Underground carbon sequestration(CS)by solid waste backfill(SWB)offers an effective pathway for collaborative disposal of coal-based solid waste and CO_(2),where the amount of carbon sequestration is an important eval...Underground carbon sequestration(CS)by solid waste backfill(SWB)offers an effective pathway for collaborative disposal of coal-based solid waste and CO_(2),where the amount of carbon sequestration is an important evaluation parameter.In this study,the concept of whole-process carbon sequestration using coal-based solid waste and CO_(2),including sequential stirring and curing stages,was proposed to evaluate the performance evolution of CS.The results showed that CO_(2) pressure and ambient temperature positively correlated with the CS amount from coal-based SWB.In particular,CO_(2) pressure prevailed in the stirring stage,while the ambient temperature effect was more significant in the curing stage.The CS amounts obtained during the stirring stage alone,the curing stage alone,and two sequential stages ranged from 0.66%–3.10%,3.53%–5.09%,and 5.12%–6.02%,respectively.The functional group and micromorphology analyses revealed that the prevailing mechanism at the CS stirring stage was the stirringdriven gas dissolution-leaching-mineralization reaction,while that at the curing stage was the hydration-driven gas permeation-dissociation-CS reaction.Both were essentially solid-liquid-gas multiphase chemical reactions.The results are instrumental in substantiating the coal-based SWB carbon sequestration evolution patterns and mechanisms and providing data support for waste disposal and carbon emission reduction in the coal industry.展开更多
Peri-urban plantations in the Mediterranean are often degraded due to human inactivity and climate change,leading to a loss of ecosystem services and biodiversity.This study investigates the impact of different thinni...Peri-urban plantations in the Mediterranean are often degraded due to human inactivity and climate change,leading to a loss of ecosystem services and biodiversity.This study investigates the impact of different thinning practices on carbon sequestration and tree stability in a degraded periurban plantation in the Italian Apennines,six years after thinning.Three treatments were compared:(a)moderate thinning from below(-25%biomass),representing the typical practice;(b)intense selective thinning(-35%biomass),representing an innovative approach;and(c)no management as the control.Growth projections were used to estimate carbon recovery for these treatments,based on site-specific models calibrated with real data.The results show that both thinning approaches increased carbon sequestration over time,with the innovative thinning achieving a 7%higher annual carbon sequestration rate than traditional thinning and 8%more than the control.Estimated payback times were9 years for recovering the harvested volume in both thinning approaches,10 years for innovative thinning to surpass traditional thinning,17 years for innovative thinning to surpass the control,and 24 years for traditional thinning to surpass the control.Additionally,tree mechanical stability improved significantly in both thinning treatments after two years,with further increases observed in the innovative thinning group after six years.These results suggest that selective thinning can accelerate forest recovery and carbon sequestration,especially in areas with high stem density,where it can reduce the negative impacts of tree mortality and deadwood accumulation.However,careful planning is required to mitigate potential short-term stability is sues,particularly in challenging environments(e.g.,windy conditions,steep slopes).Forest management strategies should therefore aim to balance growth,carbon storage,and tree stability,considering both long-term sustainability and local environmental conditions.The findings are particularly relevant for current climate change mitigation strategies,emphasizing that thinning should be carefully tailored to forest type and conditions to maximize benefits in carbon credit generation and sustainable forest management practices.展开更多
On July 2^(nd),2025,32 scientists representing 15 countries gathered at Tartu,Estonia to make on-site endorsements for the Global ONCE(Ocean Negative Carbon Emissions)Program at the 12th INTECOL Wetlands Conference.Th...On July 2^(nd),2025,32 scientists representing 15 countries gathered at Tartu,Estonia to make on-site endorsements for the Global ONCE(Ocean Negative Carbon Emissions)Program at the 12th INTECOL Wetlands Conference.This marks a significant milestone for ONCE in establishing a systematic framework for coastal wetland carbon sequestration research and global collaboration(Figs.1,2).Coastal wetlands are critical transition zones linking terrestrial and marine ecosystems,yet they face severe degradation from anthropogenic land-based activities and sea level rise that propagate impacts to the ocean.As a UN Ocean Decade Program,the Global ONCE Program champions interdisciplinary and cross-regional collaboration to enhance carbon sequestration in the ocean and coastal wetlands through science and innovation.Aligned with the Tartu Declaration on Wetlands that includes resolutions to promote the rights of global wetlands(especially peatlands)and advance the discipline of wetland science based on facts,this initiative addresses key knowledge gaps in land-ocean interactions.The goal is to harness the full potential of coastal wetlands and ocean systems for climate mitigation,thereby laying a scientific foundation for international policy formulation and implementation.展开更多
The increase in CO_(2)injectivity and shifting of CO_(2)-absorbing layers in multilayered geological CO_(2)sequestration(GCS)reservoirs in Ordos,China indicate significantpermeability variations in certain layers.To c...The increase in CO_(2)injectivity and shifting of CO_(2)-absorbing layers in multilayered geological CO_(2)sequestration(GCS)reservoirs in Ordos,China indicate significantpermeability variations in certain layers.To capture these system changes,a numerical model incorporating all 21 aquifers and internal aquitards was developed.The monitored pressure was well matched through multiphase and thermalhydraulic-mechanical(THM)coupling numerical simulations by introducing permeability variations.The results revealed that the permeability in the second layer increased on approximately day 13 due to the abrupt pressure buildup and temperature decrease.Even such a low rate of CO_(2)(2.8 kg/s)injected into the low permeability system initiated some fractures and the permeability in the second layer around the wellbore increased by 722 times.The second critical system change occurred on approximately day 386.As demonstrated in the numerical simulation,the substantial injection of cold CO_(2)induced strong thermal stress,leading to rock contraction and the initiation of several cracks.The permeability of the firstlayer around the wellbore unexpectedly increased by 4 orders of magnitude.Since no additional pressure could drive the CO_(2)into the remaining 17 layers,the total storage capability of the multilayered system was reduced.A whole picture of the system variation is fully presented and the underlying mechanisms are analyzed.It is believed that the phenomenon of thermal-hydraulic fracturing observed in this fieldand the simulation procedures will benefitother fluidinjection and production works in various geotechnical settings.展开更多
Understanding the dynamics of vegetation carbon sequestration(VCS)is essential for regional carbon neutrality strategies.This study revealed the spatiotemporal patterns of VCS and its relationship with anthropogenic c...Understanding the dynamics of vegetation carbon sequestration(VCS)is essential for regional carbon neutrality strategies.This study revealed the spatiotemporal patterns of VCS and its relationship with anthropogenic carbon emissions(ACEs)in Shandong Province,China during 2000-2020,and identified the sensitivity factors affecting VCS.The results show that:1)VCS increased consistently from 193.45 million t to 256.41 million t,with high values areas concentrated in the central,northeastern,and southeastern mountainous and hilly regions,while low values were found in water bodies and urban built-up areas.At the city level,Linyi,Yantai,Binzhou,and Jinan experienced the most significant rises-reaching up to 243000 t/yr.At the county level,Pingdu,Qixia,and Yiyuan also showed substantial growth,each exceeding 30400 t/yr.2)Digital Elevation Molde(DEM)was identified as the dominant natural factor influencing VCS distribution,while land use optimization measures,especially afforestation and farmland conversion in sloped terrain,were the primary human drivers of VCS increase.3)Urbanization and carbon neutrality were not mutually exclusive.While urban expansion locally reduced VCS,rural emigration enhanced carbon sinks in surrounding areas,partially offsetting urban losses.This compensatory mechanism supported VCS increases in nearly all cities and 90% of counties.Nevertheless,with ACEs continuing to rise and the offset ratio by VCS declining,achieving carbon neutrality requires regional strategies that integrate with accelerated energy conservation,emission reduction technologies,and energy transition.These findings provide a scientific basis for decomposing carbon neutrality targets across cities and counties in Shandong and a reference for developing localized land use policies in similar regions.展开更多
Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.C...Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.Compared with the traditional coal-fired power plant flue gas emission reduction technology,carbon fixation and emission reduction by microalgae is considered as a promising technology due to the advantages of simple process equipment,convenient operation and environmental protection.When the flue gas is treated by microalgae carbon fixation and emission reduction technology,microalgae cells can fix CO_(2) in the flue gas through photosynthesis,and simultaneously absorb NO_(x) and SO_(x) as nitrogen and sulfur sources required for growth.Meanwhile,they can also absorb mercury,selenium,arsenic,cadmium,lead and other heavy metal ions in the flue gas to obtain microalgae biomass.The obtained microalgae biomass can be further transformed into high valueadded products,which has broad development prospects.This paper reviews the mechanisms and pathways of CO_(2) sequestration,the mechanism and impacts of microalgal emission reduction of flue gas pollutants,and the applications of carbon sequestration in industrial flue gas by microalgae.Finally,this paper provides some guidelines and prospects for the research and application of green emission reduction technology for industrial flue gas.展开更多
Long-term mulching has improved crop yields and farmland productivity in semiarid areas,but it has also increased greenhouse gas(GHG)emissions and depleted soil fertility.Biochar application has emerged as a promising...Long-term mulching has improved crop yields and farmland productivity in semiarid areas,but it has also increased greenhouse gas(GHG)emissions and depleted soil fertility.Biochar application has emerged as a promising solution for addressing these issues.In this study,we investigated the effects of four biochar application rates(no biochar(N)=0 t ha^(-1),low(L)=3 t ha^(-1),medium(M)=6 t ha^(-1),and high(H)=9 t ha^(-1))under film mulching and no mulching conditions over three growing seasons.We assessed the impacts on GHG emissions,soil organic carbon sequestration(SOCS),and maize yield to evaluate the productivity and sustainability of farmland ecosystems.Our results demonstrated that mulching increased maize yield(18.68-41.80%),total fixed C in straw(23.64%),grain(28.87%),and root(46.31%)biomass,and GHG emissions(CO_(2),10.78%;N_(2)O,3.41%),while reducing SOCS(6.57%)and GHG intensity(GHGI;13.61%).Under mulching,biochar application significantly increased maize yield(10.20%),total fixed C in straw(17.97%),grain(17.69%)and root(16.75%)biomass,and SOCS(4.78%).Moreover,it reduced the GHG emissions(CO_(2),3.09%;N_(2)O,6.36%)and GHGI(12.28%).These effects correlated with the biochar addition rate,with the optimal rate being 9.0 t ha^(-1).In conclusion,biochar application reduces CO_(2) and N_(2)O emissions,enhances CH_(4) absorption,and improves maize yield under film mulching.It also improves the soil carbon fixation capacity while mitigating the warming potential,making it a promising sustainable management method for mulched farmland in semiarid areas.展开更多
Cement treatment,such as cement-mixing columns,is commonly used for deep soft soil improvement to increase the bearing capacity and reduce settlement.However,cement production entails high energy consumption and carbo...Cement treatment,such as cement-mixing columns,is commonly used for deep soft soil improvement to increase the bearing capacity and reduce settlement.However,cement production entails high energy consumption and carbon and pollutant emissions.CO_(2)capture and mineralization represent promising solutions to these issues.This study proposes a sustainable alternative:a novel CO_(2)-carbonated MgO-mixing column that integrates CO_(2)mineralization with soil reinforcement.This approach involves in situ mixing of MgO with deep soil to form columns,which are then carbonated and solidified by injecting captured CO_(2)through gas-permeable pipe piles,achieving both carbon reduction and soil improvement.In this study,CO_(2)-carbonated MgO-mixing columns were comprehensively evaluated to investigate variations in strength,deformation,pH,and CO_(2)sequestration with depth.Two rapid and cost-effective methods to assess its mechanical properties,uniformity,and CO_(2)sequestration capacity are proposed.The results show that the carbonated MgO-treated soil has good strength along the depth direction,with an average unconfined compressive strength(UCS)of 1.02 MPa and a lower pH than that of cement-mixing columns.It also achieves notable CO_(2)sequestration,ranging from 4.88%to 13.10%(average 8.31%),and exhibits good uniformity,as shown by electrical resistivity tests.Needle penetration and electrical resistivity tests could be used to effectively predict the UCS,deformation modulus,and CO_(2)sequestration.XRD,FTIR,SEM,and TG-DTG analyses reveal distinct microstructural differences at various depths,with unhydrated MgO,magnesite,and dypingite/hydromagnesite present in shallow columns,and brucite,nesquehonite,and dypingite/hydromagnesite present in deep columns.These products bind soil particles and fill pores,enhancing the strength of the MgO-mixing column.展开更多
Geological sequestration of CO_(2)is critical for deep decarbonization,but the geomechanical stability of coal reservoirs remains a major challenge.This study integrates nanoindentation,XRD/SEM-EDS chemo physical char...Geological sequestration of CO_(2)is critical for deep decarbonization,but the geomechanical stability of coal reservoirs remains a major challenge.This study integrates nanoindentation,XRD/SEM-EDS chemo physical characterization and 4D CT visualization to investigate the time-evolving mechanical degradation of bituminous coals with ScCO_(2)injection.The main results show that 4 d of ScCO_(2)treatment caused 50.47%–80.99%increase in load–displacement deformation and 26.92%–76.17%increase in creep depth at peak load,accompanied by 55.01%–63.38%loss in elastic modulus and 52.83%–74.81%reduction in hardness.The degradation exhibited biphasic kinetics,characterized by rapid surface-driven weakening(0–2 d),followed by stabilized matrix-scale pore homogenization(2–4 d).ScCO_(2)preferentially dissolved carbonate minerals(dolomite),driving pore network expansion and interfacial debonding,while silicate minerals resisted dissolution but promoted structural homogenization.These coupled geochemical-mechanical processes reduced the mechanical heterogeneity of the coal and altered its failure modes.The results establish a predictive framework for reservoir stability assessment and provide actionable insights for optimizing CO_(2)enhanced coalbed methane recovery.展开更多
CO_(2)sequestration through steel slag is one of the effective approaches to simultaneously realize the resource utilization of industrial solid waste,reduce carbon emissions,and enhance the stability of steel slag as...CO_(2)sequestration through steel slag is one of the effective approaches to simultaneously realize the resource utilization of industrial solid waste,reduce carbon emissions,and enhance the stability of steel slag as a construction base,with considerable application prospects.Nevertheless,the components responsible for CO_(2)sequestration in steel slag predominantly exist as silicates,whose chemical inertness leads to suboptimal CO_(2)sequestration efficiency in the slag.Based on the strategy of activating the silicate components in steel slag with the alkali metal potassium(K)to improve the CO_(2)sequestration performance of steel slag,both experiments and theoretical calculations were performed to give a deep insight into the effect and mechanism of K modification on enhancing the CO_(2)sequestration capability of steel slag.In experiments,CO_(2)sequestration capacity of steel slag modified with 3 wt.%K reached 100.15 g/kg at 1000 K.Theoretical analysis has revealed that although K exhibits low reactivity,it enhances the electronic transition and amplifies charge localization at specific sites within Ca_(2)SiO_(4),consequently improving its CO_(2)sequestration capacity.However,an excessive doping of K led to the partial inactivation of some active sites within Ca_(2)SiO_(4).Furthermore,CO_(2)chemisorption on Ca_(2)SiO_(4)surface predominantly occurs through the chelate configuration of CO_(3)^(2−),suggesting the formation of a CaCO_(3)precursor.Thus,both the experimental results and theoretical calculations reveal the role of K on enhancing CO_(2)sequestration capability of steel slag.In summary,K modification offers promising prospects for improving CO_(2)sequestration properties of steel slag and provides support for the industrial implementation of carbon sequestration by steel slag.展开更多
Blue carbon ecosystems,including mangroves,seagrasses,and salt marshes,play a crucial role in mitigating climate change by capturing and storing atmospheric CO_(2)at rates exceeding those of terrestrial forests.This s...Blue carbon ecosystems,including mangroves,seagrasses,and salt marshes,play a crucial role in mitigating climate change by capturing and storing atmospheric CO_(2)at rates exceeding those of terrestrial forests.This study explores the potential of HCWs(Human-Controlled Wetlands)in the Italian Venice Lagoon as an underappreciated component of the global blue carbon pool.Using GEE(Google Earth Engine),we conducted a large-scale assessment of carbon sequestration in these wetlands,demonstrating its advantages over traditional in situ methods in addressing spatial variability.Our findings highlight the significance of below-water mud sediments as primary carbon reservoirs,with a TC(Total Carbon)content of 3.81%±0.94%and a stable storage function akin to peat,reinforced by high CEC(Cation Exchange Capacity).GEE analysis identified a redoximorphic zone at a depth of 20-30 cm,where microbial respiration shifts to anaerobic pathways,preventing carbon release and maintaining long-term sequestration.The study also evaluates key factors affecting remote sensing accuracy,including tidal variations,water depth,and sky cover.The strong correlation between field-measured and satellite-derived carbon parameters(R^(2)>0.85)confirms the reliability of our approach.Furthermore,we developed a GEE-based script for monitoring sediment bioturbation,leveraging Sentinel-1 SAR(Synthetic Aperture Radar)and Sentinel-2 optical data to quantify biological disturbances affecting carbon fluxes.Our results underscore the value of HCWs for carbon sequestration,reinforcing the need for targeted conservation strategies.The scalability and efficiency of remote sensing methodologies,particularly GEE,make them essential for the long-term monitoring of blue carbon ecosystems and the development of effective climate mitigation policies.展开更多
