Billions Of Tonnes Research Articles

Dried Anaerobic Digestate from Slaughterhouse By-products: Emerging Cues for a Bio-Based Fertilization

AbstractThe slaughterhouse and meat industry are worldwide rapidly growing and produce billions of tonnes of organic wastes annually. These materials can be used to produce biogas through anaerobic digestion and the resulting digestate represents a potential source of organic carbon and nutrients that could be applied to the soil as organic fertilizer. The present work aims to assess the fertilizing potential of a dried anaerobic digestate (DD) produced from beef slaughtering waste. DD was characterized at the physic-chemical level, particularly focusing on macro- and micronutrient contents, potentially toxic element and organic contaminants. Then, a short-term soil incubation experiment was performed on two different soils. After the incubation, DD released 10–26% of their total nitrogen (N) and 13–16% of total phosphorus (P), depending on the soils that had different characteristics and responded differently to the treatments. However, DD had positive effects on the principal soil fertility indicators, such as chitinase and phosphatases, stimulating the microbial activity and therefore exploiting a fertilizing potential as well as the other organic fertilizers tested. Moreover, DD had minor effects on soil extractable carbon (Cext) suggesting the presence of recalcitrant C forms in spite of soluble C, indicating a higher stability of slaughterhouse by-products after anaerobic digestion in respect to the other organic fertilizers. The results obtained in this work raise the concrete possibility use DD as a bio-based fertilizer. Graphical Abstract

Degradation exposure scenario in the Brazilian Amazon: Edge effect on hyperdominant C-cycle tree species

The Amazon basin strongly influences the global carbon cycle, storing billions of tonnes of carbon in a relatively small number of ‘hyperdominant’ tree species. However, the Amazon carbon stock is threatened by land-use change. In the remaining forest patches, trees close to the forest border bear various physical and biotic edge effects that alter plant growth and survival. To assess how edge effects influence tree mortality and carbon storage, we investigated the occurrence of hyperdominant tree species in the Brazilian Amazon between 1988 and 2021. Evaluating tree records from a network of permanent plots and herbarium collections, we found that 22 % of tree occurrence records were in deforested areas, 35% within 1 km of the forest edge, and 43 % in continuous forest. At the local scale in Central Amazonia, tree monitoring data over 30 years revealed that forest fragments hyperdominant trees had twice the mortality rate of continuous forest ones due to edge effects during the 15 years following edge establishment. Although trees in fragments had higher initial growth, this pattern declined over the years and eventually resulted in significant carbon loss, mainly from tree mortality. Edge effects have led to annual declines in the biomass of forest remnants, suggesting that hyperdominant species are also susceptible to disturbances that lead to degradation and forest losses. Conservation of the Amazon forests requires an approach that considers the effects of local disturbances on carbon stocks in the region.

A Study on Consumer’s Perception on Green Home Appliances

A household is the building block of the society and home appliances are the main power consumers in a household. Hence, they are the best means to save energy at a household level and achieve a reduction in per capita power consumption. If the household units save energy, the nation saves the energy and thereby the ideal place to initiate the green change at the consumer level is through the home appliances sector. Appliances more than 10 years old are clunkers as they use up most of the energy. If consumers replace them with energy efficient appliances, it will not only save billions of kilowatts of energy annually but also billions of tonnes of carbon emissions globally. Most of the home appliances have a longer life. Hence its medium to long term benefits should be weighed while making a purchase decision. “Despite various green initiatives and a vibrant consumer electronics market, consumer adoption of green home appliances is still lagging behind contributing to the high-power consumption and monetary loss to the individual and the country. The study made an attempt to understand consumer understanding, perceptions and acceptance of Green Home Appliances.

