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Precise separation and efficient recovery of Pd(Ⅱ) from high-level liquid waste by XAD-based adsorbents

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Rare Metals 2024年第10期43卷 5372-5390页

作者： Hao-Ran Dong Shun-Yan Ning Zeng-Yuan Li Si-Zhi Xu Feng-Tao Hu Feng Gao You-Bin Wang Li-Feng Chen Xiang-Biao Yin Toyohisa Fujita Mohammed F.Hamza Yue-Zhou Wei school of resources Environment and MaterialsGuangxi University school of Nuclear Science and Technology University of South China

Efficient separation of palladium (Pd（II）) from high-level liquid waste （HLLW） not only helps the safe disposal of nuclear waste,but also is a vital importan supplement to Pd（II） ***,16 kinds of nove Amberlite XAD resins-based adsorbents were prepared by vacuum impregnation method for the separation of Pd（II）from simulated HLLW,and the MMBT/XAD7HP prepared using 4-methyl-2-mercaptobenzothiazole （MMBT） as ligand and Amberlite XAD7HP resin （XAD7HP） as the carrier was selected as the optimal research *** analysis experiments proved the successful preparation of MMBT/XAD7HP,which exhibited ultrahigh adsorption selectivity for Pd（II）(distribution coefficient （Kd）≥12584.5 ml·g-1,separation factor (SFPd/M)≥2818.4) and superior adsorption capacity(Q≥130.1 mg·g-1).The adsorption kinetics and adsorption isotherms for Pd（II） matched with pseudo-secondorder （PSO） kinetics model and Langmuir model,indicating that the adsorption mode for Pd（II） by MMBT/XAD7 HP was monolayer chemical *** dynamic column experiments showed that MMBT/XAD7 HP achieved efficiently separation of Pd（II） from simulated HLLW,and the recovery rate was nearly 100% The adsorption mechanism was analyzed by Fourier transform infrared spectroscopy （FTIR）,X-ray photoelectron spectroscopy （XPS） and density functional theory（DFT）,and the ultrahigh selectivity of MMBT/XAD7 HP is attributed to the preferred affinity of the soft-N,S donor atoms in MMBT for Pd（II）.MMBT has the shortest frontline molecular orbital energy band gap （HOMO–LUMO） among the four ligands,which makes it easier to become an electron donor to attract Pd2+to participate in ***3-participates in the adsorption to keep charge *** summary,MMBT/XAD7 HP has broad application prospects for the treatment of Pd（II） in HLLW

关键词： Adsorption Column experiments HLLW Palladium XAD

Analysis and optimization of performance parameters of the 220Rn chamber in flow-field mode using computational fluid dynamics method

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Nuclear Science and Techniques 2024年第10期35卷 130-145页

作者： Shao-Hua Hu Yong-Jun Ye Zheng-Zhong He De-Tao Xiao Xiang-Yu Xu Jian-Kai Wang Qing-Zhi Zhou school of Nuclear Science and Technology University of South China school of resources environment and Safety Engineering University of South China

The impact of the radiation dose produced by222Rn/220Rn and its progeny on human health has garnered increasing interest in the nuclear research field. The establishment of robust, regulatory, and competent220Rn chambers is crucial for accurately measuring radioactivity levels. However, studying the uniformity of the220Rn progeny through experimental methods is challenging, because measuring the concentration of220Rn and its progeny in multiple spatial locations simultaneously and in real time using experimental methods is difficult. Therefore, achieving precise control of the concentration of220Rn and its progeny as well as the reliable sampling of the progeny pose significant challenges. To solve this problem, this study uses computational fluid dynamics to obtain the flow-field data of the220Rn chamber under different wind speeds and progenyreplenishment rates. Qualitative analysis of the concentration distribution of the progeny and quantitative analysis of the progeny concentration and uniformity of the progeny concentration are conducted. The research findings indicated that the progeny concentration level is primarily influenced by wind speed and the progeny-complement rate. Wind speed also plays a crucial role in determining progeny concentration uniformity, whereas the progeny-complement rate has minimal impact on uniformity. To ensure the accuracy of220Rn progeny concentration sampling, we propose a methodology for selecting an appropriate sampling area based on varying progeny concentrations. This study holds immense importance for enhancing the regulation and measurement standards of220Rn and its progeny.

