CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Wenbo Wang,Guangyan Tian,Zhifang Zhang,Aiqin Wang
Silicate materials have been frequently used as stable, low-cost and efficient adsorbents for the removal of dyes and heavy metal ions from aqueous solution. Herein, at the aim of designing new adsorbent with higher adsorption capacity, natural palygorskite (PAL) was modified via a one-step hydrothermal process by introducing sodium silicate and magnesium salts. The effect of Si/Mg dosage ratio on the structure and physico-chemical features of the adsorbent was investigated, and its adsorption capability for Methylene blue (MB) and Cu(II) ions was intensively evaluated. It was found that Si/Mg dosage ratio is the key to control the adsorption properties of the adsorbent. The active magnesium silicate could be formed around PAL at the moderate Si/Mg dosage ratio, and even the undesirable quartz impurities without adsorption activity in the natural PAL minerals may transform as amorphous magnesium silicate with higher adsorption activity in this process. The adsorbent shows greater BET specific surface areas (407.3 m 2 /g), ideal surface charge distribution and superior adsorption capacity to MB and Cu(II) ions, with the maximum adsorption capacity of 527.22 mg/g for MB and 210.64 mg/g for Cu(II) ions at the Si/Mg dosage ratio of 2:1. The MB molecules and Cu(II) ion could be almost completely removed from 100 mg/L of MB solution and 25 mg/L of Cu(II) solution by the adsorbent, respectively, which is far away higher than that of raw PAL. The electrostatic attraction, ion exchange and chemical association of –Si–O − groups contribute to the enhanced adsorption for MB or Cu(II) ions.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 35
·20504-20514
·
IF 3.119
Jianwen Wei,Siqi Chen,Yu Li,Zeyu He,Linlin Geng,Lei Liao
To find an alternative adsorbent with high adsorption performance, KIT-6 was prepared by hydrothermal crystallization synthesis using tetraethyl orthosilicate as a silicon source and triblock copolymer P123 as a template. Then the silane coupling agent (3-chloropropyl)trimethoxysilane was first grafted onto KIT-6 mesoporous material and then the polyethyleneimine (PEI) was further grafted through the substitution reaction between amino groups and chlorine atoms. The functionalized KIT-6 was denoted as PEI/KIT-6. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption–desorption, elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). The Cu2+ adsorption performance was determined by inductively coupled plasma (ICP). The results showed that the average loading of the amino groups was 3.74 mmol g−1, and the modified KIT-6 still has a stable mesoporous structure without pore blockage. With the dosage of 1 g L−1 PEI/KIT-6 and at room temperature, the optimum pH value for adsorption of 100 mg L−1 Cu2+ was 6.0. The adsorption capacity of PEI/KIT-6 for Cu2+ increased with the increase of reaction temperature, and the maximum adsorption capacity of Cu2+ was 36.43 mg g−1. The adsorption capacity tends to reach equilibrium after 120 min, and the optimum adsorption temperature was 35 °C. The pseudo-second-order kinetic model was found to be well suited for the adsorption process of Cu2+. Adsorption equilibrium data could also be described well by the classical Langmuir and Freundlich isotherm models. The adsorption tends to be the chemisorption of a monolayer.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 50
·29015-29022
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IF 3.049
Yanjie Dong,Dashen Sang,Chengdong He,Xinfeng Sheng,Longwen Lei
Mxene has been widely used as a sorbent to remove heavy metal ions from sewage due to its unique two-dimensional layered structure and abundant oxygen-containing groups. However, Mxene has a relatively limited adsorption capacity for metal ions possibly due to the limited adsorption active sites. Herein, we reported novel Mxene/alginate composites for lead and copper ion removal from wastewater. The Mxene/alginate composites prepared in this study not only enhance the chelation ability of the lead and copper ions, but also accelerate the ion transport efficiency. The combined advantages of high adsorption capacity and short equilibrium time enable the Mxene/alginate composites to achieve the maximum adsorption capacity for Pb2+ and Cu2+ at 382.7 and 87.6 mg g−1, respectively, and reach the adsorption equilibrium in 15 min. We believe that the composites developed in this study can open a new avenue for designing high adsorption capacity and high efficiency adsorbents.
