摘要：
Biohazard performance of Sr radionuclide can be significantly magnified by its release from the contaminated sedimentation. In this study, hydroxyapatite nanoparticle-functionalized activated carbon electrode (AC-HAP) was synthesized and stacked to the cathode compartment of the electrokinetic (EK) system to develop a unipolar three-dimensional (3D) electrochemical process for Sr(2+) removal from spiked soils. Sr(2+) adsorption by AC-HAP can be fitted by the pseudo-first-order and pseudo-second-order kinetic models and the Langmuir, Freundlich, and Temkin isotherm models. The largest monolayer adsorption capacity of AC-HAP of 69.49mgg(-1) was evaluated in the pH range of 10-12 and at 40°C. 3D EK further intensified the adsorption process of AC-HAP and the corresponding Sr(2+) removal from aqueous environments. Voltage gradients and proposing time had a significant effect on the migration and transmission of Sr(2+) in the electrolyzer. The influence of competitive ions on Sr(2+) removal in the stock solutions followed Al(3+)<Mg(2+)<K(+)<Na(+)<Ca(2+) while followed Al(3+)<Na(+)<K(+)<Mg(2+)<Ca(2+) in 3D EK. The first three cycles for AC-HAP had taken roughly 50% of the reusability percentage. Sr(2+) removal from spiked samples in 3D EK was achieved by acid dissolution, electromigration, and selective uptake on particle electrode.
通讯机构：
[Song, Dongping] C;Changshu Inst Technol, Sch Chem & Mat Engn, 99,South 3rd Ring Rd, Changshu 215500, Jiangsu, Peoples R China.
关键词：
Green rust-coated expanded perlite;Microelectrode;Three-dimensional electrokinetics;Hexavalent chromium;Optimization;Breakthrough curve
摘要：
A green rust-coated expanded perlite (GR-coated Exp-p) microelectrode was synthesized and incorporated into a column-mode three-dimensional electrokinetic (3D-EK) platform to effectively pursue a continuous Cr(VI) removal from the aqueous solution. Brucite-like layers of GR were decorated onto the Exp-p material. The molar ratio of Fe(II) to Fe(III) played a most vital role among the three synthesis factors in influencing the performance of the particle electrode. For the equilibrium adsorption experiments, the target maximum adsorption capacity of 122mg/g was predicted by a target optimizer and desirability function at the conditions following the pH of 4.7, the initial concentration of 172.4mg/L, the dosage of 0.28g/L, and the temperature of 28.96°C, respectively. SO(4)(2-), Cl(-), and NO(3)(-) fiercely competed with Cr(VI) anions in the acidic conditions for the locally positive sites. A low concentration and a slow flow were favored in the column-mode 3D-EK platform. The pseudo-first-order and Langmuir models were suitable for describing the kinetics and isotherms of the adsorption process, respectively. Cr(VI) anions were electrostatically attracted to the silanol groups and GR surface of the adsorbent, subsequently reduced in both heterogeneity and homogeneity, and finally immobilized by coordinating with silanediol groups and silanetriol groups.
作者机构：
[Huang, Tao; Zhou, Lulu; Liu, Long-Fei] Changshu Inst Technol, Sch Mat Engn, Changshu 215500, Peoples R China.;[Huang, Tao] Changshu Inst Technol, Suzhou Key Lab Funct Ceram Mat, Changshu 215500, Peoples R China.;[Xie, Juan] Changshu Inst Technol, Sch Text Garment & Design, Changshu 215500, Peoples R China.;[Huang, Tao] China Univ Min & Technol, Sch Chem Engn & Technol, Xuzhou 221116, Peoples R China.;[Zhang, Shu-Wen] Univ South China, Nucl Resources Engn Coll, Hengyang 421001, Peoples R China.
