摘要：
This paper presents a theoretical solution for bond-slip behavior of SRC interface based on experiment, numerical simulation, and theoretical derivation. Push-out tests of five specimens were firstly carried out, based on which, the simplified bond-slip model was proposed. The specimen was fabricated using the Q345H-shape steel (400 mm x 200 mmx13 mm x 8 mm) and C50 concrete (350 mm x 600 mm) with a bonding length of 500 mm. A FE model was established based on the bond-slip model to analyze the nonlinear bonding stress that are difficult to obtain from the experiment. The research shows that although the bonding stress in the elastic stage is not uniformly distributed, it is basically uniformly distributed when the ultimate bearing capacity is reached. It proves that assuming the average interfacial bonding stress under ultimate load to replace the maximum bonding stress is reasonable, which is crucial for designer to estimate interface bearing capacity and maximum bonding stress. Moreover, five different stages were obtained by the FE model analysis and the theoretical equations of bonding stress nonlinear distribution were obtained based on the boundary condition of each stage. The theoretical solution clearly showed the relationship between interface nonlinear stress distribution and influencing parameters including the bond area, elasticity modulus of material, section area of specimen, bond-slip constitutive model, and the external load. Based on the theoretical model, the influences of different parameters can be directly obtained without conducting further experiments and establishing different FE models.
期刊：
Separation and Purification Technology,2024年335:126214 ISSN：1383-5866
通讯作者：
Xie, D
作者机构：
[Li, Suzhe; Tang, Zengming; Yang, Xiaomin] Univ South China, Sch Resource & Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Xie, D; Xie, Dong; Li, Suzhe; Tang, Zengming; Yang, Xiaomin] Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, Peoples R China.;[Xie, D; Xie, Dong] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Xie, D ] N;Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, Peoples R China.;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
摘要：
Finding an inexpensive and efficient porous adsorbent to capture the gaseous radioiodine generated during spent fuel reprocessing has been challenging. Herein, we present a design philosophy for waste control to develop porous carbon for gaseous iodine capture from sewage sludge waste. Among them, the novel in situ etching of polytetrafluoroethylene was employed to improve pore accessibility. The hazards of the conventional preparation of sludge-derived carbon using highly corrosive NaOH and HF solutions were overcome. Polytetrafluoro-ethylene etched porous carbon with large specific surface area (1103 m2/g), interconnected hierarchical porous structure, and excellent hydrophobicity (water contact angle 126.52 degrees), providing efficient adsorption of gaseous iodine in hot (30-150 degrees C) and humid (50-96% relative humidity [RH]) environments. The iodine adsorption of hierarchical porous carbon was tested under static and dynamic conditions, and high records have been achieved. Notably, due to the structural advantage of hydrophobicity, a considerable dynamic adsorption capacity (1746.77 mg/g) was also maintained in a mixed iodine gas stream containing water vapor in a humid (50% RH) hot (75 degrees C) condition. This study is the first to use an in situ etching strategy for polytetrafluoroethylene, which opens a new avenue for converting sludge waste into low-cost porous carbon and provides an attractive option for capturing iodine in hot and humid environments.
