Sequestration Process Research Articles

Carbon Sequestration of Alkaline Olivine Basalt in the Yangtze River Basin of China: Carbonation Mechanism and CO2 Storage Potential

Summary As the largest carbon-emitting region in China, the feasibility of basalt geological carbon sequestration in the Yangtze River Basin is an important way to address regional carbon neutrality. In this study, we carried out carbonation reactions in a closed experimental setup using synthetic formation water to test the basalt-CO2 interaction by using the alkaline olivine basalt from the Yangtze River Basin of China. We used scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and inductively coupled plasma mass spectrometry (ICP-MS) to characterize the solid and liquid phases before and after the reaction and to obtain the carbonation degree. Comparing the mineral characteristics with those of the unreacted samples, the results consistently show a reduction in silicate minerals and an increase in carbonate minerals, regardless of reaction conditions or time. The experimental results show that the CO2 consumption rate during the carbon sequestration process of basalt in the Yangtze River Basin has a characteristic time threshold, and after 180 days of reaction, the rate tends to stabilize under all reaction conditions. In addition, the percentage of CO2 consumed under high-pressure conditions was significantly greater than under low-pressure conditions. Considering the limitations of traditional potential calculation methods, we propose a new calculation method for predicting the CO2 sequestration potential of basalt based on the analysis and summary of changes in mineral content after the reaction. According to this calculation, the potential total CO2 reserves of Cenozoic and Mesozoic alkaline basalt distributed in southeastern China are estimated to be 2.117 billion tons of CO2, approximately equivalent to China’s carbon emissions for 2 years, providing support for the feasibility of basalt carbon sequestration in China. While these findings support the potential of basalt carbon sequestration in the region, further research is needed to validate these estimates under field conditions, considering the differences in reactive surface area between powdered and in-situ basalts.

Benthic Feeding and Diet Partitioning in Red Sea Mesopelagic Fish Resolved Through DNA Metabarcoding and ROV Footage.

Mesopelagic fish are among the most abundant vertebrates on Earth and play a crucial role in carbon sequestration through their daily vertical migration. However, their dietary ecology remains poorly understood, especially in the Red Sea, limiting our grasp of their trophic interactions and ecological roles. This study investigates the dietary composition of two common mesopelagic fish species in the Red Sea, the lanternfish (Benthosema taxa) and the endemic lightfish (Vinciguerria mabahiss), using DNA metabarcoding of the mitochondrial COI marker, supplemented by remotely operated vehicle (ROV) video observations. Our findings show that V. mabahiss exhibits higher prey diversity compared to Benthosema taxa, suggesting a more generalist feeding strategy. Both species primarily consume copepods, likely due to the high abundance of copepods in the upper 200 m of the Red Sea. Despite this commonality, distinct dietary niches were observed: Benthosema taxa consumes significant amounts of molluscs, followed by annelids and echinoderms, while V. mabahiss occasionally consumes gelatinous prey such as hydrozoans and scyphozoans. Notably, our ROV video footage demonstrates that these mesopelagic fish engage in benthic feeding on the continental slope, a behavior rarely documented. By consuming and redistributing organic material through their diel vertical migrations, mesopelagic fish contribute to the biological carbon pump, with important implications for carbon sequestration processes in the ocean. Future studies integrating DNA metabarcoding with stable isotope analysis could provide deeper insights into dietary partitioning and the ecological contributions of these mesopelagic fish species to the Red Sea ecosystem and beyond.

Long-term solar radiation forecasting in India using EMD, EEMD, and advanced machine learning algorithms

Solar radiation plays a critical role in the carbon sequestration processes of terrestrial ecosystems, making it a key factor in environmental sustainability among various renewable energy sources. This study integrates two advanced signal processing techniques—empirical mode decomposition (EMD) and ensemble empirical mode decomposition (EEMD)—with machine learning (ML) algorithms, including multilayer perceptron (MLP), random forest regression (RFR), support vector regression (SVR), and ridge regression, to forecast long-term solar radiation. Meteorological data spanning 13 years (2000–2012) from seven locations across India (Bhubaneswar, Chennai, Delhi, Hyderabad, Nagpur, Patna, and Trivandrum) were used for training and testing. The optimal model was identified based on performance metrics, including the highest linear correlation coefficient (R), and the lowest mean absolute error (MAE) and root mean square error (RMSE). The results indicate that EEMD integrated with ML algorithms consistently outperformed EMD-based approaches. Among the ML models evaluated, EEMD integrated with MLP achieved the best performance across all locations, with RMSE = 0.332, MAE = 0.26, and R2 = 0.99. Furthermore, a comparative analysis with previous studies demonstrated that the proposed approach provides superior accuracy, underscoring its efficacy in solar radiation forecasting.

