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Mechanisms of synergistic/antagonistic effects of HA-Al(III) coprecipitates on Cr(VI) adsorption and reduction: Influence of C/M ratios

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Colloids and Surfaces A: Physicochemical and Engineering Aspects 2025年 723卷

作者： Yikang Chen Jinqi Zhu Hui Wang Samuel Barnie Yankun Zhang Jia Zhang Jingjie Chang Honghan Chen MOE Key Laboratory of Groundwater Circulation and Environmental Evolution China University of Geosciences (Beijing) Beijing 100083 PR China State Environmental Protection Key laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing 100012 PR China Department of Water and Sanitation School of Physical Sciences University of Cape Coast Cape Coast Ghana Chinese Academy for Environmental Planning Beijing 100020 PR China

In natural environments, amorphous Al(OH)₃ often combines with natural organic matter, such as humic acid, to form complexes through coprecipitation. The adsorption and reduction characteristics and mechanisms of humic acid-Fe(III) coprecipitates with Cr(VI) are well understood, however, research on humic acid-Al(III) coprecipitates is limited. This study aims to investigate the adsorption and reduction characteristics and mechanisms of humic acid-Al(III) coprecipitates with varying initial C/M ratios (carbon to metal ratio 1–20) on Cr(VI). The adsorption of Cr(VI) on the coprecipitates decreased from 0.49 to 0.03 mmol/g with C/M ratios increasing from 1 to 20. The structure of the coprecipitates transformed from “mineral-like” to “organic-like” as the C/M ratio increased, with approximately the C/M ratio being equal to 5 as the turning point. When the C/M ratio was below 5, the coprecipitates exhibited a significant “mineral-like” structure. In this state, the humic acid component blocked the pore space of amorphous Al(OH)₃, favoring Cr(VI) adsorption via surface complexation, resulting in an antagonistic effect on the intra-particle diffusion of Cr(VI). Conversely, when the C/M ratio exceeded 5, the coprecipitates adopted a significant “organic-like” structure. This structural change led to a significant decrease in the coprecipitation pH pzc , increasing the electrostatic repulsion between Cr(VI) anions and negatively charged surface of coprecipitates, manifesting an antagonistic effect on the surface complexation process of Cr(VI). As the C/M ratio continued to rise, the high concentration of humic acid components inhibited the hydrolysis and precipitation of Al(III), reducing the formation of amorphous Al(OH)₃ with a porous structure, which has impacts on the surface complexation of Cr(VI) and reinforced the antagonistic effect on intra-particle diffusion. The reduction of Cr(VI) by coprecipitates with varying C/M ratios is driven by humic acid as the sole elec

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Evaluating the effectiveness of the ecological redline policy in conserving mangroves via assessment on coverage and carbon storage [Environ. Sustain. Indicat. 26 (June 2025) 100650]

Environmental and Sustainability Indicators

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environmental and Sustainability Indicators 2025年 26卷

作者： Jin Liang Yisheng Peng Hanxi Chen Yafei Wang Yu Xing Yan Liao School of Environmental Science and Engineering Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat-sen University Guangzhou 510006 China South China Institute of Environmental Sciences Ministry of Ecology and Environment State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control Guangzhou 510655 China

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Nitrogen-cycling microbial community functional potential and enzyme activities in cultured biofilms with response to inorganic nitrogen availability

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Journal of environmental Sciences 2019年第2期31卷 89-99页

作者： Shuangshuang Li Chengrong Peng Taisheng Cheng Chun Wang Liangliang Guo Dunhai Li Key Laboratory of Algal Biology Institute of HydrobiologyChinese Academy of Sciences Hebei Engineering Research Center for Water Pollution Control and Water Ecological Remediation College of Energy and Environmental EngineeringHebei University of Engineering National University of Tainan Department of Biological Sciences and Technology Environmental Simulation and Pollution Control State Key Joint Laboratory and State Environmental Protection Key Laboratory of Microorganism Application and Risk Control(SMARC) School of EnvironmentTsinghua University