作者：
Yang Yang*;Jun Zeng;Boyu Yang;Linmao Yin;Tianyou He
期刊：
International Journal of Refrigeration,2024年160:390-401 ISSN：0140-7007
通讯作者：
Yang Yang
作者机构：
[Tianyou He] School of Civil Engineering, University of South China, Hengyang 421001 Hunan, China;Key Lab of Hunan for the Technologies of Energy Conservation in Prefabricated Buildings, Hengyang 421001, Hunan, China;[Yang Yang; Jun Zeng; Boyu Yang; Linmao Yin] School of Civil Engineering, University of South China, Hengyang 421001 Hunan, China<&wdkj&>Key Lab of Hunan for the Technologies of Energy Conservation in Prefabricated Buildings, Hengyang 421001, Hunan, China
通讯机构：
[Yang Yang] S;School of Civil Engineering, University of South China, Hengyang 421001 Hunan, China<&wdkj&>Key Lab of Hunan for the Technologies of Energy Conservation in Prefabricated Buildings, Hengyang 421001, Hunan, China
摘要：
The mechanical vapor compression system (MVC) coupled with the evaporative-cooling condenser is an effective method to improve its high temperature adaptability. However, this hybrid systems typically use an evaporative cooler as a single-stage pre-cooling unit of condenser and is mainly designed for hot–dry climates. In this paper, based on conventional evaporative-cooling condenser configuration, three two-stage evaporative-cooling condenser systems (MVC-TSEC(A), MVC-TSEC(B) and MVC-TSEC(C)) were proposed. The MVC-TSEC(A) consists of one condenser and an indirect/direct evaporative-cooler. The MVC-TSEC(B) and MVC-TSEC(C) have two condensers (in series), which are coupled with a two-stage evaporative cooling system. The refrigerant in the MVC-TSEC(C) forms a counter-flow configuration with the outdoor air, while it is concurrent flow in MVC-TSEC(B). Subsequently, the effects of the ambient parameters and outdoor air flowrate on the three two-stage hybrid systems were analyzed comparatively based on detailed numerical models. Finally, the application potential of these hybrid systems was evaluated comprehensively in hot–humid climates. The results showed that the seasonal COP and energy-saving rate for the MVC-TSEC(C) are reached by 4.2–4.7 and 12.7–21.1 %, respectively. Moreover, the static equipment payback period of the three two-stage hybrid systems are 3.8, 3.3 and 3.0 years, respectively.
期刊：
Theoretical and Applied Climatology,2024年155(1):117-129 ISSN：0177-798X
通讯作者：
Wang, HQ
作者机构：
[Wang, HQ; Liu, Xinyu; Wang, Hanqing; Zhu, Dongnan; Liu, Zhenming; He, Junyi] Univ South China, Sch Civil Engn, Hengyang, Peoples R China.;[Wang, HQ; Liu, Xinyu; Wang, Hanqing; Zhu, Dongnan; Liu, Zhenming; He, Junyi] Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang, Peoples R China.;[Wang, HQ; Wang, Hanqing] Cent South Univ Forestry & Technol, Sch Civil Engn, Changsha, Peoples R China.
通讯机构：
[Wang, HQ ] U;Univ South China, Sch Civil Engn, Hengyang, Peoples R China.;Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang, Peoples R China.;Cent South Univ Forestry & Technol, Sch Civil Engn, Changsha, Peoples R China.
关键词：
WRF;Deep learning;Downscaling
摘要：
The Weather Research and Forecasting (WRF) model improves the accuracy of climate prediction and obtains meteorological parameters for fine grids; however, fine-grid climate predictions for different time periods and regions often consumes a great amount of computational resources. In this letter, the Multi Residual Attention Generative Adversarial Network (MRA-GAN) is proposed based on the generative adversarial network; the technique is applied to restore a simulated image from a coarse-grid WRF model to a simulated image from a fine-grid WRF model. The fine-grid image generated by MRA-GAN is very similar to the original fine-grid image. When compared with Super-Resolution Wasserstein Generative Adversarial Network with Gradient Penalty (SRWGAN-GP), the average of peak signal-to-noise was improved by approximately 0.54dB, and the average structural similarity index was improved by approximately 3%. After comparing the downscaling results of temperature, wind speed, and relative humidity of various models with the original data, the results show that MRA-GAN has the highest correlation, the lowest data dispersion, and the smallest data error. The trained network model was able to efficiently transform the coarse-grid meteorological fields from different time periods and different simulation variables into fine-grid meteorological fields, and it greatly reduced the computational workload.
摘要：
Mining can provide abundant resources, but it also causes heavy metal wastewater pollution, which poses a serious threat to aquatic ecosystems. In this study, Cypridopsis vidua was used as the test organism to investigate the single and combined acute toxicity of common heavy metals (such as chromium (Cr) and nickel (Ni)) in mining wastewater. Then, a random forest model (RF model) was used to predict the combined toxicity of chromium and nickel. Single acute toxicity experiments showed that the 96 h-LC(50 )values of the Cr and Ni for Cypridopsis vidua were 0.81 mg/L and 4.3 mg/L, respectively. aCr was more toxic than Ni. Furthermore, the combined acute toxicity experiments demonstrated that the toxicity of Cr-Ni was higher than Ni but lower than Cr. The predicted results of the RF model were highly consistent with the experimental results of the Cr-Ni combined acute toxicity. So, the model has accurate toxicity prediction ability.
