摘要：
This study prepared pomelo peel biochar (PBC) under different pyrolysis temperatures (T) (300-800 degrees C) and investigated the removal efficiency of tetracycline (TC) under the oxidative systems established by PBC and oxidants (hydrogen peroxide (H2O2), peroxymonosulfate (PMS), and peroxydisulfate (PDS)). The correlation between the properties of PBC and the removal efficiencies of TC was studied by Pearson analysis to clarify the critical properties of biochar in catalytic processes. The inorganic carbon (IC), ash, pH, basic functional groups (BFG), specific surface area (SSA), microporous surface area (S-micro), pore volume (PV), and graphitization degree (I-D/I-G) of PBC were positively correlated with the increase of T (p < 0.05). Notably, the SSA and PV of PBC increased from 4.294 m(2)/g and 0.002 cm(3)/g to 496.864 m(2)/g and 0.261 cm(3)/g as the pyrolysis temperature increased from 300 to 800 degrees C. In contrast, the yield, organic carbon (OC), and acidic functional groups (AFG) of PBC displayed negatively correlated with the increase of T (p < 0.05). R-ad, R-PBC/H2O2, R-PBC/PMS, and R-PBC/PDS represented the removal efficiencies of TC by PBC adsorption, PBC/H2O2, PBC/PMS, and PBC/PDS system. R-PBC/H2O2, R-PBC/PMS, and R-PBC/PDS showed a highly positive correlation to the R-ad (r = 0.965, 0.952, 0.946, p < 0.01). R-ad, R-PBC/H2O2, R-PBC/PMS, and R-PBC/PDS were positively correlated with K, Mg, ash, pH, BFG, and I-D/I-G (p < 0.01). There was no statistically significant correlation between persistent free radicals (PFRs) and the removal efficiencies of TC. Furthermore, SSA and PV showed positive relationships with the removal efficiencies of TC in the PBC/PMS and PBC/PDS systems, but no significant correlation with the removal efficiencies of TC in the PBC/H2O2 systems. Moreover, the catalytic behaviors and mechanisms were studied in the PBC-800 based oxidative systems. The quenching experiments and EPR spectra indicated that singlet oxygen (O-1(2)) was the main active species. Except for O-1(2), superoxide radical (O-2(center dot-)) also contributed to TC removal in the oxidative systems. From the changes in used PBC-800, the disordered sp(2) hybrid carbon, sp(3) C-C, and pyridinic-N were the main active sites in activation.
摘要：
Satellite-based aerosol optical depth (AOD) products are commonly used in various aerosol-related studies, such as aerosol pollution mapping and aerosol-climate interactions. However, these satellite AOD products often suffer from significant missing gaps due to cloud cover and limitations in the retrieval algorithm. To address this issue, some studies take advantage of real-time seamless simulation of numerical models and successfully fill in these gaps by establishing a regression relationship between satellite AOD and numerical model AOD. However, these previous studies usually use satellite AOD retrievals as the regression target, which limits the accuracy of the imputation results by the original accuracy of satellite AOD retrievals and also consumes a considerable amount of time. To overcome these limitations, this study proposes a spatiotemporal imputation model called Bi-ConvRNN, which combines convolutional neural networks (CNN) and bidirectional recurrent neural networks (Bi-RNN). The model takes both satellite AOD retrievals and numerical model AOD data as input and utilizes the weighted mean squared error (MSE) loss function of multiple AOD datasets, e.g., ground-based data, satellite retrievals, and numerical simulation, as the optimization target to improve the imputation accuracy. The proposed model is evaluated using hourly COMS GOCI AOD products. In the independent test set, the AOD results generated by the Bi-ConvRNN model in the region containing GOCI AOD retrievals can break the accuracy of original GOCI AOD products with the accuracy improved from R2 = 0.70 [RMSE = 0.15] to R2 = 0.84 [RMSE = 0.11], and the filling accuracy, e.g. R2 = 0.79, [RMSE = 0.14], in the region without GOCI AOD retrievals are still better than those of the original GOCI AOD retrievals. Additionally, the Bi-ConvRNN model demonstrates satisfactory filling efficiency, requiring only 0.12 s to fill in the missing gaps of hourly GOCI AOD products per day. These results highlight the efficiency and reliability of the proposed model in filling the gaps in satellite AOD products, and the filled AOD results have great potential for further aerosol-related research.
