SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Wenhao Wang,Pei Gao,Chun Yang,Zhiwei Zhao,Shucong Zhen,Youxin Zhou,Tingting Zhang
Destruction of the dense oxide layer on the surface of pristine or re-passivated micro zero-valent aluminum (mZVAl) can rejuvenated its reduction activity, which is beneficial to the removal of aqueous pollutants. To rejuvenated the reduction activity of mZVAl and rapidly recovery passivated mZVAl, in this study, a novel mZVAl/nFe 3 O 4 composite with high activity and magnetic properties was synthesized by ball milling (BM). Compared with pristine mZVAl and nFe 3 O 4 , more than 95% of Cr(VI) could be removed in 30 min at 3.0 g/L mZVAl/nFe 3 O 4 dosage over a wide range of pH (3.00–11.00). The removal of Cr(VI) conformed to the pseudo-first-order adsorption kinetic model, and the equilibrium adsorption data was in accordance with the Langmuir adsorption isotherm model. The maximum absorption (8.14 mg/g) was related to the BM parameters (the weight ratio of mZVAl/nFe 3 O 4 , BM speed and BM time). Accord to the effect of co-existing ions on the removal efficiency of Cr(VI), it was proved that the significance of the adsorption process was a prerequisite step for Cr(VI) reduction. Based on X-ray photoelectron spectroscopy (XPS) and the valence analysis of aqueous Cr, the Cr(VI) removal mechanism by mZVAl/nFe 3 O 4 was also unraveled, in addition to achieving Cr(VI) reduction, also achieves the sequestration of total Cr under neutral environment. Furthermore, the reusability of mZVAl/nFe 3 O 4 was limited by the accumulation of (hydr)oxide on its surface, but can be easily rejuvenated by BM again with a small amount of nFe 3 O 4 . In conclusion, mZVAl/nFe 3 O 4 composite are a promising green material to reductive remove Cr(VI) from near-neutral wastewater.
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高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Hualin Jiang,Menglin Li,Jun Liu,Xueqin Li,Lei Tian,Pinghua Chen
In this study, a novel CeO 2 -TiO 2 nanocomposite denoted as CeO 2 -3TiO 2 was successfully synthesized via a facile one pot hydro-thermal method without alkali. It exhibits high photocatalytic reduction reactivity toward Cr(VI) under visible light. The photocatalytic reactivity of CeO 2 -3TiO 2 is 18 times higher than that of pure CeO 2 , 28 times higher than pure TiO 2 , 15 times higher than the sample of simply mixed CeO 2 and TiO 2 . The solution with Cr(VI) initial concentration of 2780 ppb can be fast photoreduced by CeO 2 -3TiO 2 in 60 min under visible light to meet the criterion of U.S. Environmental protection Agency. Characterization results indicate CeO 2 -3TiO 2 has the good crystal form of heterojunction structure, narrow pore size distribution , narrow energy gap and high photogenerated electron-hole separation efficiency. Based on the experimental results, a speculated photocatalytic mechanism was proposed.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 51
·77344-77358
·
IF 5.19
Ding Baoting,Wang Xiaomeng,Feng Kun,Fu Jingran,Liang Jianru,Zhou Lixiang
Acidic Cr(VI)-containing wastewater has received increasing attention in recent years. Schwertmannite is a suitable adsorbent for its acid resistance and good adsorption ability. However, it shows poor Cr(VI) adsorption performance under acidic conditions. Herein, inspired by the fast neutralization-mineralization process of acid mine drainage (AMD) triggered by alkaline rocks, a novel nano-scaled schwertmannite (Sch-2.7) with high Cr(VI) adsorption capacity was synthesized at constant pH of 2.7 via adding OH − . Compared with common schwertmannite (Sch), appropriate OH − effectively improved mineral yield (the precipitation efficiency of Fe: 96.75% vs. 29.93%), specific surface area (65.1 m 2 /g vs. 18.9 m 2 /g), surface group content, and further Cr(VI) adsorption ability of Sch-2.7. The maximum adsorption capacity was 54.17 (pH = 3), 61.59 (pH = 4), and 66.5 mg/g (pH = 5) for Sch-2.7, whereas only 20.35, 24.51, and 27.17 mg/g for Sch. On average, the former was 2.53 times higher than the latter. Temperature and coexisting ions had little influences on the sorption process of Sch-2.7. The mechanism analysis demonstrated that the Cr(VI) removal by Sch-2.7 was a more thermodynamic favorable process due to abundant reactive-active components on Sch-2.7 for adsorption reaction. This work provided new insight into performance optimization and application potential on Cr(VI) removal of schwertmannite.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Ningyi Chen,Bingcai Pan