This study investigates the application of carbon dioxide (CO2) sequestration to address challenges in water-drive gas reservoirs, specifically focusing on improving gas recovery and mitigating water invasion. Traditi...This study investigates the application of carbon dioxide (CO2) sequestration to address challenges in water-drive gas reservoirs, specifically focusing on improving gas recovery and mitigating water invasion. Traditional methods like blow-down and co-production have limitations, including sand production, water coning, and inefficiency in strong aquifers. To overcome these issues, this research explores CO2 injection near the edge aquifer, aiming to reduce water influx and enhance gas recovery through the propagation of a CO2 plume in the gas-water contact zone. Both synthetic and real compositional reservoir models were studied, with CO2 injection performed while maintaining reservoir pressure below 90% of the initial level. Results show that CO2 sequestration significantly improved recovery, particularly in higher permeability reservoirs, where it reduced aquifer influx and increased gas production by 26% under challenging conditions. While CO2 dissolution in water decreased aquifer influx by 39%, its adverse effect on sweep efficiency led to a reduction in gas and water production by 4.2% and 10%, respectively. The method's effectiveness was not significantly impacted by aquifer permeability, but it was sensitive to vertical-to-horizontal permeability ratios. When applied to a real gas reservoir, the proposed method increased gas production by 14% compared to conventional techniques, with minimal CO2 production over a 112-year period. This study demonstrates the potential of CO2 sequestration as a comprehensive solution for enhancing gas recovery, reducing water production, and mitigating environmental impacts in water-drive gas reservoirs.展开更多
Tree plantations in the tropical-subtropical transition zone(TSTZ)represent crucial ecological regions where diverse biomes converge.Investigating the carbon sequestration potential and dynamic changes within these pl...Tree plantations in the tropical-subtropical transition zone(TSTZ)represent crucial ecological regions where diverse biomes converge.Investigating the carbon sequestration potential and dynamic changes within these plantation ecosystems is of considerable ecological significance.However,the spatial distribution,driving factors,and underlying mechanisms of carbon sequestration in plantations in this region are poorly understood,thereby limiting accurate assessments of their carbon sequestration potential.This study examines four types of plantation forests located within the TSTZ on the Puwen forest farm of Xishuangbanna,China.Two slope gradients were established to quantify and compare the rate of carbon sequestration across these ecosystems.Using random forest modeling and structural equation modeling,the study identifies key environmental factors influencing the rate of carbon sequestration in the plantations.The results reveal substantial variation in DBH growth rates,biomass carbon sequestration,and soil organic carbon sequestration rates(R_(SOC))among the four forest types.Critical factors affecting R_(SOC)include leaf nitrogen and phosphorus concentrations(LP),total soil nitrogen(STN),total soil phosphorus(STP),soil available phosphorus,and nitrogen concentration in ground surface litter.Among these,STN and STP exerted positive effects on R_(SOC),while LP is exerted negative.Overall,the concentration of soil carbon,nitrogen and phosphorus,along with the nitrogen and phosphorus levels in leaves,under different species and topographic slopes,play decisive roles in regulating soil carbon sequestration rates in tropical and subtropical plantations.This research provides support for vegetation protection and restoration in ecologically sensitive areas and watersheds,contributing to the enhancement of regional forest carbon sequestration capacity.展开更多
Soil organic carbon(SOC)plays a crucial role in mangrove blue carbon formation,yet the differences in microbemediated underlying SOC sequestration between introduced and native mangroves remain unclear.Here,we compare...Soil organic carbon(SOC)plays a crucial role in mangrove blue carbon formation,yet the differences in microbemediated underlying SOC sequestration between introduced and native mangroves remain unclear.Here,we compared the SOC pool,including recalcitrant organic carbon(ROC)and labile carbon pools,as well as three residual carbon sources(amino sugars,lignin phenols,and lipids)in sediments between mangroves of introduced Sonneratia apetala and native Kandelia obovata,and further connected them with microbial life strategies and C metabolism capability.The results showed that SOC accumulation in S.apetala(SA)sediment was about 30%-50% of that in K.obovata(KO)sediment.ROC was the dominant form of SOC in long-term sequestration(76%-83%),while lignin phenols,amino sugars,and lipids were important sources of ROC.In S.apetala sediments,the ROC content was positively correlated with amino sugars,resulting from the more r-strategist microbes that can rapidly convert plant-derived carbon into microbial biomass,which is subsequently transformed into microbial necromass.In contrast,in K.obovata sediments,ROC content showed a stronger positive correlation with the concentrations of lignin phenols and lipids.More K-strategist fungi in the topsoil of K.obovata increased enzyme activities,while more K-strategist bacteria in the subsoil enhanced carbon utilization capacity,thereby increasing lignin phenols and lipids from plant residues in both soil layers.Meanwhile,higher Ca^(2+)concentrations in K.obovata sediments protected three residual carbons from further microbe decomposition.This study provides valuable insights into the molecular mechanisms of SOC sequestration mediated by microbial life strategies in mangrove ecosystems.展开更多
Growing concerns about greenhouse gas emissions from underground mining have intensified the need for carbon reduction strategies at every stage.Shotcrete used in tunnel support presents a promising opportunity for ca...Growing concerns about greenhouse gas emissions from underground mining have intensified the need for carbon reduction strategies at every stage.Shotcrete used in tunnel support presents a promising opportunity for carbon emission reduction.This study investigates the carbon absorption capacity,mechanical strength,and underlying mechanisms of shotcrete when exposed to varying CO_(2)concentrations during the mine support process.Findings reveal that higher CO_(2)concentrations during the initial stages of carbonation curing enhance early strength but may impede long-term strength development.Shotcrete samples exposed to 2vol%CO_(2)for 14 d exhibited a carbonation degree approximately three times higher than those exposed to 0.03vol%CO_(2).A carbonation layer formed in the shotcrete,sequestering CO_(2)as solid carbonates.In practical terms,shotcrete in an underground return-air tunnel absorbed 1.1 kg·m^(2)of CO_(2)over 14 d,equivalent to treating 33 m^(3)of contaminated air.Thus,using shotcrete for CO_(2)curing in return-air tunnels can significantly reduce carbon emissions,contributing to greener and more sustainable mining practices.展开更多
Reducing the highly toxic Cr(Ⅵ)to safe levels is a critical challenge in water treatment,essential for protecting both ecosystems and human health.In this study,we present a facile in situ polymerization approach to ...Reducing the highly toxic Cr(Ⅵ)to safe levels is a critical challenge in water treatment,essential for protecting both ecosystems and human health.In this study,we present a facile in situ polymerization approach to prepare polypyrrole-coated layered double hydroxide composites(PPy/NiFe LDHs).Compared with other LDHs and polypyrrole-based materials,the synthesized PPy/LDHs exhibit excellent adsorption performance under mildly acidic conditions,achieving a maximum Cr(Ⅵ)adsorption capacity of440.4 mg/g at pH 5.Notably,PPy/LDH effectively reduces Cr(Ⅵ)concentration from 10 mg/L to 0.028 mg/L,well below the maximum permissible level of 0.05 mg/L for drinking water.Additionally,PPy/LDH demonstrates durable stability;at pH 5,nickel and iron ions are not detected after adsorption,and trivalent chromium remains fixed on the material without re-release into the solution following reduction.The adsorption behavior and mechanistic analysis indicate that a combination of adsorption and reduction drives Cr(Ⅵ)removal by PPy/LDHs.This work offers an innovative approach to effectively remove the low concentrations of Cr(Ⅵ)from water,showing significant potential for efficient Cr(Ⅵ)remediation.展开更多