摘要：
Novel tourmaline-biochar composites (TBs) were synthesized by introducing tourmaline (TM) into pomelo peel biochar (BC). The surface properties of TBs and BC were studied and the adsorption performances for Pb(2+) were investigated. Compared to pristine BC, the adsorption ability for Pb(2+) on TBs was enhanced with the increase of TM in TBs, and up to 514.62mg/g on 5%TB. The enrichment of inorganic metals caused by TM in TBs made the precipitation and cation ion exchange become the main mechanisms in adsorbing Pb(2+), and the amounts of adsorbing Pb(2+) by those two mechanisms on TBs were 1.10-1.48 times and 1.20-1.30 times those of BC, respectively. Furthermore, applying TBs to practical contaminated soil increased the soil pH and electrical conductivity (EC) after 15days of incubation. The increased content of residual-Pb and reduced exchangeable-Pb and DTPA-Pb indicated that TBs were favorable for the immobilization of Pb in soil. This study gives a new perspective on the synthesis of tourmaline-biochar composite and their application in Pb-polluted water and soil.
期刊：
JOURNAL OF WATER PROCESS ENGINEERING,2024年68:106370 ISSN：2214-7144
通讯作者：
Zhou, S;Jiang, HY
作者机构：
[Zou, Ye; Zhou, Shuai; Duan, Yi; Cai, Pingli; Ye, Miaobin] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.;[Jiang, Haiyan] Hunan City Univ, Coll Municipal & Mapping Engn, Yiyang 41300, Peoples R China.
通讯机构：
[Zhou, S ] U;[Jiang, HY ] H;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.;Hunan City Univ, Coll Municipal & Mapping Engn, Yiyang 41300, Peoples R China.
摘要：
In this work, cobalt-doped graphitic carbon nitride (Co-CN) was synthesized through a high-temperature calcination method and employed to activate peroxymonosulfate (PMS) for ciprofloxacin (CIP) removal. The experimental outcomes demonstrated that under optimized conditions of 0.5 g/L 0.25Co-CN, 2 mM PMS, an initial solution pH of 7, an initial CIP concentration of 5 mg/L, and at a temperature of 30 degrees C, the removal efficiency of CIP can reach 99.5 % within 45 min. The kinetics of CIP removal by Co-CN activated PMS are accurately modeled by a bi-exponential decay function, indicating a CIP removal process involving both rapid and slower reaction phases. Furthermore, after five cycles of reuse, the catalyst maintained a respectable removal efficiency of 83.3 % for CIP, with pre- and post-reaction characterizations affirming the excellent reusability and stability of 0.25Co-CN. Quenching experiments and Electron Paramagnetic Resonance (EPR) tests confirmed the predominance role of 1 O 2 in the catalytic degradation mechanism. The Co-N4 active sites within 0.25Co-CN were identified as crucial for adsorption and subsequent degradation of CIP. In this study, a novel kinetics model is proposed for fitting the CIP removal process under the synergistic effect of adsorption and catalysis, which provides new insights into the understanding of the dynamic process of organic pollutant removal.