Toxic metal-organic complexes are ubiquitous in contaminated waters but more challenging than free ion counterparts for water decontamination. Currently, almost all the available analytical methods, including Au nanoparticles-mediated colorimetric assay, cannot discriminate metal-organic complexes from the total metal content, which greatly impedes the development of specific decontamination strategies for metal-organic complexes. In this study, we found that nitrilotriacetic acid (NTA) functionalized AuNPs could be used to determine various Cr(III) complexes (Cr(III)-lactate, Cr(III)-malonate, Cr(III)-oxalate, Cr(III)-tartrate, Cr(III)-citrate and Cr(III)-EDTA) in water. Mechanism study indicated that at acidic pHs (pH = 1.6), the protonation of organic ligands resulted in partial dissociation of Cr(III) from the corresponding complexes to expose its accessible orbitals for re-coordination with NTA. Such re-coordination induces the aggregation of the dispersed NTA-AuNPs and thereafter causes considerable changes both in color and UV–Vis spectrum of the solution. The nanosensor is highly selective to Cr(III)-organic complexes with detection limits of 0.029 μM for Cr(III)-lactate, 0.043 μM for Cr(III)-malonate, 0.35 μM for Cr(III)-oxalate, 0.079 μM for Cr(III)-tartrate, 2.58 μM for Cr(III)-citrate and 0.90 μM for Cr(III)-EDTA, respectively. The feasibility of the proposed colorimetric assay has been verified by using the authentic natural and industrial water samples. We believe this study will be of fundamental significance to push forward the application of Au NPs colorimetric assay in authentic waters contaminated by toxic metals.
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高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Zhong-yi Wang,Rui-tang Guo,Zhen-zhen Guan,Xu Shi,Wei-guo Pan,Zai-guo Fu,Hao Qin,Xing-yu Liu
A sequence of Cr-modified CeZr 2 O x catalysts were synthesized through the co-precipitation way and applied in selective catalytic reduction (SCR) of NO x with ammonia. The optimal catalyst (Cr 1 CeZr 2 O x ) exhibited the excellent NH 3 -SCR activity and high SO 2 resistance. From the characterization results, Cr species in Cr 1 CeZr 2 O x could suppress the formation of ZrO 2 crystals, which could also contribute to stronger surface acidity and reducibility . Besides, more Ce 3+ and surface adsorbed oxygen species were observed on Cr 1 CeZr 2 O x catalyst. On the basis of in situ DRIFT experiments, it could be confirmed that the NH 3 -SCR process on Cr 1 CeZr 2 O x was promoted through Langmuir-Hinshelwood (L-H) mechanism. Besides, the improved NO oxidation and more ad-NO x and ad-NH 3 also played a vital role for the superior low-temperature SCR activity of Cr 1 CeZr 2 O x .
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高影响因子
Frontiers of Environmental Science & Engineering
·
2020
·Vol. 15
·期 4
·1-13
·
IF 4.053
Mao Wei,Zhang Lixun,Wang Tianye,Bai Yichen,Guan Yuntao
A visible-light-driven Bi 2 WO 6 /CuS p-n heterojunction was fabricated using an easy solvothermal method. The Bi 2 WO 6 /CuS exhibited high photocatalytic activity in a mixed system containing rhodamine B (RhB), tetracycline hydrochloride (TCH), and Cr (VI) under natural conditions. Approximately 98.8% of the RhB (10 mg/L), 87.6% of the TCH (10 mg/L) and 95.1% of the Cr(VI) (15 mg/L) were simultaneously removed from a mixed solution within 105 min. The removal efficiencies of TCH and Cr(VI) increased by 12.9% and 20.4%, respectively, in the mixed solution, compared with the single solutions. This is mainly ascribed to the simultaneous consumption electrons and holes, which increases the amount of excited electrons/holes and enhances the separation efficiency of photogenerated electrons and holes. Bi 2 WO 6 /CuS can be applied over a wide pH range (2–6) with strong photocatalytic activity for RhB, TCH and Cr(VI). Coexisiting dissolved organic matter in the solution significantly promoted the removal of TCH (from 74.7% to 87.2%) and Cr(VI) (from 75.7% to 99.9%) because it accelerated the separation of electrons and holes by consuming holes as an electron acceptor. Removal mechanisms of RhB, TCH, and Cr(VI) were proposed, Bi 2 WO 6 /CuS was formed into a p-n heterojunction to efficiently separate and transfer photoelectrons and holes so as to drive photocatalytic reactions. Specifically, when reducing pollutants (e.g., TCH) and oxidizing pollutants (e.g., Cr(VI)) coexist in wastewater, the p-n heterojunction in Bi 2 WO 6 /CuS acts as a “bridge” to shorten the electron transport and thus simultaneously increase the removal efficiencies of both types of pollutants.