As the main factor influencing the flow and preservation of underground fluids,wettability has a profound impact on CO_(2)sequestration(CS).However,the influencing factors and internal interaction mechanisms of shale ...As the main factor influencing the flow and preservation of underground fluids,wettability has a profound impact on CO_(2)sequestration(CS).However,the influencing factors and internal interaction mechanisms of shale kerogen wettability remain unclear.In this study,we used molecular dynamics to simulate the influence of temperature,pressure,and salinity on wettability.Furthermore,the results were validated through various methods such as mean square displacement,interaction energy,electrostatic potential energy,hydrogen bonding,van der Waals forces,and electrostatic forces,thereby confirming the reliability of our findings.As temperature increases,water wettability on the surface of kerogen increases.At CO_(2)pressures of 10 and 20 MPa,as the temperature increases,the kerogen wettability changes from CO_(2)wetting to neutral wetting.As the CO_(2)pressure increases,the water wettability on the surface of kerogen weakens.When the pressure is below 7.375 MPa and the temperature is 298 or 313 K,kerogen undergoes a wettability reversal from neutral wetting to CO_(2)wetting.As salinity increases,water wettability weakens.Divalent cations(Mg2+and Ca2+)have a greater impact on wettability than monovalent cations(Na^(+)).Water preferentially adsorbs on N atom positions in kerogen.CO_(2)is more likely to form hydrogen bonds and adsorb on the surface of kerogen than H_(2)O.As the temperature increases,the number of hydrogen bonds between H_(2)O and kerogen gradually increases,while the increase in pressure reduces the number of hydrogen bonds.Although high pressure helps to increase an amount of CS,it increases the permeability of a cap rock,which is not conducive to CS.Therefore,when determining CO_(2)pressure,not only a storage amount but also the storage safety should be considered.This research method and results help optimize the design of CS technology,and have important significance for achieving sustainable development.展开更多
Complex physical and chemical reactions during CO_(2)sequestration alter the microscopic pore structure of geological formations,impacting sequestration stability.To investigate CO_(2)sequestration dynamics,comprehens...Complex physical and chemical reactions during CO_(2)sequestration alter the microscopic pore structure of geological formations,impacting sequestration stability.To investigate CO_(2)sequestration dynamics,comprehensive physical simulation experiments were conducted under varied pressures,coupled with assessments of changes in mineral composition,ion concentrations,pore morphology,permeability,and sequestration capacity before and after experimentation.Simultaneously,a method using NMR T2spectra changes to measure pore volume shift and estimate CO_(2)sequestration is introduced.It quantifies CO_(2)needed for mineralization of soluble minerals.However,when CO_(2)dissolves in crude oil,the precipitation of asphaltene compounds impairs both seepage and storage capacities.Notably,the impact of dissolution and precipitation is closely associated with storage pressure,with a particularly pronounced influence on smaller pores.As pressure levels rise,the magnitude of pore alterations progressively increases.At a pressure threshold of 25 MPa,the rate of change in small pores due to dissolution reaches a maximum of 39.14%,while precipitation results in a change rate of-58.05%for small pores.The observed formation of dissolution pores and micro-cracks during dissolution,coupled with asphaltene precipitation,provides crucial insights for establishing CO_(2)sequestration parameters and optimizing strategies in low permeability reservoirs.展开更多
Dissolved organic carbon(DOC)and particulate organic carbon(POC)play essential roles in the carbon sequestration,with macroalgae being major producers of DOC and POC.The intertidal zone is the transition area between ...Dissolved organic carbon(DOC)and particulate organic carbon(POC)play essential roles in the carbon sequestration,with macroalgae being major producers of DOC and POC.The intertidal zone is the transition area between the ocean and the land,the main habitat of macroalgae.However,few studies have focused on the regulation of tidally induced desiccation-rewetting cycles on carbon sequestration by intertidal macroalgae.Therefore,we simulated the intertidal environments to investigate the effects of desiccation-rewetting cycles on the growth,DOC and POC release mechanisms of Ulva pertusa.After 14 days of experiments,the DOC release capacities of U.pertusa(per gram fresh weight)were 1.08,5.31,9.74 and 7.47 mg/g in the subtidal,low,middle and high tide zones,respectively.The corresponding POC release capacities were 0.04,1.00,3.90 and 1.38 mg/g.Combined biological carbon sequestration,the total carbon sequestration capacities of U.pertusa in the subtidal,low,middle and high tide zones were 24.73,32.84,27.83 and 16.97 mg/g,respectively.The results indicated that the highest carbon sequestration capacity of U.pertusa occurred in low tide zones.In conclusion,the results will provide support for the application of seaweed negative emissions.展开更多
The combined application of organic manure and chemical fertilizers is an effective way to enhance soil organic carbon(SOC)sequestration through its influences on organic carbon(OC)input and the stability of SOC fract...The combined application of organic manure and chemical fertilizers is an effective way to enhance soil organic carbon(SOC)sequestration through its influences on organic carbon(OC)input and the stability of SOC fractions.However,there is limited information on the carbon sequestration efficiency(CSE)of chemically separated SOC fractions and its response to OC input under long-term fertilization regimes,especially at different sites.This study used three long-term fertilization experiments in Gongzhuling,Zhengzhou and Qiyang spanning 20 years to compare the stocks and CSE in four different OC fractions(very labile OC,labile OC,less labile OC,and non-labile OC)and their relationships with annual OC input.Three treatments of no fertilization(CK),chemical nitrogen,phosphorous,and potassium fertilizers(NPK),and chemical NPK combined with manure(NPKM)were employed.The results showed that compared with CK,NPKM resulted in enhanced SOC stocks and sequestration rates as well as CSE levels of all fractions irrespective of experimental site.Specifically for the very labile and non-labile OC fractions,NPKM significantly increased the SOC stocks by 43 and 83%,77 and 86%,and 73 and 82%in Gongzhuling,Qiyang,and Zhengzhou relative to CK,respectively.However,the greatest changes in SOC stock relative to the initial value were associated with non-labile OC fractions in Gongzhuling,Zhengzhou,and Qiyang,which reached 6.65,7.16,and 7.35 Mg ha^(-1) under NPKM.Similarly,the highest CSE was noted for non-labile OC fractions under NPKM followed sequentially by the very labile OC,labile OC,and less-labile OC fractions,however a CSE of 8.56%in the non-labile OC fraction for Gongzhuling was higher than the values of 6.10 and 4.61%in Zhengzhou and Qiyang,respectively.In addition,the CSE for the passive pool(very labile+labile OC fractions)was higher than the active pool(less-labile+non-labile OC fractions),with the highest value in Gongzhuling.The redundancy analysis revealed that the CSEs of fractions and pools were negatively influenced by annual OC input,mean annual precipitation and temperature,but positively influenced by the initial SOC and total nitrogen contents.This suggests that differential stability of sequestered OC is further governed by indigenous site characteristics and variable amounts of annual OC input.展开更多
基金supported by the National Key R&D Program of China(No.2023YFC3904304)the National Natural Science Foundation of China(No.52304158)Jiangsu Key Laboratory for Clean Utilization of Carbon Resources Research Project(No.BM2024007)。
文摘Underground carbon sequestration(CS)by solid waste backfill(SWB)offers an effective pathway for collaborative disposal of coal-based solid waste and CO_(2),where the amount of carbon sequestration is an important evaluation parameter.In this study,the concept of whole-process carbon sequestration using coal-based solid waste and CO_(2),including sequential stirring and curing stages,was proposed to evaluate the performance evolution of CS.The results showed that CO_(2) pressure and ambient temperature positively correlated with the CS amount from coal-based SWB.In particular,CO_(2) pressure prevailed in the stirring stage,while the ambient temperature effect was more significant in the curing stage.The CS amounts obtained during the stirring stage alone,the curing stage alone,and two sequential stages ranged from 0.66%–3.10%,3.53%–5.09%,and 5.12%–6.02%,respectively.The functional group and micromorphology analyses revealed that the prevailing mechanism at the CS stirring stage was the stirringdriven gas dissolution-leaching-mineralization reaction,while that at the curing stage was the hydration-driven gas permeation-dissociation-CS reaction.Both were essentially solid-liquid-gas multiphase chemical reactions.The results are instrumental in substantiating the coal-based SWB carbon sequestration evolution patterns and mechanisms and providing data support for waste disposal and carbon emission reduction in the coal industry.
