SCIENCE OF THE TOTAL ENVIRONMENT
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2023
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IF 9.8
Peng Yi,Yani Yan,Ying Kong,Quan Chen,Min Wu,Ni Liang,Lijuan Zhang,Bo Pan
Wetting-drying cycles in the environment could change the inner- or outer-sphere complexation of heavy metal cations on natural organic matter (NOM) and then influence ternary interactions with organic contaminants - a rarely-discussed essential geochemical process. In this work, the sorption of sulfamethoxazole (SMX) on humic acids (HAs) mediated by cations (Cu 2+ and Cd 2+ ) was investigated. Considering that outer-sphere complexation could be transformed into inner-sphere complexation during vacuum freeze-drying, the role of inner- or outer-sphere complexation on SMX sorption was explored. The experimental sorption results and density functional theory (DFT) calculations suggested that Cu 2+ and Cd 2+ sorption on HAs was mainly outer- and inner-sphere complexation, respectively. Cd 2+ consistently promoted SMX sorption on HAs, while Cu 2+ promoted and inhibited SMX sorption before and after freeze-drying. The structure of HA-Cu complexes with inner-sphere complexation was more compact than those with outer-sphere complexation, which reduced the accessibility of sorption sites for SMX on HA-Cu and inhibited SMX sorption. However, the greater number of coordination sites of Cd 2+ may provide more sorption sites and the structure of HA-Cd was looser. These findings provide a groundbreaking understanding of the sorption of organics on natural adsorbents in the presence of cations.
研究领域:
环境科学
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土壤化学
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产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
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2024
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IF 8.1
Dan Zhou,Chao Li,Mingzheng Huang,Xiaoyan Chen,Yonglian Xia,Yi Huang
V–Ti magnetite tailings (VTMTs) contain various heavy metals , such as Fe, Mn, V, Co, and Ni. The groundwater pollution caused by the tailing metal release has become a local environmental concern. Although studies have demonstrated the influence of alternate flooding and drying cycles (FDCs) on metal form and mobility in minerals, little was known about whether FDCs affect the metal release of VTMTs and the transformation of released metals. This study investigated the metal release kinetics of VTMTs and the metal transformation under FDCs in the absence and presence of acid rain (sulfuric and nitric acids) and bio-secreted organic acids (acetic, oxalic, and citric acids). The results showed that FDCs promoted metal release whether or not acids were present. The maximum released concentrations of V, Mn, Fe, Co, and Ni were as high as 78.63 mg L −1 ,1.47 mg L −1 , 67.96 μg L −1 , 1.34 mg L −1 , and 0.80 mg L −1 , respectively, under FDCs and citric acids . FDCs enhanced the tailing metal release by increasing the metal labile fraction proportion. However, the concentrations of released Fe, Mn, V, Co, and Ni all gradually decreased due to their (co-)precipitation. These precipitates conversely inhibited the subsequent mineral dissolution by covering the tailing surface. FDCs also enhanced the tailings’ porosities by 2.94%–9.94%. The mineral dissolution, expansion and shrinkage, and changes in tension destroyed the tailing microstructure during FDCs. This study demonstrated the low metal pollution risk of VTMTs under FDCs, either in acid rain or bio-secreted organic acids. However, the increase in tailing porosity should be seriously considered as it would affect the tailing pond safety.
研究领域:
环境科学
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地球化学
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产品关联
DOI
PubMed
高影响因子
CELLULOSE
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2023
·Vol. 30
·期 8
·5201-5215
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IF 5.7
Zhou Xiaoqian,Guo Dandan,Huang Shaohua,Zhao Yufen
Inspired by wet-cool/dry-hot cycle derived prebiotic reactions, a green and efficient dry–wet cycle modification method was proposed for the preparation of polypeptide-modified bamboo fiber (P-MBF). Functionalization of P-MBF was characterized by Fourier transform infrared spectroscopy, element analysis, X-ray photoelectron spectroscopy, X-ray diffraction, and scanning electron microscopy. Compared to raw bamboo fiber materials, P-MBF showed better dispersibility in aqueous solutions, and thus exhibited better adsorption performance for glycopeptide antibiotics in sewage treatment. With vancomycin as the target antibiotic, adsorption performance of P-MBF was studied in aqueous solution. The results showed that the adsorption reached equilibrium after 15 min, and adsorption kinetics and isotherms were well correlated with pseudo-second-order model (R 2 = 0.999) and Langmuir model (R 2 = 0.996), respectively. Investigation of thermodynamic parameters implied that the adsorption was a spontaneous exothermic process. The adsorption efficiencies in standard solution and drinking water were 97.83% and 91.32%, respectively. This study provides a green, efficient and economical modified bamboo fiber material for the removal of glycopeptide antibiotics from sewage samples. Graphical abstract
研究领域:
环境科学
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材料科学
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生物化学
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产品关联
DOI
高影响因子
CHEMOSPHERE
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2022
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IF 8.943
Cheng Peng,Kailin Gong,Qiannan Li,Weiyu Liang,Huihui Song,Fang Liu,Jie Yang,Wei Zhang
Magnesium-aluminum modified biochar (MABs) has an outstanding effect on the simultaneous immobilization of arsenic (As), lead (Pb), and cadmium (Cd) in soil, but the stability of remediation effect of MAB under various natural conditions is still unknown. In this study, we investigated the effects of organic acids, dry-wet cycles (DW), freeze-thaw cycles (FT), and rainfall (pH 4, 7, and 8) on the immobilization of As, Pb, and Cd by MAB. The results showed that oxalic acid decreased the immobilization efficiencies of As, Pb, and Cd by 15.5%–38.5%; meanwhile, humic acid reduced the immobilization efficiency of Pb by 89.7%, but elevated that of Cd by 19.5%. The immobilization mechanisms of MAB-5 on three metals were mainly involved in ion exchange and surface-complexation. Compared with the 7th round, the immobilization efficiencies of As, Pb, and Cd by MAB in the 28th round was decreased by 17%–28% in DW, but was increased by 11%–18% in FT. In addition, MAB was transformed into hydrotalcite after FT and DW. After experiencing simulated rainfall, MAB caused more As, Pb, and Cd to be retained in the upper soil layer, and the immobilization effect of MBA was more significant under the stimulated rainfall with higher pH. The study provides a more theoretical basis for the application of MAB in the actual site remediation.