通讯机构：
[Tao Huang; Juan Xie] S;School of Materials Engineering, Changshu Institute of Technology, Changshu 215500, China<&wdkj&>Suzhou Key Laboratory of Functional Ceramic Materials, Changshu Institute of Technology, Changshu 215500, China<&wdkj&>School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou 221116, China<&wdkj&>School of Textile, Garment, and Design, Changshu Institute of Technology, 215500, China
关键词：
Quadrivalent cerium;Laurylsulfonate green rust;Adsorption mechanism;Rare earth element;Synthesis optimization
摘要：
The layered laurylsulfonate intercalated green rust（lauryl-S GR） was synthesized to evaluate the influence of synthesis parameters and aqueous conditions on the adsorption of CeⅣ.The maximum adsorption capacity of 305.58 mg/g by lauryl-S GR was predictably obtained.The pseudo-first-order kinetic model was appropriate in fitting the whole uptake process in a weak acid environment.Three isotherm models including Langmuir, Freundlich, and Tempkin were all reliable in depicting the isotherm adsorption process.The maximum monolayer adsorption capacity of lauryl-S GR towards CeⅣ was 315.46 mg/g.Ce species including CeO and Ce2O3 besides CeO2 were matched in the XPS distribution, directly indicating the reduction reaction brought by FeⅡ in the GR occurred to hydrated CeⅣ ions during the adsorption.Nano-sized Ce particles attached to the lauryl-S GRs after the adsorption experiments were observed in the morphological characterization.Flocculated materials were formed on the surface of the lauryl-S GR at a pH of 7, which further reduced the active sites and disrupted the continuous uptake of CeⅣ to the lauryl-S GR.This study expands the application of GRs and supplies an ideal iron-based material for the construction of the affiliated recovery pathway to the traditional separation of Ce.
通讯机构：
[Ding, Dexin] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.
关键词：
Uranium;Removal;Photoreduction;Wastewater
摘要：
Efficient elimination of U(VI) from uranium wastewater is an urgent task for sustainable nuclear energy and environmental protection. In this study, magnetic graphene oxide decorated graphitic carbon nitride (mGO/g-C3N4) nanocomposite was prepared and used for photocatalytic reduction of U(VI) in wastewater under visible LED light irradiation for the first time. The batch experiments indicated that the mGO/g-C3N4 (mGCN) nanocomposite could efficiently reduce U(VI) under visible LED light, and a high U(VI) extraction capacity of 2880.6 mg/g was obtained with an extraction efficiency of 96.02%. The transmission electron microscopy (TEM) elemental mapping, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses demonstrated that the soluble U(VI) was immobilized by transforming it to metastudtite ((UO2)O-2 center dot 2H(2)O) by mGCN nanocomposite under visible LED light irradiation. This work indicated that the mGCN is a promising visible light catalyst for treatment of uranium wastewater. (C) 2020 Elsevier Ltd. All rights reserved.
摘要：
In this paper, the developmental toxicity and apoptosis in zebrafish (Danio rerio) embryos induced by 0.01, 0.05, and 0.10-Gy gamma-ray irradiation were investigated and verified by single cell gel electrophoresis, acridine orange staining, flow cytometry, transmission electron microscopy, digital gene expression sequencing, and Western blot analysis. DNA damage, deformity rates, and apoptosis of zebrafish embryos were found to increase significantly with the increase of irradiation dose, and survival and hatching rates significantly decreased when the irradiation dose exceeds 0.10 and 0.05 Gy, respectively. Exposure to 0.10-Gy gamma-ray irradiation resulted in the swelling of cell mitochondria of zebrafish embryos and changes in their intracellular vacuoles. mRNA and protein expression levels of Shh (sonic hedgehog 19 KDa) and Smo (smoothened 86 KDa) of Hh signaling pathway associated with the development of early embryos significantly increased with the increase of irradiation dose. Expression of the AKT (56 KDa) and PiK3r3 (55 KDa) genes, which are anti-apoptotic and involved with the PI3K/Akt signaling pathway, significantly decreased, while expression of the bada gene, which is pro-apoptotic, significantly increased. The results show that gamma-ray irradiations of 0.01 and 0.05 Gy can induce developmental toxicity and apoptosis in zebrafish embryos via Hh and PI3K/Akt signaling pathways, respectively.