基金supported initially by the LIFE FoResMit Project(LIFE14 CCM/IT/000905)。
文摘Peri-urban plantations in the Mediterranean are often degraded due to human inactivity and climate change,leading to a loss of ecosystem services and biodiversity.This study investigates the impact of different thinning practices on carbon sequestration and tree stability in a degraded periurban plantation in the Italian Apennines,six years after thinning.Three treatments were compared:(a)moderate thinning from below(-25%biomass),representing the typical practice;(b)intense selective thinning(-35%biomass),representing an innovative approach;and(c)no management as the control.Growth projections were used to estimate carbon recovery for these treatments,based on site-specific models calibrated with real data.The results show that both thinning approaches increased carbon sequestration over time,with the innovative thinning achieving a 7%higher annual carbon sequestration rate than traditional thinning and 8%more than the control.Estimated payback times were9 years for recovering the harvested volume in both thinning approaches,10 years for innovative thinning to surpass traditional thinning,17 years for innovative thinning to surpass the control,and 24 years for traditional thinning to surpass the control.Additionally,tree mechanical stability improved significantly in both thinning treatments after two years,with further increases observed in the innovative thinning group after six years.These results suggest that selective thinning can accelerate forest recovery and carbon sequestration,especially in areas with high stem density,where it can reduce the negative impacts of tree mortality and deadwood accumulation.However,careful planning is required to mitigate potential short-term stability is sues,particularly in challenging environments(e.g.,windy conditions,steep slopes).Forest management strategies should therefore aim to balance growth,carbon storage,and tree stability,considering both long-term sustainability and local environmental conditions.The findings are particularly relevant for current climate change mitigation strategies,emphasizing that thinning should be carefully tailored to forest type and conditions to maximize benefits in carbon credit generation and sustainable forest management practices.
文摘On July 2^(nd),2025,32 scientists representing 15 countries gathered at Tartu,Estonia to make on-site endorsements for the Global ONCE(Ocean Negative Carbon Emissions)Program at the 12th INTECOL Wetlands Conference.This marks a significant milestone for ONCE in establishing a systematic framework for coastal wetland carbon sequestration research and global collaboration(Figs.1,2).Coastal wetlands are critical transition zones linking terrestrial and marine ecosystems,yet they face severe degradation from anthropogenic land-based activities and sea level rise that propagate impacts to the ocean.As a UN Ocean Decade Program,the Global ONCE Program champions interdisciplinary and cross-regional collaboration to enhance carbon sequestration in the ocean and coastal wetlands through science and innovation.Aligned with the Tartu Declaration on Wetlands that includes resolutions to promote the rights of global wetlands(especially peatlands)and advance the discipline of wetland science based on facts,this initiative addresses key knowledge gaps in land-ocean interactions.The goal is to harness the full potential of coastal wetlands and ocean systems for climate mitigation,thereby laying a scientific foundation for international policy formulation and implementation.
基金supports from the National Natural Science Foundation of China(Grant Nos.52179095,52378323,and 42407216)are gratefully acknowledged.
文摘The increase in CO_(2)injectivity and shifting of CO_(2)-absorbing layers in multilayered geological CO_(2)sequestration(GCS)reservoirs in Ordos,China indicate significantpermeability variations in certain layers.To capture these system changes,a numerical model incorporating all 21 aquifers and internal aquitards was developed.The monitored pressure was well matched through multiphase and thermalhydraulic-mechanical(THM)coupling numerical simulations by introducing permeability variations.The results revealed that the permeability in the second layer increased on approximately day 13 due to the abrupt pressure buildup and temperature decrease.Even such a low rate of CO_(2)(2.8 kg/s)injected into the low permeability system initiated some fractures and the permeability in the second layer around the wellbore increased by 722 times.The second critical system change occurred on approximately day 386.As demonstrated in the numerical simulation,the substantial injection of cold CO_(2)induced strong thermal stress,leading to rock contraction and the initiation of several cracks.The permeability of the firstlayer around the wellbore unexpectedly increased by 4 orders of magnitude.Since no additional pressure could drive the CO_(2)into the remaining 17 layers,the total storage capability of the multilayered system was reduced.A whole picture of the system variation is fully presented and the underlying mechanisms are analyzed.It is believed that the phenomenon of thermal-hydraulic fracturing observed in this fieldand the simulation procedures will benefitother fluidinjection and production works in various geotechnical settings.
基金Under the auspices of the National Natural Science Foundation of China(No.42476247,42461015)the Open Research Fund of Key Laboratory of Coastal Science and Integrated Management,Ministry of Natural Resources(No.2024COSIM01)Guangxi Science and Technology Base and Talent Special Project(No.GuikeAD23026194)。
文摘Understanding the dynamics of vegetation carbon sequestration(VCS)is essential for regional carbon neutrality strategies.This study revealed the spatiotemporal patterns of VCS and its relationship with anthropogenic carbon emissions(ACEs)in Shandong Province,China during 2000-2020,and identified the sensitivity factors affecting VCS.The results show that:1)VCS increased consistently from 193.45 million t to 256.41 million t,with high values areas concentrated in the central,northeastern,and southeastern mountainous and hilly regions,while low values were found in water bodies and urban built-up areas.At the city level,Linyi,Yantai,Binzhou,and Jinan experienced the most significant rises-reaching up to 243000 t/yr.At the county level,Pingdu,Qixia,and Yiyuan also showed substantial growth,each exceeding 30400 t/yr.2)Digital Elevation Molde(DEM)was identified as the dominant natural factor influencing VCS distribution,while land use optimization measures,especially afforestation and farmland conversion in sloped terrain,were the primary human drivers of VCS increase.3)Urbanization and carbon neutrality were not mutually exclusive.While urban expansion locally reduced VCS,rural emigration enhanced carbon sinks in surrounding areas,partially offsetting urban losses.This compensatory mechanism supported VCS increases in nearly all cities and 90% of counties.Nevertheless,with ACEs continuing to rise and the offset ratio by VCS declining,achieving carbon neutrality requires regional strategies that integrate with accelerated energy conservation,emission reduction technologies,and energy transition.These findings provide a scientific basis for decomposing carbon neutrality targets across cities and counties in Shandong and a reference for developing localized land use policies in similar regions.
基金supported by the National Key R&D Program of China(No.2023YFC3709500).