期刊：
Science of The Total Environment,2024年917:170369 ISSN：0048-9697
通讯作者：
Yuanyuan Gao<&wdkj&>Yayi Wang
作者机构：
[Zhou, Shuai; Huang, Zefeng; Yang, Fengjuan] Hunan Province Key Laboratory of Pollution Control and Resources Reuse Technology, School of Civil Engineering, University of South China, Hengyang 421001, China;[Zhou, Shuai] Hunan Province Key Laboratory of Rare Metal Minerals Exploitation and Geological Disposal of Wastes, School of Resources Environment and Safety Engineering, University of South China, Hengyang 421001, China;[Wang, Weigang] State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, China;[Yang, Zhengqing] College of Environmental Science and Engineering, Hunan University, Changsha 410082, China;[Jiang, Tianyun; Song, Jian] Hunan Province Key Laboratory of Rare Metal Minerals Exploitation and Geological Disposal of Wastes, School of Resources Environment and Safety Engineering, University of South China, Hengyang 421001, China
通讯机构：
[Yuanyuan Gao] H;[Yayi Wang] S;Hunan Province Key Laboratory of Rare Metal Minerals Exploitation and Geological Disposal of Wastes, School of Resources Environment and Safety Engineering, University of South China, Hengyang 421001, China<&wdkj&>State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, China
摘要：
The emergence of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) in the environment is well established as a human health crisis. The impact of radioactive heavy metals on ecosystems and ultimately on human health has become a global issue, especially for the regions suffering various nuclear activities or accidents. However, whether the radionuclides can affect the fate of antibiotic resistance in bacteria remains poorly understood. Here, the dynamics of ARB, three forms of ARGs-intracellular ARGs (iARGs), adsorbed extracellular ARGs (aeARGs), and free extracellular ARGs (feARGs)-and microbial communities were investigated following exposure to uranium (U), a representative radioactive heavy metal. The results showed that 90-d of U exposure at environmentally relevant concentrations of 0.05mg/L or 5mg/L significantly increased the ARB concentration in activated sludge (p<0.05). Furthermore, 90-d of U exposure slightly elevated the absolute abundance of aeARGs (except tetO) and sulfonamide iARGs, but decreased tetracycline iARGs. Regarding feARGs, the abundance of tetC, tetO, and sul1 decreased after 90-d of U stress, whereas sul2 showed the opposite trend. Partial least-squares path model analysis revealed that the abundance of aeARGs and iARGs under U stress was predominantly driven by increased cell membrane permeability/intI1 abundance and cell membrane permeability/reactive oxygen species concentration, respectively. Conversely, the changes in feARGs abundance depended on the composition of the microbial community and the expression of efflux pumps. Our findings shed light on the variations of ARGs and ARB in activated sludge under U exposure, providing a more comprehensive understanding of antibiotic resistance risks aggravated by radioactive heavy metal-containing wastewater.
摘要：
To investigate the strengthening effects and mechanisms of bioaugmentation on the microbial remediation of uranium-contaminated groundwater via bioreduction coupled to biomineralization, two exogenous microbial consortia with reducing and phosphate-solubilizing functions were screened and added to uranium-contaminated groundwater as the experimental groups (group B, reducing consortium added; group C, phosphate-solubilizing consortium added). β-glycerophosphate (GP) was selected to stimulate the microbial community as the sole electron donor and phosphorus source. The results showed that bioaugmentation accelerated the consumption of GP and the proliferation of key functional microbes in groups B and C. In group B, Dysgonomonas, Clostridium_sensu_stricto_11 and Clostridium_sensu_stricto_13 were the main reducing bacteria, and Paenibacillus was the main phosphate-solubilizing bacteria. In group C, the microorganisms that solubilized phosphate were mainly unclassified_f_Enterobacteriaceae. Additionally, bioaugmentation promoted the formation of unattached precipitates and alleviated the inhibitory effect of cell surface precipitation on microbial metabolism. As a result, the formation rate of U-phosphate precipitates and the removal rates of aqueous U(VI) in both groups B and C were elevated significantly after bioaugmentation. The U(VI) removal rate was poor in the control group (group A, with only an indigenous consortium). Propionispora, Sporomusa and Clostridium_sensu_stricto_11 may have played an important role in the removal of uranium in group A. Furthermore, the addition of a reducing consortium promoted the reduction of U(VI) to U(IV), and immobilized uranium existed in the form of U(IV)-phosphate and U(VI)-phosphate precipitates in group B. In contrast, U was present mainly as U(VI)-phosphate precipitates in groups A and C. Overall, bioaugmentation with an exogenous consortium resulted in the rapid removal of uranium from groundwater and the formation of U-phosphate minerals and served as an effective strategy for improving the treatment of uranium-contaminated groundwater in situ.