Applications, potential, and challenges of biochar in carbon sequestration

Biochar has great potential for carbon sequestration and has become a hot area of scientific research in recent years. Biochar can not only effectively fix atmospheric carbon dioxide in the soil, but also has multiple ecological benefits, such as improving soil structure, increasing soil fertility, and reducing greenhouse gas emissions. However, the technology still faces some challenges in practical industrial applications. In this paper, the characteristics of biochar are first described in detail, including types and properties, preparation methods, and carbon sequestration mechanisms. Subsequently, the challenges faced by biochar in the carbon sequestration process are discussed. Finally, the article proposes future directions and optimization measures for biochar, suggesting that by optimizing the raw material selection, improving the production process, assessing the long-term environmental impact, and reducing the cost. Through these measures, biochar technology is expected to further realize its carbon sequestration potential and play a more important role in the global response to climate change.

A subset of conserved phagocytic genes are likely used for the intracellular theft of cnidarian stinging organelles in nudibranch gastropods.

Phagocytosis is a universal physiological process in eukaryotes with many important biological functions. In nudibranch gastropods, a novel form of phagocytosis called nematocyst sequestration is specialized for the uptake of venomous stinging organelles stolen from their cnidarian prey. This process is highly selective. Here we use the emerging model nudibranch species Berghia stephanieae and Hermissenda opalescens to identify genes enriched within the body regions where nematocyst sequestration occurs, and investigate how the expression profile of phagocytosis, immune, and digestive genes differs between nematocyst sequestering regions relative to those where other phagocytic functions occur. We identified 166 genes with significantly higher expression in sequestering regions in B. stephanieae , including genes associated with development, membrane transport, and metabolism. Of these, 41 overlap with transcripts upregulated in H. opalescens sequestering tissues. Using Hybridization Chain Reaction in situs , we show that at least two of these genes were localized to sequestering cells in B. stephanieae , including a putative C-type lectin receptor and a collagen. Genes annotated with phagocytosis, digestion, or immunity GO terms were often expressed in both sequestering and non-sequestering tissues, suggesting that they may also play a role in sequestration processes. Our results suggest that phagocytosis genes likely play a role in the sequestration phenotype, and that a small subset of genes (e.g., collagen) may play unique functions yet to be uncovered. However, we also show that genes categorized in GO terms related to endocytosis, immunity, and digestion show a clear decrease in overall expression in sequestering tissues. This study lays the foundation for further inquiry into mechanisms of organelle sequestration in nudibranchs and other organisms.

Current Status and Reflections on Ocean CO2 Sequestration: A Review

Climate change has become one of the most pressing global challenges, with greenhouse gas emissions, particularly carbon dioxide (CO2), being the primary drivers of global warming. To effectively address climate change, reducing carbon emissions has become an urgent task for countries worldwide. Carbon capture, utilization, and storage (CCUS) technologies are regarded as crucial measures to combat climate change, among which ocean CO2 sequestration has emerged as a promising approach. Recent reports from the International Energy Agency (IEA) indicate that by 2060, CCUS technologies could contribute up to 14% of global cumulative carbon reductions, highlighting their significant potential in mitigating climate change. This review discusses the main technological pathways for ocean CO2 sequestration, including oceanic water column sequestration, CO2 oil and gas/coal seam geological sequestration, saline aquifer sequestration, and seabed methane hydrate sequestration. The current research status and challenges of these technologies are reviewed, with a particular focus on the potential of seabed methane hydrate sequestration, which offers a storage density of approximately 0.5 to 1.0 Gt per cubic kilometer of hydrate. This article delves into the formation mechanisms, stability conditions, and storage advantages of CO2 hydrates. CO2 sequestration via hydrates not only offers high storage density but also ensures long-term stability in the low-temperature, high-pressure conditions of the seabed, minimizing leakage risks. This makes it one of the most promising ocean CO2 sequestration technologies. This paper also analyzes the difficulties faced by ocean CO2 sequestration technologies, such as the kinetic limitations of hydrate formation and leakage monitoring during the sequestration process. Finally, this paper looks ahead to the future development of ocean CO2 sequestration technologies, providing theoretical support and practical guidance for optimizing their application and promoting a low-carbon economy.

CO2 geological sequestration can remove emerging contaminants in groundwater: The important role of secondary mineral carbonates.