文摘Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.Compared with the traditional coal-fired power plant flue gas emission reduction technology,carbon fixation and emission reduction by microalgae is considered as a promising technology due to the advantages of simple process equipment,convenient operation and environmental protection.When the flue gas is treated by microalgae carbon fixation and emission reduction technology,microalgae cells can fix CO_(2) in the flue gas through photosynthesis,and simultaneously absorb NO_(x) and SO_(x) as nitrogen and sulfur sources required for growth.Meanwhile,they can also absorb mercury,selenium,arsenic,cadmium,lead and other heavy metal ions in the flue gas to obtain microalgae biomass.The obtained microalgae biomass can be further transformed into high valueadded products,which has broad development prospects.This paper reviews the mechanisms and pathways of CO_(2) sequestration,the mechanism and impacts of microalgal emission reduction of flue gas pollutants,and the applications of carbon sequestration in industrial flue gas by microalgae.Finally,this paper provides some guidelines and prospects for the research and application of green emission reduction technology for industrial flue gas.
基金supported by the National Key Research and Development Program of China(2021YFE0101300 and 2021YFD1901102)the project supported by the Natural Science Basic Research Plan in Shaanxi Province,China(2023-JC-YB-185)the Ningxia Key Research and Development Program,China(2023BCF01018)。
文摘Long-term mulching has improved crop yields and farmland productivity in semiarid areas,but it has also increased greenhouse gas(GHG)emissions and depleted soil fertility.Biochar application has emerged as a promising solution for addressing these issues.In this study,we investigated the effects of four biochar application rates(no biochar(N)=0 t ha^(-1),low(L)=3 t ha^(-1),medium(M)=6 t ha^(-1),and high(H)=9 t ha^(-1))under film mulching and no mulching conditions over three growing seasons.We assessed the impacts on GHG emissions,soil organic carbon sequestration(SOCS),and maize yield to evaluate the productivity and sustainability of farmland ecosystems.Our results demonstrated that mulching increased maize yield(18.68-41.80%),total fixed C in straw(23.64%),grain(28.87%),and root(46.31%)biomass,and GHG emissions(CO_(2),10.78%;N_(2)O,3.41%),while reducing SOCS(6.57%)and GHG intensity(GHGI;13.61%).Under mulching,biochar application significantly increased maize yield(10.20%),total fixed C in straw(17.97%),grain(17.69%)and root(16.75%)biomass,and SOCS(4.78%).Moreover,it reduced the GHG emissions(CO_(2),3.09%;N_(2)O,6.36%)and GHGI(12.28%).These effects correlated with the biochar addition rate,with the optimal rate being 9.0 t ha^(-1).In conclusion,biochar application reduces CO_(2) and N_(2)O emissions,enhances CH_(4) absorption,and improves maize yield under film mulching.It also improves the soil carbon fixation capacity while mitigating the warming potential,making it a promising sustainable management method for mulched farmland in semiarid areas.
基金funded by the National Natural Science Foundation of China(Grant No.42277146)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX22_0273)the Transportation Science and Technology Project of Jiangsu Province of China(Grant No.HTSQ(B)2021-249).
文摘Cement treatment,such as cement-mixing columns,is commonly used for deep soft soil improvement to increase the bearing capacity and reduce settlement.However,cement production entails high energy consumption and carbon and pollutant emissions.CO_(2)capture and mineralization represent promising solutions to these issues.This study proposes a sustainable alternative:a novel CO_(2)-carbonated MgO-mixing column that integrates CO_(2)mineralization with soil reinforcement.This approach involves in situ mixing of MgO with deep soil to form columns,which are then carbonated and solidified by injecting captured CO_(2)through gas-permeable pipe piles,achieving both carbon reduction and soil improvement.In this study,CO_(2)-carbonated MgO-mixing columns were comprehensively evaluated to investigate variations in strength,deformation,pH,and CO_(2)sequestration with depth.Two rapid and cost-effective methods to assess its mechanical properties,uniformity,and CO_(2)sequestration capacity are proposed.The results show that the carbonated MgO-treated soil has good strength along the depth direction,with an average unconfined compressive strength(UCS)of 1.02 MPa and a lower pH than that of cement-mixing columns.It also achieves notable CO_(2)sequestration,ranging from 4.88%to 13.10%(average 8.31%),and exhibits good uniformity,as shown by electrical resistivity tests.Needle penetration and electrical resistivity tests could be used to effectively predict the UCS,deformation modulus,and CO_(2)sequestration.XRD,FTIR,SEM,and TG-DTG analyses reveal distinct microstructural differences at various depths,with unhydrated MgO,magnesite,and dypingite/hydromagnesite present in shallow columns,and brucite,nesquehonite,and dypingite/hydromagnesite present in deep columns.These products bind soil particles and fill pores,enhancing the strength of the MgO-mixing column.
基金supported by the National Natural Science Foundation of China(Nos.52204206 and U24A2090)the Fundamental Research Funds for the Central Universities of China(No.2023CDJXY-006).
文摘Geological sequestration of CO_(2)is critical for deep decarbonization,but the geomechanical stability of coal reservoirs remains a major challenge.This study integrates nanoindentation,XRD/SEM-EDS chemo physical characterization and 4D CT visualization to investigate the time-evolving mechanical degradation of bituminous coals with ScCO_(2)injection.The main results show that 4 d of ScCO_(2)treatment caused 50.47%–80.99%increase in load–displacement deformation and 26.92%–76.17%increase in creep depth at peak load,accompanied by 55.01%–63.38%loss in elastic modulus and 52.83%–74.81%reduction in hardness.The degradation exhibited biphasic kinetics,characterized by rapid surface-driven weakening(0–2 d),followed by stabilized matrix-scale pore homogenization(2–4 d).ScCO_(2)preferentially dissolved carbonate minerals(dolomite),driving pore network expansion and interfacial debonding,while silicate minerals resisted dissolution but promoted structural homogenization.These coupled geochemical-mechanical processes reduced the mechanical heterogeneity of the coal and altered its failure modes.The results establish a predictive framework for reservoir stability assessment and provide actionable insights for optimizing CO_(2)enhanced coalbed methane recovery.
基金supported by China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202202)Major Industry Innovation Plan of Anhui Province(AHZDCYCX-LSDT2023-01).
文摘CO_(2)sequestration through steel slag is one of the effective approaches to simultaneously realize the resource utilization of industrial solid waste,reduce carbon emissions,and enhance the stability of steel slag as a construction base,with considerable application prospects.Nevertheless,the components responsible for CO_(2)sequestration in steel slag predominantly exist as silicates,whose chemical inertness leads to suboptimal CO_(2)sequestration efficiency in the slag.Based on the strategy of activating the silicate components in steel slag with the alkali metal potassium(K)to improve the CO_(2)sequestration performance of steel slag,both experiments and theoretical calculations were performed to give a deep insight into the effect and mechanism of K modification on enhancing the CO_(2)sequestration capability of steel slag.In experiments,CO_(2)sequestration capacity of steel slag modified with 3 wt.%K reached 100.15 g/kg at 1000 K.Theoretical analysis has revealed that although K exhibits low reactivity,it enhances the electronic transition and amplifies charge localization at specific sites within Ca_(2)SiO_(4),consequently improving its CO_(2)sequestration capacity.However,an excessive doping of K led to the partial inactivation of some active sites within Ca_(2)SiO_(4).Furthermore,CO_(2)chemisorption on Ca_(2)SiO_(4)surface predominantly occurs through the chelate configuration of CO_(3)^(2−),suggesting the formation of a CaCO_(3)precursor.Thus,both the experimental results and theoretical calculations reveal the role of K on enhancing CO_(2)sequestration capability of steel slag.In summary,K modification offers promising prospects for improving CO_(2)sequestration properties of steel slag and provides support for the industrial implementation of carbon sequestration by steel slag.
