摘要:
A microwave (MA) irradiation-persulfate-formate system was constructed to detoxify Cr contamination and solidify the geopolymerization of the alkali-activated composite material. Three series of experiments were correspondingly conducted to evaluate the treatment for the chromate-contaminated soil. The changes in the molar ratios of formate to persulfate and the mass rates of fortifier to soil led to a significantly greater reduction of CrVI in the detoxification experiments. The increase of blast furnace slag from 50% to 80% in the composite cementitious materials (CCM) intensified the immobilization efficiencies of chromate and the compressive strengths of geopolymer blocks. MA irradiation potentially enhanced the binding of Ca cations to the aluminosilicate compounds. The degree of reaction in the phenomenological kinetics model mathematically verified the geopolymerization process. Ettringite was formed within the structure of the geopolymer in the coupling system. Sulfate radicals released from persulfate not only contributed to the detoxification process but also strengthened the immobilization process.
期刊:
Desalination and Water Treatment,2021年215:147-159 ISSN:1944-3994
通讯作者:
Huang, T.
作者机构:
[Liu, Longfei; Huang, Tao] Changshu Inst Technol, Sch Chem & Mat Engn, 99 South 3rd Ring Rd, Changshu 215500, Peoples R China.;[Huang, Tao] Changshu Inst Technol, Suzhou Key Lab Funct Ceram Mat, Changshu 215500, Peoples R China.;[Huang, Tao] China Univ Min & Technol, Sch Chem & Technol, Xuzhou 221116, Jiangsu, Peoples R China.;[Zhang, Shuwen] Univ South China, Nucl Resources Engn Coll, Hengyang 421001, Peoples R China.
通讯机构:
[Huang, T.] S;School of Chemical and Technology, China;Suzhou Key Laboratory of Functional Ceramic Materials, China;School of Chemistry and Materials Engineering, No. 99, South 3rd Ring Road, China
作者机构:
[Huang, Tao; Liu, Long-fei; Zhou, Lulu] Changshu Inst Technol, Sch Mat Engn, Changshu 215500, Jiangsu, Peoples R China.;[Huang, Tao] Changshu Inst Technol, Suzhou Key Lab Funct Ceram Mat, Changshu 215500, Jiangsu, Peoples R China.;[Huang, Tao] China Univ Min & Technol, Sch Chem Engn & Technol, Xuzhou 221116, Jiangsu, Peoples R China.;[Zhang, Shu-wen] Univ South China, Nucl Resources Engn Coll, Hengyang 421001, Peoples R China.
通讯机构:
[Huang, Tao] C;Changshu Inst Technol, Sch Mat Engn, Changshu 215500, Jiangsu, Peoples R China.
关键词:
Green rust;Functionalized composite cementitious material;Geopolymer;Chromate;Granulated blast furnace slag;Fly ash
摘要:
Green rust functionalized geopolymer of composite cementitious materials (GR-CCM) was synthesized to improve the adsorption and subsequent stabilization/solidification of chromate in a holistic operating system. The initial pH in solution exhibited the most significant effect on the chromate removal by GR-CCM among three adsorption factors. The maximum monolayer adsorption capacity and theoretical saturation capacity of GR-CCM for Cr(VI) in the acidic condition were 55.01 mg/g and 41.70 mg/g, respectively. Amorphousness brought by loading GR weakened the crystallinity of composite cementitious materials (CCM), which enhanced the adsorption capacity of CCM and boosted the solidification process. The mixed-valent iron species in the GR-CCM not only directly engaged in the adsorption and reduction of chromate also positively strengthened the solidification of Cr species during the whole treatment. This study facilitates the application of GRs on the geopolymer materials and demonstrates the combination of adsorption and immobilization for the treatment of other potential heavy metal contamination. (C) 2020 Elsevier Ltd. All rights reserved.
期刊:
Separation and Purification Technology,2021年265:118531- ISSN:1383-5866
作者机构:
[Zhang, Shu-wen; Huang, Tao; Zhou, Lulu; Liu, Long-fei] Changshu Inst Technol, Sch Mat Engn, Changshu 215500, Jiangsu, Peoples R China.;[Huang, Tao] Changshu Inst Technol, Suzhou Key Lab Funct Ceram Mat, Changshu 215500, Jiangsu, Peoples R China.;[Huang, Tao] China Univ Min & Technol, Sch Chem Engn & Technol, Xuzhou 221116, Jiangsu, Peoples R China.;[Zhang, Shu-wen] Univ South China, Nucl Resources Engn Coll, Hengyang 421001, Peoples R China.
