摘要：
To solve the problems of the poor stability and low adsorption efficiency of MXene used as an adsorbent for heavy metal removal. In this study, the microwave-assisted novel composite of chloroacetic acid-modified MXene-chitosan gel microspheres (C-TC-CS) was prepared. The experimental results demonstrated that C-TC-CS exhibited good stability and U(VI) adsorption performance, the maximum adsorption capacity of U(VI) by C-TC-CS was up to 141.96 mg/g. Pseudo-second-order and Langmuir isotherm adsorption models fit the adsorption process well, and the thermodynamic parameters showed that the adsorption process was spontaneous and endothermic. Importantly, C-TC-CS could be easily separated and regenerated. After five cycles of regeneration, the adsorption efficiency of C-TC-CS for U(VI) remained above 74%. Spectroscopic analyses indicated that the main adsorption mechanism involved electrostatic interactions, ion exchange, and complexation. This study proved that C-TC-CS could be an effective and promising adsorbent for removing U(VI) from aqueous solution.
作者机构：
[王家莉; 刘迎九; 向金晶] School of Civil Engineering, University of South China, Hunan, Hengyang, 421001, China;Hunan Province Key Laboratory of Pollution Control and Resources Reuse Technology, University of South China, Hunan, Hengyang, 421001, China;[赵发] CNNC 272 Uranium Industry Co., Ltd., Hunan, Hengyang, 421000, China;[王国华; 刘迎九; 刘金香] School of Civil Engineering, University of South China, Hunan, Hengyang, 421001, China, Hunan Province Key Laboratory of Pollution Control and Resources Reuse Technology, University of South China, Hunan, Hengyang, 421001, China
通讯机构：
[Liu, J.] S;School of Civil Engineering, Hunan, China
摘要：
Investigating the seepage characteristics of acid leaching solution affected by surfactant in the ore-bearing layer during the in-situ leaching process can be useful for optimizing the process parameters of uranium ore. Three surfactant leaching solutions of different concentrations were prepared respectively for the agitation leaching experiment, from which the best was screened out for seepage simulation experiment using a self-developed multifunctional physical and chemical seepage test device. The influence of surfactant to seepage characteristics of leaching solution were examined based on the seepage flow mechanics and physicochemical seepage theory. Results indicated that trend of seepage characteristics of different leaching solutions were the same in rock samples with similar internal pore architectures in general, both of which were horizontal seepage processes from the unsaturated stage to the saturated stage. While the seepage process of leaching solution added surfactant reached the saturation point of the set flow rate earlier, and the addition of surfactant provided improvement in the permeability coefficient with the largest increase of 29.41% in the saturation stage, the growth of seepage pressure also decreased by up to 22.72%.
摘要：
Phosphorus-rich biochar (PBC) has been extensively studied due to its significant adsorption effect on U(VI). However, the release of phosphorus from PBC into solution decreases its adsorption performance and reusability and causes phosphorus pollution of water. In this study, Alcaligenes faecalis (A. faecalis) was loaded on PBC to produce a novel biocomposite (A/PBC). After adsorption equilibrium, phosphorus released into solution from PBC was 2.32mg/L, while it decreased to 0.34mg/L from A/PBC (p<0.05). The U(VI) removal ratio of A/PBC reached nearly 100%, which is 13.08% higher than that of PBC (p<0.05), and it decreased only by 1.98% after 5 cycles. When preparing A/PBC, A. faecalis converted soluble phosphate into insoluble metaphosphate minerals and extracellular polymeric substances (EPS). And A. faecalis cells accumulated through these metabolites and formed biofilm attached to the PBC surface. The adsorption of metal cations on phosphate further contributed to phosphorus fixation in the biofilm. During U(VI) adsorption by A/PBC, A. faecalis synthesize EPS and metaphosphate minerals by using the internal components of PBC, thus increasing the abundance of acidic functional groups and promoting U(VI) adsorption. Hence, A/PBC can be a green and sustainable material for U(VI) removal from wastewater.
