Environmental Research最新文献

{"title":"Dynamic evolution of antibiotic resistance risk in sewage sludge-amended soil during crop growth: a field-based metagenomic perspective.","authors":"Junqiao Zhao, Zhenyu Guo, Langjun Tang, Xiaoyi Lu, Yonghong Li, Kun Yang","doi":"10.1016/j.envres.2025.122799","DOIUrl":"https://doi.org/10.1016/j.envres.2025.122799","url":null,"abstract":"<p><p>Sewage sludge, a ubiquitous by-product of wastewater treatment, accumulates globally. Land application, a prominent waste valorization strategy, inadvertently disseminates the sludge antibiotic resistome into ecosystems, threatening ecological security and public health. Risk assessment of antibiotic resistance (AR) during sludge land application is urgently needed. Herein, we conducted a field study by planting three crops in sludge-amended soil, and monitoring the dynamic evolution of AR risk throughout their growth cycles. Metagenomic sequencing assessed antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), virulence factors (VFs), and their co-occurrence. Sludge amendment exerted persistent, yet largely recoverable, impacts on soil microbial community and the resistome. The resulting AR risk evolution was nonlinear and fluctuating, dominated by soil microbial community reconstruction. Given the differences in crop edible parts, growth periods of crops, complex AR risk dynamics, and external factors like weather, we propose a time-sensitive control strategy targeting critical risk windows. This strategy aims to mitigate AR risk under the \"One Health\" paradigm for sustainable sludge land application.</p>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":" ","pages":"122799"},"PeriodicalIF":7.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon brush-activated electron shuttling accelerates acetoclastic methanogenesis in palm oil mill effluent","authors":"Muzzammil Ngatiman ,&nbsp;Roziana Kamaludin ,&nbsp;Siti Maryam Jasman ,&nbsp;Mohd Hafiz Puteh ,&nbsp;Taira Hidaka ,&nbsp;Mohd Hafiz Dzarfan Othman ,&nbsp;Naoko Yoshida","doi":"10.1016/j.envres.2025.122807","DOIUrl":"10.1016/j.envres.2025.122807","url":null,"abstract":"<div><div>Palm oil, an essential dietary component consumed daily by over three billion people, originates from the most productive oil crop requiring less land and water than other crops. However, its production causes environmental issues such as water pollution from palm oil mill effluent (POME) and greenhouse gas emissions during treatment. Efficient recovery of biogas produced from POME is important for maintaining the sustainability of oil palm industry. Direct interspecies electron transfer (DIET) with conductive materials represents a promising technology for enhancing biogas, but this approach has never been applied to POME treatment. This study aims to evaluate the effect of conductive material on acetoclastic methanogenesis by comparing 220-day triplicate semi-batch anaerobic POME with (CB culture) and without (P culture) carbon brush. Biogas production and sCOD degradation were rapid in CB culture, although the final CH₄ volumes were similar, indicating accelerated but not increased methane generation. Cyclic voltammetry revealed two primary redox mediators in CB culture with half redox potentials of approximately −36 mV and 364 mV, higher than CH₄/CO₂ redox potential, indicating DIET to methanogens was unlikely and suggesting VFA degradation via electron shuttling to abundant humic substances (HS). <em>Thauera,</em> which reduces HS, and <em>Methanosaeta</em>, an acetoclastic methanogen, dominated in only the CB cultures. These results suggest CB may facilitate the coupling of HS reduction with sCOD degradation to acetate, supporting acetoclastic methanogenesis in POME. This study presents first report of electron shuttles activated with conductive material that possibly enhances acetoclastic methanogenesis attributed to the unique HS abundance in POME.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"286 ","pages":"Article 122807"},"PeriodicalIF":7.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Galvanizing waste-derived Zn-induced defective Fe-based metal-organic frameworks as superior adsorbent for enhanced antibiotic removal.","authors":"Xian Zhang, Juan Xu, Yanhui Zhang, Wenlong Xiang","doi":"10.1016/j.envres.2025.122804","DOIUrl":"https://doi.org/10.1016/j.envres.2025.122804","url":null,"abstract":"<p><p>The derivation of defect-engineered metal-organic frameworks (MOFs) from industrial waste simultaneously mitigates environmental pollution, reduces MOF synthesis costs, and enhances adsorption performance. Herein, this study demonstrates a sustainable strategy for the resourceful synthesis of iron-based MOF s-MIL-100(Fe) using galvanizing pickling waste liquor (80.5 wt.% Fe²⁺, 18.8 wt.