摘要：
Cadmium (Cd)-contaminated rice paddies have been a primary environmental concern worldwide. Biochar or modified biochar application favors reducing Cd availability in paddy soil, which has been demonstrated in physical and chemical terms. However, we know little about soil microbial responses after biochar application. In this study, we revealed the immobilization effect and mechanism of Cd in paddy fields by a novel phosphorite magnetic biochar (PMCB) from the perspective of soil microbial response. The results suggested that PMCB application facilitated the conversion of highly active Cd to less active Cd in soil and reduced Cd uptake by rice by improving soil physicochemical properties and functional bacterial and gene abundance. Compared with the control, acetic acid extractable Cd and reducible Cd contents in soil and Cd content in brown rice decreased by 7.4%–18.4%, 16.2%–19.9%, and 44.0%–47.9%, respectively, and residual Cd content increased by 16.3%–25.8% under PMCB treatment. A decrease in sqr and fccB gene abundances (downregulated by 6.3% and 12.4%, respectively) inhibited CdS oxidative dissolution after 0.2% PMCB application. Conversely, other treatments stimulated the abundant proliferation of functional microbes (e.g., Anaeromyxobacter , Geobacter , and Thiobacillus ) and these genes while suppressing sulfide-producing gene abundance (sreA and phsA decreased by 30.5%–73.4% and 3.3%–11.3%, respectively). This result implies that Fe(III) mineral reduction and CdS oxidation lead to a limited secondary release of Cd. Additionally, aqueous-phase analysis of the immobilization mechanism revealed that PMCB immobilized Cd mainly by coprecipitation with PO 4 3− and CO 3 2− (34.5%) and ion exchange (32.2%), followed by surface complexation (18.7%) and cation π-bonding (13.1%).
摘要：
In this paper, a novel collector dihexyl (2-(hydroxyamino)-2-oxoethyl) phosphonate (DHHAOEP) was synthesized and used as a flotation collector to separate scheelite from quartz. Micro-flotation experiments demonstrated that DHHAOEP can effectively separate scheelite from quartz within a pH range of 6-9. Artificial mixed ores flotation experiments revealed that at a pH of approximately 8 and a DHHAOEP concentration of 8 × 10(-5) mol/L, the flotation recovery of scheelite reached 73% with a grade of 54%. The contact angle and Zeta potential measurements showed that the addition of DHHAOEP caused a positive shift in the zeta potential and enhanced the surface hydrophobicity of scheelite. The FTIR, XPS, and DFT analyses further elucidated that DHHAOEP anchored on the scheelite surface through the bonding reaction between its -C(=O)-NHOH moiety and WO(4)(2-) or Ca active sites on the scheelite surface, forming a five-membered ring. Meanwhile, the existence of the P=O group makes the distance between oxygen atoms in -C(=O)-NHOH very close to that in WO(4)(2+), which is beneficial to the reaction. The present work aims to develop a novel flotation collector with multi-functional groups to enhance scheelite recovery efficiency and selectivity.
摘要：
The development of a photoelectrode featuring both excellent reusability and a simple preparation process remains exceptionally challenging for TiO2-based photoelectrocatalytic technology. Herein, a three-dimensional photoelectrode with N doping, oxygen vacancies (Ovs), and carbon layers (NTC) was prepared via the "carbothermal reduction-pressing-calcination" method. The photoelectrode degraded 97.94% of tetracycline (TC) within 60 min. The first-order kinetic constant for this degradation was 27.3 times higher than that of TiO2-x, and the photoelectric synergy factor reached as high as 13.9. The photoelectrode also demonstrated outstanding anti-interference capability for pH, electrolyte concentration, anions, etc., and was suitable for different water matrixes and various antibiotics removal. In particular, the degradation efficiency of TC decreased by only 1.33% after 20 cycles, demonstrating the excellent reusability of NTC. Furthermore, photoexcited holes (h+) were the dominant active species, and singlet oxygen (1O2) and superoxide radicals (•O2−) played an auxiliary role in removing TC. Finally, possible degradation pathways for TC were proposed and demonstrated to be effective in reducing the toxicity of the pollutant by the Toxicity Evaluation Software Tool (T.E.S.T) and phytotoxicity experiments. This progress might bring new insights into the design and construction of TiO2-based photoelectrodes.
The development of a photoelectrode featuring both excellent reusability and a simple preparation process remains exceptionally challenging for TiO2-based photoelectrocatalytic technology. Herein, a three-dimensional photoelectrode with N doping, oxygen vacancies (Ovs), and carbon layers (NTC) was prepared via the "carbothermal reduction-pressing-calcination" method. The photoelectrode degraded 97.94% of tetracycline (TC) within 60 min. The first-order kinetic constant for this degradation was 27.3 times higher than that of TiO2-x, and the photoelectric synergy factor reached as high as 13.9. The photoelectrode also demonstrated outstanding anti-interference capability for pH, electrolyte concentration, anions, etc., and was suitable for different water matrixes and various antibiotics removal. In particular, the degradation efficiency of TC decreased by only 1.33% after 20 cycles, demonstrating the excellent reusability of NTC. Furthermore, photoexcited holes (h+) were the dominant active species, and singlet oxygen (1O2) and superoxide radicals (•O2−) played an auxiliary role in removing TC. Finally, possible degradation pathways for TC were proposed and demonstrated to be effective in reducing the toxicity of the pollutant by the Toxicity Evaluation Software Tool (T.E.S.T) and phytotoxicity experiments. This progress might bring new insights into the design and construction of TiO2-based photoelectrodes.
