ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 21
·21609-21618
·
IF 2.914
Tan Guangcai,Mao Yi,Wang Hongyuan,Junaid Muhammad,Xu Nan
Biochar (BC) and activated carbon (AC) were both produced from corn straw. Biochar-supported zerovalent iron (BC-ZVI) and activated carbon-supported zerovalent iron (AC-ZVI) were synthesized and applied for Se(IV)/Se(VI) removal. The sorption capacity of BC-ZVI for Se(IV) and Se(VI) was reported at 62.52 and 35.39 mg g −1 , higher than that of AC-ZVI (56.02 and 33.24 mg g −1 ), respectively, due to its higher iron content and more positive charges. The spectroscopic analyses showed that Se(IV)/Se(VI) were reduced to Se(0)/Se(-II) of less toxicity and solubility. The effects of various factors such as pH, ionic strength, co-existing cations and anions, and natural organic matter (NOM) were also investigated. Ionic strength showed no significant effect on Se(IV)/Se(VI) removal, but pH was critical. The presence of NO 3 − and SO 4 2− did not cause obvious inhibition to the removal, while PO 4 3− inhibited the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI) significantly. Common cations (K + , Ca 2+ , and Mg 2+ ) were found to slightly enhance the removal, while NOM significantly decreased the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI). Besides, NOM showed stronger inhibition effect on AC-ZVI than that on BC-ZVI. These results indicated that BC-ZVI, compared with AC-ZVI, could be a promising sorbent to remove Se(IV)/Se(VI) due to its low cost and high efficiency.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2017
·
IF 3.101
Tao Wu,Zhifen Wang,Hai Wang,Zhiqiang Zhang,Luc R. Van Loon
The through-diffusion method was employed to investigate the effect of the salt concentration on the diffusion behaviour of Re(VII) and Se(IV) in compacted bentonite . The accessible porosity , ε acc , of Re(VII) increased from 0.25 to 0.38 with an increase of the ionic strength from 0.1 to 1.0 mol/L. The dependency of the accessible porosity ε acc on the salt concentration could be described approximately by a first-order decay exponential function. The interlayer porosity of GMZ bentonite was 21% of the total porosity at a bulk dry density of 1600 kg/m 3 at 12 °C. The D e values of Re(VII) and Se(IV) increased from 2.6 × 10 − 11 to 6.1 × 10 − 11 m 2 /s and from 1.6 × 10 − 11 to 4.7 × 10 − 11 m 2 /s in GMZ bentonite with an increase of the ionic strength from 0.1 to 1.0 mol/L, respectively. In the case of Se(IV), the adsorption showed a different ionic strength dependency in GMZ bentonite and montmorillonite . The ionic strength has no significant effect on the adsorption (K d = 1.8 × 10 − 4 m 3 /kg) on GMZ bentonite, indicating the formation of inner-sphere surface complexes. In the case of synthetic montmorillonite, the K d values increased with increasing ionic strength. This can be explained by the fact that the electric potential of surface sites becomes less negative with increasing ionic strength resulting in an increase in the adsorption of Se(IV) at a pH above the point of zero salt effect (PZSE). The D e values of both Re(VII) and Se(IV) increased with increasing salt concentration. Both anions are totally excluded from the interlayer space and partially from the diffuse double layer. Ionic strength alters the effective diffusion coefficient of anions by controlling the thickness of the diffuse double layer. Anion diffusion data from the literature (effective and apparent diffusion coefficients) were satisfactorily evaluated by Archie's relation.
