摘要：
This paper examined the impacts of different pretreatments on the characteristics of biochar and its adsorption behavior for Pb(2+). Biochar with combined pretreatment of water-washing and freeze-drying (W-FD-PB) performed a maximum adsorption capacity for Pb(2+) of 406.99mg/g, higher than that of 266.02mg/g on water-washing pretreated biochar (W-PB) and 188.21mg/g on directly pyrolyzed biochar (PB). This is because the water-washing process partially removed the K and Na, resulting in the relatively enriched Ca and Mg on W-FD-PB. And the freeze-drying pretreatment broke the fiber structure of pomelo peel, favoring the development of a fluffy surface and large specific surface area during pyrolysis. Quantitative mechanism analysis implied that cation ion exchange and precipitation were the driving forces in Pb(2+) adsorption on biochar, and both mechanisms were enhanced during Pb(2+) adsorption on W-FD-PB. Furthermore, adding W-FD-PB to Pb-contaminated soil increased the soil pH and significantly reduced the availability of Pb.
作者机构：
[Xue, Yun; Xi, Zhen; Liu, Fenliang; Huang, Changjun] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.;[Gao, Hongshan] Lanzhou Univ, Coll Earth & Environm Sci, Key Lab Western Chinas Environm Syst, Minist Educ, Lanzhou 730000, Peoples R China.;[Li, Zongmeng] Xinyang Normal Univ, Sch Geog Sci, Xinyang 464000, Peoples R China.
通讯机构：
[Liu, FL ] H;Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.
关键词：
lacustrine sediment;terrace;river evolution;Jinsha River
摘要：
The formation of the Jinsha River drainage is a significant subject of concern in the geological and geomorphological fields. Among them, one key question is whether there was a regional paleo lake into which Lower Jinsha River drainage drained during the late Pliocene to early Pleistocene, due to massive fluvio-lacustrine sediments widely distributed in the Lower Jinsha River. Nevertheless, there has yet to be a consensus on the genesis of those fluvio-lacustrine sediments due to poor sedimentological and chronological data. In this study, to unravel the origin of those fluvio-lacustrine sediments and the formation model of the Lower Jinsha River, sedimentary characteristics, including spatial distribution, lithological composition, and stratigraphic contact relationship of those fluvio-lacustrine sediments were analyzed, and chronological determination of the fluvio-lacustrine sediments using Electron Spin Resonance and Optically stimulated luminescence method was conducted. The results show that in the Lower Jinsha River, the lacustrine sediments are mainly composed of silt and clay, with apparent horizontal bedding, stacked with fluvial cobble-gravel and sand, and are in unconformable contact with the underlying bedrock strata or paleo soil. The lacustrine sediments are spatially discontinuous and mainly distributed in the Shigu, Taoyuan, Panzhihua, and Longjie reaches. Downstream of these reaches are deeply incised gorges with an average slope >30 degrees, and many landslide landforms and deposits can be identified here. In each reach, the lacustrine sediments were closely distributed along the trunk and tributary channels in the plane and were distributed at different altitudes, forming a sequence of lacustrine terraces. Chronological analysis shows that in different reaches, the deposition ages of lacustrine sediments are significantly different. In each reach, the deposition age of the lacustrine terraces of high altitude is older than that of low altitude. The above characteristics collectively indicate that the lacustrine sediments in the Lower Jinsha River were locally deposited by individual dammed lakes, probably induced by landslide rather than a regional paleo lake by tectonic activities. During the incision process of the river valley, landslides continuously block the river channel, forming dammed lakes, and then deposited lacustrine sediments at different elevations, forming lacustrine terraces. The lacustrine sediment of the topmost lacustrine terrace in Panzhihua reach was dated to be 1.78 Ma, combined with previous studies on the fluvial terraces, indicating the Lower Jinsha River existed and started to incise its valley before the early Pleistocene. The widespread dammed lake sediment indicates that the formation of the Jinsha River valley follows the pattern of "incision-landslide-damming-aggradation-incision".