关键词： CFD simulation Progeny Regulatory Thoron

Calcium carbonate promotes the formation and stability of soil macroaggregates in mining areas of China

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Journal of Integrative Agriculture 2024年第3期23卷 1034-1047页

作者： Junyu Xie Jianyong Gao Hanbing Cao Jiahui Li Xiang Wang Jie Zhang Huisheng Meng Jianping Hong Tingliang Li Minggang Xu College of resources and environment Shanxi Agricultural UniversityTaigu 030801China Shanxi Province Key Laboratory of Soil environment and Nutrient resources Taiyuan 030031China College of land Science and Technology China Agricultural UniversityBeijing 100193China

We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to provide a theoretical basis for rapid reclamation of soil fertility in the subsidence area of coal mines in Shanxi Province,*** this study,soil samples of 0–20 cm depth were collected from four fertilization treatments of a longterm experiment started in 2008:no fertilizer (CK),inorganic fertilizer (NPK),chicken manure compost (M),and50%inorganic fertilizer plus 50%chicken manure compost (MNPK).The concentrations of cementing agents and changes in soil aggregate size distribution and stability were *** results showed that the formation of>2 mm aggregates,the aggregate mean weight diameter (MWD),and the proportion of>0.25 mm water-stable aggregates (WR_(0.25)) increased significantly after 6 and 11 years of *** concentration of organic cementing agents tended to increase with reclamation time,whereas free iron oxide (Fed) and free aluminium oxide(Ald) concentrations initially increased but then *** general,the MNPK treatment signi?cantly increased the concentrations of organic cementing agents and CaCO_(3),and CaCO_(3) increased by 60.4%at 11 years after ***,CaCO_(3) had the greatest effect on the stability of aggregates,promoting the formation of>0.25 mm aggregates and accounting for 54.4%of the variance in the proportion and stability of the *** was concluded that long-term reclamation is bene?cial for improving soil *** MNPK treatment was the most effective measure for increasing maize grain yield and concentration of organic cementing agents and CaCO_(3).

关键词： reclamation time manure combined with inorganic fertilizer soil aggregate stability cementing agents CaCO_(3)

The response of structure and nitrogen removal function of the biofilm on submerged macrophytes to high ammonium in constructed wetlands

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Journal of environmental Sciences 2024年第8期142卷 129-141页

作者： Xue Jiang Mengmeng Wang Shunqing Yang Di He Fei Fang Liuyan Yang State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China school of resources and environment Anqing Normal UniversityAnqing 246133China

The ammonium exceedance discharge from sewage treatment plants has a great risk to the stable operation of subsequent constructed wetlands(CWs).The effects of high ammonium shocks on submerged macrophytes and epiphytic biofilms on the leaves of submerged macrophytes in CWs were rarely mentioned in previous *** this paper,the 16S rRNA sequencing method was used to investigate the variation of the microbial communities in biofilms on the leaves of Vallisneria natans plants while the growth characteristics of *** plants were measured at different initial ammonium *** results demonstrated that the total chlorophyll and soluble sugar synthesis of *** plants decreased by 51.45%and 57.16%,respectively,and malondialdehyde content increased threefold after8 days if the initial NH_(4)^(+)-N concentration was more than 5 mg/*** density,bacterial quantity,dissolved oxygen,and pH increased with high ammonium *** average removal efficiencies of total nitrogen and NH_(4)^(+)-N reached 73.26%and 83.94%,*** heat map and relative abundance analysis represented that the relative abundances of phyla Proteobacteria,Cyanobacteria,and Bacteroidetes *** numbers of autotrophic nitrifiers and heterotrophic nitrification aerobic denitrification(HNAD)bacteria expanded in *** particular,HNAD bacteria of Flavobacterium,Hydrogenophaga,Acidovorax,Acinetobacter,Pseudomonas,Aeromonas,and Azospira had higher abundances than autotrophic nitrifiers because there were organic matters secreted from declining leaves of *** *** analysis of the nitrogen metabolic pathway showed aerobic denitrification was the main nitrogen removal ***,the nitrification and denitrification bacterial communities increased in epiphytic biofilms on submerged macrophytes in constructed wetlands while submerged macrophytes declined under ammonium shock loading.

