ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2020
·
IF 4.872
Teng Xu,Feng Nan,Xiaofeng Jiang,Yuling Tang,Yunhang Zeng,Wenhua Zhang,Bi Shi
This work was conducted to study the effect of soil pH (4.0, 6.0, and 8.0) on the transport, fractionation, and oxidation of trivalent chromium [Cr(III)]. Variation in pH altered soil chemical and mineralogical properties such as zeta potential, cation exchange capacity and redox potential of natural soil. Breakthrough curves and batch sorption experiments coupled with fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses demonstrated that the easy mobility of Cr(III) in pH 4.0 soil was dominated by the limited coordination effect. The high retention of Cr(III) in pH 8.0 soil was mainly ascribed to the hydrolysis. Incubation experiments indicated that the proportions of Cr in exchangeable fraction decreased with increasing of soil pH and incubation time, and kinetics analysis revealed that the time dependent transformation was controlled by mass transfer and chemical processes (e.g., hydrolysis, ion association). The XPS confirmed the oxidation of Cr(III) in pH 8.0 soil during the incubation period. Furthermore, the content of toxic hexavalent chromium [Cr(VI)] was positively associated with time and initial concentration of Cr(III) released. These results revealed the hazardousness of Cr(III) in soil contaminated simultaneously by inorganic acid and alkali.
研究领域:
环境科学
·
土壤化学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Huanggen Yang,Pei Zhang,Qi Zheng,Guochao Nie,Asif Hayat,Majed A. Bajaber,Saleem Raza,Duofu Li,Yan Sui
A unique combination of cotton fabric (CF) with a mixture of EDTA and APTES Fe 3 O 4 magnetic particles was developed and utilized for the first time as an adsorbent for removing pollutants from wastewater. Initially, Fe 3 O 4 was synthesized using the co-precipitation method. Further, the surface of Fe 3 O 4 was modified by introducing amino functional groups through a reaction with APTES, resulting in Fe 3 O 4 -NH 2 . Following this, the surface of carbon fiber (CF) was altered using ethylenediaminetetraacetic acid (EDTA) to create CF@EDTA. Through the use of EDC-HCl and NHS, Fe 3 O 4 -NH 2 was attached to the surface of CF@EDTA, resulting in the final product CF@EDTA/Fe 3 O 4 . Subsequently, the prepared CF@EDTA/Fe 3 O 4 was utilized to adsorb metal pollutants from wastewater, with a thorough analysis conducted using various characterization techniques including FTIR, SEM, EDX , XRD , VSM , and XPS to study the materials. The study specifically aimed to assess the adsorption performance of our cotton-based material towards As(III) and Cr 3+ metal ions. The pH study was also performed. Results indicated that the material exhibited an adsorption capacity of approximately 714 mg/g for As(III) ions and 708 mg/g for Cr 3+ ions. The Langmuir and Freundlich models, as well as pseudo-first and second-order models were also analyzed. The Langmuir and pseudo-second-order models were found to best fit the data. In terms of regeneration and reusability, the materials showed straightforward regeneration and recyclability for up to 15 cycles. The remarkable adsorption capacity, combined with the unique blend of cotton and Fe 3 O 4 magnet, along with its recyclability, positions our material CF@EDTA/Fe 3 O 4 as a promising contender for wastewater treatment and other significant areas in water research.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2023
·
IF 8.3
Junjun Ma,Tao E,Shuyi Yang,Liang Chen,Ying Cheng,Jia Yu,Yun Li
Stabilizing Cr(III) in tannery sludge (TS) via harmless method has always been the goal of environmental pollution treatment. In this study, a simple method to stabilize Cr(III) in TS is proposed via adding kaolin, based on the fact a large amount of organic matter contained in TS. Comprehensive characterizations confirm that kaolin can stabilize Cr(Ⅲ) via its abundant –OH and lamellar structure. Moreover, there are hydrogen bond interactions and ligand exchange-surface complexation between organic matter and kaolin, which is more conducive to form a stable ternary complex with Cr(III), in a state of organic matter-Cr(III)-kaolin. Simultaneously, the BCR sequential extraction experiment shows that the unstable water and acid soluble state of Cr(III) are reduced (from 0.61% to 0.35%), which further indicates that the stabilization of Cr(III) is successful.