期刊：
International Journal of Environmental Research and Public Health,2022年19(22):14835- ISSN：1661-7827
通讯作者：
Wei Zhang<&wdkj&>Bozhi Ren<&wdkj&>Shuyu Liu
作者机构：
[Wang, An; Lu, Sen; Zhang, Wei; Shu, Jinkai; Liu, Shuyu] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;[Ren, Bozhi; Shu, Jinkai] Hunan Univ Sci & Technol, Sch Civil Engn, Xiangtan 411201, Peoples R China.;[Wang, An; Lu, Sen; Ren, Bozhi; Zhang, Wei; Shu, Jinkai] Hunan Prov Village Drinking Water Qual Safety Eng, Yiyang 413000, Peoples R China.;[Ren, Bozhi; Shu, Jinkai] Hunan Prov Key Lab Shale Gas Resource Exploitat, Xiangtan 411201, Peoples R China.
通讯机构：
[Wei Zhang; Bozhi Ren] H;[Shuyu Liu] A;Hunan Provincial Village Drinking Water Quality Safety Engineering Technology Research Center, Yiyang 413000, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>Hunan Provincial Key Laboratory of Shale Gas Resource Exploitation, Xiangtan 411201, China<&wdkj&>School of Civil Engineering, Hunan University of Science and Technology, Xiangtan 411201, China<&wdkj&>Hunan Provincial Village Drinking Water Quality Safety Engineering Technology Research Center, Yiyang 413000, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>School of Municipal and Surveying Engineering, Hunan City University, Yiyang 413000, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>School of Municipal and Surveying Engineering, Hunan City University, Yiyang 413000, China
摘要：
Modified Shell Powder/La-Fe-TiO2 (La-Fe-TiO2@MSP) composites were fabricated using the sol-gel method and characterized by SEM, XRD, UV-vis DRS and photocurrent techniques, and their physicochemical and optical properties were analyzed. The effects of various factors on the photocatalytic degradation of pyridine and its reaction kinetics were investigated by batch experiments using pyridine, a typical nitrogen-containing heterocyclic compound in coal chemical wastewater, as the target removal species. The pyridine degradation rate of 80.23% was obtained for 800 mg/L composite solution by photocatalytic oxidation of 50 mg/L pyridine wastewater for 180 min at 35 degrees C, pH = 8 and light intensity of 560 W. The photocatalytic degradation performance was optimal. The quenching experiments determined that the active species of photodegradation were mainly hole and hydroxyl radicals, and the photocatalytic degradation mechanism was analyzed in this way.
摘要：
The potential risk of various contaminants in water has recently attracted public attention. Biochars and modified biochars have been widely developed for environmental remediation. Metal and heteroatom co-doped biochar composites (MHBCs) quickly caught the interest of researchers with more active sites and higher affinity for contaminants compared to single-doped biochar by metal or heteroatoms. This study provides a comprehensive review of MHBCs in wastewater decontamination. Firstly, the main fabrication methods of MHBCs were external doping and internal doping, with external doping being the most common. Secondly, the applications of MHBCs as adsorbents and catalysts in water treatment were introduced emphatically, which mainly included the removal of metals, antibiotics, dyes, pesticides, phenols, and other organic contaminants. Thirdly, the removal mechanisms of contaminants by MHBCs were deeply discussed in adsorption, oxidation and reduction, and degradation. Furthermore, the influencing factors for the removal of contaminants by MHBCs were also summarized, including the physicochemical properties of MHBCs, and environmental variables of pH and co-existing substance. Finally, futural challenges of MHBCs are proposed in the leaching toxicity of metal from MHBCs, the choice of heteroatoms on the fabrication for MHBCs, and the application in the composite system and soil remediation.