Action Versus Reaction: How Geometallurgy Can Improve Mine Waste Management Across the Life-Of-Mine

The raw materials industry produces billions of tonnes of mine waste per year. Given increasing metal demand and the global appetite for waste reduction, strategic opportunities to minimise its production must be embedded across the life-of-mine. Adopting a geometallurgical approach to total deposit characterisation—where mineralogical and geochemical data are routinely collected and used to model geoenvironmental domains—offers profound benefits for improving the understanding of the composition and environmental impact of different residues. Using established and emerging technologies, from handheld instruments and core scanners to synchrotrons, throughout a mine’s life—starting already during exploration—may assist the raw materials industry to reduce their waste footprint and adopt circular economy principles.

Remediating the sky: the role of geoenvironmental engineers and applied geoscientists in geochemical carbon dioxide removal

The largest environmental remediation project in human history has begun – that of removing hundreds of billions of tonnes of carbon dioxide (CO 2 ) from the atmosphere over the coming century. This removal, together with deep and rapid emissions reduction, will be essential in preventing dangerous climate change. This briefing introduces the field of geochemical CO 2 removal (gCDR), which proposes to accelerate the natural reaction of atmospheric CO 2 with rocks or anthropogenic materials. It also explores the critical role that geoenvironmental engineers and geoscientists will have in researching and deploying these technologies. While currently at an early stage of development, it is possible that gCDR will operate at a global scale (billion tonnes of CO 2 per year) by mid/late-century, resulting in an industry that generates hundreds of billions to a trillion dollars in annual revenue, equivalent in scale to the present-day oil industry. The core technical competencies of this industry will be derived from geoscience disciplines requiring the contribution of thousands and possibly tens of thousands of workers globally. To realize these opportunities, our community needs to lead in the development of gCDR, help to pioneer its deployment, create standards for monitoring and verification, and incorporate gCDR into existing education programmes and professional development. Thematic collection: This article is part of the Climate change and resilience in Engineering Geology and Hydrogeology collection available at: https://www.lyellcollection.org/topic/collections/Climate-change-and-resilience-in-engineering-geology-and-hydrogeology

Assessment of Co-Gasification Methods for Hydrogen Production from Biomass and Plastic Wastes

In recent decades, economic development and population growth has been accompanied by the generation of billions of tonnes of solid residues or municipal “wastes”, a substantial portion of which is composed of plastics and biomass materials. Combustion-based waste-to-energy is a viable and mature method of extracting calorific value from these end-of-life post-recyclable materials that are otherwise landfilled. However, alternative thermochemical methods, such as gasification, are becoming attractive due to the ability to synthesize chemical precursors for supply chain recirculation. Due to the infancy of gasification technology deployment, especially in the context of anthropogenic CO2 emission reduction, additional systems engineering studies are necessary. Herein, we conduct an attributional life cycle analysis to elucidate the syngas production and environmental impacts of advanced thermochemical gasification methods for the treatment of biomass and plastic wastes obtained from municipal solid wastes, using a comprehensive thermodynamic process model constructed in AspenTech. Feedstock composition, process parameters, and gasification methods are varied to study the effects on syngas quality, yield, power generation potential, and overall greenhouse gas emissions. Steam-based gasification presents up to 38% reductions in CO2 emissions when compared to conventional thermochemical methods. Using gasifier-active materials, such as metal hydroxides, can also further reduce CO2 emissions, and realizes a capture load of 1.75 tonnes of CO2 per tonne of plastic/stover feedstock. This design alteration has implications for reductions in CAPEX due to the mode of CO2 capture utilized (e.g., solid sorbent vs. liquid SELEXOL). The use of renewable energy to provide a method to generate steam for this process could make the environmental impact of such MSW gasification processes lower by between 60–75% tonnes of CO2 per tonne of H2. Overall, these results can be used to inform the guidance of advanced waste gasification methods as a low-carbon transition towards a circular economy.

