COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2021
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IF 4.539
Ziyan Yang,Xiaoli Yang,Tianhui Wang,Rui Hu,Junfeng Wu
Biochars treated with acids always presented enhanced sorption capacities for heavy metals. Biochars pyrolyzed at various temperatures have different compositions and present different oxidation states for the acid treatment. To optimize the surface oxidation of biochars, an appropriate pyrolysis temperature of biomass is of great importance. In this work, raw biochars prepared from Typha angustifolia at 300, 400, 450, 500 and 600 °C were oxidized by HNO 3 . The function of HNO 3 mainly focused on the surface oxidation of biochars rather than the creation of micropores in matrixes. Biochars pyrolyzed at the higher temperature were more difficult to be oxidized by the acid. The HNO 3 -activated biochars (NABCs) enriched Pb(II) and Cd(II) under various geochemical conditions including contact time, pH, ionic strengths , coexisting HA, initial heavy metal concentrations and temperatures. NABCs exhibited excellent sorption capacities (i.e., 232.6 mg/g for Pb(II), 88.9 mg/g for Cd(II) at pH 5.0 and 298 K) which were 6.9 and 5.5 times higher than these of untreated biochars. The maximum uptake capacities toward Pb(II) and Cd(II) showed an excellent linearity with the values of [O C O content × Surface area], demonstrating the essential role of the surface O C O species to coordinate heavy metals. NABCs could be well reused for six cycles through desorption using the acid pickling.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2023
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IF 6
Haixin Xia,Yaohong Zhang,Qian Chen,Renrong Liu,Hai Wang
Two functionalized biochar composites (ZF@CBC and SZF@CBC) were fabricated and applied for capturing Pb(II) and Cd(II) from wastewater. SZF@CBC were achieved by loading Zn/Fe nanoparticles (NPs) and coating starch onto corn cobs biochar (CBC) surface, while ZF@CBC was realized by loading Zn/Fe NPs onto CBC surface. The characterization analysis (SEM-EDS, XRD and FTIR) revealed that Zn/Fe NPs and starch were successfully introduced onto CBC surface. The adsorption data of Pb(II) and Cd(II) by ZF@CBC and SZF@CBC conformed to the model of pseudo second order kinetic and Langmuir isothermal and the capture Pb(II) and Cd(II) was a chemisorption process. The maximum sorption capacities of SZF@CBC for Pb(II) and Cd(II) reached 199.98 mg/g and 183.93 mg/g, which were 3.37 and 3.84 times high as that of CBC, respectively. Due to the presence of plentiful exposed adsorption sites (–OH, –COOH, Zn-O and Fe-O) on SZF@CBC surface, which endowed it to accelerate Pb(II) and Cd(II) adsorption. In addition, complexation, electrostatic attraction, ion exchange and physical adsorption took part in the adsorption process. Besides, SZF@CBC still exhibited very good removal capacity for Pb(II) and Cd(II) even in the coexistence of multiple interfering ions and maintained stable adsorption capacity after five consecutive cycles. Therefore, SZF@CBC could be used as an excellent adsorbent for decontaminating Pb(II) and Cd(II) from wastewater with multiple pollutants, and also could be used in resource utilization of biomass waste, which possessed potential applications prospects.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
WASTE MANAGEMENT
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2020
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IF 5.448
Tao Huang,Lulu Zhou,Long Chen,Wanhui Liu,Shuwen Zhang,Longfei Liu
Traditional cementation technique is insufficient in making municipal solid waste incineration (MSWI) fly ashes meet the permissible leaching threshold. Aluminum supplementation and electrokinetic (EK) activation were combinedly incorporated into the traditional solidification pathway to enhance the geopolymerization and the immobilization of Pb and Cd in MSWI fly ashes in this study. The aluminum addition remarkably affected the geopolymer formation. The minimum toxicity leaching as well as the maximum compressive strength were achieved at the combination of the voltage gradient of 1.0 V/cm, the proposing time of 48 or 72 h, the mass ratio of alkali activator to fly ash of 11.5%, and the modulus of 2.1. Chloride reduction in the mortar obtained during the EK process increased the negative charge relativity of oligomers. The leaching concentrations of Pb and Cd from the geopolymer were successfully predicted by a linear model based on the compressive strengths at 28 d. Higher reaction degree was found in the EK-activated mortar in the geopolymerization kinetics. Aluminum supplementation had induced the production of some amorphous aluminosilicate minerals including Al 6 Si 2 O 13 , CaAl 2 Si 2 O 8 ·4H 2 O, Ca 2 Al 3 (Si 3 O 12 )OH, Ca 2 Al(OH) 7 ·3H 2 O, and Ca 4 Al 2 O 6 Cl 2 ·10H 2 O during the EK process. Larger particles observed in the EK-treated specimen directly verified the EK-activated pozzolanic reactions.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
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2018
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IF 3.057
Chonghe Xu,Zhichao Yu,Kangkang Yuan,Xiaotong Jin,Shuying Shi,Xinqiang Wang,Luyi Zhu,Guanghui Zhang,Dong Xu,He Jiang
Mesoporous MgO has been used as an adsorbent for the removal of contaminants in water and exhibited outstanding performances. However, the agglomeration phenomena of nanoscale MgO adsorbents suppressed the adsorption capabilities. Herein, compound citrate and propionate ligands were selected as template-free precursors to fabricate the electrospun mesoporous MgO ceramic fibers . The MgO ceramic fibers possessed mesoporous structure with high surface area of 232.34 m 2 /g and high total pore volume of 0.560 cm 3 /g. Structure and composition of fibers heat-treated in air and water vapor were investigated systematically. And the MgO ceramic fiber showed high adsorption capacities of 2983.4 mg/g and 1824.0 mg/g for Pb(II) and Cd(II), respectively. The interaction mechanism between MgO fibers and heavy metal ions were thoroughly discussed. The high capacity of mesoporous MgO ceramic fiber was benefited from the hydroxyl-rich surface to release sufficient OH - and the good movability in water. Mesoporous MgO ceramic fibers prepared in the present method with fine quality might become an effective prescription for heavy metal pollution.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