Biofilms mediate crucial biochemical processes in aquatic ecosystems. It was hypothesized that eutrophication may promote the growth of biofilms, resulting in larger numbers of functional genes. However, the metabolic activity and the roles of biofilms in N cycling will be affected by ambient inorganic nitrogen availability, not by the abundance of functional genes. Biofilms were cultured either with replete inorganic nitrogen(N-rep) or without exogenous inorganic nitrogen supply(N-def) in a flow incubator, and the N-cycling gene abundances(nifH, N_2 fixation; amoA, ammonia oxidation, archaea and bacteria; nirS and nirK, denitrification) and enzyme activities(nitrogenase and nitrate reductase) were analyzed. The results showed that, comparing the N-def and N-rep biofilms, the former contained lower nifH gene abundance, but higher nitrogenase activity(NA), while the latter contained higher nifH gene abundance, but lower NA. Different patterns of NA diel variations corresponded to the dynamic microbial community composition and different stages of biofilm colonization. Ammonia oxidizing bacteria(AOB), detected only in N-def biofilms, were responsible for nitrification in biofilms. N-rep biofilms contained high nirS and nirK gene abundance and high denitrification enzyme activity, but N-def biofilms contained significantly lower denitrification gene abundance and activity. In general,the strong N_2 fixation in N-def biofilms and strong denitrification in N-rep biofilms assured the balance of aquatic ecosystems. The results suggested that evaluation of the functional processes of N cycling should not only focus on genetic potential, but also on the physiological activity of biofilms.

关键词： Cultured biofilms Nitrogen availability Nitrogen-cycling enzymes Nitrogen-cycling genes

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Humic Acid Enhances Bioreduction of Facet-Dependent Hematite by Shewanella Putrefaciens Cn-32: Interfacial Mechanism Study

SSRN

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SSRN 2022年

作者： Lu, Yang Hu, Shiwen Zhang, Hanyue Song, Qingmei Zhou, Wenjing Shen, Xinyue Xia, Di Liu, Chongxuan 7 West Street Yuancun Guangdong Guangzhou510655 China State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of the Environmental Science and Engineering Southern University of Science and Technology Shenzhen518055 China CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province Chengdu Institute of Biology Chinese Academy of Sciences Chengdu610041 China

Interfacial reaction on iron (Fe) mineral surface and activity of bacteria during the dissimilatory Fe reduction affect the extracellular electron transfer, and the presence of organic matter (OM) and exposed facets of Fe minerals may complicate this process. However, the underlying interfacial mechanism of facet-dependent hematite and its toxicity toward microbe during the bioreduction under the impact of OM remains unknown. Herein, humic acid (HA), as a typical OM, was selected to investigate its influence on the bioreduction of hematite {100} and {001}. When HA concentration increased from 0 to 500 mg L-1, the bioreduction rates of Fe mineral increased from 0.02 to 0.04 h-1 for hematite {100} and 0.026 to 0.05 h-1 for hematite {001}. Since hematite {001} owned lower resistance than hematite {100} irrespective of HA concentrations, hematite {100} was less favorable for reduction. Microscopic analysis showed that more hematite {001} nanoparticles were adhered onto cell surface and bound more closely to bacteria and less damage of cell was observed in HA-hematite {001} treatments. As the reaction processed, partial of bacteria inactivate or die, and higher bacterial survival found in HA-hematite {001} treatments after bioreduction based on confocal laser scanning microscope. Spectroscopic analysis revealed that facet-dependent binding was primarily realized by surface complexation of carboxyl functional group with structural Fe atoms and the binding order of FA functional groups and hematite was affected by exposed facets. Our results uncovered that exposed facets of hematite can influence the electrochemical property and the activity of bacterial as well as the binding of bacteria and Fe mineral in the presence of OM, thereby governing the extracellular electron transfer and concomitant bioreduction of Fe mineral. These results provide new insights into the interfacial reactions between OM and facet-dependent Fe minerals in anoxic soil environments. © 2022, The Aut

关键词： Hematite

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Temporal responses of DOM molecular characteristics to conversion from dryland to paddy field: Insights from soil aggregate size fractionation

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environmental Technology & Innovation 2025年 39卷