研究领域:
环境科学
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土壤修复
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污染控制
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2025
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IF 5.1
Min Zhang,Dandan Guo,Yan Zhu,Shaohua Huang
Inspired by prebiotic reactions derived from wet-cool/dry-hot cycles, a green and efficient dry-wet cycling modification method was proposed for preparing peptide-modified polymer matrices, which are used as mixed-mode stationary phases for HPLC. Using polystyrene-divinylbenzene-glycidyl methacrylate (PS-GMA) as the matrices, alanine monomers were polymerized into peptide on the PS-GMA substrate surface through the dry-wet cycle reaction. By varying the number of dry-wet cycles, the length and density of peptides modified on PS-GMA were easily manipulated. The surface structures of the synthesized stationary phases were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, element analysis, Brunauer-Emmett-Teller test and liquid chromatography-mass spectrometry. Chromatographic separation results demonstrated that the stationary phase after six cycle reactions (PS-GMA-Ala-6C) exhibited the satisfactory selectivity for separating both hydrophilic and hydrophobic analytes. Using PS-GMA-Ala-6C column as the research object, the effects of chromatographic conditions on retention behavior were investigated. The retention mechanisms of the proposed mixed-mode chromatography were deeply analyzed through comparative studies with commercial reversed phase chromatography column, HILIC column and the unmodified PS-GMA column by Tanaka test. Finally, the proposed stationary phase was successfully applied to the qualitative and quantitative analysis of the dihydromyricetin in a real vine tea sample. This work not only presents a green and economically viable method for preparation but also achieves the controllable fabrication of the mixed-mode stationary phase, which is of great significance for the future development of chromatographic stationary phases.
研究领域:
分析化学
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生物化学
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产品关联
DOI
高影响因子
POWDER TECHNOLOGY
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2023
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IF 5.2
Gege Huang,Hongjie Lin,Jinze Li,Jiankun Liu
Hydrophobized soils (or so-called artificial hydrophobic soils) are a novel geomaterial with a great potential in engineering applications due to its low affinity to water. For saline soils, hydrophobizing such soils can mitigate the soil salinization and subsequent engineering disasters such as salt expansion and corrosion by chlorides. To induce soil hydrophobicity , hydrophobic agents are widely used such as organo-silanes, fatty acids, and waxes. Correspondingly, the engineering properties and durability of these hydrophobized soils have been comprehensively investigated. However, all these studies focused on the clean mineral soils, i.e. , the soils without salts and in a moderate pH. For saline soils, the feasibility, stability and durability of these hydrophobic agents are unclear. This paper aims to propose suitable and feasible hydrophobic agents in hydrophobizing saline soils, by investigating its hydrophobicity change and having an insight into the mechanisms. The saline soils used were collected from Qinghai, China, and were treated by five different hydrophobic agents at different concentrations, with the hydrophobicity quantified by water drop penetration time, surface tension and contact angle. The soil hydrophobicity change was recorded after the treatment and wetting-drying cycles, in order to assess its stability and durability. Fourier transform infrared spectroscopy (FTIR), Raman spectrum and N 2 adsorption experiment were carried out to study the mechanism of soil hydrophobicity formation and degradation. The results showed two agents, namely Sodium methyl siliconate and Polymethylhydrosiloxane, provided the greatest and most durable hydrophobicity in saline soils. Their different formation mechanisms at particle- and nano-scale were also discussed. A further assessment on the soil mechanical properties revealed that both compaction behavior and strength were negligibly influenced by these two agents.
研究领域:
土木工程
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土壤学
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环境工程
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材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）