期刊：
Energy and Buildings,2022年276:112498 ISSN：0378-7788
通讯作者：
Li, Nianping(linianping@hnu.edu.cn)
作者机构：
[Li, Nianping; Peng, Jinqing; Liu, Qingqing; Duan, Jiaojiao] Hunan Univ, Coll Civil Engn, Changsha 410082, Hunan, Peoples R China.;[Zhou, Xuehua; Duan, Jiaojiao] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413099, Peoples R China.;[Li, Nianping; Peng, Jinqing; Liu, Qingqing; Duan, Jiaojiao] Hunan Univ, Key Lab Bldg Safety & Energy Efficiency, Minist Educ, Changsha, Peoples R China.;[Zhou, Xuehua] Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, Peoples R China.
通讯机构：
[Nianping Li] C;College of Civil Engineering, Hunan University, Changsha, Hunan 410082, China<&wdkj&>Key Laboratory of Building Safety and Energy Efficiency (Hunan University), Ministry of Education, China
关键词：
Air conditioning (AC);High-rise residential building;Occupant behaviour;Start-up temperature;Start–stop time;Statistical analysis
摘要：
The synthesis of CuO-TiO2 hybrid nanostructures using the sol-gel method, as well as their characterization as photocatalysts for photodegradation of p-nitrophenol (PNP) in industrial wastewater under sunlight irradiation, were presented in this paper. According to SEM and XRD investigations, the CuO-TiO2 hybrid nanostructure had a mixture of monoclinic structure CuO and anatase phase TiO2, indicating that the CuO-TiO2 hybrid nanostructure was successfully synthesised using the sol-gel method. Optical band gap values for CuO, TiO2, and CuO- TiO2 were determined to be 1.64, 3.02, and 2.10 eV, respectively. Electrochemical tests revealed that CuO-TiO2 has a longer electron lifetime, a higher separation efficiency, and a faster diffusion rate. After 75, 65, and 50 minutes of sunshine irradiation, full elimination of 200 mL of 10 mg/l PNP was obtained employing the photocatalytic activity of TiO2, CuO, and CuO-TiO2, respectively. These findings support CuO-high TiO2's photocatalytic activity when exposed to sunlight, owing to the synergistic effect of CuO and TiO2 in forming a CuO-TiO2 heterojunction with efficient separation of photo-generated electrons and holes, which improves electron transport. After 35, 90, and 150 minutes of UV irradiation, 100% treatment of 5, 30, and 100 mg/L of PNP was obtained, respectively. The CuO-practical TiO2's photocatalytic removal capacity was tested for degradation of a 200 mL 5 mg/L PNP solution generated from genuine industrial wastewater, demonstrating CuO-efficient TiO2's photocatalytic activity for PNP removal from real industrial wastewater.
作者机构：
[Fang, Xin; Xiong, Liwei] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.;[Li, Shenxin; Zou, Bin] Cent South Univ, Sch Geosci & Infophys, Changsha 410083, Peoples R China.
通讯机构：
[Bin Zou] S;School of Geosciences and Info-Physics, Central South University, Changsha 410083, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
air pollution;AOD;spatial–temporal variations;environmental modeling;population exposure
摘要：
Fine particulate matter (PM2.5), which can cause adverse human health effects, has been proven as the first air pollutant in China. In situ observations with ground-level monitoring and satellite-based concentrations have been used to analyze the variations in PM2.5. However, variation analyses based on these two kinds of measurement have mainly focused on the concentration itself and ignored the effects on the population. Therefore, this study not only investigated these two kinds of measurements, but also performed weighted population analyses to study the variations in PM2.5. Firstly, daily models of timely structure adaptive modeling (TSAM) were constructed to simulate satellite-derived PM2.5 levels from January 2013 to December 2016. Secondly, population-weighted concentrations were calculated based on TSAM-derived PM2.5 surfaces. Finally, observed, TSAM-derived, and population-weighted concentrations were used to analyze the variations in PM2.5. The results showed the different importance of various input parameters; AOD had the highest rank. Additionally, TSAM models demonstrated good performance, fitting R ranging from 0.86 to 0.91, and validating R from 0.82 to 0.89. According to the air quality standard in China, TSAM-derived PM2.5 showed that the increase in area lower than Level II was 29.03% and the increase in population was only 14.81%. This indicates that the air quality exhibited an overall improvement in spatial perspective, but some areas with high population density showed a relatively low improvement due to uneven distributions in China. The population-weighted PM2.5 concentration could better represent the health threats of air pollutants compared with in situ observations.
