Environmental Science-Nano
·
2023
·Vol. 10
·期 9
·2500-2513
·
IF 7.3
Chao Xue,Xiaoyun Yi,Yuebei Yang,Feng Jiang,Hua Yin,Zhi Dang
It has been widely believed that the adsorption mechanism of cadmium on iron (oxyhydr)oxide is solely the inner-sphere complexation based on extended X-ray absorption fine structure spectroscopy (EXAFS). However, these results were obtained at specific experiment settings (high ionic strength and high cadmium surface loading). In natural cadmium-polluted soil and water environments, such as acidic mineral drainage (AMD) areas, the pH/ionic strength is relatively low. Therefore, under practical conditions, the bonding pathway of cadmium could be different and may comprise other potential mechanisms. This work focuses on the proportion of different cadmium sorption pathways on goethite by employing a chemical extraction procedure. Cadmium is mostly adsorbed on goethite via electrostatic adsorption and inner-sphere complexation in a pH range of 5.5–7.5 under 10 mM ionic strength conditions. Through quantitative calculation, it is confirmed that the amount of Mg(NO3)2-extracted cadmium can refer to the content of electrostatically adsorbed cadmium. Two types of surface hydroxyls contributed differently to inner-sphere complexed Cd(II) at different pH values, and the emergence of surface-induced precipitates at higher pH could also be included in the retention mechanism. The behavior of electrostatically adsorbed cadmium and inner-sphere complexed Cd(II) was found to be different at different pH values when sulfate was introduced. Based on zeta potential and total reflectance Fourier transform infrared spectral analyses, sulfate would modify the surface charge of goethite, but, moreover, sulfate might form pseudo ion-group species with cadmium, which could influence the sorption pathway of cadmium.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Bo Yang,Qi Chai,Xiumin Li,Xiao Du,Fengfeng Gao,Xiaogang Hao
A film electrode materials of iron-manganese oxide composite carbon nanotubes (FeMnO x /CNTs) with dual adsorption sites was obtained by a co-precipitation method, which exhibited excellent selectivity of WO 4 2- in an electrochemically switched ion exchange (ESIX) system. The main components of FeMnO x are MnO x and Fe(OH) 3 . In FeMnO x /CNTs composite film , Fe(OH) 3 with abundant hydroxyl functional groups on its surface improved the ion storage capacity, while MnO x served as the main selective separation material to selectively adsorb the WO 4 2- . A scalable ESIX pilot system was also designed to examine the effect of different operating conditions on system performance. The W(Ⅵ) adsorption capacity was as high as 187.76 mg/g and the separation factor of W/Mo was 21.03. Combining experimental characterization and results, it was confirmed that the highly efficient selective extraction of WO 4 2- in neutral solution should be derived from the dual-site (i.e., electrochemical coordination sites on MnO x and electrochemically induced inner-sphere complexation sites on Fe(OH) 3 ) adsorption. Hence, it is believed that such a novel electroactive FeMnO x /CNTs film electrode with dual adsorption sites could be a promising candidate for industrialized tungsten-molybdenum separation by ESIX technology.
研究领域:
材料科学
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环境工程
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2020
·
IF 4.605
Yaowu Cao,Qinghai Guo,Mengsi Liang,Weihao Sun
Antimony enrichment in aquatic environments is of great concern to international community. High-temperature geothermal waters usually contain excessive Sb, which are apt to contaminate the groundwaters or surface waters used as drinking waters in and around a hydrothermal area. However, Sb removal from geothermal water is rarely documented and the effect of high temperature on Sb removal has not received much attention. In this study, batch sorption experiments were conducted to investigate Sb removal from water by a hydroxyl-intercalated, mechanochemically synthesized Mg-Fe-LDH (i.e. Mg-Fe-OH-LDH) capable of avoiding secondary pollutions commonly related to other Mg-Fe-LDH intercalated by undesirable anions, such as Cl − and NO 3 − . The sorption capacities of Mg-Fe-OH-LDH for Sb(III) and Sb(V) were up to 48.7 and 30.0 mg/g, respectively. Notably, Mg-Fe-OH-LDH performed even better in removing aqueous Sb(V) at higher temperatures, superior to sorption of Sb by iron oxides that is generally exothermic and tends to be inhibited by increasing reaction temperature. The removal of Sb(V) existing as Sb(OH) 6 − by Mg-Fe-OH-LDH was attributable to its exchange with interlayer hydroxyl, and therefore could be impaired to some degree by coexisting anions with stronger electronegativity or smaller ionic radii . In contrast, anion exchange didn't contribute so much to Sb(III) sorption, because the main Sb(III) species at pH < 10 is neutral Sb(OH) 3 . XPS analyses confirmed that inner-sphere complexation between sorbed Sb(III) and Fe on Mg-Fe-OH-LDH layers was formed, which was hardly affected by competitive anions. Mg-Fe-OH-LDH is promising to be practically applied in removing both Sb(III) and Sb(V) from contaminated natural waters, wastewaters, or geothermal waters potentially acting as a pollution source .
研究领域:
环境科学
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水处理
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地球化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
PHYSIOLOGIA PLANTARUM
·
2024
·Vol. 176
·期 2
·e14314
·
IF 5.4
Gang Li,Zhenshuo Wang,Haiying Ren,Xingjiang Qi,Hao Han,Xiangyang Ding,Li Sun,Rahila Hafeez,Qi Wang,Bin Li
The ancient bayberry demonstrates superior resistance to both biotic and abiotic stresses compared to cultivated bayberry, yet the underlying mechanisms remain largely unexplored. This study investigates whether long-term bayberry cultivation enhances stress resistance through modulation of tissue-specific microbes and metabolites. Employing microbiome amplicon sequencing alongside untargeted mass spectrometry analysis, we scrutinize the role of endosphere and rhizosphere microbial communities and metabolites in shaping the differential resistance observed between ancient and cultivated bayberry trees. Our findings highlight the presence of core microbiome and metabolites across various bayberry tissues, suggesting that the heightened resistance of ancient bayberry may stem from alterations in rhizosphere and endosphere microbial communities and secondary metabolites. Specifically, enrichment of Bacillus in roots and stems, Pseudomonas in leaves, and Mortierella in rhizosphere soil of ancient bayberry was noted. Furthermore, correlation analysis underscores the significance of enriched microbial species in enhancing ancient bayberry's resistance to stresses, with elevated levels of resistance-associated metabolites such as beta-myrcene, benzothiazole, L-glutamic acid, and gamma-aminobutyric acid identified through GC–MS metabolomics analysis. The beneficial role of these resistance-associated metabolites was further elucidated through assessment of their promotive and allelopathic effects, as well as their phytostatic and antioxidant functions in lettuce plants. Ultimately, our study delves into the intrinsic reasons behind the greater resistance of ancient bayberry to biotic and abiotic stresses by evaluating the impact of long-term planting on the microbial community and metabolites in the bayberry endosphere and rhizosphere, shedding light on the complex dynamics of host-microbial interactions.
研究领域:
植物学
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微生物学
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代谢组学
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植物抗逆生理学
✓ 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）