摘要：
The mass production of municipal solid waste incineration (MSWI) fly ashes has caused severe concerns in regarding to the inherently ecological harm and the decreasing landfilling space. To relieve the heavy metal contamination into the environment and complete a closed-loop electrokinetics (EK), the sequential effects of electrokinetics and alkali activating solidification/stabilization (S/S) technique on the immobilization of HMs in the remnant of MSWI fly ashes were investigated in the research. The compressive strength for the remnant-based solidified product at the proposing time of 18 days was 2.58MPa, 104.76% higher than that of the MWSI-based specimen with the optimal curing parameters being adopted for the production of the solidified matrices. The leaching concentrations of Zn, Pb, and Cu were 9.74, 0.21, and 0.75mg/L, correspondingly reduced by 57.84%, 80.19%, and 17.58%, respectively. The opposite correlation between the compressive strength and the leaching concentration was demonstrated for both two groups of the curing samples. The mechanism results showed that the electrokinetics had significantly changed the micromorphology characteristics of MSWI fly ashes and distinctly affected the whole curing process. The cementation and geo-polymerization were comprehensively determined as two of main mechanisms for the immobilization of HMs in the curing matrices.
期刊：
Journal of Environmental Radioactivity,2019年208:106036 ISSN：0265-931X
通讯作者：
Ding, De-xin
作者机构：
[Chen, Si-yu; Dai, Zhong-ran; Zhang, Hui; Hu, Nan; Sha, Yin-hua; Ding, De-xin] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Henyang 421001, Peoples R China.;[Zou, Chao; Wang, Yong-dong] Univ South China, Hunan Prov Key Lab Green Dev Technol Exetremely L, Henyang 421001, Peoples R China.;[Ding, De-xin] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, 28 West Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Ding, De-xin] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, 28 West Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.
关键词：
Artificial plant community plot;Contaminated soil;Enhanced phytoremediation;Uranium
摘要：
In order to develop an artificially constructed plant community plot for the enhanced phytoremediation of uranium contaminated soils, three uranium accumulators including Bamboo-willow (Salix sp.), Paspalum scrobiculatum linn and Macleaya cordata were used to construct four artificial plant community plots, and greenhouse experiments were conducted to investigate the bioaccumulation of uranium by the plants and the organic acid content, enzyme activity, and the change of microbial community structure in their rhizosphere soils. The transfer factor (TF) and the total bioaccumulation amount (TBA) of uranium were used to describe remediation efficiencies in this paper. It was found that their remediation efficiencies were in the order Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn-Macleaya cordata > Bamboo-willow (Salix sp.)-Macleaya cordata > Paspalum scrobiculatum linn-Macleaya cordata > Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn. The bioaccumulation amount of uranium by each plant in the Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn-Macleaya cordata community plot was significantly (P < 0.05) higher than that by its single population, the bioaccumulation amounts of uranium by Bamboo-willow (Salix sp.), Paspalum scrobiculatum linn and Macleaya cordata were 0.29, 0.32 and 2.19 mg/plant, respectively, and they were increased by 31.82%, 77.78% and 146.07%, respectively, and the transfer efficiencies by the plants were increased by 150%, 110% and 52.17%, respectively. The interaction between the plants' roots and the microorganisms in the rhizosphere soil of the Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn-Macleaya cordata community plot resulted in the high content of organic acids such as oxalic acid in the rhizosphere soil of the plant community plot, which was significantly (P < 0.05) higher than that of its single population. The chelation of the organic acids with uranium led to an increase in the proportion of exchangeable uranium in soil solution. In addition, Burkholderia, which is an iron-producing carrier bacterium and can increase the uptake and accumulation of uranium by plants, and Leptolyngbya, which is a plant growth promoting rhizobacteria and can increase the biomass of plants, emerged in the rhizosphere soil of the plant community plot. These may be the mechanisms by which the phytoremediation of the uranium contaminated soils was enhanced by the plant community plot.