CO2 geological sequestration can remove emerging contaminants in groundwater: The important role of secondary mineral carbonates.

Development of a Concept for Integrated Processing of Waste Incinerator Plants

Technological approaches to the integrated use of waste generated during the incineration of municipal solid waste (MSW) to produce products suitable for use in traditionally waste-intensive industries are considered . The current directions in world practice for the disposal of ash and slag from waste incineration plants and the main prospects for the process of carbon dioxide sequestration using ash and slag waste are covered. An analysis of the limiting factors for the disposal of ashes and slag in the production of building materials, agriculture and geotechnologies is presented. The dispersed and material composition of slags and ashes from the combustion of MSW has been studied, and the morphostructural features of slag silicate grains have been established. The results of tests of pneumatic separation of slag in a cascade-gravity classifier with the production of sand for construction geotechnical work at landfills are presented. The possibility of using waste from a waste incineration plant for the production of compacts of technogenic powdered materials and products of their processing has been shown in order to create materials with specified technological properties and reduce the toxicity of waste

Fly ash-doped biochar fabricated by pyrolysis and hydrothermal strategies: characteristics and potentialities of carbon sequestration

The oxidation of biochar occurs due to both natural and human influences during the soil carbon sequestration process. Therefore, it is crucial to produce high-stability biochar to achieve carbon neutrality. Fly ash-doped biochar was obtained from fly ash and corn stalks by employing hydrothermal/pyrolysis treatment, along with alkali impregnation at different temperatures. The microstructural characteristics and carbon sequestration potentials were studied as an essential performance parameter that was influenced by mineral doping and treatment temperature. The yield and carbon retention of P500-1:2 improved by 54.15% and 6.81%, respectively, and the carbon loss following H2O2 oxidation was only 9.93% as depicted by the results. In comparison with hydrothermal biochar, pyrolysis biochar is superior in terms of its carbon sequestration potential. SiO2, Al2O3 and other components in fly ash continue to dissolve at high temperatures and react with carbon in biochar, promoting the formation of aromatic carbon and generating a physical protective layer to prevent biochar from oxidation, hence improving the chemical and thermal stability of biochar. High temperature and mineral interaction also contribute to high aromatic structure (H:C < 0.4) formation, significantly improving the specific surface area and thermal stability of biochar.Graphical

Effect of marine anoxia on the conversion of macroalgal biomass to refractory dissolved organic carbon.

Effect of marine anoxia on the conversion of macroalgal biomass to refractory dissolved organic carbon.

Geological Complexity: Bridging Cosmic Evolution and the Evolution of Life

Earth occupies a unique position in Big History as a bridge between cosmic evolution and the rise of complex life. While discussions often emphasize monumental events like the Big Bang or the rise of civilizations, the intermediate phase of planetary formation and life’s emergence reveals the intricate interplay of cosmic, geological, and biological processes. Earth’s development—from the chaotic dynamics of the early solar system, including the Moon-forming collision, to the establishment of a protective magnetic field and diverse energy gradients—created the conditions necessary for life to arise and co-evolve with the planet’s systems. This co-evolution is evident in feedback loops such as carbon sequestration, atmospheric oxygenation, and life-driven erosion processes, which shaped Earth’s environment over billions of years. Despite challenges like Snowball Earth events, asteroid impacts, and mass extinctions, the planet’s systems maintained a delicate balance of habitability, with life itself playing an active regulatory role as suggested by the Gaia hypothesis. Understanding Earth’s improbable trajectory highlights the rarity of life-bearing planets, the fragility of planetary systems, and the profound interconnectedness of cosmic and biological evolution. As human activity increasingly disrupts Earth’s delicate balance, this perspective provides valuable insights into planetary sustainability and informs the search for life on other worlds.

Organic ligands in whale excrement support iron availability and reduce copper toxicity to the surface ocean

Nutrient recycling by marine megafauna is a key ecosystem service that has been disturbed by anthropogenic activity. While some hypotheses attribute Southern Ocean ecosystem restructuring to disruptions in micronutrient cycling after the elimination of two million great whales, there is little knowledge of trace metal lability in whale excrement. Here we measured high concentrations of dissolved iron and copper in five baleen whale fecal samples and characterized micromolar levels of organic metal-binding ligands as a proxy for their availability. The iron-ligand pool consisted of weakly-binding ligands and intermediate-binding ligands which enhanced iron stability and potential bioavailability. In comparison, 47 novel strongly-binding metallophores dominated copper-binding, curtailing its potential toxicity. These results illustrate how marine megafauna transform prey biomass into highly-labile micronutrients that they inject directly into the surface ocean, a mechanism whaling reduced by over 90%. Thus, the rapid restructuring of pelagic ecosystems through overharvesting may cause large biogeochemical feedbacks, altering primary productivity and carbon sequestration processes in the ocean.