研究领域:
环境科学
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材料科学
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化学工程
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污染控制
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水处理
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Tiantian Nie,Pulin Hao,Zhendong Zhao,Wenjun Zhou,Lizhong Zhu
The bamboo biochars pyrolyzed at 400 °C and 600 °C (BC400 and BC600) were modified by hydrogen peroxide (H 2 O 2 ) to obtain the oxidized biochars. Biochar stability and the effect of oxidation treatment on the adsorption and co-adsorption of tetracycline (TC) and Cu 2+ onto biochars were investigated. The calculated carbon loss of biochars after oxidation treatment indicated that BC600 presented higher carbon stability than BC400 due to the condensed aromatic structure of biochar. Moreover, oxidation treatment introduced O-containing functional groups on biochar surface, but destructed the aromatic structures of oxidized biochars, which in turn affected the adsorption capacity of biochars for TC and Cu 2+ . Oxidation treatment obviously enhanced the adsorption of TC and Cu 2+ onto BC400 owing to the increase of O-containing functional groups, but significantly decreased TC and Cu 2+ adsorption onto BC600 because of the decreased π - π dispersive forces between biochar and adsorbate. The promotion effect of Cu 2+ on TC adsorption onto BC400 changed into inhibition effect after chemical oxidation owing to the pore blockage. However, the promotion degree of Cu 2+ for TC adsorption onto BC600 was enhanced through oxidation treatment due to electrostatic attraction and complexation. Meanwhile, oxidation treatment reduced the inhibition degrees of TC for Cu 2+ adsorption onto biochars, which was attributed to the increased amount of electron-rich groups. The results are helpful for the application of biochars in the soils remediation .
研究领域:
环境科学
·
土壤修复
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Jing Liu,Jing Wang,Jie Zhang,Yang Mu
In this study, the impact of Cu 2+ on the formation of iodo-trihalomethanes (I-THMs) during chlorination and chloramination of iodide-containing waters was investigated. Initially, the oxidant consumption and evolution of hypoiodous acid (HOI) were determined during disinfection in the presence of Cu 2+ and the interaction between natural organic matter humic acid (HA) and Cu 2+ was also analyzed. Subsequently, the formation of the I-THMs at various Cu 2+ concentrations was evaluated for chlorination and chloramination. Moreover, in order to explore the possible underlying mechanisms, five model compounds based on the HA structure were used to investigate the I-THMs formation with and without Cu 2+ during disinfection. The results indicated that the presence of Cu 2+ markedly affected the conformation of the HA rather than the HOI evolution during disinfection. The concentration of the I-THMs decreased from 34.5 ± 0.8 to 20.9 ± 0.8 nM as the Cu 2+ concentration increased from 0 to 20 μM during chlorination. In contrast, during chloramination, the total I-THMs concentration decreased from 320.7 ± 7.4 to 267.2 ± 10.7 nM as the Cu 2+ concentration increased from 0 to 5 μM and then increased to 315.0 ± 1.7 nM when the Cu 2+ concentration reached 20 μM. The disinfection experiments with the model compounds suggested that the impact of Cu 2+ on the I-THMs formation largely depended on the organic structures in the HA, thus leading to different results during chlorination and chloramination.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Jing Hu,Hanjiao Chen,Xiandeng Hou,Xiaoming Jiang
Herein, we report a discovery that photochemical vapor generation (PCVG) of molybdenum (Mo) can be synergistically enhanced dramatically by cobalt and copper ions sourced from acetates in the medium of formic acid, utilizing a flow-through reactor. The nature of this new PCVG was probed for the first time by an electron paramagnetic resonance (EPR) spin trapping technique for its possible reaction mechanism. Carboxyl and hydroxyl free radicals were verified during PCVG processes, and the results indicate that variations in the relative amounts and proportions of free radical species may account for the synergistic effect from concomitant Co2+ and Cu2+, as well as the generation of molybdenum hexacarbonyl from the UV-induced photolysis of formic acid. Under “dry” plasma conditions, the simultaneous spiking of Co2+ and Cu2+ to 20% (v/v) formic acid solutions and a 60 s irradiation time could give rise to a 15-fold enhancement in signal intensities, together with a blank-limited but still impressive limit of detection of 6 ng L–1 (6 ppt) by inductively coupled plasma mass spectrometry (ICP-MS). The accuracy and reliability of this methodology was validated by analysis of molybdenum in a seawater certified reference material, CASS-6, as well as two varieties of drinking water and seawater samples, with satisfactory spike recoveries (91–101%).