关键词：
Adsorption;Hexametaphosphate green rust;Hexavalent chromium removal;Intercalated anion;Layered double hydroxides
摘要：
Hexametaphosphate intercalated green rust (hexa-P GR) was fabricated by a coprecipitation process in an anaerobic environment to improve the adsorption of hexa-P GR for Cr(VI) and the total Cr under various aqueous conditions. Three kinetic models including the pseudo-first-order, intraparticle, and Elovich were appropriate in describing the adsorption of hexa-P GR towards Cr(VI) and the total Cr. The maximum mono-layer adsorption capacities (mg/g) of hexa-P GR for Cr(VI) at pH of 2 and 7 were 87.64 and 92.25, respectively, with the theoretical maximum capacity (mg/g) of 52.73 being obtained at pH of 7. Some competing cations existing in solutions such as Al(3+), Ca(2+), and Mg(2+) would consume more hexa-P GR to remove Cr species. The neutral and weak alkaline environment was conducive to the hexa-P GR reuse, while the strong alkaline environment was beneficial to the removal of the total Cr. The orthogonal variables including the initial pH, the flow rate, and the Cr(VI) concentration all significantly influenced Cr removal. The sequences of reaction pathways referring to the adsorption of hexa-P GR differently occurred in various pH conditions.
摘要：
A greenhouse pot experiment was performed to investigate the enhancement of repeated applications of citric acid (CA), ethylenediamine disuccinic acid (EDDS), and Oxalic acid (OA) on phytoremediation of uranium (U) contaminated soil by Macleaya Cordata. The chelates followed the order CA > EDDS > OA in terms of the enhancement on uranium uptake by M. cordata. The repeated applications of the chelates were found to be more effective than the one time application at the equal dose as the U concentration of soil solution increased significantly from the 8th to 14th day. The repeated applications of 10 mmol kg(-1) CA promoted the solubilization of U in the U-contaminated soil by significantly decreasing the pH of soil solution, achieved the maximum U concentration of soil solution (1463.6 microg L(-1)), bioconcentration factors (BCFs, 11.4), bioaccumulation factors (BAFs, 21.4) and transfer factors (TFs, 1.9), which were 215.2, 5.7, 30.6 and 16.3 times as compared with the control group, respectively. The three applied chelates significantly affected the activities of the antioxidant enzymes in the leaves. Repeated applications of CA further enhanced the activities of the antioxidant enzymes in the leaves of M. cordata as compared with the control, EDDS and OA, mitigated the oxidative stress induced by uranium and chelates, and maximized the enhancement on the uranium uptake, which will be beneficial for the enhancement on the phytoremediation of uranium contaminated soil by U hyperaccumulating plants. These results indicated that the phytoavailability of uranium in soil solution as well as the accumulation of U by M. cordata were both significantly increased after repeated applications of CA, and that the repeated applications of 10 mmol kg(-1) CA increased the activities of the antioxidant enzymes and promoted U accumulation by M. cordata. The study provided an environmentally friendly alternative for the enhancement on the phytoremediation of uranium contaminated soil using M. cordata.
作者机构：
[Li Feng; Zou Chao; Dai Zhong-ran; Ding De-xin; Li Guang-yue; Hu Nan; Wang Yong-dong; Cui Yue-ting; Sun Jing; Sha Yin-hua; Zhang Hui] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Heng Yang 421001, Hunan, Peoples R China.
通讯机构：
[Wang Yong-dong] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Heng Yang 421001, Hunan, Peoples R China.
作者机构：
[Xie, Shuibo; Gao, Xiang; Zeng, Taotao; Wang, Guohua; Zhang, Shiqi] Univ South China, Hunan Prov Key Lab Pollut Control & Resources Reu, Hengyang, Peoples R China.;[Zeng, Taotao; Lens, Piet N. L.] UNESCO, IHE Inst Water Educ, Delft, Netherlands.;[Xie, Shuibo] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang, Peoples R China.