SPECTROSCOPY LETTERS
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2016
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IF 0.885
Yujiao Tu,Shuangqiao Ju,Pingyan Wang
In this research, ferroferric oxide nanoparticles were coated with silicon dioxide and further functionalized with alizarin complexone as the adsorbent of magnetic solid-phase extraction, thus aiming for extraction and preconcentration of heavy metals in Gastrodiae rhizoma samples. The determination of heavy metals was carried out by flame atomic absorption spectrometry. The results showed that the functionalized magnetic nanoparticles demonstrated higher extraction efficiency for copper, lead, and cadmium. The synthesized magnetic sorbents were characterized by transmission electron microscope, X-ray diffraction, and Fourier-transformed infrared spectra. Different parameters influencing the extraction efficiency including the amount of sorbent, sample pH, sorption time, solution volume, elution solvent, and reuse times were optimized. Under the optimal conditions, the method detection limit was 0.18, 0.25, and 0.12 µg/L for copper, lead, and cadmium, respectively. The proposed method was successfully applied to extract copper, lead, and cadmium in Gastrodiae rhizoma samples, and the recoveries of the samples ranged from 90.0 to 102.0% and relative standard deviations (n = 5) were in the range of 1.93–3.82%.
研究领域:
分析化学
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药用植物学
✓ 已验证
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
Yingying Wang,Fuyu Zhang,Mengshuo Du,Bihe Chen,Yifeng Xu,Wenzhi Tang,Zhonghong Li
Highly toxic Pb(Ⅱ) and Cd(Ⅱ) persist in water and soil, disrupting ecosystems while threatening human health through bioaccumulation. Metal-organic frameworks (MOFs) as adsorbents toward heavy metal ions have garnered significant research attention. However, their adsorption capacity and retrieval are limited by small pore size and powder form. Herein, we designed a defective MIP-202 composite aerogel (DMCA) to efficiently remove Pb(Ⅱ) and Cd(Ⅱ). Mixed ligand (mercaptosuccinic acid) and modulator (butyric acid) were involved in the synthesis of MIP-202, and competed with the original amino acid ligand for binding to Zr clusters leading to the disruption of the original structure of MIP-202 and defect formation. Defective MIP-202 (D-MIP-202) possessed larger BET surface area (from 35.79 to 129.57 m 2 /g) and pore size (from 6.16 to 11.78 nm). Moreover, D-MIP-202 powder and sodium alginate were synthesized into DMCA with abundant adsorption sites and porous structures to enhance the sorption capacities, which were 434.7 mg/g (Pb(II)) and 202.6 mg/g (Cd(II)). The adsorption process primarily occurs on the heterogeneous surface of the material and represents a spontaneous chemisorption behavior. The adsorption mechanism is attributed to chelation, and ion exchange. This study presents an effective strategy for the remediation of heavy metal ions in aqueous systems.
研究领域:
环境科学
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材料科学
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污染控制化学
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吸附分离
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功能材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
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2021
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IF 7.086
Ni Tang,Xue Liu,Meng-Ru Jia,Xin-Yao Shi,Jing-Wei Fu,Dong-Xing Guan,Lena Q. Ma
In this study, a two-step functionalizing strategy by combining co-condensation with grafting procedures was employed to synthesize well-ordered Amino- and Thiol-Bifunctionalized SBA-15 (ATBS) mesoporous silica. Its physicochemical properties , performance, and mechanisms in immobilization of toxic metals Pb and Cd in water and soil were investigated. After bi-functionalization, X-ray diffractometer , transmission electron microscope , and N 2 adsorption-desorption measurements confirmed that the ATBS maintained a highly-ordered mesoporous structure, large surface area and pore volume. The elemental analysis, Fourier transform infrared spectroscopy and X-ray Photoelectron Spectroscopy (XPS) evidenced the successful incorporation of amine and thiol groups into ATBS. These structure and functional characteristics of ATBS benefited Pb and Cd sorption . Sorption isotherms of Pb and Cd were better fit with Sips and Redlich-Peterson models. Sorption kinetics suggested that Pb sorption was mainly regulated by chemical reactions, whereas both diffusion process and chemical reactions were rate-regulating steps in Cd sorption. ATBS showed the maximum sorption capacities for Pb and Cd at 120 and 38 mg g −1 , respectively. The sorption mechanisms revealed by XPS measurements suggested that Cd sorption was mainly attributed to thiol groups while Pb was efficiently bond to both thiol and amino groups. High and stable sorption efficiencies were attained in the pH range of 4–6, with a higher affinity towards Pb than Cd. Furthermore, its ability to immobilize Pb and Cd in soils was examined with an incubation experiment, which showed that ATBS reduced 30–56% of MgCl 2 -extractable Pb and Cd in a contaminated soil. The synthesized sorbent via the two-step functionalizing strategy shows high sorption efficiency towards Pb and Cd, and thus it has potential application in remediating Pb and Cd contaminated water and soils.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）