期刊：
Applied Radiation and Isotopes,2024年205:111145 ISSN：0969-8043
通讯作者：
Xie, SB
作者机构：
[Xie, Shuibo; Mai, Yingqing; Wang, Guohua; Zhang, Haibo] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.;[Xie, Shuibo] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.;[Wang, Shuiyun] Nonferrous Met Design & Res Inst, Changsha 410000, Peoples R China.;[Xie, Shuibo] Univ South China, 28 Changshen Rd, Zhengxiang Dist, Hengyang 421001, Peoples R China.
通讯机构：
[Xie, SB ] U;Univ South China, 28 Changshen Rd, Zhengxiang Dist, Hengyang 421001, Peoples R China.
关键词：
Acid wastewater;Adsorption;PT-CS;U(VI)
摘要：
With sodium tripolyphosphate (STPP) as cross-linker, Persimmon tannin-chitosan microspheres (PT-CS) were synthesized by hydrothermal for removing U(VI) from acidic effluent. The batch experiments indicated that PT-CS adsorbed U(VI) most effectively at pH 1.5, the maximum adsorption capacity for PT-CS was 245mg/g. Compared to pure CS dissolved at pH 3, PT-CS still maintain high stability at pH 1. Moreover, single system of common metal ions in rare earth wastewater only slightly affected the adsorption of uranium at pH 1.5, but this process was inhibited about 30% at pH 5. Those results indicated that the selectivity of PT-CS for uranium removal could be controlled by regulating the pH and there are excellent potentials for PT-CS using in acid metal water treatment. Its adsorption selectivity and ability to adapt different condition was demonstrated with uraniferous rare earth wastewater treatment. The adsorption for PT-CS to U(VI) were well fitted for both Langmuir isothern and pseudo-secondary kinetic model equations, and that meant chemisorption dominated the removal process. Spectroscopic analyses confirmed that the adsorption of U(VI) occurred via surface complexation by -OH and ion exchange with Na(+). Therefore, this study provides a high-efficiency, low-cost, valuable and highly adaptable method for the treatment of acidic uranium-containing effluents.
作者：
Bo Pang;Gaixia Miao;Minghui Wang;Yunsheng Zhang;Aoxiang Zhou;...
期刊：
Buildings,2024年14(3):848- ISSN：2075-5309
通讯作者：
Bo Pang<&wdkj&>Yunsheng Zhang
作者机构：
[Gaixia Miao; Aoxiang Zhou; Yan’e Yang] School of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050, China;[Minghui Wang] School of Civil Engineering, University of South China, Hengyang 421001, China;Authors to whom correspondence should be addressed.;School of Civil Engineering, Qingdao University of Technology, Qingdao 266525, China;[Bo Pang] Authors to whom correspondence should be addressed.<&wdkj&>School of Civil Engineering, Qingdao University of Technology, Qingdao 266525, China
通讯机构：
[Bo Pang; Yunsheng Zhang] A;Authors to whom correspondence should be addressed.<&wdkj&>School of Civil Engineering, Qingdao University of Technology, Qingdao 266525, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>School of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050, China
摘要：
The properties of a large number of concrete infrastructures in China are deteriorating year by year, raising the need for repairing and strengthening these infrastructures. By introducing waterborne polymers into a cement concrete system, brittle cracks and easy bonding performance defects of concrete can be compensated for to form a long-life, semi rigid, waterborne polymer-modified cementitious repair material with a promising development prospect. This paper investigates the modification effect of polymer emulsions on ordinary cement mortar. Our research mainly focused on the physical and mechanical properties, durability, microstructure and application status of waterborne polymer-modified cementitious composites. Literature studies show that with the increase in waterborne polymer content (0 wt%~20 wt%), the performance of cement mortar significantly improves, which in turn expands its application range. Compared with ordinary cement mortar, the introduction of waterborne polymers blocks some of the pores in the cement to a certain extent, thus improving its permeability, freeze–thaw resistance and durability. Finally, this paper describes the application of waterborne polymer–cementitious composites in western saline soil environments, as well as discusses the prospects of their development.