摘要：
Microplastic (MP) pollution poses a significant challenge for municipal solid waste (MSW) management, while landfills have been recognized as a primary source of secondary MPs, waste incineration offers a potential solution for MP elimination. This study discovered a kind of specifically MP-rock blends, which are generated through the melt-recrystallization of different plastics during incineration. MP-rock blend of polypropylene (PP) and polyethylene (PE) was confirmed using in-situ FTIR microscopy (LUMOS II), and three distinct morphologies, i.e., the type of overlapping intertwined, surface welded, and secondary molten recrystallization, were observed based on bonding intensity. Inorganic materials, such as calcium oxide (CaO) and silica (SiO₂), were observed embedded within MP surfaces. MP blends, including PP+PE, PP + polystyrene (PS), and PS + polyvinyl chloride (PVC), were found in bottom ash from ten incineration plants, with MP concentrations ranging from 0.6 to 3.9 mg/kg of ash and Loss on ignition percentages of 5.55–15.57%. The formation process exhibited strong temperature dependence, as plastic-inorganic sintering occurred above 900°C, corresponding to typical operational temperatures in these incineration facilities. The formation of plastic–inorganic hybrids revealed three plastic blend systems demonstrating distinct structural evolution pathways and hybridization behaviors under high-temperature incineration conditions, as characterized by two-dimensional correlation spectroscopy analysis of simulated byproducts. This work provides empirical evidence for anthropogenic plastic-inorganic hybrids, which should be considered seriously for the potential resource process.
Microplastic (MP) pollution poses a significant challenge for municipal solid waste (MSW) management, while landfills have been recognized as a primary source of secondary MPs, waste incineration offers a potential solution for MP elimination. This study discovered a kind of specifically MP-rock blends, which are generated through the melt-recrystallization of different plastics during incineration. MP-rock blend of polypropylene (PP) and polyethylene (PE) was confirmed using in-situ FTIR microscopy (LUMOS II), and three distinct morphologies, i.e., the type of overlapping intertwined, surface welded, and secondary molten recrystallization, were observed based on bonding intensity. Inorganic materials, such as calcium oxide (CaO) and silica (SiO₂), were observed embedded within MP surfaces. MP blends, including PP+PE, PP + polystyrene (PS), and PS + polyvinyl chloride (PVC), were found in bottom ash from ten incineration plants, with MP concentrations ranging from 0.6 to 3.9 mg/kg of ash and Loss on ignition percentages of 5.55–15.57%. The formation process exhibited strong temperature dependence, as plastic-inorganic sintering occurred above 900°C, corresponding to typical operational temperatures in these incineration facilities. The formation of plastic–inorganic hybrids revealed three plastic blend systems demonstrating distinct structural evolution pathways and hybridization behaviors under high-temperature incineration conditions, as characterized by two-dimensional correlation spectroscopy analysis of simulated byproducts. This work provides empirical evidence for anthropogenic plastic-inorganic hybrids, which should be considered seriously for the potential resource process.
摘要：
Herein, a novel surfactant dihexyl (2-amino-2-(hydroxyimino)ethyl) phosphonate (DHAHEP) was synthesized by combining phosphonate and amidoxime groups in the same molecule, and used as a flotation collector for quartz vein-type wolframite. The Micro-flotation results showed that DHAHEP has excellent collection performance for wolframite, at pH 2 ∼ 4.5, the flotation recovery of DHAHEP for wolframite was over 90 %, while that for quartz was less than 60 %. The wolframite-quartz artificial mixed ores experiments demonstrated that at pH ∼ 4 and DHAHEP concentration of 8 × 10-5 mol·L-1, the flotation recovery of wolframite was 64.5 % and the grade was 48.9 %. Zeta potential and contact angle experiments elucidated that DHAHEP anchored on the wolframite surface mainly in the form of cations, increasing the hydrophobicity of the surface and thus separating the wolframite from quartz by flotation. FTIR, XPS, and DFT calculation further revealed that DHAHEP had an obvious flotation separation effect on quartz vein-type wolframite, it was mainly electrostatically adsorbed on the WO42- sites of the wolframite surface in the form of cations, and also captured wolframite by forming chemical bonds with the Fe active sites through the phosphoryl and amidoxime groups in its molecular structure.
Herein, a novel surfactant dihexyl (2-amino-2-(hydroxyimino)ethyl) phosphonate (DHAHEP) was synthesized by combining phosphonate and amidoxime groups in the same molecule, and used as a flotation collector for quartz vein-type wolframite. The Micro-flotation results showed that DHAHEP has excellent collection performance for wolframite, at pH 2 ∼ 4.5, the flotation recovery of DHAHEP for wolframite was over 90 %, while that for quartz was less than 60 %. The wolframite-quartz artificial mixed ores experiments demonstrated that at pH ∼ 4 and DHAHEP concentration of 8 × 10-5 mol·L-1, the flotation recovery of wolframite was 64.5 % and the grade was 48.9 %. Zeta potential and contact angle experiments elucidated that DHAHEP anchored on the wolframite surface mainly in the form of cations, increasing the hydrophobicity of the surface and thus separating the wolframite from quartz by flotation. FTIR, XPS, and DFT calculation further revealed that DHAHEP had an obvious flotation separation effect on quartz vein-type wolframite, it was mainly electrostatically adsorbed on the WO42- sites of the wolframite surface in the form of cations, and also captured wolframite by forming chemical bonds with the Fe active sites through the phosphoryl and amidoxime groups in its molecular structure.
关键词：
Policy;FVC;Artificial reclamation;Remote sensing;Historic mines;Moran index
摘要：
The vegetation in Huayuan County was seriously damaged during the mining process. Using remote sensing data, the vegetation coverage in the Huayuan County lead–zinc mining area was analysed to explore the temporal trends and driving factors of the FVC. As calculated from remote sensing data, the average FVC decreased rapidly from 0.74 to 0.36 from 2000--2008, with no significant change from 2009 to -2018, and gradually recovered from 0.36 to 0.5 from 2019--2024. Two typical mining areas were selected for research. After artificial reclamation, the damaged vegetation can be restored, whereas the vegetation in the naturally restored mining area is difficult to restore. The cluster map of the mining area is obtained via the Moran index, which reveals that artificial reclamation has an obvious effect on vegetation restoration. The destruction of vegetation in mining areas is affected primarily by human activities, while human activities are affected primarily by changes in policy; thus, policy factors are the main factors driving changes in vegetation in mining areas, whereas natural factors have a small influence on changes in the FVC in mining areas. This study provides a theoretical basis for vegetation restoration in other mining areas and promotes sustainable development.