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 CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2019
·
IF 2.813
Dong-Dong Zhou,Qian Zhang,Hao Zhang,Yin-Zhen Wang,Feng-Qing Yang,Sheng-Peng Wang,Yi-Tao Wang
In this paper, Cu 2+ functionalized Fe 3 O 4 @polydopamine core-shell (Fe 3 O 4 @PDA@Cu 2+ ) magnetic microspheres were prepared by the chelation between Cu 2+ and catechol of polydopamine surface. The synthetic magnetic adsorbent was characterized by Fourier transform infrared spectroscopy , energy dispersive X-ray spectroscopy, vibrating sample magnetometry , thermogravimetric analysis , scanning electron microscope and transmission electron microscopy . Four purines include guanine , adenine , hypoxanthine and xanthine were selected as model compounds to evaluate the applicability of this adsorbent. Several parameters that effected the extraction efficiency, such as extraction time, adsorbent amount, solution pH, ionic strength , eluent type, concentration of eluent and eluent time, were investigated. Under the optimized conditions, good linearity was obtained with correlation coefficients between 0.9983 and 0.9999 for the four analytes, and their LOD and LOQ were 0.42–2.15 ng/mL and 1.41–6.50 ng/mL, respectively. Meanwhile, the RSDs of intra-day and inter-day precision were in the range of 1.43%–5.55% and 4.56%–7.01%, respectively. The spiked recoveries of four purines in real sample were 70.01%–102.42%, indicating this proposed method might have potential applications for the analysis of purines in real samples. In addition, the developed method was used to monitor the concentrations of adenine in rat plasma at different time points after intragastric administration.
研究领域:
分析化学
·
生物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2020
·
IF 4.966
Dachao Ma,Liwu Liang,Erfeng Hu,Huaquan Chen,Dongbo Wang,Chao He,Qingge Feng
Hydrothermal treatment (HTT) is able to remove chlorine effectively from polyvinyl chloride (PVC), however, the reaction temperature is critical in practical application. Less energy-intensive hydrothermal dechlorination condition with cupric ion (Cu 2+ ) has been proposed in this study. In particular, Cu 2+ was applied in HTT of PVC at temperature ranging from 200 °C to 240 °C. It has been found that the introduction of Cu 2+ distinctly accelerated PVC decomposition and dechlorination at 220 °C. When Cu 2+ concentration was increased from 0.01 mol/L to 0.20 mol/L, the dechlorination efficiency was significantly improved from 15.46 %–67.89 %. Dramatic dechlorination occurred as residence time was longer than 15 min during HTT. Besides, both elimination and substitution dominated the HTT dechlorinaton. The facilitated dechlorination after the addition of Cu 2+ was mainly due to the enhanced dispersion and formation of micropores in hydrochar. On the whole, HTT could be a promising pretreatment technology for copper-containing PVC in electronic wastes to prepared chlorine free hydrochar for combustion or pyrolysis applications, the optimal HTT condition would be 220 °C, 60 min with 0.1 mol/L Cu 2+ .
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2013
·
IF 3.535
Lijun Qu,Caixia Yin,Fangjun Huo,Yongbin Zhang,Yingqi Li
The commercially available fluorescent probe, 1,8-diamino naphthalene with a naphthalene ring as a chromophore and two amino groups as binding sites has been developed for sensitive detection of copper ions by fluorescence spectrometer in aqueous solution. It displayed an excellent selectivity and sensitivity for Cu 2+ over other metal ions. The mechanism is that the fluorescence of probe was quenched by the paramagnetic effect from spin–orbit coupling of the Cu 2+ after probe coordinated with Cu 2+ , and mechanism was proved by ESI-MS. The probe can be used to react to Cu 2+ in live cells, providing a potentially powerful approach for probing Cu 2+ chemistry in biological system.