关键词:
Electrokinetics;Adsorption;Activated carbon-supported hydroxycarbonate green rust;Removal;Sr cations
摘要:
Activated carbon-supported hydroxycarbonate green rust (GR-AC) was prepared, characterized, and used to remove Sr2+ ions from stock solutions. The electrokinetics coupling with the adsorption was further designed to enhance the uptake of Sr2+ ions in the fixed-bed column. The adsorption capacities (mg/g) of GR-AC experienced a U-shaped change over the pH of 2?13 for each concentration of Sr2+. The equilibrium adsorption capacities for the adsorbent in the initial concentrations of Sr2+ of 50, 100, 150, 200, and 250 mg/g were 48.36, 67.42, 73.25, 81.59, and 84.47, respectively. The pseudo-first-order and Elovich kinetic models were appropriate for modeling the adsorption of Sr2+ onto the GR-AC in the static equilibrium-adsorption experiments in terms of the whole pH range, while the intraparticle model was only suitable for the modeling in the alkaline aqueous environment. For the column-mode experiments, the changes in the voltage gradients, flow rates, and initial pH all had a significant effect on the removal of Sr2+ cations. A maximum breakthrough volume of 26.52 L was obtained in the orthogonal design. The correspondingly optimal combination of parameters determined for the column-mode experiments included the voltage gradient of 1.0 V/cm, the initial pH of 10, and a relatively slow flow rate of 5?15 mL/min. The application of EK enhanced the removal kinetics of Sr2+ from the stock solutions while had not significantly affected the interactions between Sr2+ and GR-AC. The specific reaction pathways determined for the Sr2+ removal was different with different pH ranges. The research provides an efficient method for removing radioactive Sr from wastewater in the future.
作者机构:
[Liu, Yuelin] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[Liu, Yuelin] Hunan Univ Technol, Sch Civil Engn, Zhuzhou 412007, Peoples R China.;[Wu, Shanshan; Xie, Shuibo; Liu, Yingjiu] Univ South China, Hunan Prov Key Lab Pollut Control & Resources Reu, Hengyang 421001, Peoples R China.;[Liu, Jun] Hunan Univ Technol, Sch Life Sci & Chem, Hunan Key Lab Biomed Nanomat & Devices, Zhuzhou 412007, Peoples R China.;[Xie, Shuibo] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
通讯机构:
[Xie, Shuibo] U;Univ South China, Hunan Prov Key Lab Pollut Control & Resources Reu, Hengyang 421001, Peoples R China.;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
摘要:
Photocatalytic technology is a valid solution for the remediation of wastewater containing uranium. In this study, the synthesis of Z-scheme g-C3N4/TiO2 catalysts was made by a thermal synthetic approach for photocatalytic U(VI) reduction. The characterization results revealed the successful synthesis of g-C3N4/TiO2 nanostructures. The g-C3N4 surface was uniformly coated with TiO2 nanoparticles. The depletion of U(VI) in water evaluated the photocatalytic activity of g-C3N4/TiO2 under UV light irradiation. The photocatalytic tests showed that g-C3N4/TiO2 exhibited more effective photocatalytic activity than the raw materials (1.64 and 56.97 times higher than TiO2(P25) and g-C3N4, respectively). Besides, a pseudo-first-order model was followed by the experimental kinetic data for the photocatalytic process. Moreover, g-C3N4/TiO2 still presented high photocatalytic activity after four reacting cycles. Based on these experiment results, the improved photocatalytic activity could be attributed to the Z-scheme mechanism, which decreased the recombination of photo-produced electrons and holes. The synthesis of these g-C3N4/TiO2 nanomaterials provides a facile and inexpensive method for treating wastewater containing U(VI).
通讯机构:
[Long, Ding-Xin] U;Univ South China, Sch Publ Hlth, Hengyang 421001, Peoples R China.