通讯机构：
[Yaoning Chen] C;College of Environmental Science and Engineering, Hunan University, Changsha 410082, China<&wdkj&>Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
关键词：
Sludge biochar;Manganese dioxide;AOPs;Peroxymonosulfate;Methylene blue
摘要：
Diclofenac (DCF), as a typical representative of PPCPs, has potential ecotoxicity to the water environment. In this study, ultrasound (US) enhanced ferrous sulfide (FeS)-activated persulfate (PDS) technology (US/FeS/PDS) was used to degrade DCF. By comparing the degradation effects of US, US/PDS, FeS/PDS and US/FeS/PDS systems on DCF, this study confirmed the synergy and strengthening effects of US. The influences of single-factor experimental conditions on the US/FeS/PDS system were investigated and optimized. The FeS catalysts before and after the reaction were characterized and analyzed by X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS). The heterogeneous reaction proceeded on the surface of FeS, and a small part of FeS(2) was formed on FeS surface. During the reaction, the proportion of S(2-) on the catalyst surface decreased from 51% to 44%. Correspondingly, the proportion of S(x)(2-) increased from 21% to 26%. It indicated that S(2-) was oxidized into S(x)(2-) in the reaction, and the loss electrons of S(2-) caused the reduction of Fe(3+) to Fe(2+)on the FeS surface, which promoted the cycle between Fe(2+) and Fe(3+) in turn. Furthermore, SO(4)(-) and ‧OH were the main active free radicals, of which the contribution rate of ‧OH was about 34.4%, while that of SO(4)(-) was approximately 52.2%. In US/FeS/PDS, the introduction of US could promote the dissolution of iron on the FeS surface. US contributed to the formation of a redox power motor between S(2-)S(x)(2-) and Fe(2+)-Fe(3+), which continuously decomposed PDS to generate sufficient active SO(4)(-) and ‧OH radicals, thereby efficiently and continuously degrading DCF. Finally, the related mechanism of DCF degradation by US/FeS/PDS was summarized. Overall, US/FeS/PDS can not only efficiently degrade and remove DCF, but also has potential application value in organic pollution removal and wastewater purification.
摘要：
Soil pollution by potentially toxic elements (PTEs) is a serious threat to human health and ecosystem function. Soil washing using EDTA is one of the permanent disposal options available to remove PTEs from soil. Based on published studies, this paper summarized the current progress of remediation techniques using EDTA to mobilize and remove PTEs from contaminated soils. Firstly, the key factors to control EDTA washing were discussed, such as the concentration of EDTA, the pH of the washing solution, the washing time, multiple washing, and the liquid/solid ratio. Afterwards, the complicated changes in soil properties after washing were discussed. The change of soil properties is inevitable, so some measures need to be taken to reduce the damage to the soil by washing. Finally, the current improvements were summarized for the problems existing in the EDTA washing process. EDTA could be used in combination with other agents such as other chelating agents, reducing agents, acid compounds, and surfactants to improve efficiency of EDTA washing. The purpose of this paper is to provide a reference for further research and practical application of remediation of PTEs contaminated soil by EDTA washing. [GRAPHICS] .