% Zn²⁺) as metal precursors. While zinc ions do not incorporate into MOF frameworks, their co-existence induced the generation of coordinatively unsaturated metal sites (CUMS), enabling s-MIL-100(Fe) to achieve an ultra-high adsorption capacity of 721 mg g^-1 for doxycycline (DOX) at 303.15 K. In addition, Zn-mediated defect engineering increased the porosity of s-MIL-100(Fe) with optimized textural parameters (specific surface area: 733.4 m² g^-1; pore volume: 0.74 cm³ g^-1), outperforming commercial c-MIL-100(Fe) by 48.4% in adsorption capacity and a shorter equilibrium time. Furthermore, s-MIL-100(Fe) exhibited robustness across pH 2-10, multi-ion matrices and humic acid interference, while retaining 90% capacity over four regeneration cycles. Synergistic mechanisms involve CUMS-driven coordination, π-π stacking, and pore confinement, supplemented by hydrogen bonding and electrostatic interactions. By transforming hazardous metallurgical waste into high-performance adsorbents, this study offers a sustainable approach that simultaneously addresses industrial waste management and advanced material synthesis. Critically, s-MIL-100(Fe) demonstrates >97% DOX removal efficiency in real contaminated waters including aquaculture effluents, municipal wastewater, and river systems, validating its practical utility in environmental remediation. The Zn-assisted defect modulation strategy provides new insights into structure-property optimization of waste-derived MOFs, highlighting the untapped potential of impurity ions in functional material synthesis.</p>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":" ","pages":"122804"},"PeriodicalIF":7.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145032437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Construction of melem/BiVO4/g-C3N5 photocatalyst with a conjugated S-scheme charge transfer pathway for boosting photocatalytic activity under LED light irradiation","authors":"Vinh Huu Nguyen ,&nbsp;Hiep Quang Ha ,&nbsp;Oanh T.K. Nguyen ,&nbsp;Truc Thanh Thai ,&nbsp;Que-Minh T. Doan ,&nbsp;Lan-Anh T. Hoang ,&nbsp;Taeyoon Lee ,&nbsp;Trinh Duy Nguyen","doi":"10.1016/j.envres.2025.122805","DOIUrl":"10.1016/j.envres.2025.122805","url":null,"abstract":"<div><div>The development of novel multijunction heterostructure photocatalysts is critical for the efficient degradation of organic pollutants, attributed to their ability to enhance the separation of photogenerated electron-hole pairs. In our study, a ternary composite, melem/BiVO₄/g-C₃N₅ (BVO/CNMH), was synthesized via an acid-soaking method followed by calcination, using g-C₃N₅ as a sacrificial precursor in the presence of BiVO₄. This approach yielded a porous, interconnected architecture in BVO/CNMH. Detailed analyses revealed the retention of crystalline phases, enhanced light absorption, expanded photoactive surface sites, and improved charge separation kinetics. The heterostructure demonstrated exceptional photocatalytic performance in degrading tetracycline hydrochloride (TCH), achieving a removal efficiency of up to 99.68 % within 60 min of LED light irradiation, corresponding to rate constants 2.6 to 31.7 times higher than those of the individual semiconductors. Moreover, the heterostructure demonstrated excellent photocatalytic stability, retaining over 80 % of its TCH removal efficiency after five reuse cycles. The superior photocatalytic performance can be ascribed to the conjugated S-scheme charge transfer pathway, which collectively promoted the efficient preservation of highly active photogenerated charge carriers. Trapping experiments identified the reactive species, including ^•O₂⁻, photogenerated electrons, ^•OH, and photogenerated holes, as the main contributors to TCH degradation. Based on experimental data, a degradation mechanism and pathway for TCH were proposed. The final degradation products exhibited significantly reduced acute and chronic toxicity compared to the parent compound. This study provides a novel strategy for constructing advanced g-C₃N₅-based multijunction heterostructure photocatalysts with strong potential for antibiotic wastewater remediation.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"286 ","pages":"Article 122805"},"PeriodicalIF":7.