The vegetation in Huayuan County was seriously damaged during the mining process. Using remote sensing data, the vegetation coverage in the Huayuan County lead–zinc mining area was analysed to explore the temporal trends and driving factors of the FVC. As calculated from remote sensing data, the average FVC decreased rapidly from 0.74 to 0.36 from 2000--2008, with no significant change from 2009 to -2018, and gradually recovered from 0.36 to 0.5 from 2019--2024. Two typical mining areas were selected for research. After artificial reclamation, the damaged vegetation can be restored, whereas the vegetation in the naturally restored mining area is difficult to restore. The cluster map of the mining area is obtained via the Moran index, which reveals that artificial reclamation has an obvious effect on vegetation restoration. The destruction of vegetation in mining areas is affected primarily by human activities, while human activities are affected primarily by changes in policy; thus, policy factors are the main factors driving changes in vegetation in mining areas, whereas natural factors have a small influence on changes in the FVC in mining areas. This study provides a theoretical basis for vegetation restoration in other mining areas and promotes sustainable development.
作者机构：
[Zhou, Yihui; Yi, Shi; Lei, Xiping; Zhou, YH; Yi, S] Hunan Automot Engn Vocat Coll, Zhuzhou 412001, Peoples R China.;[Zhou, Yihui; Qiu, Jingxian; Zhou, YH] Aerosp Kaitian Environm Technol Co Ltd, Changsha 410100, Peoples R China.;[Peng, Qingjuan] Hunan Univ, Coll Chem & Chem Engn, Changsha, Peoples R China.;[Liu, Kang; Hu, Simeng] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha, Peoples R China.;[Cai, Qunhuan] Hunan New Frontier Sci & Tech Co Ltd, Changsha, Peoples R China.
通讯机构：
[Zhou, YH; Yi, S ] H;[Zhou, YH ] A;Hunan Automot Engn Vocat Coll, Zhuzhou 412001, Peoples R China.;Aerosp Kaitian Environm Technol Co Ltd, Changsha 410100, Peoples R China.
关键词：
Mn2+;Pulse-alternating current coagulation;parameter optimization;removal mechanism;wastewater
摘要：
To assess the effectiveness and underlying mechanism of pulse-alternating current coagulation (PACC) for treating manganese-laden wastewater, we examined the influence of various parameters. Specifically, we investigated the impact of current density, initial pH, initial Mn2+ concentration, electrolyte concentration, and alternating current frequency on the removal efficacy. The removal mechanism was meticulously examined using an adsorption kinetics analysis, Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectrum (FTIR), and X-ray Photoelectron Spectroscopy (XPS). The findings indicated that the concentration of R-e(Mn2+) was 99.09% under the specified conditions: j = 2.5 A<middle dot>m(-2), pH(0 )= 7, c(0)(Mn2+) = 50 mg<middle dot>dm(-3), f = 500 Hz, c(0)(NaCl) = 500 mg<middle dot>dm(-3) and t = 40 min. When R-e(Mn2+) = 98%, the energy consumption (EEC) was significantly lower for PACC at 1.23 kWh<middle dot>m(-3), compared to 1.52 kWh<middle dot>m(-3) for direct current condensation (DCC). This indicated a reduction in EEC by 19.1% when using PACC over DCC. The adsorption process of Mn2+ by the iron sol adheres to the principles of pseudo-second order kinetics. The primary component of flocs generated in the PACC process is alpha-FeOOH. The mechanism of Mn2+ removal in the PACC process involved the synthesis of Mn oxides, the formation of metal hydroxide precipitates and adsorption by nano-iron sol. This study provides a theoretical basis and technical support for the application of PACC technology in the field of manganese-containing wastewater treatment. [GRAPHICS] .
期刊：
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING,2025年13(6):119343 ISSN：2213-2929
通讯作者：
Li, QZ
作者机构：
[Yang, Weichun; Zhou, Kang; Li, Qingzhu; Wang, Qingwei; Si, Mengying; Liao, Qi; Xing, Yukang; Yang, Zhihui; Huang, Xiaofeng; Wan, Yuhan] Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.;[Yang, Weichun; Li, Qingzhu; Wang, Qingwei; Si, Mengying; Liao, Qi; Yang, Zhihui] Cent South Univ, Natl Engn Res Ctr Control & Treatment Heavy Met Po, Changsha 410083, Peoples R China.;[Yang, Weichun; Li, Qingzhu; Wang, Qingwei; Si, Mengying; Liao, Qi; Yang, Zhihui] State Key Lab Adv Met Nonferrous Met, Changsha 410083, Peoples R China.;[Peng, Peiqin; Long, Jian] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Peoples R China.
通讯机构：
[Li, QZ ] C;Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.
