JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2021
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IF 8.128
Xiaoyong Qiu,Jun Huang,Hui Wang,Yulu Qi,Jiwei Cui,Jingcheng Hao
Hypothesis Water contamination from heavy metal ions is a major global environmental concern. Adsorbents based on biomaterials have been demonstrated to possess remarkable removal efficiency for metal ions, but the adsorption model of biosorbents is not clear and much efforts should be devoted to study the adsorption behaviors and understand the adsorption mechanism. Experiments The multifunctional rhodamine-modified chitosan (RMC) hydrogel for Hg 2+ adsorption with fluorescent turn-ON properties was fabricated through grafting the rhodamine-modified poly (ethylene glycol) benzaldehyde (RM-PEG) onto the hydrogel network serving as the fluorescence/colorimetric sensing receptor. The adsorption behaviors and colorimetric sensing mechanism of RMC hydrogel towards Hg 2+ were investigated in detail. Findings RMC hydrogel can remove more than 96.5% of Hg 2+ from aqueous solution with significant fluorescence response and colorimetric change. The high adsorption selectivity and colorimetric sensing mechanism of RMC hydrogel towards Hg 2+ can be explained by the hard and soft acid/base (HSAB) theory. The O atom in hydroxyl and carbonyl groups together with the N atom in amine/imine groups of RMC hydrogel play a vital role in the adsorption of Hg 2+ , while the colorimetric response and fluorescence enhancement of the hydrogel after adsorption are attributed to the specific spiro-lactam structure of rhodamine moieties. The adsorption isotherms and kinetics were investigated and well described by Freundlich isotherm and pseudo-second-order kinetic model . Furthermore, RM-PEG showed low cytotoxicity towards mouse embryonic fibroblast cells and RMC hydrogel can be used as a fluorescent pH indicator from 4.2 to 7.4, demonstrating the potential applications of RMC hydrogel in biological diagnosis.
研究领域:
环境科学
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生物材料学
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分析化学
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
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IF 3.573
Mingbo Shi,Daiwu Lin,Renliang Huang,Wei Qi,Rongxin Su,Zhimin He
The treatment of multicontaminant wastewater has attracted extensive attention in recent years. Herein, we synthesized a porous and hydrophobic composite (Zr-MOF-SH/MF) via the in situ growth of mercapto-functionalized Zr-metal–organic frameworks (MOFs) (Zr-MOF-SH) on the surface of a melamine formaldehyde (MF) sponge. The successful growth of hydrophobic Zr-MOF-SH, as confirmed by SEM, XRD, and XPS analysis, made the MF sponge become hydrophobic with a water contact angle of 125°. The adsorption capacity of the Zr-MOF-SH/MF composite for dichloromethane can reach up to 113 g/g. Moreover, the composite can efficiently and selectively remove Hg2+ ions from water. Especially, PCN-224-MAA/MF had an adsorption capacity of 412.5 mg/g for Hg2+ ions. The removal efficiency of Hg2+ ions increased as the oil content in the oil–water mixture increased. In addition, PCN-224-MAA/MF can be recovered and reused five times with only a slight decrease in adsorption capacity. This study provides a promising strategy for the synthesis of a dual-functional composite that exhibits excellent performance in removing oil and heavy metal ions simultaneously from water.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2022
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IF 8.91
Xiangchu Zeng,Guanghua Zhang,Xiuling Li,Junfeng Zhu,Zhe Wu
The adsorbents with recyclable, large adsorption capacity and selective adsorption can effectively remove the pollution and harm of heavy metal ions in water. Therefore, two magnetic composites containing sulfur ( MCP-S4 and MCP-S8 ) on the hyper-branched surface were prepared, furthermore, their structures were characterized and adsorption performance was analyzed by FTIR , XRD , TGA, BET, SEM, TEM, VSM and ICP. The results showed that both MCP-S4 and MCP-S8 had superparamagnetism with saturation susceptibility of 22.10 and 22.26 emu/g, and owned a specific surface area of 11.394 and 11.235 m 2 /g, respectively. MCP-S4 and MCP-S8 could selectively adsorb Hg 2+ with the exist of Fe 3+ , Cu 2+ , Co 2+ , Ni 2+ , Mn 2+ , and Al 3+ in solution. The adsorption kinetics accorded with pseudo-second-order model and Boyd film diffusion model , and the adsorption isotherm was fitted better with Langmuir isotherm model and D-R model, furthermore, the adsorption was an entropic-increasing and endothermic process . The removal rate of Hg 2+ from simulated sewage by the two materials was more than 91%, and the adsorption retention rate was more than 85% after five adsorption-desorption cycles. The adsorption mechanism was analyzed by comparing the changes of FTIR, EDS and XPS spectra before and after adsorption. It was found that functional groups (C–N, CONH, C S, SH) could form stable chelates with Hg 2+ , which was the main reason why MCP-S4 and MCP-S8 could adsorb Hg 2+ selectively, furthermore, S atoms of C S and –SH played a leading role in the process of adsorption. In addition, DFT calculation was also used as an auxiliary means to verify the adsorption mechanism.
研究领域:
环境科学
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材料科学
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化学
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水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）