作者：
Su, Chi;Hua, Yilong;Liu, Yi;Tao, Shu;Jia, Fei;...
期刊：
PLOS ONE,2024年19(3):e0300800 ISSN：1932-6203
作者机构：
[Hua, Yilong; Liu, Yi; Su, Chi; Zhao, Wenhui] School of Resources Environment and Safety Engineering, University of South China, Hengyang, China;[Tao, Shu] School of Mathematics and Physics, University of South China, Hengyang, China;[Jia, Fei] School of Civil Engineering, University of South China, Hengyang, China;[Zhao, Wenhui] Shanxi Province Changzhi City Wuxiang County Jia Huo Township People's Government, Changzhi, China;[Lin, Wangyang] College of Mechanical Engineering, University of South China, Hengyang, China
摘要：
Mining wastewater with heavy metals poses a serious threat to the ecological environment. However, the acute single and combined ecological effects of heavy metals, such as chromium (Cr) and nickel (Ni), on freshwater ostracods, and the development of relevant prediction models, remain poorly understood. In this study, Heterocypris sp. was chosen to investigate the single and combined acute toxicity of Cr and Ni. Then, the quantitative structure-activity relationship (QSAR) model was used to predict the combined toxicity of Cr and Ni. The single acute toxicity experiments revealed high toxicity for both Cr and Ni. In addition, Cr exhibited greater toxicity compared to Ni, as evidenced by its lower 96-hour half-lethal concentration (LC50) of 1.07 mg/L compared to 4.7 mg/L for Ni. Furthermore, the combined acute toxicity experiments showed that the toxicity of Cr-Ni was higher than Ni but lower than Cr. Compared with the concentration addition (CA) and independent action (IA) models, the predicted results of the QSAR model were more consistent with the experimental results for the Cr-Ni combined acute toxicity. So, the high accuracy of QSAR model identified its feasibility to predict the toxicity of heavy metal pollutants in mining wastewater.
通讯机构：
[Zeng, S ] U;Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Peoples R China.
关键词：
Anchor bolts;Pull-out load;Cement-sand ratio;Anchorage defect;Key dynamic testing signal
摘要：
Pull-out load and the cement -sand ratio (CSR) can affect the non-destructive testing (NDT) results of anchor bolts. Therefore, in this article, NDT experiments were conducted on both fully and defectively grouted anchor bolts, and variation patterns of key dynamic testing signal parameters were analyzed. A longitudinal vibration model of defectively grouted anchor bolts considering dynamic and static damping was proposed, and simulated NDT of anchor bolts with varying qualities. The results indicated that grouting defects resulted in an increase in wave velocity, along with a decrease in the fundamental frequency and dynamic stiffness of anchor bolts. When grouting defects and pull-out load acted concurrently, the fundamental frequency, and dynamic stiffness of the defectively grouted anchor bolts were consistently smaller than those of fully grouted ones during the initial loading phase. With pull-out load increasing, wave velocity decreased first, then increased; fundamental frequency increased, followed by a decrease; dynamic stiffness rose. When the CSR of defectively grouted anchor bolts was reduced, wave velocity decreased, fundamental frequency increased slightly, and a substantial increase in dynamic stiffness was observed. Pull-out loads were more sensitive to anchor bolt key dynamic signals than defects and CSR. Simulated validation demonstrated the reliability of the proposed theory.
作者：
Lin Peng;Houzhen Bai;Lishan Rong;Jinxiang Liu*;Guohua Wang;...