关键词：
Cadmium and arsenic;Co-contamination;Fractionation;Key drivers;Cd isotope
摘要：
Assessing cadmium(Cd) and arsenic(As) co-contamination and understanding their drivers are crucial for soil pollution management and remediation. However, the specific patterns of environmental factors and their contributions to the transformation and fractionation of Cd and As across soil particle size fractions remain unclear. This study clarifies key drivers (e.g., soil minerals, particle size, environmental factors) of Cd and As speciation transformation. Sequential extraction revealed distinct speciation patterns: Cd dominated exchangeable/carbonate-bound phases (>60 % total), whereas As primarily resided in stable crystalline Fe oxides and residual forms (>70 % total). Notably, Cd's active fraction concentrated in 1–5 μm particles, while As exhibited higher availability concentrations in 5–50 μm fractions. Redundancy analysis (RDA) revealed that mineral fractions and soil properties accounted for 61.57 % of the variation in Cd fractionation transformation, with pH(11.5 %), amorphous Fe(10.6 %), and exchangeable Ca (8.4 %) identified as the dominant factors. The main drivers of As transformation were Fe(II)(11.7 %), amorphous iron(12.7 %) and water-soluble calcium(8.9 %). In addition, Cd isotope fractionation results indicate that Cd interacts with soil calcium salts via chemical precipitation and with iron (hydroxide) oxides by adsorption. These results elucidate Cd and As speciation dynamics in microscale soil matrices, revealing key drivers among soil constituents and informing remediation strategies for co-contaminated soils.
Assessing cadmium(Cd) and arsenic(As) co-contamination and understanding their drivers are crucial for soil pollution management and remediation. However, the specific patterns of environmental factors and their contributions to the transformation and fractionation of Cd and As across soil particle size fractions remain unclear. This study clarifies key drivers (e.g., soil minerals, particle size, environmental factors) of Cd and As speciation transformation. Sequential extraction revealed distinct speciation patterns: Cd dominated exchangeable/carbonate-bound phases (>60 % total), whereas As primarily resided in stable crystalline Fe oxides and residual forms (>70 % total). Notably, Cd's active fraction concentrated in 1–5 μm particles, while As exhibited higher availability concentrations in 5–50 μm fractions. Redundancy analysis (RDA) revealed that mineral fractions and soil properties accounted for 61.57 % of the variation in Cd fractionation transformation, with pH(11.5 %), amorphous Fe(10.6 %), and exchangeable Ca (8.4 %) identified as the dominant factors. The main drivers of As transformation were Fe(II)(11.7 %), amorphous iron(12.7 %) and water-soluble calcium(8.9 %). In addition, Cd isotope fractionation results indicate that Cd interacts with soil calcium salts via chemical precipitation and with iron (hydroxide) oxides by adsorption. These results elucidate Cd and As speciation dynamics in microscale soil matrices, revealing key drivers among soil constituents and informing remediation strategies for co-contaminated soils.
摘要：
The accumulation of environmental pollutants and dust, along with the formation of dirt, has led to severe surface contamination, resulting in the deterioration and contamination of substrate surfaces, which has significantly escalated cleaning and maintenance expenses. Although various anti-dust surfaces have been developed in previous studies, challenges still persist in achieving long-lasting dust protection while maintaining transparency and functional diversity. The present study aims to develop a three-layer composite coating, which exhibits superhydrophilic self-cleaning performances and can be applied onto various substrates at ambient temperature. This innovative coating integrates the principles of anti-static behavior and micro-nanostructured surface topography to effectively prevent dust accumulation. The surface resistance of the coating can be maintained in the range of 10 4 –10 6 Ω/sq, ensuring long-lasting dust resistance in outdoor environments and facilitating self-cleaning of the coated surfaces due to their superhydrophilic properties (water contact angle less than 5°). In addition, the coating exhibits exceptional transmittance with a peak transmittance of 97 % within the 400–800 nm wavelength range. This attribute renders it highly suitable for extensive utilization in applications such as photovoltaics, glass facades, and other fields that demand superior transparency. Notably, by ingeniously incorporating cellulose nanocrystals renowned for their remarkable mechanical properties, the coating achieves a hardness rating of 6 H at room temperature, thereby meeting outdoor requirements across various scenarios.
The accumulation of environmental pollutants and dust, along with the formation of dirt, has led to severe surface contamination, resulting in the deterioration and contamination of substrate surfaces, which has significantly escalated cleaning and maintenance expenses. Although various anti-dust surfaces have been developed in previous studies, challenges still persist in achieving long-lasting dust protection while maintaining transparency and functional diversity. The present study aims to develop a three-layer composite coating, which exhibits superhydrophilic self-cleaning performances and can be applied onto various substrates at ambient temperature. This innovative coating integrates the principles of anti-static behavior and micro-nanostructured surface topography to effectively prevent dust accumulation. The surface resistance of the coating can be maintained in the range of 10 4 –10 6 Ω/sq, ensuring long-lasting dust resistance in outdoor environments and facilitating self-cleaning of the coated surfaces due to their superhydrophilic properties (water contact angle less than 5°). In addition, the coating exhibits exceptional transmittance with a peak transmittance of 97 % within the 400–800 nm wavelength range. This attribute renders it highly suitable for extensive utilization in applications such as photovoltaics, glass facades, and other fields that demand superior transparency. Notably, by ingeniously incorporating cellulose nanocrystals renowned for their remarkable mechanical properties, the coating achieves a hardness rating of 6 H at room temperature, thereby meeting outdoor requirements across various scenarios.
关键词：
Cadmium;Functionalized biochar;Soil limitation factors;Soil remediation;Soil-rice system
摘要：
Alleviating cadmium (Cd) risk in paddy soils is a global research hotspot. Although biochar reduces Cd mobility, a holistic perspective on the effects of biochar on Cd fraction distribution in rice rhizosphere and its immobilization mechanisms is lacking. Here, we developed a pathway model that links soil physicochemical properties, IP formation, enzyme activity, microbial biomass, porewater nutrients, and soil Cd fractions to fill knowledge gaps. Results revealed that phosphorus-loaded magnetic biochar (PMLB) application increased soil pH, available phosphorus (AP), total phosphorus (TP), microbial biomass, and TP and Fe contents in porewater while inhibiting soil enzyme activities. Compared with the control, 0.2 %-1 % w / w PMLB treatment reduced soil acetic acid-extractable Cd (Aci-Cd) content during the tillering, filling, and maturity periods by 23.71–32.92 %, 25.45–37.33 %, and 7.39–18.40 %, respectively. Cd content in brown rice was reduced by 44.02–47.86 %. Soil pH, AP and urease activity were the primary drivers of soil Aci-Cd reduction. Soil microbial biomass contributed most to reducing Cd content in rice tissues (total path coefficient: −0.48), followed by enzyme activity and IP. Additionally, PMLB promoted IP formation and altered the immobilization methods of Cd by IP, from coprecipitation with iron (hydr)oxides and phosphate to ternary complex formation with phosphate as a bridge to band Cd and iron (hydr)oxides.