摘要：
The electric field-assisted composting system (EACS) is an emerging technology that can enhance composting efficiency, but little attention has been given to electrode materials. Herein, an EACS was established to investigate the effects of electrode materials on humic substance formation and heavy metal speciation. Excitation-emission matrix analysis showed that carbon-felt and stainless-steel electrodes increased humic acid (HA) by 48.57% and 47.53%, respectively. In the EACS with the carbon-felt electrode, the bioavailability factors (BF) of Cu and Cr decreased by 18.00% and 7.61%, respectively. Despite that the stainless-steel electrodes decreased the BF of As by 11.26%, the leaching of Cr, Ni, Cu, and Fe from the electrode itself is an inevitable concern. Microbial community analyses indicated that the electric field increased the abundance of Actinobacteria and stimulated the multiplication of heavy metal-tolerant bacteria. Redundancy analysis indicates that OM, pH, and current significantly affect the evolution of heavy metal speciation in the EACS. This study first evaluated the metal leaching risk of stainless-steel electrode, and confirmed that carbon-felt electrode is environment-friendly material with high performance and low risk in future research with EACS.
通讯机构：
[Chen, YN ; Li, YP ] H;Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Peoples R China.;Hunan City Univ, Sch Municipal & Geomatics Engn, Yiyang 413000, Hunan, Peoples R China.
关键词：
Co-composting;EDTA pretreatment;Cr;Cd;Humification;EDTA-Fenton-like system
摘要：
Improving the efficiency of traditional composting in humic acid (HA) formation and heavy metal (HM) remediation is widely concerned. This study investigated the effects of three pretreatments (ultrapure water, citric acid, and ethylenediaminetetraacetic acid disodium (EDTA)) on the evolution of humification and HMs during the co-composting of rice straw and sediment. The results showed that EDTA pretreatment established an EDTA-Fenton-like system in the co-composting, and observably improved the remediation of HMs and the formation of humic substances (HS). The co-composting with EDTA pretreatment had a lower content of Cr (62.00 mg/kg) and Cd (1.18 mg/kg) than the co-composting without pretreatment (Cr: 83.76 mg/kg, Cd: 3.44 mg/kg). Furthermore, the combined treatment increased the residual fractions of Cr and Cd by 10.35% and 5.80 %, respectively, and simultaneously promoted the formation of HS and HA by 5.20 g/kg and 9.58 g/kg, respectively. In particular, redundancy analysis and structural equation models evidenced that the EDTA-Fentonlike system enhanced the passivation of HMs by facilitating humification during the combined treatment. Our research demonstrates that the EDTA-Fenton-like system could be conducive to the remediation of HM pollution in sediments by co-composting.
摘要：
In this study, tin sulphide (SnS2) and nickel-chromium hydrotalcite (NiCr-LDH) complexes (SnS2/NiCr-LDH) were used for the simultaneous removal of U(VI) and humic acid (HA) from U(VI)-containing wastewater. The results showed that the adsorption of HA by the SnS2/NiCr-LDH was greatly enhanced, which was 4.07 and 2.94 times higher than that of pure SnS2 and NiCr-LDH, respectively, and the highest U(VI) adsorption quantity over SnS2/NiCr-LDH increased from 127.81 to 446.68 mg g(-1) when HA was present. Density functional theory (DFT) calculations revealed that the enhanced U(VI) adsorption on SnS2/NiCr-LDH was facilitated by the formation of a robust inner-sphere surface complex between U(VI) and HA.
关键词：
Image retrieval;Feature extraction;Airplanes;Remote sensing;Visualization;Sports;Image color analysis;Image retrieval with text feedback;multimodal features;remote sensing (RS) image retrieval;scene graph
摘要：
In the realm of image retrieval with text feedback, existing studies have predominantly concentrated on the intrinsic attribute of target objects, neglecting extrinsic information essential for remote sensing (RS) images, such as spatial relationships. This research addresses this gap by incorporating RS image scene graphs as side information, given their capacity to encapsulate internal object attributes, external structural features between objects, and the relationships among images. To fully leverage the features from the reference RS image, scene graph, and modifier sentence, we propose a scene graph-aware hierarchical fusion network (SHF), which optimally integrates the multimodal features in a two-stage fusion process. Initially, image and scene graph features are fused hierarchically, followed by transforming content information with a proposed multimodal global content (MGC) block, ultimately transforming style information. To validate the superiority of SHF, we constructed three datasets with images from several popular RS datasets, named Airplane (3461 image + text-image pairs), Tennis (1924 image + text-image pairs), and WHIRT (3344 image + text-image pairs). Extensive experiments conducted on these datasets show that SHF significantly outperforms state-of-the-art methods.