期刊：
WATER AIR AND SOIL POLLUTION,2024年235(4):1-17 ISSN：0049-6979
通讯作者：
Jinxiang Liu
作者机构：
Hunan Provincial Key Laboratory of Pollution Control and Resources Technology, School of Civil Engineering, University of South China, Hengyang, China;School of Civil Engineering, University of South China, Hengyang, China;[Lin Peng; Houzhen Bai; Lishan Rong; Jinxiang Liu; Guohua Wang; Jinsong Wang; Han Xian] Hunan Provincial Key Laboratory of Pollution Control and Resources Technology, School of Civil Engineering, University of South China, Hengyang, China<&wdkj&>School of Civil Engineering, University of South China, Hengyang, China
通讯机构：
[Jinxiang Liu] H;Hunan Provincial Key Laboratory of Pollution Control and Resources Technology, School of Civil Engineering, University of South China, Hengyang, China<&wdkj&>School of Civil Engineering, University of South China, Hengyang, China
摘要：
In order to solve the problem of uranium pollution during the development and application of nuclear energy, magnetic ZnFe2O4/ZrO2(ZFOZO) composite material was synthesized by hydrothermal method to treat uranium containing wastewater. In this study, the surface properties and mechanism of the synthesized ZFOZO were analyzed by various characterization methods. The effects of adsorption time, pH, dosage of adsorbent, coexisting ions, and initial concentration of uranium (VI) solution on the adsorption performance of uranium (VI) by ZFOZO were investigated. ZFOZO exhibited the maximum adsorption rate of 99.8% under the conditions of CU (VI) = 10 mg/L, pH = 6, M/V = 0.3g/L, t =120 min, and T = 303K. The adsorption process was found to be a spontaneous endothermic process and conformed to the pseudo-second-order kinetic model and the Freundlich isothermal adsorption model. The adsorption mechanism of ZFOZO on U (VI) is mainly electrostatic adsorption, surface complexation, and oxygen vacancy. The maximum adsorption capacity of ZFOZO for U (VI) can reach 552.36mg/g. Adsorption–desorption experiment demonstrated that ZFOZO has a good reusability, after five cycles of adsorption and desorption, the adsorption efficiency is still above 75%. Cu2+ and Fe3+ will produce competitive adsorption and reduce the adsorption performance of ZFOZO on U (VI). In summary, this study provides a high efficiency, low cost, and rapid recovery adsorbent for the treatment of uranium containing wastewater in the future.
摘要：
Levels of cadmium (Cd) and lead (Pb) correspond to common composition in acid mine wastewater of Hunan Province of China. The removal path of Cd and Pb and the structure of microbial community were investigated by developing constructed wetlands (CWs) with different layer positions of biochar. The biochar as a layer at the bottom of CW (BCW) system exhibited maximum Cd and Pb removal efficiencies of 96.6-98.6% and 97.2-98.9%, respectively. Compared with original soil, BCW increased the relative proportions of Proteobacteria, Firmicutes, Acidobacteriota, Verrucomicrobiota, Desulfobacterota, Armatimonadota, Bacteroidota, Patescibacteria, Basidiomycota (phylum level) and Burkholderia-Caballeronia-Paraburkholderia, Citrifermentans, Chthonomonadales, Cellulomonas, Geothrix, Terracidiphilus, Gallionellaceae, Microbacterium, Vanrija, Apiotrichum, Saitozyma, Fusarium (genus level). The concentrations of Cd and Pb were positively correlated with the abundance of Verrucomicrobiota, Basidiomycota (phylum level), and Methylacidiphilaceae, Meyerozyma, Vanrija (genus level). This study demonstrates that BCW system can improve removal performance toward Cd and Pb, as well as alter microbial community.
摘要：
Geopolymer is an amorphous cementitious material produced by geopolymerization using minerals or industrial waste as the main raw material under the action of activators. It can be used for safe treatment of heavy metal and radioactive pollution. This study applied molecular dynamics simulation to investigate the transport behaviour of uranyl nitrate in nanochannel of geopolymer, and focused on the influence of changes in the Si/Al ratio of geopolymer on the adsorption and diffusion of ions and water molecules. The simulation results described by density distribution, radial distribution function (RDF), hydrogen bonding network structure, mean square displacement (MSD) and diffusion coefficient. The density distribution shows that geopolymer has the strongest adsorption capacity for UO22+, followed by NO3-, and finally H2O. The results also indicate that the changes in molecular composition of geopolymer have a significant impact on kinetic characteristics of UO22+, NO3- and H2O. As the Si/Al ratio decreases, the adsorption capacity of geopolymer shows an upward trend, with the most significant improvement in the adsorption of UO22+. In addition, when the Si/Al ratio reduces, the migration rate of UO22+ and NO3- slows down. It could hinder the diffusion of ions in nanopores of geopolymer. The work could optimize the preparation of geopolymer adsorbent, and reveal the transport mechanism of uranyl nitrate in nanopore of geopolymer with different Si/Al ratios at the atomic scale.
