LWT-FOOD SCIENCE AND TECHNOLOGY
·
2021
·
IF 4.952
Qinglan Wu,Mingfei Ren,Xinxia Zhang,Cheng Li,Ting Li,Zhi Yang,Zhengxing Chen,Li Wang
Rice bran, an underutilized by-product obtained from outer rice layers, has received wide interest due to its abundance, eco-friendliness, and low cost. In this research, cellulose , hemicellulose and lignin as the main components of rice bran were fractionated, and their Cd(II) adsorption capacity, behavior and mechanism were further studied. The adsorption capacity of cellulose for Cd(II) was 5.79 mg/g within the equilibrium time of 10 min, which was 1.8 and 3.6 times those of hemicellulose and lignin, respectively. The Cd(II) adsorption onto cellulose exhibited monolayer surface behavior, whilst the heterogeneous adsorption behavior was observed for hemicellulose and lignin. These differences were related to the discrepancy of morphology and chemical composition in three polymers. The multi-hole sticks morphology of cellulose and porous blocky structure of hemicellulose were observed, while lignin showed compact and agglomerated blocky structure. Cellulose had numerous available adsorption sites including the oxygen-containing functional groups, which bonded with Cd(II) driven by chemical interaction. In conclusion, it highlights that cellulose from rice bran has the great potential of being applied as adsorbent for the Cd(II) removal.
研究领域:
环境科学
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生物化学
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DOI
高影响因子
Arabian Journal of Chemistry
·
2022
·
IF 6.212
Jiacheng Li,Lisha Liao,Yannan Jia,Tian Tian,Shiwei Gao,Chenyue Zhang,Wei Shen,Zheng Wang
In this study, the preparation of magnetic Fe 3 O 4 /ZIF-8 (MFZ) and its adsorption properties for Cd(II) from water were investigated. Various characterizations demonstrate that the as-prepared MFZ has well magnetic-separation performance and thermal stability. In batch adsorption tests, the effects of pH, initial concentration, and adsorbent dosage were evaluated. According to the findings, when the pH is 7 and the dosage is 150 mg/L, the adsorption capacity for a 40 mg/L Cd(II) solution reaches 102.3 mg/g in 180 min. The Cd(II) adsorption processes was found to correspond to pseudo-first-order kinetics and Langmuir model according to the adsorption kinetics and isotherms. The Langmuir model predicted a maximal saturation adsorption capacity of 160.26 mg/g at 298 K. Thermodynamic analysis revealed that the Cd(II) adsorption is an endothermic, spontaneous process. Ion exchange, coordination reaction, and electrostatic interaction are all involved in Cd(II) adsorption by MFZ. The optimum conditions for Cd(II) adsorption were proposed and confirmed in accordance with the results of the response surface optimization experiments. Furthermore, regeneration tests demonstrate the great repeated regeneration ability of MFZ. According to the anticipated production cost, treating wastewater with a Cd(II) concentration of 40 mg/L would cost roughly US$ 8.35/m 3 . MFZ showed good potential for Cd(II) removal from water.