作者： Shuhe Chen Yiman Gao Xuemin Ma Dan Li Fei Fang Ying Yuan Beidou Xi Wenbing Tan State Key Laboratory of Environmental Criteria and Risk Assessment and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing 100012 China College of Water Sciences Beijing Normal University Beijing 100875 China Research Center of Environmental Pollution Control Technology Chinese Research Academy of Environmental Sciences Beijing 100012 China Technical Centre for Soil Agriculture and Rural Ecology and Environment Ministry of Ecology and Environment Beijing 100012 China

Dissolved organic matter (DOM) is predominantly present within soil aggregates and its structure critically influence the environmental behavior of pollutants. However, the long-term evolution of DOM structure across aggregate sizes following dryland-to-paddy conversion remains unclear. This study examined the structure characteristics of DOM in paddy soils at land use change sequence (5, 12, 21, 29, 41, and 53 years) across different aggregate size fractions (<2, 2–53, 53–250 and 250–2000 μm). Three-dimensional fluorescence spectroscopy, UV–visible spectroscopy, and elemental composition analysis were employed. The results showed that < 2 μm aggregates contained protein-like, tryptophan-like, LVA-like humic substances (Longer wavelength humic-like component), humic acid-like, and LVC-like humic substances (Lower wavelength humic-like component), with < 5 % variation throughout the conversion; 2–53 μm aggregates exhibited relatively uniform DOM component distribution; 53–250 μm aggregates were dominated by LVC-like humic substances and humic acid-like components (collectively 60 %); 250–2000 μm aggregates primarily contained humic acid-like and LVA-like humic substances. Spectral parameter analysis (SUVA 254 , E 4 /E 6 , and A 240–400 , S R and HIX) elucidated the co-evolutionary dynamics of DOM structure with aggregate size fractions and land-use conversion chronology. The results demonstrated that DOM in smaller aggregates (<2 μm and 2–53 μm) exhibited elevated aromaticity and stabilized humification features, while the 250–2000 μm fraction was dominated by high-molecular-weight DOM with pronounced aromaticity fluctuations across conversion stages. Two-way ANOVA confirmed significant time-size interactive effects ( P  < 0.001). These findings offer new insights into DOM structure dynamics during paddy soil evolution, with implications for carbon pool management in agroecosystems.

关键词： Land use change Sized-aggregate Molecular structure Spectroscopic analysis

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Study on weak signal amplitude detection and circuit simulation based on a new chaotic system

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Chaos, Solitons and Fractals 2025年 198卷

作者： Zhao, Zhijie Yang, Ruyue Liu, Jing Liu, Guoqiang Institute of Electrical Engineering Chinese Academy of Sciences Beijing100190 China School of Electronic Electrical and Communication Engineering University of Chinese Academy of Sciences Beijing100049 China State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing100012 China

The filtering circuit is a crucial component in signal conditioning systems for noise reduction. However, its susceptibility to the measurement environment makes it challenging for signal conditioning circuits to process weak signals with high precision. In the context of flow signal detection using slurry-type electromagnetic flowmeters, the limited capability of traditional filter circuits to detect weak signals has led to difficulties in the measurement of small flow signals. To address this, in this study, we present a novel N-dimensional nonlinear dynamic system designed to outperform conventional filter circuits in weak signal detection. Under the excitation of weak low-frequency square wave signals, we verified the existence of chaotic states in the proposed system and analysed its chaos synchronisation. We proposed a method for detecting weak low-frequency square wave signals in the time domain using chaos synchronisation, thus overcoming the limitation of traditional chaotic systems, which are typically constrained to phase diagram analysis for weak signal detection. Numerical simulation and circuit simulation experiments were conducted, and the results showed that, in the absence of noise, the chaos synchronisation curve outputted by the new chaotic system demonstrates a linear relationship with the inputted weak square wave signal. The peak-to-peak values derived from the curve were used to accurately determine the amplitudes of weak square wave signals. A signal processing procedure was proposed to identify the amplitudes of weak signals under strong noise interference based on the peak-to-peak values outputted by the new chaotic system and two traditional analogue filters. Circuit simulation results showed that, under the influence of noise, the accuracy of the new chaotic circuit in linearly recognising the weak square wave amplitude was as high as 93.39 %, whereas those of the band-pass and low-pass filter circuits were only 81.76 % and 74.42 %, respe