Alleviating cadmium (Cd) risk in paddy soils is a global research hotspot. Although biochar reduces Cd mobility, a holistic perspective on the effects of biochar on Cd fraction distribution in rice rhizosphere and its immobilization mechanisms is lacking. Here, we developed a pathway model that links soil physicochemical properties, IP formation, enzyme activity, microbial biomass, porewater nutrients, and soil Cd fractions to fill knowledge gaps. Results revealed that phosphorus-loaded magnetic biochar (PMLB) application increased soil pH, available phosphorus (AP), total phosphorus (TP), microbial biomass, and TP and Fe contents in porewater while inhibiting soil enzyme activities. Compared with the control, 0.2 %-1 % w / w PMLB treatment reduced soil acetic acid-extractable Cd (Aci-Cd) content during the tillering, filling, and maturity periods by 23.71–32.92 %, 25.45–37.33 %, and 7.39–18.40 %, respectively. Cd content in brown rice was reduced by 44.02–47.86 %. Soil pH, AP and urease activity were the primary drivers of soil Aci-Cd reduction. Soil microbial biomass contributed most to reducing Cd content in rice tissues (total path coefficient: −0.48), followed by enzyme activity and IP. Additionally, PMLB promoted IP formation and altered the immobilization methods of Cd by IP, from coprecipitation with iron (hydr)oxides and phosphate to ternary complex formation with phosphate as a bridge to band Cd and iron (hydr)oxides.
关键词：
Hybrid capacitive deionization;Prussian blue analogues;Mn doped;Particle size reduction
摘要：
The hybrid capacitive deionization (HCDI) technology has demonstrated improved efficiency compared to conventional capacitive deionization (CDI). Prussian blue analogues (PBAs) possess high capacity and rapid ion transfer capability, recognized as promising materials for HCDI electrodes. PBAs with a more uniform morphology and smaller particle size could enhance contact with the electrolyte, and facilitate rapid ion transport. It has been observed that adding manganese can reduce the particle size of these materials and lead to a more uniform structure. In this study, nickel-based Prussian blue analogues were modified with varying manganese doping ratios to enhance desalination properties. The optimal desalination performance was achieved when the atomic ratio of manganese to nickel was 3:7 (MNP-3), yielding a maximum deionization rate of 20.59 mg·(g·min) −1 and a high desalination capacity of 58.82 mg·g −1 in batch mode testing at an applied voltage of 1.2 V in a 500 mg·L −1 NaCl feed solution. Furthermore, MNP-3 exhibited higher specific capacitance and smaller transfer resistance than the undoped material, which were advantageous for sodium ion storage. This study emphasizes the impact of particle size on HCDI performance, providing valuable insights for future HCDI application studies.
The hybrid capacitive deionization (HCDI) technology has demonstrated improved efficiency compared to conventional capacitive deionization (CDI). Prussian blue analogues (PBAs) possess high capacity and rapid ion transfer capability, recognized as promising materials for HCDI electrodes. PBAs with a more uniform morphology and smaller particle size could enhance contact with the electrolyte, and facilitate rapid ion transport. It has been observed that adding manganese can reduce the particle size of these materials and lead to a more uniform structure. In this study, nickel-based Prussian blue analogues were modified with varying manganese doping ratios to enhance desalination properties. The optimal desalination performance was achieved when the atomic ratio of manganese to nickel was 3:7 (MNP-3), yielding a maximum deionization rate of 20.59 mg·(g·min) −1 and a high desalination capacity of 58.82 mg·g −1 in batch mode testing at an applied voltage of 1.2 V in a 500 mg·L −1 NaCl feed solution. Furthermore, MNP-3 exhibited higher specific capacitance and smaller transfer resistance than the undoped material, which were advantageous for sodium ion storage. This study emphasizes the impact of particle size on HCDI performance, providing valuable insights for future HCDI application studies.
作者机构：
[Dong, Zhunqin; Zhao, Zongwen] Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.;[Dong, Zhunqin; Zhao, Zongwen] Shandong Humon Smelting Co Ltd, Yantai 264109, Peoples R China.;[Wang, Zhongbing] Nanchang Hangkong Univ, Sch Environm & Chem Engn, Nanchang 330063, Peoples R China.;[Song, Yuxia] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410007, Peoples R China.
通讯机构：
[Wang, ZB ] N;[Zhao, ZW ] C;Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.;Shandong Humon Smelting Co Ltd, Yantai 264109, Peoples R China.;Nanchang Hangkong Univ, Sch Environm & Chem Engn, Nanchang 330063, Peoples R China.
关键词：
amorphous phase;bridging oxygen;chemical corrosion;corundum–mullite refractory material
摘要：
Corundum-mullite refractory material is an important material in rotary kiln incinerators due to its excellent properties, e.g., high temperature stability and chemical resistance, etc. However, in the process of use, the complexity of the sintering process will inevitably produce a large amount of spent corundum-mullite refractory material. Therefore, it is important to study the failure mechanism of corundum-mullite refractory material to prolong its service life. In this manuscript, the scrapping mechanism for the corundum-mullite refractory material was studied by XRD, XPS, SEM-EDS, FTIR, etc. The results indicate that chemical corrosion caused by impurity elements, such as Fe, Ca, Mg, Ti, etc., is one of the important scrapping mechanisms. The corundum structure remains stable throughout the service life, while mullite exhibits the opposite phenomenon. The Al-O-Si bonds in the mullite structure are depolymerized by impurity elements to release free tetrahedral structures, including the [AlO(4)] tetrahedron and [SiO(4)] tetrahedron. In the intervention of iron, the free tetrahedra, including [AlO(4)], [FeO(4)], and [SiO(4)] can bond with each other by sharing bridging oxygen (BO), probably forming Fe-O(BO)-Si, Fe-O(BO)-Al, and Al-O(BO)-Si in an Al(2)O(3)-SiO(2)-Fe(2)O(3)-Me(x)O(y) (Me = Ca, Mg, Ti, etc.)-based amorphous phase. These findings provide theoretical support for prolonging the service life of refractory materials in rotary kiln incinerators.