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高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Jiahao Li,Rong Cheng,Jiaao Chen,Jirong Lan,Shiyao Li,Min Zhou,Tianyu Zeng,Haobo Hou
A series of nitrogen-doped carbon aerogels (NCAs) were obtained through phase reaction polymerization and different carbonization temperatures to enhance adsorption efficacy of hexavalent chromium (Cr[VI]) from wastewater significantly. Factors that influence adsorption properties of carbon aerogel microspheres toward Cr(VI), such as pH, adsorbent content, initial Cr(VI) concentrations, and coexisting anion, were investigated. Three isotherm (Langmuir, Freundlich, and Sips) and three kinetic (pseudofirst-order, pseudosecond-order, and Elovich) models were used to interpret the adsorption process. The adsorption capacity of Cr(VI) reached 180.62 mg·g −1 , which was superior to that of most aerogel adsorbents. In addition to the adsorption effect, the XPS results also showed that N-containing groups on the NCA surface reduce the adsorbed Cr(VI) to the less toxic Cr(III). The prepared sorbent demonstrates a negligible loss in adsorption capacity after 6 cycles. NCAs show acceptable application prospects in selective removal of Cr(VI) ions.
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DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Quan Huo,Xiaoran Qi,Jianshu Li,Gongquan Liu,Yao Ning,Xubiao Zhang,Boyu Zhang,Yanfei Fu,Suyan Liu
A series of direct Z-scheme α-Fe 2 O 3 /MIL-101(Cr) hybrids were successfully prepared through a facile hydrothermal method in this work. And, the materials were characterized by some technologies including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), N 2 adsorption-desorption, photoluminescence (PL) spectroscopy, Ultraviolet-visible (UV–vis) diffuse reflectance spectroscopy (DRS) and electron spin resonance (ESR). The photocatalytic activities of the hybrids were evaluated by degradation of carbamazepine (CBZ) under visible light irradiation. It is found that 100% of CBZ was able to be removed after 180 min irradiation over the optimum α-Fe 2 O 3 (0.3)/MIL-101(Cr) hybrid. The superior activity was engendered from good textural properties and the formation of a direct Z-scheme heterojunction in the hybrid. The decomposition process of CBZ and the formation of intermediate products were analyzed through liquid chromatography-tandem mass spectrometry (LC–MS) and a possible photodegradation pathway of the CBZ was proposed. Also, the possible mechanism for the photodegradation process was provided to illustrate the excellent performance. The work has paved a new way for the application of MOF materials in the design of efficient Z-scheme system for organic pollution degradation in wastewater.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Xiong Tao,Fengxi Chen,Jun Li,Yunling Liu,Xiaowu Hu,Rong Chen
Emerging Bi 2 S 3 -based nanotechnology has great potential in Cr(VI)-contaminated wastewater treatment . In this work, it was found for the first time that Bi 2 S 3 nanoparticles (BS-D) prepared from dual sulfur sources of L-cysteine and ammonium sulfide efficiently promoted Cr(VI) removal with excellent selectivity for simultaneous removal of Cr(VI) and Cu 2+ from aqueous solutions containing various co-existing ions (including Na + , K + , Ca 2+ , Zn 2+ , Ni 2+ , Cd 2+ , NO 3 – , SO 4 2− and Cl − ) at pH > 3, preferably at pH of 4.5. Besides, BS-D had stable performance for co-removal of Cr(VI) and Cu 2+ in five recycling tests. Kinetic and thermodynamic studies indicated that the adsorption of Cr(VI) or Cu 2+ by BS-D was a spontaneous endothermic process and conformed to pseudo-second-order kinetic model. The adsorbed Cr(VI) ions were partially reduced to Cr(III), which were leached into the solution at pH ≤ 3, inhibiting the adsorption of Cu 2+ on BS-D and its promotional effect on Cr(VI) removal by BS-D. The mutual promotional effects between Cu 2+ and Cr(VI) during their co-removal by BS-D were ascribed to electrostatic attraction between HCrO 4 − and Cu 2+ and smaller pH variation in mixed Cr(VI)-Cu 2+ solutions. Finally, potential applications of BS-D were demonstrated by co-removal of Cr(VI) and Cu 2+ from real electroplating wastewater and contaminated groundwater. This work provided a promising BS-D adsorbent for Cr(VI)-contaminated wastewater treatment, and shed insight on the influence of Cu 2+ on the Cr(VI) removal by BS-D.