研究领域:
分析化学
·
生物化学
·
细胞生物学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2017
·
IF 3.359
Chao Han,Wei Wang,Feng Xie,Ting'an Zhang
Mercury is one of the most severe environmental pollutants due to its high toxicity, and the detoxification of mercury-containing solid wastes is a critical issue worldwide. In this work, thiosulfate solution has been used to leach mercury from mercuric sulfide. The influence of leaching conditions, including initial pH, molar ratio of copper to thiosulfate ([Cu]/[S 2 O 3 2− ]), and temperature on mercury leaching from mercuric sulfide, was investigated. The mercury leaching rate can reach as high as 92.37% after 7-h leaching under the optimized condition of initial pH 8.50, molar ratio of copper to thiosulfate 0.1 and leaching temperature 313 K. X-ray diffraction (XRD), scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) was used to analyze the leaching residue. The results show that copper in its thiosulfate complex can be substituted by mercury via Lewis substitution and cuprous sulfide was formed on the surface of leaching residue. The kinetics of mercuric sulfide leaching with cuprous-thiosulfate solutions was controlled by the product layer diffusion.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Guichen Gong,Jie Liu,Yuexin Han,Yimin Zhu
Cu 2+ was found to have intensive and selective depressing effects on fluorite in the flotation separation of cassiterite from fluorite using 2-carboxyethylphenylphosphinic acid (CEPPA) as a collector at pH 4.0. The depressing mechanism was investigated by flotation tests, zeta potential measurements, X-ray photoelectron spectroscopy (XPS) analyses and density functional theory (DFT) calculations. Flotation test results demonstrated that Cu 2+ selectively depressed the fluorite in an artificially mixed cassiterite-fluorite ore. Zeta potential measurement and XPS analysis results indicated that Cu 2+ could be anchored on cassiterite surface by adsorption or substitution but not on fluorite surface, and the adsorption of CEPPA on fluorite surface was cut off by Cu 2+ . DFT calculation results demonstrated that CEPPA had stronger affinity for Cu 2+ than for fluorite, and the adsorption or substitution of Cu 2+ on cassiterite (110) surface showed no negative effects on the adsorption of CEPPA monoanion on cassiterite (110) surface. Based on these results, the depressing mechanism of Cu 2+ on fluorite was that Cu 2+ consumed the collector CEPPA in solution, and little free CEPPA was left to be adsorbed on fluorite surface while the adsorption of CEPPA on cassiterite was normal. Thus, the floatation of fluorite was selectively and intensively weakened.
研究领域:
矿物加工工程
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 64
·59677-59683
·
IF 3.289
Xin Wu,Xiaojuan Gong,Wenjuan Dong,Jun Ma,Jianbin Chao,Chenzhong Li,Li Wang,Chuan Dong
A new colorimetric probe, 5-chlorosalicylaldehyde fluorescein hydrazone (CSFH), has been synthesized and characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry, elemental analysis and X-ray single crystal diffraction. CSFH had nearly no absorption in visible region. In the presence of copper(II) ion a rapid color changes from colorless to yellow along with an obvious new absorption band appeared at 495 nm. CSFH was highly selective to Cu2+ only in the aqueous solution, instead of common metal ions. The absorbance intensity and the color of CSFH solution increased gradually with the increase of Cu2+ concentration. Common metal ions did not show any interference on the determination of Cu2+. The chemical stoichiometric ratio between the CSFH and Cu2+ was 1 : 1 and corresponding association constant was 6.85 × 105 L mol−1, and the linear range for Cu2+ detection was 0.25–14 μmol L−1. The detection limits were 0.25 μmol L−1 and 1.0 μmol L−1 of Cu2+ using the UV-Vis changes and the visual color changes by the naked eye respectively. The proposed method was applied to the determination of Cu2+ in drinking water samples and the recoveries were 96–106%. The preparation of CSFH exhibited the quick, simple and facile advantages. The results showed that CSFH can be a good candidate for simple, rapid and sensitive colorimetric detection of Cu2+ in aqueous solution.
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
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