作者机构：
[Cui, Jicui; Kong, Long; Liu, Wei; Lou, Ziyang; Lu, Jingyi; Lou, ZY] Shanghai Jiao Tong Univ, Sch Environm Sci & Engn, Shanghai 200240, Peoples R China.;[Cui, Jicui; Morawska, Lidia; Morawska, L] Queensland Univ Technol, Int Lab Air Qual & Heath, Brisbane 4001, Australia.;[Huang, Qiujie] Chinese Res Inst Environm Sci, Beijing 100012, Peoples R China.;[Yuan, Zhihang] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Peoples R China.;[Zhang, Minchao] Tech Ctr Ind Prod & Raw Mat Inspect & Testing Shan, Shanghai 201210, Peoples R China.
通讯机构：
[Lou, ZY ] S;[Morawska, L ] Q;Shanghai Jiao Tong Univ, Sch Environm Sci & Engn, Shanghai 200240, Peoples R China.;Queensland Univ Technol, Int Lab Air Qual & Heath, Brisbane 4001, Australia.
关键词：
Waste-to-energy;Social cost;Municipal solid waste;Flue gas pollutants;Human health burden
摘要：
Waste-to-energy (WTE) incineration has been long argued for the emission of hazardous flue gas pollutants (FGPs), while the contribution to health burden of individual components is ambiguous, resulting empirical control measures. We constructed a comprehensive framework to assess the health burden by monetizing premature mortalities, combining nine kinds of regulated FGPs from WTE plants. NO x and SO 2 were identified as the main contributors to health risk, accounting for around 88.87 % and 6.97 % respectively in 2020. The annual social cost of mortalities (SCM) increased from USD 6.09 billion in 2010 to USD 13.60 billion in 2015, and to USD 16.71 billion in 2020, related to the surge in WTE capacity, which grew 10-fold over the past decade. The SCM per ton of municipal solid waste, however, significantly decreased from 329 USD/t in 2010 to 213 USD/t in 2015, and to 88 USD/t in 2020, due to updating of the standards and technological advances, pushing the emission factors down by 33.75–98.63 %. SCM will be continuously mitigated by the tightened emission limits, with the greatest benefits seen in a reduction of up to 50 % in NO x to 80 mg/m 3 by selective catalytic reduction and selective non-catalytic reduction. Coastal regions were recommended as a high priority for further control, on account of their greater population density, higher economic level, and greater WTE capacity, which made up 60–71 % of total reduction benefits. These findings provide data support and recommendations for policymakers and stakeholders to mitigate FGPs emissions to efficiently reduce the health risk of WTE plants.
Waste-to-energy (WTE) incineration has been long argued for the emission of hazardous flue gas pollutants (FGPs), while the contribution to health burden of individual components is ambiguous, resulting empirical control measures. We constructed a comprehensive framework to assess the health burden by monetizing premature mortalities, combining nine kinds of regulated FGPs from WTE plants. NO x and SO 2 were identified as the main contributors to health risk, accounting for around 88.87 % and 6.97 % respectively in 2020. The annual social cost of mortalities (SCM) increased from USD 6.09 billion in 2010 to USD 13.60 billion in 2015, and to USD 16.71 billion in 2020, related to the surge in WTE capacity, which grew 10-fold over the past decade. The SCM per ton of municipal solid waste, however, significantly decreased from 329 USD/t in 2010 to 213 USD/t in 2015, and to 88 USD/t in 2020, due to updating of the standards and technological advances, pushing the emission factors down by 33.75–98.63 %. SCM will be continuously mitigated by the tightened emission limits, with the greatest benefits seen in a reduction of up to 50 % in NO x to 80 mg/m 3 by selective catalytic reduction and selective non-catalytic reduction. Coastal regions were recommended as a high priority for further control, on account of their greater population density, higher economic level, and greater WTE capacity, which made up 60–71 % of total reduction benefits. These findings provide data support and recommendations for policymakers and stakeholders to mitigate FGPs emissions to efficiently reduce the health risk of WTE plants.
摘要：
Manganese ore, as an important strategic metal resource for the country, was subject to unreasonable mining practices and outdated smelting technologies in early China, leading to severe ecological damage in mining areas. This study examines the trends in vegetation cover change in the historical manganese mining areas of Yongzhou under the influence of policy, providing technical references for mitigating the ecological impact of these legacy mining areas and offering a basis for adjusting mine restoration policies. This paper takes the manganese mining area in Yongzhou City, Hunan Province as a case study and selects multiple periods of Landsat satellite images from 2000 to 2023. By calculating the Normalized Difference Vegetation Index (NDVI) and the Fractional Vegetation Coverage (FVC), the spatiotemporal changes and driving factors of vegetation coverage in the Yongzhou manganese mining area from 2000 to 2023 were analyzed. The analysis results show that, in terms of time, from 2000 to 2012, the vegetation coverage in the manganese mining area decreased from 0.58 to 0.21, while from 2013 to 2023, it gradually recovered from 0.21 to 0.40. From a spatial perspective, in areas where artificial reclamation was conducted, the vegetation was mainly mildly and moderately degraded, while in areas where no artificial restoration was carried out, significant vegetation degradation was observed. Mining activities were the primary anthropogenic driving force behind the decrease in vegetation coverage, while effective ecological protection projects and proactive policy guidance were the main anthropogenic driving forces behind the increase in vegetation coverage in the mining area.