关键词： Low pass filters

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Continuous and comprehensive atmospheric observations in Beijing:a station to understand the complex urban atmospheric environment

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Big Earth Data 2020年第3期4卷 295-321页

作者： Yongchun Liu Chao Yan Zemin Feng Feixue Zheng Xiaolong Fan Yusheng Zhang Chang Li Ying Zhou Zhuohui Lin Yishou Guo Ying Zhang Li Ma Wenshuo Zhou Zhikun Liu Lubna Dada Kaspar Dallenbach Jenni Kontkanen Runlong Cai Tommy Chan Biwu Chu Wei Du Lei Yao Yonghong Wang Jing Cai Juha Kangasluoma Tom Kokkonen Joni Kujansuu Anton Rusanen Chenjuan Deng Yueyun Fu Rujing Yin Xiaoxiao Li Yiqun Lu Yiliang Liu Chaofan Lian Dongsen Yang Weigang Wang Maofa Ge Yuesi Wang Douglas R.Worsnop Heikki Junninen Hong He Veli-Matti Kerminen Jun Zheng Lin Wang Jingkun Jiang Tuukka Petaja Federico Bianchi Markku Kulmala Aerosol and Haze Laboratory Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical TechnologyBeijingChina Institute for Atmospheric and Earth System Research/Physics Faculty of ScienceUniversity of HelsinkiHelsinkiFinland State Key Joint Laboratory of Environment Simulation and Pollution Control State Environmental Protection Key Laboratory of Sources and Control of Air Pollution ComplexSchool of EnvironmentTsinghua UniversityBeijingChina State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijingChina Department of Environmental Science&Engineering Fudan UniversityShanghaiChina State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijingChina Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Nanjing University of Information Science&TechnologyNanjingChina State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina Aerodyne Research Inc. BillericaMassachusettsUSA Institute of Physics University of TartuTartuEstonia Joint International Research Laboratory of Atmospheric and Earth System Sciences School of Atmospheric SciencesNanjing UniversityNanjingChina

Due to profound impact on climate and human health,air quality has attracted attention from all levels of the civil *** key step in the provision of required tools for the society to tackle the complex air quality problem is to characterize it in a comprehensive manner with a long-term ***,we describe a continuous and comprehensive observation station and its accompanying state-ofthe-art instrumentation that was established to investigate the complex urban atmospheric environment in a rapidly developing Chinese *** station,located in downtown Beijing,aims to study air quality by identifying the major atmospheric pollutants and key processes determining their formation and loss mechanisms.A few hundreds of parameters are continuously measured with the state-of-the-art instruments,including trace gas concentrations,aerosol particle size distributions,and mass concentrations,covering aerosol particle chemical composition from molecules to micrometer-sized aerosol *** produced long-term,comprehensive big data with around 1�10^(11)bytes per *** this paper,we provide an overview on the facilities of the station,the instrumentation used,the workflow of continuous observations and examples of results from 2018 to 2019 and a basis for establishing a modern long-term,comprehensive atmospheric urban observation station in other megacities.

关键词： Continuous and comprehensive atmospheric observation air pollution complex photochemical smog haze new particle formation

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Stress-Resistant Plants Cyndon Dactylon in a Riparian Zone of the Three Gorges Reservoir Has Additional Nitrogen-Fixing Functions from Bacterial Endophytes

SSRN

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SSRN 2022年

作者： Li, Shanze Wang, Yuchun Hu, Lechen Zhao, Jianwei Liao, Xiaolin Xie, Tian Wen, Jie Bao, Yufei Li, Longfei State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower Research Beijing100038 China Department of Water Ecology and Environment China Institute of Water Resources and Hydropower Research Beijing100038 China Laboratory of Eco-Environmental Engineering Research State Environmental Protection Key Laboratory of Soil Health and Green Remediation Huazhong Agricultural University Wuhan430070 China College of Biology and the Environment Nanjing Forestry University Jiangsu Nanjing210037 China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing100875 China