摘要：
Hollow microspheres Bi2WO6 (HBWO) were prepared by the solvothermal method for the adsorption of U(VI) from aqueous solutions. Batch experiments and characterization analysis investigated the adsorption performance and mechanism. The results showed that the adsorption equilibrium could be reached in 30 min at T = 303 K, pH = 6, C-U(VI) = 10 mg/L, m/V = 0.1 g/L. The removal efficiency of HBWO for U(VI) in solution was 95.53%, which was about 20% higher than Bi2WO6 nanosheets. The maximum Langmuir adsorption capacity could reach 523.13 mg/g. FTIR and XPS analysis indicated that the interaction mechanism of U(VI) with HBWO is mainly surface complexation of strong ionic bond (M-O) and hydroxyl (-OH) groups. In addition, HBWO has strong ion selectivity for U(VI) and good regeneration and reuse performance. These results demonstrated that HBWO might potentially remediate actual uranium-containing wastewater.
通讯机构：
[Xie, D ] U;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
关键词：
Obesity and overweight;Environmental chamber experiments;Thermal comfort during indoor running;Subjective votes;Physiological indexes
摘要：
Regular and adequate physical exercise plays a pivotal role in enhancing physical fitness, mitigating the occurrence of obesity, and upholding body weight. The comfort of individuals engaging in exercise is significantly impacted by various environmental factors within sports fields, including ambient temperature, humidity, air velocity, and mean radiant temperature. To investigate the influence of ambient temperature, relative humidity, and body mass index (BMI) on the comfort levels of individuals with high body fat during exercise, treadmill running experiments were conducted within controlled environmental chambers. Furthermore, the subjects' subjective sensations and physiological indexes were recorded. The results implied that subjects exhibited a broader range of acceptable thermal sensations during exercise compared to rest periods. Moreover, individuals with a higher BMI displayed heightened sensitivity to elevated temperatures and a greater propensity for perceiving sensations of heat, resulting in a narrower range of acceptable exercise conditions. Additionally, the findings highlighted that air temperature exerted a more pronounced impact on comfort levels than humidity. For indoor running exercises, it was advisable to maintain ambient temperatures within the ranges of 15.1 degrees C-24.3 degrees C and 16.1 degrees C-27.8 degrees C for obese and overweight individuals, respectively. Furthermore, it was recommended to maintain a relative humidity level between 50% and 80% in the exercise environment.
作者机构：
[Qiao, Jiaxing; Liu, Xiqi; Wang, Gang; Song, Leibo] Shaoxing Univ, Collaborat Innovat Ctr Prevent & Control Mt Geol H, Shaoxing 312000, Peoples R China.;[Ma, Xiaoming] Huahui Engn Design Grp Co Ltd, Shaoxing 312000, Peoples R China.;[Chen, Wenzhao] Univ South China, Sch Civil Engn, Hengyang 421000, Peoples R China.
通讯机构：
[Wang, G ] S;Shaoxing Univ, Collaborat Innovat Ctr Prevent & Control Mt Geol H, Shaoxing 312000, Peoples R China.
摘要：
The tailings pond is a dangerous source of man-made debris flow with high potential energy. The oxidative acidification of tailings may cause the instability of the pond and induce serious safety accidents. The influence of oxidation and acidification degree on macro mechanical properties of tailings is discussed from the aspects of mineral composition and microstructure. The results show that as the degree of oxidation and acidification of tailings sand increases, the overall structural performance and load-bearing capacity decrease, and its cohesion (c) and internal friction angle (φ) show a decreasing trend. In fact, the engineering properties of tailings with different oxidation and acidification degrees are dominated by the physicochemical composition and structural characteristics. On the one hand, as the degree of oxidation increases, acidic substance will neutralize with CaCO(3) and CaMg(CO(3))(2), resulting in the loss of cemented substance and the decrease of cementation force between tailing sand particles as well as the gradual destruction of the integrity of tailing sand. On the other hand, the increase of oxidation and acidification degree of tailing sand leads to a gradual reduction of outline (2D) fractal dimension and gray surface (3D) fractal dimension of surface laminated structure as well as the obvious reduction of laminated structure and its roughness of tailings sand.