研究领域:
环境科学
·
污染治理
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产品关联
DOI
PubMed
高影响因子
FUEL
·
2023
·
IF 7.4
Mengxia Qing,Wenbin Liu,Liang Liu,Sibiao Huang,Zihang He,Yanshan Yin,Jun Xiang
Enhancing biochar's adsorption and solidification performance in compound-polluted aqueous solutions remains a crucial task for achieving the cost-effective removal of heavy metals from water bodies. The study examined the removal performances and mechanisms of Cu(II) and Cr(III) using biochar prepared from food waste at temperatures of 350 °C, 450 °C, and 550 °C (FWB-350, FWB-450, and FWB-550). FWB-450 exhibited the highest overall effectiveness in adsorbing Cu(II) and Cr(III), demonstrating the adsorption capacity (Q e ) of 40.283 and 21.456 mg/g in single-solution, respectively. Thermodynamic parameters indicate that the adsorption process involves physical and chemical reactions involving heat absorption. The impact of Cr(III) on the adsorption of Cu(II) is more apparent in the mixed competitive system. The pH, the oxygen-functional groups and carbonate ion quantity of FWB are crucial in improving Cu(II) and Cr(III) adsorption by affect the hydrolysis, complexation, and ion exchange processes. The presence of alkaline earth metal ions in FWB, like Ca(II), aids in the elimination of Cu(II) and Cr(III) through ionic precipitation and ion exchange, correspondingly. Furthermore, FWB adsorbed with Cu(II) and Cr(III) is relatively less hazardous than solid waste. The study validates the resource utilization of FW and its potential application of biochar in heavy metal adsorption.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ORGANOMETALLICS
·
2016
·
IF 4.186
Wenlong Luo,Antai Li,Shaofeng Liu,Hongqi Ye,Zhibo Li
A series of chromium(III) complexes, LCrCl3 (Cr1–Cr4: L = 2-(N-R2-benzimidazol-2-yl)-6-(3,5-R1-pyrazol-1-yl)pyridine; Cr1: R1 = H, R2 = H; Cr2: R1 = Me, R2 = H; Cr3: R1 = Me, R2 = Me; Cr4: R1 = Me, R2 = Bn), were synthesized and characterized by IR spectroscopy and elemental analysis. The studies of the solid state of Cr2 and Cr3 revealed distorted octahedral geometries around the chromium centers by X-ray diffractions. In the presence of MAO, Cr1–Cr4 exhibited high activities toward ethylene oligomerization (up to 2.17 × 106 g·mol–1(Cr)·h–1) and ethylene polymerization (up to 6.78 × 105 g·mol–1(Cr)·h–1). The oligomers were produced with high selectivity for α-olefins (>99%), confirmed by FT-IR and 13C NMR, and the distributions followed the Schulz–Flory equation. Various reaction parameters including the amount of cocatalyst, reaction temperature, and time were evaluated in detail, and it was evident that the title complexes had good thermal stability and the substituents on imidazole-N of the ligands dramatically impacted the catalytic activities as well as the distribution of the products.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2015
·Vol. 45
·期 20
·8347-8354
·
IF 4.197
Chen Dong,Genhua Wu,Zhuqing Wang,Wenzhi Ren,Yujie Zhang,Zheyu Shen,Tianhua Li,Aiguo Wu
A colorimetric assay is proposed for the selective detection of Cr(III) and Cr(VI) via the aggregation-induced color change of gallic acid capped gold nanoparticles (GA-AuNPs). The AuNPs are characterized using UV-vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier-transform infrared spectrometry (FT-IR). To detect Cr(III) and Cr(VI) coexisting in a sample, citrate and thiosulfate were applied to mask Cr(VI) for the detection of Cr(III), and ethylenediaminetetraacetic acid disodium salt (EDTA) was applied to mask Cr(III) for the detection of Cr(VI). At optimized experimental conditions, the selectivity of these AuNPs-based detection systems is excellent for Cr(III) and/or Cr(VI) compared with other types of metal ions. The limit of detections (LODs) of a mixture of Cr(III) and Cr(VI), Cr(III) and Cr(VI) by eye vision are 1.5, 1.5 and 2 μM, respectively, and those by UV-vis spectroscopy are 0.05, 0.1 and 0.1 μM, respectively. The minimum detectable concentrations for Cr(III) or Cr(VI) are all below the guideline value set by the US Environmental Protection Agency (EPA). The applicability of the AuNPs-based colorimetric sensor is also validated by the detection of Cr(III) and Cr(VI) in electroplating wastewater and real water samples with high recoveries.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL SCIENCES
·
2017
·Vol. 33
·期 8
·963-967
·
IF 1.228
Sui Ning,Liu Fengya,Li Tailing,Wang Lina,Wang Tao,Liu Manhong,Yu William W.