文摘Blue carbon ecosystems,including mangroves,seagrasses,and salt marshes,play a crucial role in mitigating climate change by capturing and storing atmospheric CO_(2)at rates exceeding those of terrestrial forests.This study explores the potential of HCWs(Human-Controlled Wetlands)in the Italian Venice Lagoon as an underappreciated component of the global blue carbon pool.Using GEE(Google Earth Engine),we conducted a large-scale assessment of carbon sequestration in these wetlands,demonstrating its advantages over traditional in situ methods in addressing spatial variability.Our findings highlight the significance of below-water mud sediments as primary carbon reservoirs,with a TC(Total Carbon)content of 3.81%±0.94%and a stable storage function akin to peat,reinforced by high CEC(Cation Exchange Capacity).GEE analysis identified a redoximorphic zone at a depth of 20-30 cm,where microbial respiration shifts to anaerobic pathways,preventing carbon release and maintaining long-term sequestration.The study also evaluates key factors affecting remote sensing accuracy,including tidal variations,water depth,and sky cover.The strong correlation between field-measured and satellite-derived carbon parameters(R^(2)>0.85)confirms the reliability of our approach.Furthermore,we developed a GEE-based script for monitoring sediment bioturbation,leveraging Sentinel-1 SAR(Synthetic Aperture Radar)and Sentinel-2 optical data to quantify biological disturbances affecting carbon fluxes.Our results underscore the value of HCWs for carbon sequestration,reinforcing the need for targeted conservation strategies.The scalability and efficiency of remote sensing methodologies,particularly GEE,make them essential for the long-term monitoring of blue carbon ecosystems and the development of effective climate mitigation policies.
文摘This study investigates the application of carbon dioxide (CO2) sequestration to address challenges in water-drive gas reservoirs, specifically focusing on improving gas recovery and mitigating water invasion. Traditional methods like blow-down and co-production have limitations, including sand production, water coning, and inefficiency in strong aquifers. To overcome these issues, this research explores CO2 injection near the edge aquifer, aiming to reduce water influx and enhance gas recovery through the propagation of a CO2 plume in the gas-water contact zone. Both synthetic and real compositional reservoir models were studied, with CO2 injection performed while maintaining reservoir pressure below 90% of the initial level. Results show that CO2 sequestration significantly improved recovery, particularly in higher permeability reservoirs, where it reduced aquifer influx and increased gas production by 26% under challenging conditions. While CO2 dissolution in water decreased aquifer influx by 39%, its adverse effect on sweep efficiency led to a reduction in gas and water production by 4.2% and 10%, respectively. The method's effectiveness was not significantly impacted by aquifer permeability, but it was sensitive to vertical-to-horizontal permeability ratios. When applied to a real gas reservoir, the proposed method increased gas production by 14% compared to conventional techniques, with minimal CO2 production over a 112-year period. This study demonstrates the potential of CO2 sequestration as a comprehensive solution for enhancing gas recovery, reducing water production, and mitigating environmental impacts in water-drive gas reservoirs.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFE0105100-5-2)the Fundamental Research Funds of CAFYBB2022SY034)+2 种基金the Guangxi Science and Technology Base and Talents Fund(Grant No.GUIKE AD22035117)the Scientific Research Foundation for Highlevel Talent of Sanming University(Grant No.20YG02)Natural Science Foundation of Fujian Province(Grant No.2023J011022)。
文摘Tree plantations in the tropical-subtropical transition zone(TSTZ)represent crucial ecological regions where diverse biomes converge.Investigating the carbon sequestration potential and dynamic changes within these plantation ecosystems is of considerable ecological significance.However,the spatial distribution,driving factors,and underlying mechanisms of carbon sequestration in plantations in this region are poorly understood,thereby limiting accurate assessments of their carbon sequestration potential.This study examines four types of plantation forests located within the TSTZ on the Puwen forest farm of Xishuangbanna,China.Two slope gradients were established to quantify and compare the rate of carbon sequestration across these ecosystems.Using random forest modeling and structural equation modeling,the study identifies key environmental factors influencing the rate of carbon sequestration in the plantations.The results reveal substantial variation in DBH growth rates,biomass carbon sequestration,and soil organic carbon sequestration rates(R_(SOC))among the four forest types.Critical factors affecting R_(SOC)include leaf nitrogen and phosphorus concentrations(LP),total soil nitrogen(STN),total soil phosphorus(STP),soil available phosphorus,and nitrogen concentration in ground surface litter.Among these,STN and STP exerted positive effects on R_(SOC),while LP is exerted negative.Overall,the concentration of soil carbon,nitrogen and phosphorus,along with the nitrogen and phosphorus levels in leaves,under different species and topographic slopes,play decisive roles in regulating soil carbon sequestration rates in tropical and subtropical plantations.This research provides support for vegetation protection and restoration in ecologically sensitive areas and watersheds,contributing to the enhancement of regional forest carbon sequestration capacity.
基金supported by grants from the National Natural Science Foundation of China(Nos.42076117 and 32160051)the Guangdong Basic and Applied Basic Research Foundation(Nos.2023A1515012772,2024A1515011721,and 2024A1515012249).
文摘Soil organic carbon(SOC)plays a crucial role in mangrove blue carbon formation,yet the differences in microbemediated underlying SOC sequestration between introduced and native mangroves remain unclear.Here,we compared the SOC pool,including recalcitrant organic carbon(ROC)and labile carbon pools,as well as three residual carbon sources(amino sugars,lignin phenols,and lipids)in sediments between mangroves of introduced Sonneratia apetala and native Kandelia obovata,and further connected them with microbial life strategies and C metabolism capability.The results showed that SOC accumulation in S.apetala(SA)sediment was about 30%-50% of that in K.obovata(KO)sediment.ROC was the dominant form of SOC in long-term sequestration(76%-83%),while lignin phenols,amino sugars,and lipids were important sources of ROC.In S.apetala sediments,the ROC content was positively correlated with amino sugars,resulting from the more r-strategist microbes that can rapidly convert plant-derived carbon into microbial biomass,which is subsequently transformed into microbial necromass.In contrast,in K.obovata sediments,ROC content showed a stronger positive correlation with the concentrations of lignin phenols and lipids.More K-strategist fungi in the topsoil of K.obovata increased enzyme activities,while more K-strategist bacteria in the subsoil enhanced carbon utilization capacity,thereby increasing lignin phenols and lipids from plant residues in both soil layers.Meanwhile,higher Ca^(2+)concentrations in K.obovata sediments protected three residual carbons from further microbe decomposition.This study provides valuable insights into the molecular mechanisms of SOC sequestration mediated by microbial life strategies in mangrove ecosystems.
基金financially funded by the 14th Five Years Key Programs for Science and Technology Development of China(No.2021YFC2900400)the National Natural Science Foundation of China(Nos.52274151,552104156,52074351,and 22376221)+2 种基金the Science and Technology Innovation Program of Hunan Province,China(No.2021 RC3125)the Natural Science Foundation of Hunan Province,China(No.2024JJ2074)the Young Elite Scientists Sponsorship Program by CAST(No.2023QNRC 001)。
文摘Growing concerns about greenhouse gas emissions from underground mining have intensified the need for carbon reduction strategies at every stage.Shotcrete used in tunnel support presents a promising opportunity for carbon emission reduction.This study investigates the carbon absorption capacity,mechanical strength,and underlying mechanisms of shotcrete when exposed to varying CO_(2)concentrations during the mine support process.Findings reveal that higher CO_(2)concentrations during the initial stages of carbonation curing enhance early strength but may impede long-term strength development.Shotcrete samples exposed to 2vol%CO_(2)for 14 d exhibited a carbonation degree approximately three times higher than those exposed to 0.03vol%CO_(2).A carbonation layer formed in the shotcrete,sequestering CO_(2)as solid carbonates.In practical terms,shotcrete in an underground return-air tunnel absorbed 1.1 kg·m^(2)of CO_(2)over 14 d,equivalent to treating 33 m^(3)of contaminated air.Thus,using shotcrete for CO_(2)curing in return-air tunnels can significantly reduce carbon emissions,contributing to greener and more sustainable mining practices.