通讯机构：
[Zeng, Taotao] U;Univ South China, Hunan Prov Key Lab Pollut Control & Resources Reu, Hengyang, Peoples R China.;UNESCO, IHE Inst Water Educ, Delft, Netherlands.
关键词：
Uranium;Anaerobic granular sludge;Bacterial community composition;High-throughput sequencing
作者：
Ye, Yong-jun*;Zhang, Yun-feng;Dai, Xin-tao;Ding, De-xin
期刊：
Journal of Environmental Radioactivity,2017年177:135-141 ISSN：0265-931X
通讯作者：
Ye, Yong-jun
作者机构：
[Ye, Yong-jun; Ding, De-xin] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.;[Dai, Xin-tao; Ye, Yong-jun; Zhang, Yun-feng] Univ South China, Sch Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Ye, Yong-jun] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.
关键词：
Free radon production rate;Granulated porous media;Permeability;Porosity;Radon diffusion coefficient
摘要：
The particle size and heaped methods of exhalation media have important effects on physical parameters, such as the free radon production rate, porosity, permeability, and radon diffusion coefficient. However, existing methods for determining those parameters are too complex, and time-consuming. In this study, a novel, systematic determining method was proposed based on nuclide decay, radon diffusion migration theory, and the mass conservation law, and an associated experimental device was designed and manufactured. The parameters of uranium ore heap and sandy soil of radon diffusion coefficient (D), free radon production rate (alpha), media permeability (k), and porosity (epsilon) were obtained. At the same time, the practicality of the novel determining method was improved over other methods, with the results showing that accuracy was within the acceptable range of experimental error. This novel method will be of significance for the study of radon migration and exhalation in granulated porous media. (C) 2017 Elsevier Ltd. All rights reserved.
摘要：
The biological effects of low-dose or low-dose-rate ionizing radiation on normal tissues has attracted attention. Based on previous research, we observed the morphology of liver tissues of C57BL/6J mice that received <50, 50-500, and 500-1000 muGy/h of 137Cs radiation for 180 d. We found that the pathological changes in liver tissues were more obvious as the irradiation dose rates increased. Additionally, differential protein expression in liver tissues was analyzed using a proteomics approach. Compared with the matched group in the 2D gel analysis of the irradiated groups, 69 proteins had >/= 1.5-fold changes in expression. Twenty-three proteins were selected based on >/=2.5-fold change in expression, and 22 of them were meaningful for bioinformatics and protein fingerprinting analysis. These molecules were relevant to cytoskeleton processes, cell metabolism, biological defense, mitochondrial damage, detoxification and tumorigenesis. The results from real-time PCR and western blot (WB) analyses showed that calreticulin (CRT) was up-regulated in the irradiated groups, which indicates that CRT may be relevant to stress reactions when mouse livers are exposed to low-dose irradiation and that low-dose-rate ionizing radiation may pose a cancer risk. The CRT protein can be a potential candidate for low-dose or low-dose-rate ionizing radiation early-warning biomarkers. However, the underlying mechanism requires further investigation.
摘要：
The endophyte Pseudomonas sp. XNN8 was separated from Typha orientalis which can secrete indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate deaminase and siderophores and has strong resistance to uranium it was then colonized in the Syngonium podophyllum; and the S. podophyllum-Pseudomonas sp. XNN8 symbiotic purification system (SPPSPS) for uranium-containing wastewater was constructed. Afterwards, the hydroponic experiments to remove uranium from uranium-containing wastewater by the SPPSPS were conducted. After 24 days of treatment, the uranium concentrations of the wastewater samples with uranium concentrations between 0.5 and 5.0 mg/L were lowered to below 0.05 mg/L. Furthermore, the uranium in the plants was assayed using Fourier transform infrared spectroscopy (FTIR) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The Pseudomonas sp. XNN8 was found to generate substantial organic groups in the roots of the Syngonium podophyllum, which could improve the complexing capability of S. podophyllum for uranium. The uranium in the roots of S. podophyllum was found to be the uranyl phosphate (47.4 %) and uranyl acetate (52.6 %).