研究领域:
环境科学
·
地球化学
✓ 已验证
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2023
·
IF 6.8
Chengke Fu,Yichao He,Chengyun Yang,Jieyu He,Luna Sun,Yixin Pan,Liping Deng,Rui Huang,Manli Li,Kaikai Chang
Selenium (Se) as an essential nutrient for human beings at trace concentrations, the allowable concentration for the human is only 40 μg/L. Iron sulfide (FeS) nanoparticles have been applied for excessive of selenium (Se) remediation in surface water and groundwater. In this study, FeS nanoparticles were anchored onto biochar (BC) to reduce agglomeration of FeS and prepared into the composite of FeS-BC by pyrolysis to economically and efficiently remove Se(IV) from simulated wastewater based on the excellent performance of FeS and the low cost of BC. Characterizations presented the uniform anchorage of FeS on the BC surface to prevent agglomeration. The results of batch experiments revealed that the removal of Se(IV) by FeS-BC nanomaterials significantly depended on the pH value, with the maximum removal of ∼174.96 mg/g at pH 3.0. A pseudo-second-order kinetic model well reflected the kinetic removal of Se(IV) in pure Se(IV) solution with different concentration, as well as the coexistence of K + , Ca 2+ , Cl - , and SO 4 2- ions. The presence of K + ions significantly inhibited the removal of Se(IV) with the increase of K + ion concentration compared with the effect of the other three ions. SEM-EDS and XPS analyses indicated that the removal process was achieved through adsorption by surface complexation, and reductive precipitation of Se(IV) into Se 0 with the electron donor of Fe(II) and S(-II) ions. The FeS-BC nanomaterial exhibited an excellent application prospect in the remediation of Se(IV).
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
Surfaces and Interfaces
·
2023
·
IF 6.2
Xiangyue Wei,Yixin Pan,Jisheng Kou,Rui Huang
The removal of selenium (IV) from aqueous solutions was the focus of research that led to the discovery of a novel type of composite adsorbent called FeS@h-BN nanocomposite . This adsorbent was studied, characterized, and put to use in a fixed bed column. SEM, FTIR, XRD, and XPS analyses were conducted to learn more about the coated layer's surface properties. The effect of several adsorbent materials on the remediation of Se(IV) in dynamic water was examined. The Adams-Bohart model, the Thomas model, and the Yoon-Nelson model were all utilized to get optimal fits to the kinetic data obtained from the adsorption process. Moreover, the Adams-Bohart model was only applicable to the beginning portion of the dynamic behavior of the FeS and FeS@h-BN columns. The Thomas and Yoon-Nelson models were sufficient for describing the breakthrough curve under all experimental conditions. For this dynamic process, the theoretical breakthrough curve profile was compared to an experimentally derived profile. It was discovered that FeS@h-BN nanocomposites are the most effective at removing Se(IV), and the adsorption of Se(IV) by a variety of adsorbent materials is enough for all three dynamic models.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·Vol. 333
·期 5
·2273-2280
·
IF 1.5
Zhang Hui,Wang Ju,Wu Wangsuo,Luo Mingbao,Hua Rong,Zhou Zhichao,Ling Hui
This paper presents the first laboratory-based, simultaneous diffusion experiments of Re(VII) and Se(IV) in Tamusu (TMS) clay, using the capillary method. We determined diffusion coefficients ( D a ) and adsorption values ( K d ) for these nuclides under varying clay compaction densities, solution pH values, ionic strengths, and in the presence of humic acid (HA). The results indicated rapid acquisition of diffusion data, the D a values predominantly ranging from 10 −9 m 2 /s to 10 −10 m 2 /s, and weak adsorption for both Re(VII) and Se(IV). While the presence of HA augmented the D a and K d values for Re(VII) and Se(IV) diffusion in clay, these values did not exhibit significant alterations in response to increasing HA concentrations.
研究领域:
环境科学
·
地质学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Jisheng Kou,Xiangyue Wei,Hui Wu,Wensheng Linghu,Guodong Sheng,Yixin Pan
The removal of U(VI) and Se(IV) in an aqueous solution was investigated by batch experiments and characterized by spectroscopy techniques such as FTIR, XRD, SEM, TEM, XPS, using FeS@h-BN nanocomposite which was synthesized by hexagonal BN (h-BN) as the stabilizer anchored onto FeS nanoparticles to address the agglomeration of the FeS. The effects of pH, adsorbent concentration, contact time, and initial concentration of U(VI) and Se(IV) on FeS@h-BN adsorption U(VI) and Se(IV) were studied. Results showed that FeS@h-BN nanocomposite showed an excellent decontamination performance due to the large surface area and surface potential. A pseudo-second-order kinetic model well reflected the kinetic adsorption of U(VI) and Se(IV) which indicated chemical interaction mainly contributed to U(VI) and Se(IV) adsorption on FeS@h-BN. The adsorption process of removing U(VI) fitted Freundlich and D-R models well which presented multilayer adsorption on the nanocomposite surface. The Langmuir model fitted well with sorption isotherm data of Se(IV) removal displaying a single monolayer reaction between Se(IV) and FeS@h-BN. The adsorption of U(VI) and Se(IV) was high pH-dependent since pH affected the FeS@h-BN nanocomposite surface potential and U(VI) and Se(IV) speciation. The maximum sorption capacity of U(VI) and Se(IV) reached 163.11 and 196.39 mg/g, respectively. These results reveal that FeS@h-BN nanocomposite could be promising for the effective decontamination of U(VI) and Se(IV).