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145032477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of chicken manure-derived black soldier fly organic fertilizer on soil carbon and nitrogen cycling: insights from metagenomic and microbial network analysis.","authors":"Zhengzheng Zhao, Bingqi Gao, Ahmed R Henawy, Kashif Ur Rehman, Joshua W K Ho, Yan Xue, Jianfeng Wu, Núria Jiménez, Jessica Subirats, Longyu Zheng, Feng Huang, Chan Yu, Jibin Zhang, Minmin Cai","doi":"10.1016/j.envres.2025.122775","DOIUrl":"https://doi.org/10.1016/j.envres.2025.122775","url":null,"abstract":"<p><p>Black soldier fly (BSF) organic fertilizer is known to enhance soil fertility and promote plant growth. However, its effects on soil carbon (C) and nitrogen (N) cycling remains unclear. In this study, we established a BSF chicken manure bioconversion system to produce BSF organic fertilizer and investigate its impacts on soil C and N cycling, as well as microbial ecological networks through metagenomic analysis. Compared to the control, BSF organic fertilizer significantly increased soil organic matter by 16.1% (p < 0.05) and total potassium by 11.0% (p < 0.05). Metagenomic sequencing revealed that BSF organic fertilizer significantly enhanced soil C and N cycling. For instance, the abundance of carbon fixation genes such as Calvin-Benson-Bassham (CBB) cycle genes pyc, pycA, and pycB increased by 35.7% (p < 0.01), 107.1% (p < 0.001), and 14.6% (p < 0.05), respectively. In nitrogen cycling, denitrification genes nirB, nirK, and nirS increased by 181.5 % (p < 0.001), 102.7% (p < 0.001), and 25.9% (p < 0.05), respectively. Furthermore, soils amended with BSF organic fertilizer displayed a 9.9% higher proportion of positive microbial interactions, particularly enhancing synergistic associations between bacteria and fungi, suggesting improved microbial community stability. Importantly, bacteria and fungi were interdependent in regulating C and N cycling processes, together orchestrating soil ecosystem functions. Overall, BSF organic fertilizers effectively promoted soil C and N cycling and maintained the stability of microbial communities. These findings provide valuable insights for the rational selection of fertilizers and the optimization of fertilization management practices, thereby contributing to the sustainable development of agricultural production.</p>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":" ","pages":"122775"},"PeriodicalIF":7.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145028676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards real life exposure: nasal epithelial cell stimulation with pollen particle aerosols","authors":"Annika Eggestein ,&nbsp;Swetlana Urban ,&nbsp;Elke Hümmer ,&nbsp;Natalia Nunes ,&nbsp;Johannes Zenk ,&nbsp;Matthias Reiger ,&nbsp;Lorenz Aglas ,&nbsp;Claudia Traidl-Hoffmann ,&nbsp;Stefanie Gilles","doi":"10.1016/j.envres.2025.122762","DOIUrl":"10.1016/j.envres.2025.122762","url":null,"abstract":"<div><h3>Background</h3><div>Currently, most researchers apply pollen extracts or -suspensions to assess the effects of pollen exposure on airway epithelia. How respiratory epithelia respond to pollen aerosols is not well studied because standardised methods to aerosolize pollen were not available until recently.</div></div><div><h3>Aim of study</h3><div>To develop and test a near-natural exposure model for pollen grains based on differentiated human nasal epithelial cells and a novel particle aerosoliser.</div></div><div><h3>Methods</h3><div>Primary human nasal epithelial cells were differentiated at the air-liquid interface and exposed to birch, timothy grass and ragweed pollen, either as aqueous extract, suspension, or particle aerosol generated with the VitroCell PowderX device. Morphology, physical barrier function, and cytokine responses were compared.</div></div><div><h3>Results</h3><div>The cells responded to pollen aerosol exposure with strong mucus production and coordinated ciliary beating in attempt to clear the pollen grains. Pollen aerosols did not affect the transepithelial electrical resistance (TEER), whereas grass pollen extracts led to a significant TEER decrease. Extract exposure resulted in apical and basolateral cytokine release; aerosol exposure led to a directed, predominantly basolateral dose-dependent cytokine response. Cytokine responses to birch, grass and ragweed pollen differed, with birch pollen inducing lower levels of inflammatory cytokines, while timothy and ragweed pollen induced high levels of inflammatory cytokines and alarmins.</div></div><div><h3>Conclusion</h3><div>We were able to establish and characterize a biologically relevant pollen aerosol exposure system characterized by a directed cytokine response. The differences in response patterns to different pollen types likely reflect differential sensitisation mechanisms, warranting further research.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"286 ","pages":"Article 122762"},"PeriodicalIF":7.