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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DOI
高影响因子
Journal of Chemistry
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2022
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IF 3.241
Anxiang Huang,Wenlian Bai,Shoulu Yang,Zhongwei Wang,Nengying Wu,Yanxiong Zhang,Ning Ji,Dan Li
The purpose of this study was to fabricate a low-cost and eco-friendly adsorbent using bamboo biochar (BB), a kind of charcoal composed of high Brunauer–Emmett–Teller surface area and variety of functional groups, and chitosan as substrates for remediation of Cd(II) in Cd(II) contaminated water and characterized the functional group characteristics, surface morphology, and Cd(II) adsorption effect using the Fourier transform infrared (FT-IR), scanning electron microscope (SEM), and energy-dispersive X-ray spectrometer (EDS). Results showed that chitosan-modified bamboo biochar (CBB) provided more active adsorption sites (such as –NH2, –COOH, –OH, and C=O) on the surface to enhance the Cd(II) removal efficiency in Cd(II) contaminated wastewater. Meanwhile, the optimal pH, contact time, and dose of CBB on the Cd(II) removal efficiency are 7, 120 min, and 600 mg, respectively. In addition, the adsorption isotherm results revealed that the possible adsorption mechanisms might include surface adsorption, electrostatic adsorption, and ion exchanges. Furthermore, the maximum adsorption capacity (Qm) values predicted from the Langmuir model were 37.74 and 93.46 mg/g for BB and CBB, respectively, also indicating a potential application of CBB in practical wastewater. Desorption and regeneration of CBB were attained simultaneously and the results showed that even after five cycles of adsorption-elution, the adsorption and desorption of CBB exhibited a slight decline and still reached at 71.70% and 65.92%. Results from this study would provide a reference to functionalized CBB for Cd(II) adsorption in contaminated water.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
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2017
·Vol. 53
·期 3
·2277-2289
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IF 2.599
Meng Jian,Cui Jianlan,Yu Jing,Huang Wei,Wang Peng,Wang Kui,Liu Mingqiao,Song Changyuan,Chen Peng
Chitosan chains (CTS) were grafted onto polyvinyl alcohol fibers (PVAf) with the aid of coupling agent γ -glycidoxypropyltrimethoxysilane, producing grafted fibers PVAf- g -CTS. Then, chloroacetic acid (CA) was used to react with the chitosan chains on the PVAf- g -CTS surface via nucleophilic substitution reaction to produce fibrous PVAf- g -CACTS with multiple adsorption sites. The products were characterized by using FTIR, SEM, XRD and XPS, revealing that the reaction followed the S
N
2 mechanism. Optimum parameters, including a reaction temperature of 50 °C and a mass ratio of PVAf- g -CTS to CA of 1:0.12, were determined for the reaction. Adsorption experiments confirmed that PVAf- g -CACTS showed greater adsorption characteristics for Cd(II) in aqueous solutions compared with PVAf- g -CTS and PVAf. In particular, the rate of Cd(II) uptake by using PVAf- g -CACTS was higher, and the equilibrium was reached within 80 min. When pH was 7, the saturated adsorption capacity reached 47.65 mg g −1 . The adsorption kinetics conformed to the pseudo-second-order model, and the adsorption process was in accordance with the Langmuir and Temkin isotherm model. Adsorption–desorption cycle experiments showed that PVAf- g -CACTS had good performance of reuse, and the adsorption mechanism was analyzed further by using XPS.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2018
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IF 2.829
Xubing Sun,Jianfa Zhu,Qiuyue Gu,Yaohui You
To introduce carboxyl groups on the surface of chitin and improve the adsorption performance of Cd(II) from aqueous solution, chitin was modified by 2, 2, 6, 6-tetramethylpiperidine-1-oxyl radical (TEMPO) with hypochlorite (NaClO) and sodium bromide (NaBr). Structure characterization demonstrated the carboxyl groups were successfully introduced on the surface of chitin. Batch experiments with various parameters of the content of carboxyl group, pH, contact time, initial concentration of Cd(II) and ionic strength on the adsorption performance were investigated. The surface-modified chitin exhibited enhancement for the Cd(II) adsorption capacity than original chitin. The Cd(II) adsorbed on carboxylated chitin increased rapidly in the first 30 min and reached equilibrium within 120 min. The dynamic data followed the pseudo-second-order kinetic model . Both Frendlich and Langmuir isotherm models fitted well to the equilibrium data and the maximum adsorption capacity calculated from Langmuir model was about 207.9 mg/g at 298 K. The adsorption of Cd(II) tended to increase with an increase of pH varying from 2.0 to 5.0, but decrease with an increase of ionic strength. The Cd(II) removal mechanism on carboxylated chitin was mainly through electrostatic interaction to form outer-sphere complexes and ion exchange.
研究领域:
环境化学
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材料科学
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水处理
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）