通讯机构：
[Yaoning Chen; Yuanping Li] C;College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China<&wdkj&>Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China<&wdkj&>College of Municipal and Mapping Engineering, Hunan City University, Yiyang, Hunan, 413000, China
关键词：
Exergy;Solid waste;Gasification;Updraft;Downdraft;Fixed bed
摘要：
The most commonly used for gasification of village-level solid waste is the fixed-bed gasifier, but there is no reasonable method to evaluate the gasification process. This paper attempts to find a gasifier that is most suitable for gasification of village-level solid wastes through exergy analysis method. Based on experimental data from literature, the exergy efficiencies and LHV(Low Heat Value) of product gas from updraft and downdraft fixed bed gasifier are studied in this paper. The results show that the updraft fixed bed gasifier has higher exergy efficiency, and the gas produced by the downdraft fixed bed gasifier has a higher heating value. Air gasification has higher exergy efficiency than steam gasification and pure oxygen gasification. The highest exergy efficiency at a gasification temperature of about 1000 degrees C and ER (Equivalence Ratio) value in the range of 0.33-0.36. The volatile content of gasification raw materials is higher, and the gasification efficiency is higher. Through the research of this paper, a new path to reasonably evaluate the gasification process is obtained. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
作者机构：
[Xue, Yun; Liu, Fen-Liang; Zhang, Wei] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;[Xue, Yun] Cent South Univ, Key Lab Metallogen Predict Nonferrous Met & Geol, Changsha 410083, Peoples R China.;[Wen, Yi-Min] Guilin Univ Elect Technol, Sch Comp Sci & Informat Secur, Guilin 541004, Peoples R China.;[Duan, Zhong-Man] Hunan Prov Nat Resources Affairs Ctr, Changsha 410004, Peoples R China.
通讯机构：
[Xue, Yun] H;[Xue, Yun] C;Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;Cent South Univ, Key Lab Metallogen Predict Nonferrous Met & Geol, Changsha 410083, Peoples R China.
关键词：
spectral absorption characteristics;chlorophyll-a;Dongting Lake
摘要：
The envelope removal method has the advantage of suppressing the background spectrum and expanding the weak absorption characteristic information. However, for second-class water bodies with a relatively complex water quality, there are few studies on the inversion of chlorophyll a (Chl-a) concentration in water bodies that consider the spectral absorption characteristics. In addition, the current research on the inversion of the Chl-a concentration was carried out under the condition of sample concentration equilibrium. For areas with a highly variable Chl-a concentration, it is still challenging to establish a highly applicable and accurate Chl-a concentration inversion model. Taking Dongting Lake in China as an example, this study used high-concentration samples and spectral absorption characteristics to invert the Chl-a concentration. The decap method was used to preprocess the high-concentration samples with large deviations, and the envelope removal method was used to extract the spectral absorption characteristic parameters of the water body. On the basis of the correlation analysis between the water Chl-a concentration and the spectral absorption characteristics, the water Chl-a concentration was inverted. The results showed the following: (1) The bands that were significantly related to the Chl-a concentration and had a large correlation coefficient were mainly located in the three absorption valleys (400-580, 580-650, and 650-710 nm) of the envelope removal curve. Moreover, the correlation between the Chl-a concentration and the absorption characteristic parameters at 650-710 nm was better than that at 400-580 nm and 580-650 nm. (2) Compared with the conventional inversion model, the uncapped inversion model had a higher R-P(2) and a lower RMSEP, and was closer to the predicted value of the 1:1 line. Moreover, the performance of the uncapped inversion model was better than that of the conventional inversion model, indicating that the uncapped method is an effective preprocessing method for high-concentration samples with large deviations. (3) The predictive capabilities of the ER_New model were significantly better than those of the R_New model. This shows that the envelope removal method can significantly amplify the absorption characteristics of the original spectrum, which can significantly improve the performance of the prediction model. (4) From the inversion models for the absorption characteristic parameters, the prediction models of A(650-710 nm)_New and D650-710 nm_New exhibited the best performance. The three combined models (A(650-710 nm)& D650-710 nm_New, A(650-710 nm)& NI_New, A(650-710 nm)& DI_New) also demonstrated good predictive capabilities. This demonstrates the feasibility of using the spectral absorption feature to retrieve the chlorophyll concentration.