摘要:
The biological effects and regulatory mechanisms of low-dose and low-dose-rate radiation are still rather controversial. Therefore, in this study we investigated the effects of low-dose-rate radiation on zebrafish neurodevelopment and the role of miRNAs in radiation-induced neurodevelopment. Zebrafish embryos received prolonged gamma-ray irradiation (0 mGy/h, 0.1 mGy/h, 0.2 mGy/h, 0.4 mGy/h) during development. Neurodevelopmental indicators included mortality, malformation rate, swimming speed, as well as the morphology changes of the lateral line system and brain tissue. Additionally, spatiotemporal expression of development-related miRNAs (dre-miR-196a-5p, dre-miR-210-3p, dre-miR-338) and miRNA processing enzymes genes (Dicer and Drosha) were assessed by qRT-PCR and whole mount in situ hybridization (WISH). The results revealed a decline in mortality, malformation and swimming speed, with normal histological and morphological appearance, in zebrafish that received 0.1 mGy/h; however, increased mortality, malformation and swimming speed were observed, with pathological changes, in zebrafish that received 0.2 mGy/h and 0.4 mGy/h. The expression of miRNA processing enzyme genes was altered after irradiation, and miRNAs expression was downregulated in the 0.1 mGy/h group, and upregulated in the 0.2 mGy/h and 0.4 mGy/h groups. Furthermore, ectopic expression of dre-miR-210-3p, Dicer and Drosha was also observed in the 0.4 mGy/h group. In conclusion, the effect of low-dose and low-dose-rate radiation on neurodevelopment follows the threshold model, under the regulation of miRNAs, excitatory effects occurred at a dose rate of 0.1 mGy/h and toxic effects occurred at a dose rate of 0.2 mGy/h and 0.4 mGy/h. (C) 2021 by Radiation Research Society
摘要:
The relationship between energy input and particle size of ore samples after crushing and effect of microwave pretreatment on impact crushing of lead-zinc ore were studied by drop weight impact test. The results showed that the lead-zinc ore became softer and had higher degree of crushing after microwave pretreatment. Compared with continuous microwave pretreatment, pulsed microwave pretreatment could improve the drop weight impact crushing efficiency of lead-zinc ore. When the specific comminution energy were 5 kW h/t, 10 kW h/t respectively, the crushing characteristic parameters <i>t<i/><sub>10<sub/> were 60.42% and 67.46% respectively by continuous microwave. But the values of <i>t<i/><sub>10<sub/> were increased to 68.64% and 75.88% respectively after pulsed microwave radiation under same microwave power and time. In addition, water quenching could more promote the impact crushing efficiency of lead-zinc ore after microwave irradiation.
摘要:
A chelating agent in an adequate dose used to enhance phytoremediation of radionuclide-contaminated soil should not inhibit the growth of the plant. If this constraint condition is satisfied, the total bioaccumulation amount (TBA) of radionuclide by the plant can be maximized. This is a constrained optimization problem to determine the adequate dose of the chelating agent for phytoremediation of radionuclide-contaminated soil. In this research, an adequate dose of a chelating agent for phytoremediation of radionuclide-contaminated soil was determined by a novel approach using pot experiments. The proposed approach was applied to specify the adequate doses of citric acid (CA) and S,S-ethylenediamine disuccinic acid (EDDS) for phytoremediation of uranium contaminated soil by M. Cordata. By using this method, the adequate doses of CA and EDDS for phytoremediation of (238)U, (232)Th and (226)Ra contaminated soils by M. cordata were measures as 10.0 and 5.0mmolkg(-1), respectively. The results showed that the approach could be used to establish the adequate dose of a chelating agent for phytoremediation of radionuclide or other toxic heavy metal contaminated soil by a plant.
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.
作者机构:
[Yi Haitao; Li Feng; Wang Yongdong; Zhang Yue; Li Guangyue; Ding Dexin; Hu Nan; Dai Zhongran; Sun Jing; Zhang Hui; Ma Jianhong; Zhai Kaige] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Heng Yang 421001, Hunan, Peoples R China.