摘要：
As an important coal-producing region in China, open-pit coal mining in Shaoyang, Hunan Province, has a significant impact on the ecological environment. This study focuses on the three major open-pit mining areas in the city, utilizing remote sensing data from 1998 to 2024. By calculating the normalized difference vegetation index (NDVI) and fractional vegetation cover (FVC), and combining climate factors such as temperature and precipitation with Net Primary Productivity (NPP), this study analyzes the spatiotemporal evolution characteristics of vegetation cover and carbon sinks, and explores the impact of climate and environmental policies on vegetation recovery. The study employed trend analysis and autoregressive integrated moving average (ARIMA) model predictions, which showed that vegetation cover in the mining areas decreased overall from 1998 to 2011, gradually recovered after 2011, and reached a relatively high level by 2024. Changes in carbon sinks were consistent with the trends in vegetation cover. Spatially, the north mining area experienced the most severe vegetation degradation in the early stages, the middle area recovered earliest, and the south area had the fastest vegetation cover recovery rate. Climate factors had a certain influence on vegetation recovery, but precipitation, temperature, and FVC showed no significant correlation. The study indicates that vegetation recovery in mining areas is jointly influenced by mining intensity, climate conditions, and policy interventions, with geological environment management policies in Hunan mining areas playing a key role in promoting vegetation recovery.
摘要：
Microplastics (MPs) are recognized as emerging soil contaminants. However, the potential risks of MPs to agroecosystems have not been fully revealed, especially the compound toxic effects of MPs with co-existing organic or inorganic pollutants (OPs/IPs) in agricultural fields. In this study, we quantified the contributions of different agronomic practices to the sources of MPs in soil and highlighted the important influences of long-term tillage and fertilization on the migration and aging of MPs in agricultural fields. In addition, the antagonistic and synergistic interactions between MPs and OPs/IPs in soil were explored. We emphasized that the degree of adsorption of MPs and soil particles to OPs/IPs is a key determinant of the co-toxicity of those contaminants in soil. Finally, several directions for future research are proposed, and these knowledge gaps provide an important basis for understanding the contamination process of MPs in agricultural soils.
摘要：
Here, we report a general ultrasound-assisted photodynamic strategy that overcomes this challenge by employing hypocrellin B (HB), originally a narrow-spectrum agent initially effective against Gram-positive bacteria, to eradicate Gram-negative bacteria. By applying exogenous ultrasound (US), we induce interfacial electron movement and leverage the cavitation effect to disrupt the lipid bilayer structure of the outer membrane (OM). Consequently, 200 μg mL −1 of HB@ZIF-8 (ZHB) achieves an almost 7-log reduction in Escherichia coli counts within 20 min, which is sixfold higher compared to the antibacterial activity exhibited by HB alone. Molecular dynamics simulations combined with 1.3-fold increase in fluorescence signals in OM permeability experiments confirm that the synergy of ultrasound and photodynamic treatment promotes OM permeability, facilitating rapid diffusion of ROS and HB into inner membrane and intracellular regions. Furthermore, the ZHB exhibited superior inhibition of bacterial proliferation, remarkably extending Shine Muscat grapes shelf life by up to 15 days. Therefore, the sonodynamic interfacial-assisted photosensitizer ZHB prepared in this work was found effective in enhancing the antimicrobial effect against foodborne pathogens.
Here, we report a general ultrasound-assisted photodynamic strategy that overcomes this challenge by employing hypocrellin B (HB), originally a narrow-spectrum agent initially effective against Gram-positive bacteria, to eradicate Gram-negative bacteria. By applying exogenous ultrasound (US), we induce interfacial electron movement and leverage the cavitation effect to disrupt the lipid bilayer structure of the outer membrane (OM). Consequently, 200 μg mL −1 of HB@ZIF-8 (ZHB) achieves an almost 7-log reduction in Escherichia coli counts within 20 min, which is sixfold higher compared to the antibacterial activity exhibited by HB alone. Molecular dynamics simulations combined with 1.3-fold increase in fluorescence signals in OM permeability experiments confirm that the synergy of ultrasound and photodynamic treatment promotes OM permeability, facilitating rapid diffusion of ROS and HB into inner membrane and intracellular regions. Furthermore, the ZHB exhibited superior inhibition of bacterial proliferation, remarkably extending Shine Muscat grapes shelf life by up to 15 days. Therefore, the sonodynamic interfacial-assisted photosensitizer ZHB prepared in this work was found effective in enhancing the antimicrobial effect against foodborne pathogens.
摘要：
The prolonged consumption of arsenic-contaminated water is linked to an elevated risk of cancer. As(III) in wastewater exhibits greater mobility, biotoxicity, and removal challenges than As(V). Acidic mine drainage (AMD) sludges are solid wastes produced by mining industry. In this study, a novel biochar modified with AMD sludge (AMDs@PB 2 ) was prepared via co-pyrolysis of AMD sludge and pine needles to remove As(III) from the solution. The effects of preparation conditions (pyrolysis temperature, raw material ratio) and environmental factors (solution pH, solution temperature, coexisting ions) of biochar on arsenic adsorption were investigated, and the arsenic adsorption performance of AMDs@PB 2 was analyzed by kinetic, isothermal and thermodynamic models. The results show that the optimal pyrolysis temperature for AMDs@PB 2 is 800 °C, and the mass ratio of AMD sludge to pine needles is 2:1. AMDs@PB 2 can effectively remove As(III) from water, thereby achieving the ‘treating waste with treated waste’ concept. The maximum theoretical adsorption capacity (Q e, the ) of AMDs@PB 2 for As(III) in wastewater is 83.35 mg g −1 , which is approximately 1.07–31.18 folds greater than Q e, the reported in previous studies. AMDs@PB 2 adsorption was slightly affected by anions (15–75 mg L −1 CI − , NO 3 − , SO 4 2− , PO 4 3− ) and humic acid and its removal rate ranged from 83.48 to 97.57 %. In addition, the AMDs@PB 2 adsorption process involves multilayer heterogeneous adsorption. As(III) adsorption by AMDs@PB 2 at 25 °C is thermo respiratory and spontaneous. The oxidation-reduction reaction, surface complexation, and coprecipitation dominated the immobilization of As(III) in the water environment by AMDs@PB 2 .
