
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 2
·333
·
IF 3.426
Yifan Chen,Qian Li,Yujie Li,Qijun Zhang,Jingda Huang,Qiang Wu,Siqun Wang
In this work, cellulose nanocrystals (CNCs) obtained by the acid hydrolysis of waste bamboo powder were used to synthesize cellulose nanocrystal-g-poly(acrylic acid-co-acrylamide) (CNC-g-P(AA/AM)) aerogels via graft copolymerization followed by freeze-drying. The structure and morphology of the resulting aerogels were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), and the CNC-g-P(AA/AM) aerogels exhibited excellent absorbent properties and adsorption capacities. Subsequent Pb(II) adsorption studies showed that the kinetic data followed the pseudo-second-order equation, while the adsorption isotherms were best described using the Langmuir model. The maximum Pb(II) adsorption capacity calculated by the Langmuir model reached up to 366.3 mg/g, which is a capacity that outperformed that of the pure CNC aerogel. The CNC-g-P (AA/AM) aerogels become structurally stable through chemical cross-linking, which enabled them to be easily regenerated in HCl solution and retain the adsorption capacity after repeated use. The aerogels were found to maintain 81.3% removal efficiency after five consecutive adsorption–desorption cycles. Therefore, this study demonstrated an effective method for the fabrication of an aerogel adsorbent with an excellent reusability in the effective removal of Pb(II) from aqueous solutions.Keywords:cellulose nanocrystal;graft copolymerization;aerogel;adsorption;lead
研究领域:
材料科学
·
环境科学
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DOI
PubMed
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2025
·
IF 4.7
Han Zhang,Xuefeng Bai,Hua Ji,Xiaochuan Yu,Rui Li,Sijia Sun,Guocheng Lv,Hao Ding
Lead ions (Pb(Ⅱ)) cause serious environmental pollution and endanger human health and it is urgent to carry out efficient treatment. Herein, a strategy was proposed to enhance the immobilization and removal of Pb(Ⅱ) (including trace Pb(Ⅱ)) from water by coating SiO 2 on the surface of CaCO 3 to prepare CaCO 3 @SiO 2 composites using the carbonation method. The findings revealed that SiO 2 coating exhibits strong activation effects on CaCO 3 . The SiO 2 coating (loaded at 8.62 wt%) increased CaCO 3 specific surface area by over 20-fold, confirming its activating effect. The maximum immobilization amount of Pb(Ⅱ) by CaCO 3 @SiO 2 reached 3354 mg/g (over twice that of CaCO 3 ), and the removal rate of trace Pb(Ⅱ) (100 μg/L) was 99.5 %. The residual Pb(Ⅱ) concentration (5.5 μg/L) complies with WHO drinking water standard. Furthermore, CaCO 3 @SiO 2 showed selective removal of Pb(II), maintaining an 87 % percentage removal after 5 cycles of recycling. This study quantified dual mechanisms: surface adsorption-complexation dominated at low concentrations (100 % at 10 mg/L), while dissolution-precipitation plays the primary role at high concentrations (99.39 % at 500 mg/L), the removal mechanism of CaCO 3 @SiO 2 was greatly affected by the initial concentration of Pb(Ⅱ), therefore, the accurate contribution rate of each mechanism at different concentrations was calculated. The synergistic effect of CaCO 3 , its surface coated SiO 2, and the rate of increase in the system pH value was found to be the fundamental reason for the significant increase in the immobilization of Pb(Ⅱ) by CaCO 3 @SiO 2 .
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