基金supported by the National Natural Science Foundation of China(Nos.52370070,and 52070047)。
文摘Reducing the highly toxic Cr(Ⅵ)to safe levels is a critical challenge in water treatment,essential for protecting both ecosystems and human health.In this study,we present a facile in situ polymerization approach to prepare polypyrrole-coated layered double hydroxide composites(PPy/NiFe LDHs).Compared with other LDHs and polypyrrole-based materials,the synthesized PPy/LDHs exhibit excellent adsorption performance under mildly acidic conditions,achieving a maximum Cr(Ⅵ)adsorption capacity of440.4 mg/g at pH 5.Notably,PPy/LDH effectively reduces Cr(Ⅵ)concentration from 10 mg/L to 0.028 mg/L,well below the maximum permissible level of 0.05 mg/L for drinking water.Additionally,PPy/LDH demonstrates durable stability;at pH 5,nickel and iron ions are not detected after adsorption,and trivalent chromium remains fixed on the material without re-release into the solution following reduction.The adsorption behavior and mechanistic analysis indicate that a combination of adsorption and reduction drives Cr(Ⅵ)removal by PPy/LDHs.This work offers an innovative approach to effectively remove the low concentrations of Cr(Ⅵ)from water,showing significant potential for efficient Cr(Ⅵ)remediation.
基金supported by the China Scholarship Council(Grant No.202306440152)the CNPC Science and Technology Major Project of the Fourteenth Five-Year Plan(Grant No.2021DJ0101)+1 种基金the Science Foundation of China University of Petroleum,Beijing(Grant No.2462022YXZZ007)the National Natural Science Foundation of China(Grant No.42102145).
文摘As the main factor influencing the flow and preservation of underground fluids,wettability has a profound impact on CO_(2)sequestration(CS).However,the influencing factors and internal interaction mechanisms of shale kerogen wettability remain unclear.In this study,we used molecular dynamics to simulate the influence of temperature,pressure,and salinity on wettability.Furthermore,the results were validated through various methods such as mean square displacement,interaction energy,electrostatic potential energy,hydrogen bonding,van der Waals forces,and electrostatic forces,thereby confirming the reliability of our findings.As temperature increases,water wettability on the surface of kerogen increases.At CO_(2)pressures of 10 and 20 MPa,as the temperature increases,the kerogen wettability changes from CO_(2)wetting to neutral wetting.As the CO_(2)pressure increases,the water wettability on the surface of kerogen weakens.When the pressure is below 7.375 MPa and the temperature is 298 or 313 K,kerogen undergoes a wettability reversal from neutral wetting to CO_(2)wetting.As salinity increases,water wettability weakens.Divalent cations(Mg2+and Ca2+)have a greater impact on wettability than monovalent cations(Na^(+)).Water preferentially adsorbs on N atom positions in kerogen.CO_(2)is more likely to form hydrogen bonds and adsorb on the surface of kerogen than H_(2)O.As the temperature increases,the number of hydrogen bonds between H_(2)O and kerogen gradually increases,while the increase in pressure reduces the number of hydrogen bonds.Although high pressure helps to increase an amount of CS,it increases the permeability of a cap rock,which is not conducive to CS.Therefore,when determining CO_(2)pressure,not only a storage amount but also the storage safety should be considered.This research method and results help optimize the design of CS technology,and have important significance for achieving sustainable development.
基金support of the National Natural Science Foundation of China(Grant Nos.52174030,52474042 and 52374041)the Postgraduate Innovation Fund Project of Xi'an Shiyou University(No.YCX2411001)the Natural Science Basic Research Program of Shaanxi(Program Nos.2024JCYBMS-256 and 2022JQ-528)。
文摘Complex physical and chemical reactions during CO_(2)sequestration alter the microscopic pore structure of geological formations,impacting sequestration stability.To investigate CO_(2)sequestration dynamics,comprehensive physical simulation experiments were conducted under varied pressures,coupled with assessments of changes in mineral composition,ion concentrations,pore morphology,permeability,and sequestration capacity before and after experimentation.Simultaneously,a method using NMR T2spectra changes to measure pore volume shift and estimate CO_(2)sequestration is introduced.It quantifies CO_(2)needed for mineralization of soluble minerals.However,when CO_(2)dissolves in crude oil,the precipitation of asphaltene compounds impairs both seepage and storage capacities.Notably,the impact of dissolution and precipitation is closely associated with storage pressure,with a particularly pronounced influence on smaller pores.As pressure levels rise,the magnitude of pore alterations progressively increases.At a pressure threshold of 25 MPa,the rate of change in small pores due to dissolution reaches a maximum of 39.14%,while precipitation results in a change rate of-58.05%for small pores.The observed formation of dissolution pores and micro-cracks during dissolution,coupled with asphaltene precipitation,provides crucial insights for establishing CO_(2)sequestration parameters and optimizing strategies in low permeability reservoirs.
基金the National Key Research and Development Program of China(No.2022YFC 3106001)the National Natural Science Foundation of China(No.42206131)+2 种基金the Projects of Science&Technology Plan in Yantai City(No.2023ZDCX039)the Ocean Negative Carbon Emissions(ONCE)Programthe Key Technology Research and Application of Ecological and Efficient Comprehensive Utilization in‘Fishery-Photovoltaic Integration’Seawater Ponds in the Yellow River Delta(No.DYYG2024-10)。
文摘Dissolved organic carbon(DOC)and particulate organic carbon(POC)play essential roles in the carbon sequestration,with macroalgae being major producers of DOC and POC.The intertidal zone is the transition area between the ocean and the land,the main habitat of macroalgae.However,few studies have focused on the regulation of tidally induced desiccation-rewetting cycles on carbon sequestration by intertidal macroalgae.Therefore,we simulated the intertidal environments to investigate the effects of desiccation-rewetting cycles on the growth,DOC and POC release mechanisms of Ulva pertusa.After 14 days of experiments,the DOC release capacities of U.pertusa(per gram fresh weight)were 1.08,5.31,9.74 and 7.47 mg/g in the subtidal,low,middle and high tide zones,respectively.The corresponding POC release capacities were 0.04,1.00,3.90 and 1.38 mg/g.Combined biological carbon sequestration,the total carbon sequestration capacities of U.pertusa in the subtidal,low,middle and high tide zones were 24.73,32.84,27.83 and 16.97 mg/g,respectively.The results indicated that the highest carbon sequestration capacity of U.pertusa occurred in low tide zones.In conclusion,the results will provide support for the application of seaweed negative emissions.
基金support from the National Natural Science Foundation of China(42177341)is highly acknowledged。
文摘The combined application of organic manure and chemical fertilizers is an effective way to enhance soil organic carbon(SOC)sequestration through its influences on organic carbon(OC)input and the stability of SOC fractions.However,there is limited information on the carbon sequestration efficiency(CSE)of chemically separated SOC fractions and its response to OC input under long-term fertilization regimes,especially at different sites.This study used three long-term fertilization experiments in Gongzhuling,Zhengzhou and Qiyang spanning 20 years to compare the stocks and CSE in four different OC fractions(very labile OC,labile OC,less labile OC,and non-labile OC)and their relationships with annual OC input.Three treatments of no fertilization(CK),chemical nitrogen,phosphorous,and potassium fertilizers(NPK),and chemical NPK combined with manure(NPKM)were employed.The results showed that compared with CK,NPKM resulted in enhanced SOC stocks and sequestration rates as well as CSE levels of all fractions irrespective of experimental site.Specifically for the very labile and non-labile OC fractions,NPKM significantly increased the SOC stocks by 43 and 83%,77 and 86%,and 73 and 82%in Gongzhuling,Qiyang,and Zhengzhou relative to CK,respectively.However,the greatest changes in SOC stock relative to the initial value were associated with non-labile OC fractions in Gongzhuling,Zhengzhou,and Qiyang,which reached 6.65,7.16,and 7.35 Mg ha^(-1) under NPKM.Similarly,the highest CSE was noted for non-labile OC fractions under NPKM followed sequentially by the very labile OC,labile OC,and less-labile OC fractions,however a CSE of 8.56%in the non-labile OC fraction for Gongzhuling was higher than the values of 6.10 and 4.61%in Zhengzhou and Qiyang,respectively.In addition,the CSE for the passive pool(very labile+labile OC fractions)was higher than the active pool(less-labile+non-labile OC fractions),with the highest value in Gongzhuling.The redundancy analysis revealed that the CSEs of fractions and pools were negatively influenced by annual OC input,mean annual precipitation and temperature,but positively influenced by the initial SOC and total nitrogen contents.This suggests that differential stability of sequestered OC is further governed by indigenous site characteristics and variable amounts of annual OC input.