Au nanoparticles (AuNPs) dispersed in water were stabilized by tripolyphosphate (P 3 O 10 5- ). When Cr 2 O 7 2- (Cr(VI)) was present, the AuNPs did not change; when Cr 3+ (Cr(III)) was present, the AuNPs would aggregate because of cooperative metal-ligand reaction. Aggregated AuNPs showed different color from the non-aggregated ones. Thus, a simple colorimetric assay was made using AuNPs-Cr(VI) to detect ascorbic acid (AA). Upon introducing AA to the AuNPs- Cr(VI) system, Cr(VI) was reduced to Cr(III), and the aggregation of AuNPs occurred. This colorimetric assay performed high selectivity and a linear concentration response in the range of 0.2 to 10 μM; its limit of detection was 0.15 μM.
研究领域:
分析化学
·
纳米科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2017
·
IF 1.753
Qi Yao,Chenying Li,Henghui Huang,Hualin Chen,Bailing Liu
A series of carboxyl-terminated hyperbranched oligomer polyester (HBP) with different degree of branching (DB) and number average molar mass ( M ¯ n ) have been prepared. The molecular structure, degree of branching, molecular mass and its distribution of HBP were investigated by FTIR, 1 H NMR, and GPC , respectively. And the coordination number , stability constant and degree of dissociation (α) between HBP and chromium(Ⅲ) were measured via continuous variation method (Job's plot). Experimental results show that the coordination capability between HBP and chromium(Ⅲ) affected by both DB and molecular mass, and the latter plays a decisive role. Moreover HBP outperforms low molecular weight of organic acids (citric acid, acetic acid) and linear polyacrylic acid with similar molecular mass. The coordination number and stability constants of HBP-3 ( M ¯ n = 1713 Da, M ¯ w / M ¯ n (PDI) = 1.11 and DB = 0.72) can reach 4 and 6.55e+008, which demonstrated it can be selected as a good ligand to coordination with chromium(Ⅲ). Therefore HBP can be used as chrome auxiliary in chrome tanning to improve the absorption of chromium.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
·
IF 2.752
Xiaokun Wang,Yingqin Wei,Shasha Wang,Lingxin Chen
In this work, a simple “red-to-blue” colorimetric method for highly sensitive and selective determination of Cr (III) and Cr (VI) was presented, which was based on the aggregation of Tween 20-stabilized gold nanoparticles (Tween 20-Au NPs). This strategy relied upon the distance-dependent optical properties of gold nanoparticles (Au NPs), strong chelating between Cr (III) and citrate, and the reduction of Cr (VI) to Cr (III) by ascorbic acid (AA). Cr (III) could chelate with citrate to form a stable Cr (III)-citrate complex and thereby induce the aggregation of Tween 20-Au NPs. Thus, the sensing of Cr (III) and Cr (VI) based on aggregation of Au NPs was developed with the color of the Au NPs changing from red to blue, which was readily seen by the naked eye. The color change and surface plasmon resonance (SPR) absorption were used to monitor Cr (III) and Cr (VI) levels. Under the optimal assay conditions, good linear relationship was obtained, and the detection limit of Cr (III) and Cr (VI) were 0.016 μM and 0.009 μM in standard aqueous solution, respectively. Furthermore, the colorimetric method exhibited a good selectivity over other metal ions and was successfully applied to detect Cr (III) and Cr (VI) in real water samples.