通讯机构:
[Yongdong, W.] K;Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, China
期刊:
Environmental Science and Pollution Research,2021年28(26):34824-34837 ISSN:0944-1344
通讯作者:
Huang, Tao;Jin, Jun-Xun;Yang, Chun-Hai
作者机构:
[Fan, Xin-Chuan; Jin, Jun-Xun; Cao, Zhen-Xing; Huang, Tao; Liu, Long-Fei; Yang, Chun-Hai] Changshu Inst Technol, Sch Mat Engn, Changshu 215500, Jiangsu, Peoples R China.;[Cao, Zhen-Xing; Huang, Tao; Liu, Long-Fei; Yang, Chun-Hai] Changshu Inst Technol, Suzhou Key Lab Funct Ceram Mat, Changshu 215500, Jiangsu, Peoples R China.;[Fan, Xin-Chuan; Huang, Tao] China Univ Min & Technol, Sch Chem Engn & Technol, Xuzhou 221116, Jiangsu, Peoples R China.;[Jin, Jun-Xun] Changshu Co Ltd, East China Sci & Technol Res Inst, Suzhou 215500, Peoples R China.;[Jin, Jun-Xun] Zhejiang Gongshang Univ, Sch Environm Sci & Engn, Hangzhou 310012, Zhejiang, Peoples R China.
通讯机构:
[Yang, Chun-Hai; Huang, Tao; Jin, Jun-Xun] S;School of Materials Engineering, Changshu Institute of Technology, Changshu, 215500, China.;Suzhou Key Laboratory of Functional Ceramic Materials, Changshu Institute of Technology, Changshu, 215500, China.;School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China.;The East China Science and Technology Research Institute of Changshu Co., Ltd, Suzhou, 215500, China.
通讯机构:
[Guohua Wang] H;Hunan Provincial Key Laboratory of Pollution Control and Resources Technology, University of South China, Hengyang, People’s Republic of China<&wdkj&>Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, People’s Republic of China
摘要:
The adsorption performance and mechanism of the amino-modified zirconium-based metal organic framework (UiO-66-NH2) for the removal of U(VI) in aqueous solution were studied. Compared with UiO-66, UiO-66-NH2 shows better adsorption performance due to the introduction of amino groups. The adsorption characteristics of factors such as pH, UiO-66-NH2 dosage and contact time were investigated. The results show that the maximum adsorption capacity is 384.6mgg−1 at pH = 6 and T = 313K. The adsorption conforms to the quasi-second-order kinetic model and the Langmuir isotherm model. The thermodynamic parameters indicate that the adsorption process of U(VI) is endothermic and spontaneous. After five cycles, the removal rate of U(VI) still exceeded 83.53%. The results indicate that UiO-66-NH2 is a promising adsorbent that can effectively remove U(VI) in radioactive wastewater.
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.
摘要:
Protection against low-dose ionizing radiation is of great significance. Uranium tailings are formed as a byproduct of uranium mining and a potential risk to organisms. In this study, we identified potential biomarkers associated with exposure to low-dose radiation from uranium tailings. We established a Wistar rat model of low dose rate irradiation by intratracheal instillation of a uranium tailing suspension. We observed pathological changes in the liver, lung, and kidney tissues of the rats. Using isobaric tags for relative and absolute quantification, we screened 17 common differentially expressed proteins in three dose groups. We chose alpha-1 antiproteinase (Serpina1), keratin 17 (Krt17), and aldehyde dehydrogenase (Aldh3a1) for further investigation. Our data showed that expression of Serpina1, Krt17, and Aldh3a1 had changed after the intratracheal instillation in rats, which may be potential biomarkers for uranium tailing low-dose irradiation. However, the underlying mechanisms require further investigation.
摘要:
Sewage sludge-derived biochar (SSB) was prepared at 600 degrees C pyrolysis temperature and modified by co-precipitation with Fe3O4 to obtain Fe3O4@SSB. The adsorption process of U(VI) onto the Fe3O4@SSB was accurately described by the pseudo-second order and Langmuir isotherm model. The maximum removal capacity of U(VI) was 149.15 mg/g at 303 K and initial pH of 4.0 by Langmuir isotherm model analysis. The removal mechanisms included complexation, ion exchange, reduction and electrostatic attraction. The U(VI) removal efficiency by Fe3O4@SSB remained above 90% after five adsorption-desorption. This work provided a reference for sewage sludge resource utilization and biochar modification for uranium-containing wastewater treatment.
摘要:
Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.