Water conservancy and hydropower projects have greatly altered the ecological balances in riparian zones, including nitrogen cycling. The riparian zone of the Three Gorges Reservoir is now dominated by a perennial stress tolerant plant, Cyndon dactylon, where long-term wet and dry alternation has caused severe soil nitrogen leaching. This study investigated whether this plant species employs mechanisms for enhanced nitrogen assimilation or other nitrogen compensation strategies to counter soil nitrogen loss in its habitat. Our study found for the first time that the C. dactylon in the Three Gorges Reservoir riparian zone had endophytic nitrogen-fixing bacteria, which were particularly enriched in the plant leaves. The abundance of endophytic nitrogen-fixing bacteria was significantly negatively correlated with soil ammonia, nitrate, and organic matter, and significantly positively correlated with total phosphorous and moisture content. The endophytic nitrogen-fixing bacteria in C. dactylon were highly diverse, with Proteobacteria as the main dominant genera. The mutual cooperation mode among bacterial species made the endophytic nitrogen-fixing bacteria community of C. dactylon more resilient to environmental pressure, thus were capable of more readily adapting to conditions of repeated flooding in the riparian zone of the Three Gorges Reservoir. © 2022, The Authors. All rights reserved.

关键词： Nitrogen

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Numerical simulation of Tidal Beach Seawater-groundwater Circulations Using Dimensionless Method

SSRN

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SSRN 2024年

作者： Wang, Wei Cui, Laitong Geng, Xiaolong Luo, Manhua Yu, Shengchao Wang, Qianqian Li, Hailong School of Environmental Science and Engineering Southern University of Science and Technology Shenzhen518055 China State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and Engineering Southern University of Science and Technology Shenzhen China School of Water Resources and Environment China University of Geosciences-Beijing Beijing100083 China Department of Earth Sciences University of Hawai‘i at Mānoa HonoluluHI96822 United States Water Resources Research Center University of Hawai‘i at Mānoa HonoluluHI96822 United States Department of Civil and Resource Engineering Center for Water Resources Studies Dalhousie University HalifaxNS Canada State Key Laboratory of Estuarine and Coastal Research East China Normal University Shanghai China

Our previous study developed a dimensionless model to quantify seawater-groundwater circulations in tidally influenced beach systems, wherein the model parameters were non-dimensionalized. Although the model can be reasonably transformed to apply to various dimensionalized beach domains with slopes ranging from 3.16% to 31.6%, the model was limited by a narrow applicable range of the permeability parameter (K) values, excluding very permeable or less permeable beaches (i.e., the hydraulic conductivity K > 10-3 m/s or © 2024, The Authors. All rights reserved.

关键词： Hydraulic conductivity

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Preparation and characterization of colorful graphene oxide papers and flexible N-doping graphene papers for supercapacitor and capacitive deionization

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Carbon Energy 2020年第4期2卷 656-674页

作者： Hao Zhang Aiyang Li Ying Yuan Yuquan Wei Di Zheng Zhuning Geng Haichuan Zhang Guanghe Li Fang Zhang School of Environment and State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijingChina National Engineering Laboratory for Site Remediation Technologies BeijingChina Chinese Research Academy of Environmental Sciences BeijingChina Beijing Key Laboratory of Biodiversity and Organic Farming College of Resources and Environmental SciencesChina Agricultural UniversityBeijingChina

An efficient method that utilizes simple techniques,easy operation,and low-cost production to create flexible graphene-based materials is a worthy practical challenge.A rapid strategy for preparing flexible,functional graphene oxide(GO)is introduced using GO-ethanol dispersion *** filtration process is highly efficient and drying time is significantly reduced by employing ethanol as solvent,due to the fact that ethanol is a volatile *** GO papers can be harvested with ultralarge size(700 cm2),color variety,and writable *** reduction,N-doped graphene(NDG)papers still maintain good foldability with improved electric conductivity and porous *** used as an electrode for a supercapacitor,the flexible NDG paper device demonstrates good electrochemical performance even with size expansion and extreme double ***,this NDG paper capacitor device shows a good electrosorption performance for capacitive deionization of sulfate and chromate in groundwater *** flexible GO and NDG papers promise potential to facilitate the production of graphene-based materials for practical applications in energy and environmental related fields.

关键词： colorful graphene oxide energy storage flexible graphene paper N-doped graphene supercapacitor

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