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Jing Xiong,Kailai Xu,Xiandeng Hou,Peng Wu
The excellent fluorescence property of Au nanoclusters (AuNCs) has received great attention for various chemosensing and biorelated applications, but the sample matrix is still an important problem that causes undesirable fluorescence variation. On the one hand, hydride generation (HG) is an effective strategy to separate the target analyte from the complex sample matrices, but the implementation of HG with AuNC-based fluorescent assays was not realized. On the other hand, due to the ultrasmall size of AuNCs and good catalytic performance of Au, AuNCs are also featuring intriguing catalytic applications. Herein, we proposed a new type of AuNC-based fluorescence assay for Se(IV) detection, in which hydride generation of Se(IV) was coupled with the fluorescence/catalytic dual functions of AuNCs. In a batch hydride generation mode, Se(IV) was first converted to volatile H2Se. When it spread in the headspace to contact with AuNCs supported paper, AuNC-catalyzed oxidation of H2Se by O2 to yield elemental selenium occurred, which further deposited on the surface of AuNCs to induce fluorescence quenching. The catalytic effect of AuNCs was studied in depth via both experimental and theoretical (density functional theory) investigations. Three main steps for H2Se oxidation were identified, with energy barriers in the presence of AuNCs significantly lower than those without. Benefiting from the reduced matrix interference by hydride generation and the unique catalysis/fluorescence of AuNCs, the proposed assay featured high selectivity, good sensitivity, and simplicity, with successful applications for selenium detection in real samples.
研究领域:
分析化学
·
纳米科技
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·
IF 1.5
Tian Yunting,Li Yongmei,Tan Kaixuan,Li Chunguang,Li Xiaojie,Liu Wei,Tang Zhipeng,Liu Longcheng
Bentonite colloids and fluid velocity significantly influence the migration behavior of the redox sensitive nuclide Se(IV) in the disposal repository. In this study, the migration behavior of Se(IV) in artificial fracture, which was created by Beishan granite and polyethylene pipe, was studied under reduced condition, with Br − as a tracer. The effects of bentonite colloids and fluid flow rate on the migration of Se(IV) in the fracture were explored. The results show that a part of Se(IV) would adsorb on the surface of granite in reduced condition. The maximum penetration rate of Se(IV) increases with the decrease of water flow rate. In addition, the colloids hindered the migration of nuclide Se(IV) in the fissure to some extent during the process of co-migration.
研究领域:
环境科学
·
放射性废物管理
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2011
·Vol. 173
·期 1
·267-273
·
IF 2.578
Wang Yang,Luo Xiaoyu,Tang Jie,Hu Xiaoya
A method is presented for matrix separation, preconcentration and determination by hydride generation atomic fluorescence spectrometry of trace amounts of Se(IV). It is based on solidified floating drops of 1-undecanol that are capable of extracting the target analyte after chelation with a water soluble ligand and subsequent ultrasound-assisted back-extraction into a aqueous solution. Hydride generation was then accomplished by reaction with a solution of sodium borohydride. Under optimized conditions, an enrichment factor of 15 and a linear calibration plot in the range from 0.01 to 5.0 μg L −1 were achieved using a 10.0 mL sample. The detection limit (3σ) is 7.0 ng L −1 , and the relative standard deviation (RSD) is 2.1% at 1.0 μg L −1 ( n = 11). The method was applied to determination of Se(IV) in different real water samples through recovery experiments and subsequently validated against two certified reference materials.
A solidified floating organic drop microextraction coupled with hydride generation atomic fluorescence spectrometry for the determination of Se(IV) is described.
研究领域:
分析化学
·
环境科学
✓ 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）