关键词： Ammonium shock loading Biofilm Autotrophic nitrifiers Heterotrophic nitrification aerobic denitrification bacteria Submerged macrophyte

Novel Cs-Mg-Al mixed oxide with improved mobility of oxygen species for passive NOx adsorption

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Green Energy & environment 2024年第10期9卷 1581-1591页

作者： Yimeng Yin Chizhong Wang Lei Qiu Xing Li Feilin Zhao Jie Yu Jinchi Han Huazhen Chang school of environment and Natural resources Renmin University of China Department of Earth System Science Tsinghua University

The development of passive NOxadsorbers with cost-benefit and high NOxstorage capacity remains an on-going challenge to after-treatment technologies at lower temperatures associated with cold-start ***,Cs1Mg3Al catalyst prepared by sol±gel method was cyclic tested in NOxstorage under 5 vol%*** 100°C,the NOxstorage capacity (1219μmol g-1) was much higher than that of Pt/Ba O/Al2O3(610μmol g-1).This provided new insights for non-noble metal catalysts in low-temperature passive *** addition of Cs improved the mobility of oxygen species and thus improved the NOxstorage *** XRD,XPS,IR spectra and in situ DRIFTs with NH3probe showed an interaction between CsOxand AlOxsites via oxygen species formed on Cs1Mg3Al *** improved mobility of oxygen species inferred from O2-TPD was consistent with high NOxstorage capacity related to enhanced formation of nitrate and additional nitrite species by ***,the addition of Mg might improve the stability of Cs1Mg3Al by stabilizing surface active oxygen species in cyclic experiments.

关键词： Passive NO x adsorber Low-temperature NO x storage Cesium Oxygen mobility

An approach to estimate tree height using PolInSAR data constructed by the Sentinel-1 dual-pol SAR data and RVoG model

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Journal of Electronic Science and Technology 2024年第3期22卷 69-79页

作者： Yin Zhang Ding-Feng Duan school of resources and environment University of Electronic Science and Technology of ChinaChengdu611731China

We estimate tree heights using polarimetric interferometric synthetic aperture radar(PolInSAR)data constructed by the dual-polarization(dual-pol)SAR data and random volume over the ground(RVoG)*** the Sentinel-1 SAR dual-pol(SVV,vertically transmitted and vertically received and SVH,vertically transmitted and horizontally received)configuration,one notes that S_(HH),the horizontally transmitted and horizontally received scattering element,is *** S_(HH)data were constructed using the SVH data,and polarimetric SAR(PolSAR)data were *** proposed approach was first verified in simulation with satisfactory *** was next applied to construct PolInSAR data by a pair of dual-pol Sentinel-1A data at Duke Forest,North Carolina,*** to local observations and forest descriptions,the range of estimated tree heights was overall *** the heights with the ICESat-2 tree heights at 23 sampling locations,relative errors of 5 points were within±30%.Errors of 8 points ranged from 30%to 40%,but errors of the remaining 10 points were>40%.The results should be encouraged as error reduction is *** instance,the construction of PolSAR data should not be limited to using SVH,and a combination of SVH and SVV should be ***,an ensemble of tree heights derived from multiple PolInSAR data can be considered since tree heights do not vary much with time frame in months or one season.

关键词： Constructed polarimetric SAR data Dual polarization Sentinel-1 SAR data Polarimetric interferometric SAR Random volume over the ground model Tree height estimation

Participatory Risk Governance for Seoul, South Korea's Flood Risk Management

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International Journal of Disaster Risk Science 2024年第03期15卷 317-331页

作者： Bokjin Ro Gregg Garfin school of Geography Development and Environment The University of Arizona Interdisciplinary Program for Disaster Crisis and Risk Management Sungkyunkwan University school of Natural resources and the environment The University of Arizona

Risk governance is a widely used framework in natural and societal risk management research. Risks from natural hazards in urban areas call for the establishment of rigorous and participatory urban risk governance. In this study, we examined participatory risk governance(PRG) of flood risk management(FRM) in Seoul, South Korea. We conducted key informant interviews and implemented a survey with citizens, to explore perceptions of flood risks and risk management, and to examine prospects for improving PRG in Seoul. We found a gap between the perceptions of key informants and *** informants believed that citizens' low awareness of flood risks hinders PRG. Yet our research found that citizens' risk awareness was not low, and risk awareness may not be the main barrier to participation in PRG. Instead, we found that citizens lacked knowledge of FRM actions, and they assigned government bodies a high level of responsibility for FRM,compared to the level of responsibility that citizens assigned to themselves. Moreover, the actors involved in FRM tended not to trust each other, which implies a lack of mutual understanding. To increase the eff ectiveness of PRG, we suggest a polycentric governance structure anchored by a leading actor group, and active promotion of the participation of actors at multiple levels of governance. Communication between government and citizen participants, designed to foster improved understanding and recognition of one another's roles and contributions to FRM, will enhance trust and improve the implementation of PRG in Seoul.

