SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2017
·
IF 2.536
Hui Zhang,Ge Zhang,Jingkun Xu,Yangping Wen,Shouli Ming,Jie Zhang,Wanchuan Ding
Trivalent chromium (Cr 3 + ) can cause severely environment pollution, declining quality of edible agro-products in plants and animals, and human diseases. Poly( N -(9-fluorenylmethoxycarbonyl)- l -histidine) (PFLH) synthesized by the direct electro-polymerization of its corresponding commercially available monomer in both boron trifluoride diethyl etherate and dichloromethane mixed system. The “turn-on” type fluorescent sensor based on PFLH displayed high sensitivity and selectivity for Cr 3 + detecting. The structure of PFLH was rationally proved by 1 H NMR spectra, FT-IR spectra, quantum chemical calculations , and its optical properties were characterized. The electro-synthesized PFLH exhibited a “turn-on” fluorescent response towards Cr 3 + , which was employed as a sensing platform for the “turn-on” fluorescent analysis of Cr 3 + in a wide linear range from 5.1 nM to 25 μM with a low limit of detection as low as 1.7 nM. The possible mechanism of fluorescent “turn-on” sensor based on PFLH for Cr 3 + was proposed. The sensor displayed high sensitivity, good selectivity, satisfactory practicability, suggesting that PFLH has potential fluorescent application for “turn-on” sensing Cr 3 + in agricultural environments and edible agro-products of plants and animals.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2022
·Vol. 39
·期 7
·1839-1849
·
IF 3.146
Zhang Xiaoting,Zhang Shusheng,Ouyang Gangfeng,Han Runping
A zirconium-based metal organic framework (UiO-66-NH 2 ) was prepared using a greener approach for the removal of hexavalent chromium (Cr(VI)) from solution. The characterization of UiO-66-NH 2 was performed using several methods, and the influence of the solution pH, adsorbent dosage, salt, adsorption time, Cr(VI) concentration and adsorption temperature on adsorption quantity was performed in batch mode. UiO-66-NH 2 can efficiently remove Cr(VI) through the synergistic effect of adsorption and reduction. At pH solution of 1.1 and solid-to-liquid ratio of 2 g·L −1 , the removal rate of 100 mg·L −1 Cr(VI) increased to 95.2%. The maximum adsorption capacity of UiO-66-NH 2 from Langmuir model was 252 mg·g −1 . The adsorption equilibrium process can be well described by Langmuir, Koble-Corrigan and Temkin models, while the kinetic process can be predicted by pseudo-second-order and Elovich model. UiO-66-NH 2 showed a good adsorption capacity in a wide range of pH (pH=1.1–10) and also had better regeneration performance after five cycles using 0.01 mol·L −1 NaOH; consequently, it can be a promising adsorbent for the removal of Cr(VI) from solution.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 3
·1-9
·
IF 5.479
Mutuyimana Félicité Pacifique,Liu Juanjuan,Nsanzamahoro Stanislas,Na Min,Chen Hongli,Chen Xingguo
The authors describe a one-step method for the preparation of yellow fluorescent carbon dots (CDs) starting from 4-aminoacetanilide hydrochloride and 4-acetamidobenzaldehyde. The CDs have excitation/emission peaks at 470/550 nm, good water solubility, salt-tolerance and photostability. Their fluorescence is quenched by hexavalent chromium [Cr(VI)] via static quenching. Fluorescence intensity drops linearly in the 1 to 400 μM Cr(VI) concentration range, and the limit of detection is 0.13 μM. This method is selective for Cr(VI) over potential metal ion interferences and was successfully applied to the detection of Cr(VI) in spiked water and biological tissue samples. Recoveries from spiked samples ranged from 97.7% to 103.8%.