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145028686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel thermal modification of phosphate tailings for enhanced heavy metals immobilization in soil","authors":"Shengning Deng ,&nbsp;Yanwei Hou ,&nbsp;Zhao Liu ,&nbsp;Youchi Zhang ,&nbsp;Frederic Coulon ,&nbsp;Yu-Ting Tang ,&nbsp;Chao Cai","doi":"10.1016/j.envres.2025.122796","DOIUrl":"10.1016/j.envres.2025.122796","url":null,"abstract":"<div><div>Recent interest in amendments derived from industrial by-products has highlighted their potential for both resource recycling and heavy metal remediation. Phosphate tailings (PT), primarily dolomite-based solid waste with low utilization rates, offer a promising yet underexplored solution. This study pioneers the thermal modification of PT into a novel amendment, thermally modified phosphate tailings (TPT), to assess its adsorption performance, underlying mechanisms, and effectiveness in immobilizing heavy metals in soils. The thermal modification process transformed dolomite in PT into calcite and periclase, dramatically enhancing the maximum adsorption capacities by 28-fold for both Cd²⁺ and Cu²⁺, and 7-fold for Pb²⁺, with the capacities reaching 248, 531, and 433 mg g⁻¹ for Cd²⁺, Pb²⁺, and Cu²⁺, respectively. The dominant removal mechanism for TPT was surface precipitation, complemented by electrostatic adsorption, surface complexation, and ion exchange. Practical applications of TPT in contaminated soil reduced TCLP-extracted Cd, Pb, and Cu by up to 44 %, 60 %, and 61 %, respectively, effectively transforming heavy metals into relatively stable form. This study demonstrates the potential of TPT as a novel amendment for heavy metal immobilization, providing both effective contamination control and enhanced resource utilization, thus addressing a critical gap in the remediation of contaminated soils. Given its low-cost nature derived from industrial waste, TPT holds significant promise for large-scale application, making it a practical and sustainable solution for soil remediation.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"286 ","pages":"Article 122796"},"PeriodicalIF":7.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145028642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing CO2 adsorption capacity through Fe2O3/CaO ratio engineering in simulated fly ash-derived zeolite synthesis through gradient oxide modulation","authors":"Yukun Cao ,&nbsp;Qingping Wang ,&nbsp;Huang Zhou ,&nbsp;Jingyi Cai ,&nbsp;Zhenfei Lv ,&nbsp;Bin Wang ,&nbsp;Sumayya Fayyaz ,&nbsp;Xin Wang ,&nbsp;Meng Li ,&nbsp;Xiujuan Feng ,&nbsp;Liang Yuan","doi":"10.1016/j.envres.2025.122739","DOIUrl":"10.1016/j.envres.2025.122739","url":null,"abstract":"<div><div>Zeolite synthesis from fly ash offers recycling and environmental benefits for carbon dioxide capture, but varying fly ash composition from different sources has different compositions, leading to inconsistent adsorption results. To achieve high CO₂ adsorption performance and stability in zeolite synthesis from fly ash systems, this study established an element-controlled simulated fly ash system with Ca/Fe gradient differences. Hydrothermal synthesis yielded zeolites with optimized oxide ratios for CO₂ adsorption. Solid wastes such as red mud were then added to adjust the composition of natural fly ash, resulting in improved adsorption performance and synthesis process stability. Analysis of the simulated fly ash system showed that when CaO content was 4–6 % and Fe₂O₃ content was 12–16 %, the synthesized zeolite achieved the best CO₂ adsorption effect, reaching 34.58 cm³/g and outperforming standard industrial zeolites. Adjusting the oxide ratio of natural fly ash to the optimal performance range with red mud increased the adsorption capacity of natural fly ash-based zeolites by more than three times at 50 °C, while maintaining stable adsorption performance over 20 industrial cyclic adsorption tests. Economic analysis confirmed greater benefits from this waste-enhanced approach, offering promising strategy for industrial CO₂ capture.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"286 ","pages":"Article 122739"},"PeriodicalIF":7.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145028684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emission characteristics of full-volatility organic compounds from China's aluminum-products industry and their impacts on secondary organic aerosol and ozone potentials","authors":"Dongyang Wu ,&nbsp;Qing'e Sha ,&nbsp;Shan Jiang ,&nbsp;Luyun Liu ,&nbsp;Citao Zhang ,&nbsp;Jialin Song ,&nbsp;Junhao Xu ,&nbsp;Haoqi Chen ,&nbsp;Guanghui Li ,&nbsp;Zhangmin Xiang ,&nbsp;Bin Jiang ,&nbsp;Zhuangmin Zhong ,&nbsp;Duohong Chen ,&nbsp;Shupin Situ ,&nbsp;Guanying Xu ,&nbsp;Jianlin Hu ,&nbsp;Boguang Wang ,&nbsp;Junyu Zheng","doi":"10.1016/j.envres.2025.122742","DOIUrl":"10.1016/j.envres.2025.122742","url":null,"abstract":"<div><div>China's aluminum-products industry, a large-scale consumer of industrial paints, is a potentially significant source of full-volatility organic compounds (F-VOCs). However, the emission characteristics of F-VOCs, including VOCs, intermediate-, semi-, and low-volatility organic compounds (I/S/LVOCs), and their role in ozone formation potentials (OFP), and secondary organic aerosol formation