Sequestration process and mechanism of U(VI) on montmorillonite-aspergillus niger composite.

Sequestration process and mechanism of U(VI) on montmorillonite-aspergillus niger composite.

Formation of amorphous molybdenum sulfide in abiotic and biotic sulfidic conditions: A comparative study on molybdenum sequestration mechanisms

Abstract Concentrations of sedimentary molybdenum (Mo) have been used as a proxy for palaeoceanographic redox conditions based on the distinctive behaviour of Mo under oxic versus euxinic (i.e., anoxic and sulfidic) conditions. However, the mechanisms that govern Mo sequestration in various euxinic settings are not fully resolved. It has previously been proposed that sulfate-reducing bacteria (SRB), the main drivers and regulators of euxinic conditions, can actively take up and reduce Mo intracellularly and passively induce Fe-independent Mo complexation and reduction at their cell surfaces. However, uncertainties remain regarding the underlying interactions and relative contributions of these proposed biotic Mo sequestration pathways. In this study, systematic experiments were carried out to examine the interactions among Mo(VI) species (MoO42- or MoS42-), ferrous iron (Fe2+) and SRB with a focus on combinations of conditions that lead to reductive Mo precipitation. The speciation of aqueous Mo and composition, structure, oxidation states and bonding environment of precipitated Mo-sulfides were analysed using UV-vis spectrophotometry (UV-vis), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and synchrotron-based X-ray absorption spectroscopy (XAS). Results indicate that SRB does not directly reduce Mo but, rather, plays a passive role in mediating Mo sequestration by providing sulfide and potential nucleation sites at their reactive cell surfaces for precipitation. However, even in the presence of SRB cells, Fe2+ was required for Mo precipitation in all conditions tested. By identifying the limiting (and non-limiting) factors in the Mo reduction and sequestration process, this study provides significant new insights for interpreting Mo palaeoredox proxies.

Modeling Thermocatalytic Systems for CO2 Hydrogenation to Methanol

The hydrogenation of CO2 to CH3OH over Cu-based catalysts holds significant potential for advancing carbon sequestration and sustainable chemical processes. While numerous studies have focused on catalyst development, the environmental...

The combined effects of microplastics and their additives on mangrove system: From the sinks to the sources of carbon.

The combined effects of microplastics and their additives on mangrove system: From the sinks to the sources of carbon.

Visualization study of the effects of polycarboxylates on CO2 hydrate generation and interfacial property.

Visualization study of the effects of polycarboxylates on CO2 hydrate generation and interfacial property.

Exploring the impact of CO2 sequestration on plastic properties, mechanical performance, and microstructure of concrete

In view of global warming, carbon sequestration techniques are being employed across the globe to minimize the damaging effects of greenhouse gases on the environment. Studies have revealed that adding CO2 during the mixing or curing stage of concrete enhances its mechanical properties and long-term durability. This study aims to examine the effect of CO2 addition during the mixing stage on the plastic, mechanical and microstructural properties of concrete. Various CO2 dosages, ranging from 0.1 to 1%, were injected during mixing to analyze the plastic and hardened properties of concrete. CO2 primarily reacts with calcium hydroxide in concrete to form calcium carbonate (CaCO3), thereby densifying its microstructure and improving its compressive strength by 10–20%. An optimum strength of up to 20% was achieved with 0.75% dosage. Additionally, the results show a 5–10% improvement in flexural and split tensile strength with CO2 addition over the control mix, with 0.75% dosage yielding optimal strength. Semi-adiabatic calorimetry test on early hydrating concrete shows a 14% peak temperature rise at 0.75% CO2 dosage compared to control concrete, indicating enhanced early-age strength development. Thermal Pyrolysis tests, microscopy and infrared spectroscopy indicated the presence of CaCO3, thereby confirming the carbonation process. However, CO2 dosages above 0.5% by weight of cement resulted in a drop in the workability of concrete in the plastic stage. This research attempts to create a simplified CO2 sequestration process in concrete, develop a predictive model to estimate the compressive strength and utilize material characterization techniques to identify the mineralization process.HighlightsInjecting CO2 into fresh concrete improves its strength and lowers its environmental impact.A multiple linear regression model predicts the compressive strength of CO2-injected concrete.Semi-adiabatic calorimetry shows that CO2 injection speeds up early hydration.Thermal Pyrolysis detects mass loss stages linked to dehydration and calcite breakdown.Microscopy and spectroscopy indicate CaCO3 crystal formation in CO2-sequestered concrete.