Schematic presentation of ( a ) the preparation of the CD fluorescent probe and ( b ), the principle of Cr(VI) determination
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2019
·
IF 4.527
Huanlong Peng,Yukun Wu,Tong Guan,Wei He,Liang Xu,Yongmei Liang,Wei Liu
In this study, we analyzed the effects of sludge aging pre-treatment on the stabilization mechanisms of heavy metals during sludge pyrolysis . First, the form of copper (Cu) and chromium (Cr) was conducted using the sequential extraction procedure proposed by the European Community Bureau of Reference (BCR). The stabilization mechanisms for the sludge pyrolysis of Cu and Cr were then analyzed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Results indicate the following: 1) with aging pre-treatment, the improvement in adsorption performance and the formation of newly crystallized materials, like polyhydroxy copper phosphate and chromium phosphate minerals , occur concurrently with the stabilization of heavy metals during pyrolysis; 2) after four weeks of aging, active functional groups like amino and carboxyl groups were significantly sharpened, and caused sustained complexation of the heavy metals. Results suggested that the aging pre-treatment aided the stabilization of heavy metals during sludge pyrolysis. Notably, the aging effect can decrease the potential ecological risk of heavy metals.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2020
·
IF 2.627
Dongmei Jia,Huamin Cai,Yongzheng Duan,Jiangbao Xia,Jia Guo
Chromium is a common harmful pollutant with high toxicity and low bearing capacity of soil and water. Excellent salinity resistance, a wide pH range, and high regeneration capacity were essential for qualified adsorbents used in removing hexavalent chromium (Cr(VI)) from polluted water. Herein, iron oxalate modified weak basic resin (IO@D301) for the removal of Cr(VI) was prepared by the impregnation method. The IO@D301 was characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Owing to abundant amine, carboxyl groups and iron ions existing on the surface, IO@D301 possesses high adsorption and salinity resistance capacity for Cr(VI). The maximum adsorption capacity of IO301 towards Cr(VI) reached 201.30 mg·g −1 at 293 K and a pH of 5. The adsorption equilibrium was well fitted by the Freundlich model, and the adsorption process was described by the pseudo-first-order kinetics model as spontaneous and exothermic. The mechanism may be identified as electrostatic attraction, coordination, and reduction, which was confirmed by FT-IR and X-ray photoelectron spectroscopy.
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
FOOD CONTROL
·
2018
·
IF 3.667
Hui Liang,Wei-Liang Wu,Yong-Hui Zhang,Shao-Jun Zhou,Chao-Yang Long,Jian Wen,Bo-Yuan Wang,Zhi-Ting Liu,Chao-Zheng Zhang,Pan-Pan Huang,Ning Liu,Xiao-Ling Deng,Fei Zou
To systematically investigate the presence of toxic heavy metals and evaluate the potential health risks of heavy metals (HMs), the levels of cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), and chromium (Cr) in a total of 4401 representative samples of highly consumed fresh vegetables sampled from 21 prefecture-level cities of Guangdong Province, China, were determined by inductively coupled plasma mass spectrometry (ICP-MS). In the analyzed vegetables, the heavy metal concentrations exceeded the maximum allowable concentrations (MACs) set by Chinese legislation were of 2.41% for Cd, 1.61% for Pb, 0.55% for As, and 0.48% for Cr. The concentrations of HMs indicated significant differences ( p < 0.05) in vegetable groups and regions. Cd, and Pb were the major contaminants in vegetables according to the results of principal component analysis. During the four-year survey, a temporary rising trend was observed in As and Cr. The results from hierarchical cluster analysis also demonstrated that the status of HMs contaminations in vegetables from various regions displayed certain changes over time. The health risks associated with the intake of these HMs via vegetable consumption were evaluated in term of estimated daily intake (EDI), and noncarcinogenic and carcinogenic risks by target hazard quotient (THQ) and carcinogenic risk (CR). EDI values of each HM at both common and high consumption levels were observed to be less than the corresponding provisional tolerable daily intakes. The THQs of individual HMs and total target hazard quotients (TTHQs) were less than 1, indicating low health hazards for local residents. However, high consumption of stalk and stem vegetables, leafy vegetables , and root and tuber vegetables, and high consumption of vegetables marketed in the northern region (NR) of Guangdong Province resulted in TTHQs that approach 1 and may cause health risks to increase. The carcinogenic risks (CRs) of Cd, Pb and As were below the threshold level (10 −6 ) or residual level (10 −4 ), suggesting low potential CR from these HM exposures via vegetables consumption. However, highly consumed vegetable categories with high Cd concentrations and vegetables marketed in NR resulted in the CRs of Cd and TCRs exceeding the acceptable range, indicating that serious potential carcinogenic risks to human health may exist. In summary, the findings of this study reveal safe exposures of HMs via vegetable consumption, however, great concern should be focused on the noncarcinogenic and carcinogenic risks associated with high exposures of HMs, especially Cd, Pb and As, via high vegetable intake.