The prolonged consumption of arsenic-contaminated water is linked to an elevated risk of cancer. As(III) in wastewater exhibits greater mobility, biotoxicity, and removal challenges than As(V). Acidic mine drainage (AMD) sludges are solid wastes produced by mining industry. In this study, a novel biochar modified with AMD sludge (AMDs@PB 2 ) was prepared via co-pyrolysis of AMD sludge and pine needles to remove As(III) from the solution. The effects of preparation conditions (pyrolysis temperature, raw material ratio) and environmental factors (solution pH, solution temperature, coexisting ions) of biochar on arsenic adsorption were investigated, and the arsenic adsorption performance of AMDs@PB 2 was analyzed by kinetic, isothermal and thermodynamic models. The results show that the optimal pyrolysis temperature for AMDs@PB 2 is 800 °C, and the mass ratio of AMD sludge to pine needles is 2:1. AMDs@PB 2 can effectively remove As(III) from water, thereby achieving the ‘treating waste with treated waste’ concept. The maximum theoretical adsorption capacity (Q e, the ) of AMDs@PB 2 for As(III) in wastewater is 83.35 mg g −1 , which is approximately 1.07–31.18 folds greater than Q e, the reported in previous studies. AMDs@PB 2 adsorption was slightly affected by anions (15–75 mg L −1 CI − , NO 3 − , SO 4 2− , PO 4 3− ) and humic acid and its removal rate ranged from 83.48 to 97.57 %. In addition, the AMDs@PB 2 adsorption process involves multilayer heterogeneous adsorption. As(III) adsorption by AMDs@PB 2 at 25 °C is thermo respiratory and spontaneous. The oxidation-reduction reaction, surface complexation, and coprecipitation dominated the immobilization of As(III) in the water environment by AMDs@PB 2 .
摘要：
Strong acidity of antimony (Sb) mine drainage enhances Sb and arsenic (As) mobility, posing serious environmental risks. The secondary iron-rich minerals (e.g., goethite, ferrihydrite, and hematite) in acid mine drainage (AMD) sludge can serve as effective iron sources and significantly enhance the Sb immobilization capacity of biochar modified with iron-rich minerals through the specific coordination of its surface iron (hydr)oxides with Sb. Based on above evidence, this study was conducted to develop a “using waste to treat pollution” strategy by developing a novel pH-responsive AMD sludge-modified biochar (SPNB 2 : 800°C and 2:1 AMD sludge/pine needle ratio). Results demonstrated that the maximum adsorption capacities (Qe) of SPNB 2 were 47.54 mg/g (Sb(III)) and 147.92 mg/g (Sb(V)), following a spontaneous, temperature-enhanced multilayer chemisorption mechanism. SPNB 2 maintained optimal performance in strongly acidic (pH 2–3) and complex anionic environments (Cl⁻/NO₃⁻/SO₄²⁻, 10–150 mg/L), enabling synergistic immobilization of As(III)-Sb(III/V) with combined Qe values of 84.52 mg/g (As(III)-Sb(III)) and 184.61 mg/g (As(III)-Sb(V)). Immobilization mechanisms of SPNB 2 predominantly involve surface complexation, hydrogen bonding, redox reactions, π π interactions, and pore filling. SPNB 2 effectively immobilized Sb in soil at a 4 % dosage via mixed filling, converting highly mobile Sb fractions (nonspecifically/specifically adsorbed forms) to residual Sb and reducing Sb leaching risk. These results highlighted the satisfactory performance of SPNB 2 in the remediation of Sb-contaminated water and soil.
Strong acidity of antimony (Sb) mine drainage enhances Sb and arsenic (As) mobility, posing serious environmental risks. The secondary iron-rich minerals (e.g., goethite, ferrihydrite, and hematite) in acid mine drainage (AMD) sludge can serve as effective iron sources and significantly enhance the Sb immobilization capacity of biochar modified with iron-rich minerals through the specific coordination of its surface iron (hydr)oxides with Sb. Based on above evidence, this study was conducted to develop a “using waste to treat pollution” strategy by developing a novel pH-responsive AMD sludge-modified biochar (SPNB 2 : 800°C and 2:1 AMD sludge/pine needle ratio). Results demonstrated that the maximum adsorption capacities (Qe) of SPNB 2 were 47.54 mg/g (Sb(III)) and 147.92 mg/g (Sb(V)), following a spontaneous, temperature-enhanced multilayer chemisorption mechanism. SPNB 2 maintained optimal performance in strongly acidic (pH 2–3) and complex anionic environments (Cl⁻/NO₃⁻/SO₄²⁻, 10–150 mg/L), enabling synergistic immobilization of As(III)-Sb(III/V) with combined Qe values of 84.52 mg/g (As(III)-Sb(III)) and 184.61 mg/g (As(III)-Sb(V)). Immobilization mechanisms of SPNB 2 predominantly involve surface complexation, hydrogen bonding, redox reactions, π π interactions, and pore filling. SPNB 2 effectively immobilized Sb in soil at a 4 % dosage via mixed filling, converting highly mobile Sb fractions (nonspecifically/specifically adsorbed forms) to residual Sb and reducing Sb leaching risk. These results highlighted the satisfactory performance of SPNB 2 in the remediation of Sb-contaminated water and soil.