通讯机构：
[Chen, Yaoning; Li, Yuanping] H;Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Peoples R China.;Hunan Univ, Minist Educ, Key Lab Environm Biol & Pollut Control, Changsha 410082, Peoples R China.;Hunan City Univ, Coll Municipal & Mapping Engn, Yiyang 413000, Hunan, Peoples R China.
摘要：
Visible-light-driven photocatalysis, as an emerging environmental restoration technology, has become a focus of attention recently. In this work, a novel SrCO3-SrTiO3/Ag3PO4 heterojunction was successfully synthesized, and its structure, composition, and optical performance were systematically characterized. In addition, SrTiO3/Ag3PO4 was also synthesized, and its type II heterojunction had certain defects. The active species trapping experiments of SrCO3-SrTiO3/Ag3PO4 showed that center dot OH and center dot O-2(-) participated during the reaction. The photodegradation efficiency of SrCO3-SrTiO3/Ag3PO4 heterojunction was 1.4 times and 2.0 times that of Ag3PO4 and SrCO3-SrTiO3, respectively. A novel Z-scheme mechanism could be used to explain the photoreaction process of SrCO3-SrTiO3/Ag3PO4. The excellent photocatalytic property was due to the enhancement of visible-light absorption, the effective separation of photogenerated charges, and the generation of abundant active species.
作者机构：
[Wen, Yimin; Xu, Zhi] Guilin Univ Elect Technol, Guangxi Key Lab Image & Graph Intelligent Proc, Guilin 541004, Peoples R China.;[Wen, Yimin; Yi, Haiyang] Guilin Univ Elect Technol, Guangxi Key Lab Trusted Software, Guilin 541004, Peoples R China.;[Li, Yujian] Guilin Univ Elect Technol, Sch Artificial Intelligence, Guilin 541004, Peoples R China.;[Fan, Zhigang] Zebra Technol China Corp, Shanghai 200122, Peoples R China.;[Xue, Yun] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Yimin Wen] G;Guangxi Key Laboratory of Image and Graphic Intelligent Processing, Guilin University of Electronic Technology, Guilin 541004, China<&wdkj&>Guangxi Key Laboratory of Trusted Software, Guilin University of Electronic Technology, Guilin 541004, China
关键词：
Domain adaptation;Discriminative analysis;Single sample face recognition;Transfer learning;Gallery-sensitive
摘要：
Taking advantage of labeled auxiliary training data whose distribution is similar to the distribution of the gallery, single sample face recognition (SSFR) has achieved encouraging performance. However, in many real-world applications, it is difficult to collect such an auxiliary training dataset, while it may be easier to collect an unlabeled target training dataset whose distribution is similar to the distribution of the gallery and a labeled source training dataset whose distribution may be different to the distribution of the gal-lery. How can these three datasets be effectively leveraged to handle SSFR? To address this issue, this paper proposes a new method of Gallery-Sensitive Single Sample Face Recognition based on Domain Adaptation (GS-DA). First, GS-DA employs the method of TSD (targetize the source domain) to construct a common subspace and a targetized source domain. Secondly, it projects each gallery image into the common subspace and obtains the sparse representation of each gallery image in the common subspace. Thirdly, it reconstructs each gallery image from the targetized source domain to estimate the within-class scatter matrix and the between-class scatter matrix of the gallery. Lastly, it learns a discriminant model by maximizing the sum of the traces of the between-class scatter matrix of the gallery and the between-class scatter matrix of the targetized source domain as well as minimizing the sum of the traces of the total scatter matrix of the gallery and the total scatter matrix of the target training data. The experimental results on five datasets illustrate the superiority of GS-DA in leveraging these three datasets for SSFR. (c) 2020 Elsevier B.V. All rights reserved.