研究领域:
环境科学
·
食品安全
·
公共卫生
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2022
·
IF 4.05
Chen Dong,Chen Shanshuai,He Liang,Guan Qingqing,Miao Rongrong
Porous biochar was prepared from agricultural and forestry wastes to remove Cr(VI) in sewage, which solved the problem of water pollution and realized the reuse of wastes. Herein, in this work, the bagasse pith residues after alkali pre-extraction have been used as the raw material for preparing porous biochars ( BPR -BC), which could be further used for efficiently purifying the simulated Cr(VI) wastewater. The results showed that the as-prepared biochars had an ultra-high specific surface area of 2745.7 m 3 /g and Cr(VI) removal capacity of 185.07 mg/g. The kinetic and isotherms studies were best described by pseudo-second-order model and Langmuir adsorption isotherm model, respectively. The thermodynamic studies showed that the adsorption process was endothermic and spontaneous. Furthermore, based on the concept of “waste to waste,” the Cr-contained waste adsorbent by doping Cu has been converted into a bagasse pith residues biochar supported Copper-Chromium catalyst (Cu-CrOx/ BPR -BC) for further hydrogenation of furfural. The catalytic experimental result showed that the furfural 1 can be selectively converted into furfuryl alcohol (FOL) and difurfuryl ether (DEF) catalyzed by the prepared Cu-CrOx/ BPR -BC catalyst, provided a new idea for the further utilization of Cr(VI) containing adsorbents.
研究领域:
环境科学
·
催化化学
·
废水处理
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2015
·Vol. 7
·期 6
·2653-2658
·
IF 1.821
Jing Sun,Zhaoguang Yang,Hsiaowan Lee,Lin Wang
The simultaneous separation and determination of As(III), As(V), monomethylarsenic acid (MMA), dimethylarsenic acid (DMA), Cr(III), Cr(VI) and Cd(II) in water samples have been carried out by anion exchange liquid chromatography with inductively coupled plasma mass spectrometry. Ethylenediaminetetraacetic acid was used to form negatively charged complexes with Cr(III) and Cd(II). For achieving the optimum chromatographic conditions, the effects of competing ion type, mobile phase concentration and pH on speciation have been investigated. By compromising among analysis time, chromatographic resolution and sensitivity, 40 mM ammonium nitrate at pH 8.6 has been selected as the mobile phase for real sample applications. The baseline separation of all the target species has been achieved under isocratic elution conditions. Under the optimized conditions, the limit of detection was in the range of 0.07–0.12 μg L−1 for the various species. The proposed method was applied to the determination of the target species in surface water and drinking water samples. Arsenate was the dominant arsenic species in all the tested samples. Neither MMA nor DMA was detected in real water samples. The recoveries for spikes of individual species in water samples tested ranged from 88% to 116%.