摘要：
The stability of side slope is very important to the construction and operation of high-speed railway. In this study, we proposed to jointly apply Interferometric synthetic aperture radar (InSAR) and BeiDou Navigation Satellite System (BDS) techniques to identify and monitor side slope along the Changgan high-speed railway. Deformation information along the Changgan high-speed railway was firstly derived by time-series InSAR (TSInSAR) using 68 Sentinel-1A SAR images spanning September 2019 to December 2021 for side slope identification, and then the identified unstable side slope (i.e., Xiahen side slope) was jointly monitored and analyzed by TSInSAR, BDS and unmanned aerial vehicle (UAV). The results show that: (1) TSInSAR can effectively identify unstable side slope, and monitoring results of side slope obtained by TSInSAR and BDS showed good agreement. (2) A large subsidence bowl was identified in the Xiahen side slope, and the maximum subsidence velocity reached − 57 mm/a. (3) Side slope stability was related to side slope treatment. The rainfall change was one of the important factors that affected the deformation of the Xiahen side-slope. The subsidence mainly happened in the rainy season, and a certain lag effect was observed in the subsidence change. (4) Geological structure had a certain influence on side slope deformation.
摘要：
Composting is not only a green and sustainable way to treat and reuse agricultural waste but also an effective method for passivating heavy metals. However, there is no research on the co-composting of the by-products of Camellia oleifera and sediment to simultaneously achieve the remediation of heavy metal and resource utilization of Camellia oleifera by-products. Moreover, MnO 2 and biochar have been widely used to promote humification in the composting process. However, few studies have investigated the efficiency of MnO 2 -loaded biochar in promoting the passivation of heavy metals in the co-composting system of Camellia oleifera by-products and sediment, and its effects on composting biological characteristics are often ignored. Therefore, this study investigated the changes in the heavy metal bioavailability and the microbial communities in sediment and Camellia oleifera by-products co-composting with the additives of MnO 2 -loaded biochar. The results showed that the MnO 2 -loaded biochar effectively passivated heavy metals and improved microbial diversity and structure, which increased the Copper and Lead residual fractions (RES-Cu and RES-Pb) by 14.01 % and 17.57 %, respectively, while the Cadmium exchangeable fraction (EXC-Cd) and the Zinc bioavailability fraction (BF-Zn) decreased by 24.72 % and 10.99 %, respectively. pH, temperature, and bacterial community were the critical regulators for heavy metals passivation by MnO 2 -loaded biochar. This study not only provides a promising resource utilization approach for Camellia oleifera by-products but also provides a new perspective and theoretical reference for the remediation of heavy metals contaminated sediment by composting.
摘要：
The current research studied how Fe(3)O(4) nanomaterials (NMs) and CaO(2) affect humification and Cr(VI) immobilization and reduction during the composting of oil-tea Camellia meal and Cr-contaminated soil. The results showed that Fe(3)O(4) NMs and CaO(2) successfully construct a Fenton-like reaction in this system. The excitation-emission matrix-parallel factor (EEM-PARAFAC) demonstrated that this Fenton-like treatment increased the generation of humic acids and accelerated the humification. Meantime, RES-Cr increased by 5.91% and Cr(VI) decreased by 16.36% in the treatment group with CaO(2) and Fe(3)O(4) NMs after 60days. Moreover, the microbial results showed that Fe(3)O(4) NMs and CaO(2) could promote the enrichment of Cr(VI) reducing bacteria, e.g., Bacillus, Pseudomonas, and Psychrobacter, and promote Cr(VI) reduction. This study gives a novel view and theoretical reference to remediate Cr(VI) pollution through composting.