研究领域:
分析化学
·
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Dashi Lei,Yiyao Zhang,Xiaofei Sun,Liqin Li,Qingchao Zhao,Xiangyu Peng,Juanqin Xue,Yubin Wang,Jing Zhang
Reduced chromite ore processing residue (rCOPR) is vulnerable to the surrounding conditions in environments, which can induce the release and oxidation of Cr(III). This work found the synergistic effect of light and sulfite on destroying rCOPR stability, causing the significant release of Cr(VI), which was 4∼7 times higher than that under single factor action. In CrxFe1–x(OH)3/sulfite/light system, Cr(VI) release rate could reach 11.11 × 10–7 M min–1 g–1, because of the rapid formation of ·OH, O2·–, SO4·–, and quadrivalent iron [Fe(IV)]. In addition, this study found that the oxidized chromium residue could continuously release Cr(III) after being transferred to the dark environment. This should be attributed to the obvious change in the iron coordination structure of rCOPR caused by the catalytic reaction of sulfite with light, which greatly weakened the ability of the Fe–O structure to encase chromium elements in a solid. These insights are crucial for predicting the environmental risks of rCOPR in the presence of visible light and sulfur-containing compounds.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2014
·Vol. 97
·期 11
·3413-3417
·
IF 2.428
Daixiong Zhang,Xueming Li,Bo Qin,Xiaolin Li,Xiaogang Guo,Chuan Lai
Chromium (III) oxide has been widely used as a coating material for corrosion resistance. In this study, electrophoretic deposition (EPD) of nano chromium (III) oxide (Cr 2 O 3 ) particle (60 nm) was investigated to develop coatings with potential applications of anticorrosive material. The stable suspension of Nano-Cr 2 O 3 particles were obtained in the mixture of acetylacetone and ethanol containing 0.00025 M nitric acid. The coating growth rate was studied with using different deposition times in the range of 1–30 min at voltages of 50–150 V with various concentrations of suspension. The electrophoretic Cr 2 O 3 coating was sintered at 1000°C and 1200°C for 2 h. The micro-morphology of coating was qualitatively characterized by focused ion beam scanning electron microscopy (FIB/SEM). The SEM micrographs obviously showed that the electrophoretic Cr 2 O 3 coating has formed a uniform and dense ultrathin layer after sintering at 1200°C. We demonstrated that nano-Cr 2 O 3 coating could be easily obtained by EPD for the surface modification of metallic materials for potential interest in hard wear-resistant and/or low-friction coatings.
研究领域:
材料科学
·
表面工程
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 14
·16745-16753
·
IF 3.056
Yu Cheng,Zhang Yi,Fang Yu,Tan Yujie,Dai Ke,Liu Shilin,Huang Qiaoyun
Shewanella oneidensis MR-1 (MR-1)-impregnated alginate capsules with 3D porous structure were prepared through cation crossing-linking and was used for the Cr(VI) reduction and removal. After being encapsulated by alginate, the endurance of the MR-1 was largely enhanced under conditions of high Cr(VI) concentrations (up to 4 mM) and low pH (pH 5). The Cr(VI) reduction over the MR-1-impregnated alginate capsules could be fitted by pseudo first-order kinetic model. With the Cr(VI) initial concentration increasing from 1 to 4 mM, the first-order rate constant for the encapsulated MR-1 ( k capsules ) and free cells ( k cells ) fell by 26.3% and 82.4%, respectively. At pH 5, the k capsules value was 0.19 h − 1 , which was about 3.7 times higher than k cells . Moreover, the encapsulated MR-1 held 90.5% of the Cr(VI) reduction ability after 15 days of resting time, while the free MR-1 held 19.7%. After bioreduction, 73.6% of total chromium was adsorbed on the MR-1 impregnated Ca-alginate capsules. XPS results showed 85% of the adsorbed chromium was Cr(III). The mechanism for chromium removal over the MR-1-impregnated Ca-alginate capsules was proposed with the following steps: (1) Cr(VI) was bioreduced via the encapsulated MR-1; (2) the reduced soluble Cr(III) was adsorbed by alginate selectively. In the study, the Ca-alginate shell of the cabbage-like MR-1 impregnated capsules could be a shelter for encapsulated MR-1 to endure unfavorable conditions (e.g., low pH and high concentration of Cr(VI)) and immobilize the soluble chromium. Considering the obtained capsules derived from biomolecules were environment-friendly, the MR-1-impregnated Ca-alginate capsules were potential for the application in the remediation of environmental pollution.
Graphical abstract
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）