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
Sustainability
·
2018
·Vol. 10
·期 11
·4250
·
IF 2.075
Shuang Xu,Weiguang Yu,Sen Liu,Congying Xu,Jihui Li,Yucang Zhang
A low-cost biochar was prepared through slow pyrolysis of banana pseudostem biowaste at different temperatures, and characterized by surface area and porosity analysis, scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). It was shown that the biochar prepared at low pyrolysis temperature was rich in oxygen-containing groups on the surface. Adsorption experiments revealed that the biochar prepared at 300 °C (BB300) was the best adsorbent for Cr(VI) with 125.44 mg/g maximum adsorption capacity at pH 2 and 25 °C. All the adsorption processes were well described by pseudo-second-order and Langmuir models, indicating a monolayer chemiadsorption. Furthermore, it was demonstrated that adsorption of Cr(VI) was mainly attributed to reduction of Cr(VI) to Cr(III) followed by ion exchange and complexation with the biochar.Keywords:biochar;banana pseudostem;chromium;adsorption mechanism
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
JOURNAL OF HAZARDOUS MATERIALS
·
2015
·
IF 4.529
Jian Rong Zhang,Ai Lian Zeng,Hong Qun Luo,Nian Bing Li
In this work, a simple and sensitive Cr(VI) sensor is proposed based on fluorescent polyethyleneimine-stabilized Ag nanoclusters, which allows the determination over a wide concentration range of 0.1 nM–3.0 μM and with a detection limit as low as 0.04 nΜ and a good selectivity. The quenching mechanism was discussed in terms of the absorption and fluorescence spectra, suggesting that Cr(VI) is connected to Ag nanoclusters by hydrogen bond between the oxygen atom at the vertex of tetrahedron structure of Cr(VI) and the amino nitrogen of polyethyleneimine that surrounded Ag nanoclusters and electron transfer from Ag nanoclusters to highly electron-deficient Cr(VI) results in fluorescence quenching. Despite the failure to quench the fluorescence efficiently, Cr(III) can also be measured using the proposed Ag nanoclusters by being oxidized to Cr(VI) in alkaline solution (pH ∼9) containing H 2 O 2 . Therefore, our approach could be used to detect Cr(VI), Cr(III) and the total chromium level in aqueous solution. In addition, Cr(VI) analysis in real water samples were satisfactory, indicating this method could be practically promising for chromium measurements.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Linheng Chen,Weixi Liu,Yang Wu,Jumei Li,Yibing Ma
There is uncertainty in quantifying the toxic effects of total chromium (Cr) in the environment by modeling the toxicity of individual Cr(III) or Cr(VI). In the present study, the effects of Cr(III) and Cr(VI) on barley root elongation were investigated in a hydroponic system where Cr(III) and Cr(VI) combination dose-response experiments under monotoxicity concentration, single-dose addition, and fixed concentration ratios were designed to identify and quantify their combined phytotoxicity of one element with various valences. The results show that the calculated mixed toxicity unit values for 50% inhibition (TU mix50 ) ranged from 1.06 to 1.45, indicating the weak antagonism effects of Cr(III) and Cr(VI) on barley root toxicity. Also, the single-dose group experiment has proved that the EC 50 of Cr(VI) was increased from 71.2 μM to 119.9 μM with Cr(III) addition, which suggested that Cr(III) has antagonism on the toxicity of Cr(VI). While EC 50 of Cr(III) was not affected by Cr(VI) addition. After introducing the expansion coefficient of Cr(III) on Cr(VI) toxicity, both the extended concentration addition model (e-CA) based on the log-logistic and Weibull equations and the extended independent action model (e-IA) could more accurately predict the barley root elongation under Cr(III) and Cr(VI) interaction. The e-CA model based on the Weibull equation had almost the best correlation coefficient (R 2 ) and lowest root mean square error (RMSE) between the measured and predicted values. Finally, the combined toxicity and antagonism of the same element with co-existing different valences simultaneously were successfully and firstly identified and quantified in the present study.
研究领域:
植物学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2022
·Vol. 12
·期 11
·1429
·
IF 4.501
Yali Song,Huan Zhang,Ziyan Li,Long Huang,Junhao Xie,Long Han,Ruoying Zheng,Yuqing Zhang,Hongzhong Zhang
Previous studies have displayed various conclusions about the effect of preparation factors on the photoreduction property of ZnIn2S4. Therefore, it is not easy to figure out the optimal preparation conditions of ZnIn2S4for Cr(VI) photoreduction. To ensure Cr(VI) reduction efficiency, various ZnIn2S4photocatalysts were prepared in different solvents (i.e., water and ethylene glycol) and temperatures (i.e., 120 °C, 150 °C and 180°C). Different characterization methods were used to explain the difference in optical performance and photocatalytic property among the obtained samples. The results show that all the samples exhibit a similar band gap. The reaction solvent and temperature have a great influence on the surface morphology and optical property, leading to the different photocatalytic properties. ZnIn2S4synthesized at 120 °C in the solvothermal condition shows the optimal efficiency on Cr(VI) photoreduction due to the effective utilization of photo-induced carriers. The reasonable analysis and effective conclusion presented may provide the optimal synthesis method of ZnIn2S4to effectively remove Cr(VI) from water environment.Keywords:ZnIn2S4;Cr(VI);solvothermal;hydrothermal;photoreduction
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
危险品化学品经营许可证（带存储）