关键词： Citizen participation Flood risk management Participatory risk governance Risk awareness South Korea Urban flood risk

Research progress in assessment and strategies for sustainable food system within planetary boundaries

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Science China Earth Sciences 2024年第2期67卷 375-386页

作者： Minglei WANG Wenjiao SHI Key Laboratory of land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China College of resources and environment University of Chinese Academy of SciencesBeijing100049China

Meeting the increasing food demand in a manner that ensures both resources and environmental sustainability poses a global *** conceptual framework of planetary boundaries(PBs)has emerged as a crucial reference in the study of sustainable food system,with specific focuses on key dimensions such as land use change,freshwater use,nitrogen(N)and phosphorus(P)cycles,and greenhouse gas(GHG)*** this study,we summarized the threshold applications of PBs in sustainable food system research at both the global and national(China)*** on these thresholds,we evaluated the sustainability conditions of the food system,considering resources such as cropland,freshwater,N and P applications,as well as environmental impacts including N and P losses,and GHG *** addition,we explored the impacts of single or combined management strategies on sustainable food *** strategies included dietary changes,improvements in technologies and management,reductions in food loss and waste,and optimization in agricultural production ***,we outlined future research directions in sustainable food system,including enhancing research on the interaction mechanisms among PBs elements within food systems,conducting downscaling studies of PBs elements at national and regional levels,and ensuring the rationality of policy-making for sustainable food systems in *** study can provide a theoretical foundation and strategies guidance for sustainable food system and agricultural land use management in the future both globally and in China.

关键词： Food system Resource use environmental impacts Sustainable strategy Planetary boundaries

Co-incorporation of Chinese milk vetch(Astragalus sinicus L.)and chemical fertilizers alters microbial functional genes supporting short-time scale positive nitrogen priming effects in paddy soils

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Pedosphere 2024年第3期34卷 567-576页

作者： Limin WANG Chunmei HE Dongfeng HUANG Juhua YU Cailing LIU Qinghua LI Yibin HUANG Juan LI Fei WANG Institute of resources Environment and Soil FertilizerSoil and Fertilizer InstituteFujian Academy of Agricultural SciencesFuzhou 350012(China) school of resources and environment Engineering Anhui UniversityHefei 230601(China)

Nitrogen(N)priming is a microbially mediated biochemical process as affected by different incorporation ***,little information is known about the microbial mechanisms driving the response of N priming to co-operation of Chinese milk vetch(CMV,Astragalus sinicus L.)and different rates of chemical fertilizers in paddy soils in South ***,an anaerobic incubation experiment was conducted to study N priming effects(PE)and their relationships with soil microbial functional genes after CMV incorporation alone(M),co-incorporation of CMV with 100%(normal dosage)chemical fertilizers(MC100),and co-incorporation of CMV with 80% chemical fertilizers(MC80).Co-incorporation of CMV and chemical fertilizers enhanced the short-time scale(the first 20 d of incubation)positive PE of N,while no significant differences existed among the three treatments on day 60 or 90 of incubation(P>0.05).Compared with the M treatment,gross priming effect(GPE)in the MC100 and MC80 treatments significantly increased by 34.0% and 31.3%,respectively,and net priming effect(NPE)increased by 47.7% and 47.8%,respectively,during the first 20 d of incubation(P<0.05).This was likely attributed to soil nutrient availability and added substrate *** MC100 and MC80 treatments increased the gdhA gene abundance by 5.0% and 9.8%,increased the gdh2 gene abundance by 12.7% and 45.7%,and increased the nasB gene abundance by 9.5% and 41.4%,respectively,in comparison with the M treatment on day 20 of *** analyses indicated that soil microbial functional genes involved in N mineralization(gdhA and gdh2),assimilatory nitrate reduction(nasB),and nitrification(amoB)were significantly correlated with N priming under different incorporation practices during the incubation period(P<0.05).Thus,co-incorporation of CMV and chemical fertilizers can regulate soil microbial community functional gene structure,which may accelerate mineralization and assimilatory nitrate reduction and inhibit

关键词： green manure gross priming effect incorporation practice microbial mechanism net priming effect rice field soil