摘要：
Tetracycline (TC) is an important antibiotic extensively used in livestock breeding and aquaculture, and so an effective removal strategy is urgently needed. This study explores the use of a series of hydroxyapatite calcinated at different temperatures (300, 400, 500, 600, and 700 degrees C) to activate peroxymonosulfate (PMS) for the removal of TC. The optimal conditions for the removal of 10 mg/L TC using hydroxyapatite calcinated at 600 degrees C (CHAP600) as a catalyst were determined to be: pH of 6.0, a catalyst dosage of 0.2 g/L and a PMS concentration of 0.3 mM. Under these conditions, the removal efficiency of TC reached 94 %. The potential degradation pathway of TC was proposed by identifying the intermediates using High Performance Liquid Chromatography/ Triple Quad mass spectrometry. The characterization analysis revealed that the presence of calcium carbonate on the surface of CHAP600 promoted the generation of singlet oxygen (1O2). Additionally, the phosphate group in CHAP600 served as a catalyst for the production of sulfate radicals (SO4 & BULL;-) from PMS, which subsequently react with hydroxyl or surface hydroxyl group to generate hydroxyl radicals (& BULL;OH). And the active species 1O2 is the most significant contributor to the catalytic degradation process of TC by CHAP600 activated PMS, followed by & BULL;OH, and then SO4 & BULL;-. This study provides new insight for the mechanism of removing organic contaminants using PMS activated with calcined hydroxyapatite.
摘要：
In this work, AgBr/LaFeO3 (ALFO) Z-scheme heterojunction photocatalyst was successfully synthesized by simple in-situ precipitation method, and photocatalysis was coupled with peroxymonosulfate (PMS) to remove acid orange 7 (AO7) by enhanced electron transfer. The Z-scheme heterojunction between AgBr and LaFeO3 provides the driving force for charge transfer and improves the charge separation rate. At the same time, PMS can act as an electron acceptor to promote photogenerated charge separation and maximize the generation of reactive oxygen species. The obtained results showed that the prepared ALFO photocatalyst has excellent reusability and excellent AO7 removal efficiency. This work successfully demonstrated the synergistic effect of ALFO photocatalyst, promoted light utilization and PMS activation, and provided a potential application prospect for effectively reducing environmental pollution by using solar energy.
期刊：
Journal of Building Engineering,2023年72:106503 ISSN：2352-7102
通讯作者：
Xie, D
作者机构：
[Zhang, Zixuan; Xie, D; Xie, Dong; Zhou, Lifeng; Wang, Lize] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.;[Zhang, Zixuan; Xie, Dong; Zhou, Lifeng; Wang, Lize] Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, Peoples R China.
通讯机构：
[Xie, D ] U;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
关键词：
Building energy prediction;Bi-directional gated recurrent unit;Convolution neural network;Attention mechanism;Residual connection
摘要：
Accurate building energy consumption prediction is crucial to the rational planning of building energy systems. The energy consumption of buildings is influenced by various elements and is characterized by non-linearity and non-stationarity. To fully tap the time series characteristics of building energy consumption and heighten the model's prediction accuracy, this paper proposes a hybrid neural network prediction model combining attention mechanism, Bidirectional Gate Recurrent Unit (BiGRU), Convolutional Neural Networks (CNN), and the residual connection. The model uses BiGRU to train the extracted feature vectors by CNN on a two-way cycle. The attention mechanism highlights the key information extracted, and the residual connection is used to learn the features fully. Taking the energy consumption data of an office building in Guangzhou, China, as the object of study, the results indicate that the proposed model shows a stronger prediction accuracy than the commonly used model with an R2 of 90.74% and a CV-RMSE of 19.24%. Compared with the other five common models, the RMSE, MAPE, and MAE of the proposed model achieve lower error rates. Besides, the length 24 of the sliding window exceeds other lengths in the established model. The prediction accuracy of the established model in working hours outperforms the non-working hours of the office building. Building energy consumption prediction in the same season is better than that in the whole year.