potentials (SOAP) remain unclear. In this study, we collected in-field samples from three industrial paints (solvent-based, water-based and powder paints) at spraying and drying processes, and treatment devices to analyze the emission characteristics of F-VOCs, OFP, SOAP. Results revealed water-based and powder paints—often marketed as eco-friendly—emitted non-negligible SOA precursors. The F-VOC emission factors of three paints based on the field measurement method and the material balance method were 3.3–57.3 and 1.5–61.8 (kg/t-raw materials), respectively. Due to overlooking I/S/LVOCs, conventional material balance methods underestimated F-VOC emissions from powder by 46.9–53.9 %, and SOAP and OFP from three paints by 18.1–80.9 % and 14.5–77.8 %, respectively. Despite comprising less than 25.0 % of total emissions, I/S/LVOCs dominated 70.0–80.0 % SOAP. The paint types and treatment devices rather than industrial processes are the main factors influencing volatility, phase distributions, and source profiles. Current controls reduce OFP by ∼80.0 % but SOAP by only ∼20.0 %, highlighting the evasion of I/S/LVOCs from mitigation strategies. In 2023, China's aluminum-products industry emitted 258.4 kt of F-VOCs, comparable to those from on-road diesel transportation. The findings indicate substantial F-VOC emissions from aluminum production and inadequate I/S/LVOC controls, necessitating their inclusion in emission inventories and air-quality models to enhance pollution control.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"286 ","pages":"Article 122742"},"PeriodicalIF":7.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145028652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water resistance and hydration mechanism of phosphogypsum cemented paste backfill under composite curing agent modification","authors":"Shulong Liu ,&nbsp;Yiming Wang ,&nbsp;Aixiang Wu ,&nbsp;Zhuen Ruan ,&nbsp;Cheng Bi ,&nbsp;Yuanchang Li","doi":"10.1016/j.envres.2025.122797","DOIUrl":"10.1016/j.envres.2025.122797","url":null,"abstract":"<div><div>Cemented paste backfill has made outstanding contributions to the large-scale consumption of phosphogypsum (PG), but poor water resistance significantly weakens the mechanical strength, promotes the leaching of total soluble phosphate (TP) and fluoride ions (F), and reduces its attractiveness in mine engineering. This research synthesized a curing agent (CA) using sodium methylsilicate, sodium silicate, and polyaluminum chloride (PAC). PG produced from Deyang Haohua Qingping Phosphate Mine Co., Ltd. in Sichuan Province, China was modified by CA. Concomitantly, the effects of CA content and soaking time on the softening coefficient, water absorption, mechanical properties, and leaching behavior of phosphogypsum-based cemented paste backfill (PCPB) were investigated. The results indicated that CA displayed advantages in promoting hydration reaction and improving pore structure. Upon the addition of CA, the water absorption of PCPB diminished rapidly, and this trend persisted with the extension of soaking time. More exactly, when the CA content was 3 % and the soaking time was 1 day, the water absorption and softening coefficient obtained the minimum value (4.62 %) and maximum value (0.97), respectively. The softening coefficient rose with increasing CA content within 7 days of soaking time. Nonetheless, when prolonged beyond 14 days, PCPB with higher content CA exhibited a low softening coefficient, which was ascribed to the negative effects of microcracks and pores in the later stage. The enhancement of water resistance is primarily attributed to two aspects. On the one hand, the hydrophobic film formed by sodium methylsilicate played an isolation role. On the other hand, the network structure created by intertwining ettringite and C-(A)-S-H gels optimized the distribution of connected pores and further prevented the migration of water molecules. Encouragingly, the 28-day compressive strength with added CA far exceeded the 0.5 MPa requirement in GB/T 32124-2024. Herein, the mechanical parameters showed a rising and then declining tendency with 2 % CA as the critical content, and the peak was reached at 56 days (compressive strength: 6.08 MPa, flexural strength: 2.01 MPa, tensile strength: 440.32 kPa, elastic modulus: 340.28 MPa). The leaching toxicity test demonstrated that the leaching concentrations of TP and F at various curing ages and different soaking times met the Class I standard limits in GB 8978-1996. These findings can provide theoretical support for the performance regulation of PCPB in mine backfill engineering.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"286 ","pages":"Article 122797"},"PeriodicalIF":7.7,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145022553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}