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高影响因子
Environmental Science-Nano
·
2025
·
IF 5.1
Yanchun Liao,Wenhao Lao,Chenyi He,Junchun Li,Longyong Lin,Yiping Feng,Yirong Deng
Ferrihydrite (Fh), a metastable iron(oxyhydr)oxide abundant in soils and sediments, plays a pivotal role in regulating phosphorus bioavailability and contaminant Cr(VI) fate, but its rapid phase transformation to low-reactivity crystalline phases limits its long-term functionality. This study investigated how light (Nd3+) and heavy (Y3+) rare earth elements (REEs) modulate Fh's phase transformation and Cr(VI)/PO43− sequestration. The results showed that LREE Nd3+ predominantly adsorbed onto Fh surfaces, forming a protective layer that shielded reactive Fe–OH sites and delayed hydroxyl displacement. In contrast, HREE Y3+ underwent isomorphic substitution into Fh's octahedral Fe–O framework, inducing lattice distortion and suppressing acicular goethite crystallization by ca. 26%. Both REEs preserved Fh's metastability, and maintained Fe in the oxidized Fe3+ state. In addition, both Nd3+ and Y3+ integration into hematite during transformation slowed Fh conversion to low-adsorptivity crystalline phases. Consequently, after 30 days of aging, REE-doped Fh exhibited significantly enhanced Cr(VI)/PO43− sequestration (qmax,Cr(VI) = 19.39 mg g−1 and qmax,P = 43.33 mg g−1 for Fh–Nd, 24.47 and 64.03 mg g−1 for Fh–Y) compared to pristine Fh (qmax,Cr(VI) = 4.91 and qmax,P = 24.03 mg g−1). These enhancements might be driven by prolonged amorphous Fh persistence, REE–Cr(VI)/PO4 surface precipitation, and REE–O–Fe ternary binding sites. These findings clarify how REE–Fe coupling regulates Cr(VI)/PO43− fates in terrestrial ecosystems and also provide insights for designing REE-modified adsorbents for long-term contaminant/nutrient retention in soils or aquatic systems, where Fh's natural transformation would otherwise compromise such efficacy.
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Yali Song,Cairong Yang,Xiaoyu Wen,Xiaojing Zhang,Yongpeng Ma,Mengke Shi,Hongzhong Zhang
Flower–shaped ZnIn 2 S 4 made by the traditional solvothermal method has a high rate of e – –h + recombination, limiting the photocatalytic reactions and its application. To address this issue, potassium sodium tartrate was added during solvothermal synthesis process to prepare ZnIn 2 S 4 photocatalysts with excellent photocatalytic performance. When the added dosage of potassium sodium tartrate was 0.4 g, the obtained ZnIn 2 S 4 photocatalysts (ZIS–0.4) showed a sheet–like structure and exposed more active (110) facet. Multiple characterization methods indicated that ZIS–0.4 exhibited the highest separation efficiency of photogenerated e – –h + pairs and electron migration. As a result, ZIS–0.4 showed the most superior photocatalytic efficiency in reducing Cr(VI). Following 20 minutes of exposure to visible light, ZIS–0.4 achieved a reduction rate of 99.3 % for Cr (VI), while the reduction efficiency of flower–shaped ZnIn 2 S 4 prepared without potassium sodium tartrate (ZIS–0) was only 28.5 %. The pseudo–first order kinetic reaction rate constant of ZIS–0.4 (0.244 min –1 ) was 15.25 times higher than ZIS–0 (0.016 min –1 ). Electron paramagnetic resonance and radical trapping experiments have verified that the main reactive substances were e – and ·O 2 – in Cr(VI) reduction process.
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Qianwei Liang,Hanjin Luo,Junjie Geng,Jingda Chen
A novel nitrogen-doped ultra-light graphene oxide (GO) aerogel with three-dimensional (3D) network structure is used for removing of Cr(VI) from aqueous solution, which is fabricated by a facile one step hydrothermal self-assembly process and an environmentally friendly freeze-drying technique. GO and organic amine are used as the precursors to synthesize the aerogels, in which pyrrole and Tetraethylenetetramine (TEPA) are introduced as nitrogen sources to obtain the amino functional groups, meanwhile, they also play the roles as cross-linking agents to control the assembly of GO sheets in the 3D structure. The obtained TEPA/polypyrrole/GO aerogel (TPGA) has a high adsorption capacity for Cr(VI) anions (up to 408.48 mg/g) at an optimal pH of 2.0. The kinetics process of Cr(VI) adsorption on TPGA can be fitted well with the pseudo-second-order kinetic model. The mechanism of adsorption is analyzed by intraparticle diffusion and external film diffusion models, which indicates that the overall rate of Cr(VI) adsorption process is influenced by multi-steps. The isotherm and thermodynamic studies confirms that adsorption of Cr(VI) on TPGA is a spontaneous and endothermic process in the monolayer adsorption pattern. Furthermore, the prepared TPGA exhibits a good regeneration ability and satisfactory recovery for Cr(VI) anions in practical water samples. This work provides a simple and environmentally friendly method to synthesize the nitrogen-doped GO aerogel, which show a great potential and promise for practical application in the field of waste water treatment.
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高影响因子
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