Research Frontiers in Ecological Restoration and Carbon Sequestration in Mining Areas: A Visual Analysis Using VOSviewer

The functioning and progress of modern industrial systems are deeply reliant on mineral resources. While mining offers substantial economic and social gains, it also imposes notable environmental impacts. In the context of global climate change, sustainable mining and ecological restoration in mined areas are increasingly connected to carbon sequestration efforts. Enhancing carbon sink capacity in ecological restoration processes is crucial for achieving carbon neutrality. This study aims to review the current research landscape, identify key research areas, and explore future trends in this field. Relevant literature from the Web of Science was selected, key information extracted, and co-occurrence networks were mapped and analyzed using VOSviewer. Covering publications from 2000 to the present, the analysis spans 84 countries and regions, 1,184 institutions, 3,757 authors, and 858 papers. The main research areas include: (1) strategies for ecological and vegetative restoration of mining areas; (2) carbon sequestration processes in vegetation and soil in mining areas; (3) mechanisms for soil health restoration in mining areas; (4) the role of plants and microbes in pollution remediation; (5) importance of water resource management and wetland restoration in mining areas; and (6) ecological succession and biomass accumulation in mining area rehabilitation. This study highlights major contributors, countries, and institutions, elucidates research hotspots, and outlines directions for future development. By systematically summarizing research trends and hotspots in ecological restoration and carbon sequestration in mining areas, this work provides a valuable reference for researchers seeking to navigate and advance this dynamic field.

A pore-scale resolved direct numerical simulation study for scaling analysis of the solutal convection in porous media

Understanding the solutal convection is a crucial step towards accurate prediction of CO $_2$ sequestration in deep saline aquifers. In this study, pore-scale resolved direct numerical simulations (DNS) are performed to analyse the scaling laws of the solutal convection in porous media. The porous media studied are composed of uniformly distributed square or circular elements. The Rayleigh numbers in the range $426 \le Ra \le 80\,000$ , the Darcy numbers in the range $1.7\times 10^{-8} \le Da \le 8.8\times 10^{-6}$ and the Schmidt numbers in the range $250 \le Sc \le 10^4$ are considered in the DNS. The main time, length and velocity scales affecting the solutal convection are classified as the diffusive scales ( $t_I$ , $l_I$ and $u_I$ ), the convective scales ( $t_{II}$ , $l_{II}$ and $u_{II}$ ) and the shut-down scales ( $t_{III}$ , $l_{III}$ and $u_{III}$ ). These scales determine the pore-scale Rayleigh number $Ra_K$ and the Rayleigh number $Ra$ . Based on the DNS results, the scaling laws for the transient dissolution flux are proposed in the different regimes of convection. It is found that the onset time of convection ( $t_{oc}$ ) and the period of the flux-growth regime ( $\Delta t_{fg}$ ) vary linearly with the convective time scale $t_{II}$ . The merging of the original plumes and the re-initiation of the new plumes start in the same period, resulting in the merging re-initiation regime. Horizontal dispersion plays an important role in plume merging. The dissolution flux $F$ and the time since the onset of convection $t^{\ast }$ have an $F / u_{II} \sim (t^{\ast }/ t_{II})^{-0.2}$ scaling in the later stage of the merging re-initiation regime. This scaling is caused by the merging of the low-wavenumber plumes. It becomes more pronounced with decreasing porosity and leads to the nonlinear relationship between the Sherwood number $Sh$ and $Ra$ when the domain is not high enough for the plumes to fully develop. According to the DNS results, a regime is expected that is independent of both $Ra$ and $Ra_K$ , while the dimensionless constant flux $F_{cf}/u_{II}$ in this regime decreases with decreasing porosity. When the mean solute concentration reaches approximately 30 %, convection enters the shut-down regime. For large $Ra$ , the dimensionless flux in the shut-down regime follows the scaling law $F/u_{III}\sim (t/t_{III})^{-1.2}$ at large porosity ( $\phi =0.56$ ) and $F/u_{III}\sim (t/t_{III})^{-1.5}$ at small porosity ( $\phi =0.36$ or $0.32$ ). The study shows the significant pore-scale effect on the convection. The DNS cases in this study are mainly for simplified geometries and large $Ra_K$ . This can lead to uncertainties of the obtained scaling coefficients. It is important to determine the scaling coefficients for real geological formations to predict a real CO $_2$ sequestration process.