A comparative study on partial replacement of coarse aggregates in concrete with sustainable waste materials

The present study focuses on identifying suitable and sustainable waste materials in concrete by replacing for coarse aggregates. Investigations have been conducted to determine how well the inappropriate wastes, palm kernel shells, periwinkle shells, and coconut shells perform as substitute for coarse materials in concrete. PKS, PS, and CS were developed as a replacement in 45 cubes and cylinders. Tests were conducted on their characteristic strength in compression and elasticity and workability. Concrete's elasticity and compressive capabilities declined when PKS, PS, and CS concentration rose. When compared with Periwinkle Shell Concrete (PSC), Coconut Shells Concrete, Palm Kernel Shell Concrete (PKSC) had lesser tensile and compressive strengths for all curing periods (CSC). The 28-day control concrete's constrict and elastic strength was 25 N/mm2 and 12 N/mm2, respectively. Considering PKSC, strength needed with 25% of replacement were 22 N/mm2 and 8.2 N/mm2; on 25% replacement, PS exhibited a compressive and elasticity of 21 N/mm2 and 10.4 N/mm2, respectively, while 25% replacement, the CS exhibited the values of 22 N/mm2 and 11 N/mm2, respectively. Thus a 25% replacement with the alternative materials satisfied the member strength of control concrete. Besides the technical assurance, the use of the ‘alternatives’ flags the usefulness of reusing the waste materials to protect the ecology of the area. Such cross sectoral material reuse may act as a game-changer in both the donor and receiver sectors. It also means that the world's building companies may conserve billions of tonnes of organic coarse aggregates and make significant financial savings thereby conserving our environment.

The numerical simulation of soil–structure interaction containing sustainable materials

As a result of urban transformation activities, natural disasters, regional and global wars, billions of tonnes of waste concrete occur. Therefore, the remediation process of waste concrete is one of the critical research topics of recent years. The sustainability concept provides a primary bridge between the demand for natural concrete material and the remediation process of waste concrete. Recycled aggregate and recycled concrete aggregate, which may be named sustainable materials, are obtained by the recycling process of waste concrete. Many experimental and numerical studies have been conducted in recent years to show that this sustainable material is an alternative product to natural aggregate. In this study, a comprehensive numerical simulation of foundation beams resting on soils incorporating conventional and sustainable materials has been performed. The foundation beams considered include some with conventional concrete properties and some with sustainable concrete properties. Additionally, the material conditions of soils are assessed, using six different mixed recycled aggregates as filling material. Based on the numerical simulation, the deflection, rotation, bending moment, shear force and spring force capacities of conventional and sustainable foundation beams resting on soils exhibited slightly different behaviour depending on the recycled concrete aggregate and mixed recycled aggregate ratios. Finally, comparing the numerical simulation results of soil–structural interaction members incorporating conventional and sustainable materials indicated that the soil–structure interaction modeling process applied to conventional foundation beams resting on soils is also valid for sustainable members.

Compressive Strength of the 5cmx5cm Coconut Empty Fruit Bunch Fiber Reinforced Cement Cubes

As coconut cultivation expands, billions of tonnes of coconut waste, including empty fruit bunches (EFB) fibres are generated annually and mostly disposed in the landfills. The increase in environmental concern pertaining disposal of waste has leads to an interest to use empty fruit bunch (EFB) fibre from coconut waste as an alternative reinforcement in the construction materials, as presented in this research. The objectives of this research are to fabricate coconut EFB fibre reinforced cement cubes, investigate the effectiveness of the fibres in improving the compressive strength of the cement cubes, and also to analyse the fractured surface of the cubes after the compressive strength test. The cement cubes of 5cm x 5cm were prepared by mixing the cement, water, and coconut EFB fibres at several mixing designs. In comparison to the control-plain cement cubes, the compressive strength of the fibre reinforced cement cubes improved with the addition of the coconut EFB fibres by 1.6 times. The fractured surface analysis on the compressed cement cubes revealed that the control-plain cement cubes shatter into many pieces and completely parted. Meanwhile, in the EFB fibre reinforced cement cubes, the fractured pieces remain attached due to the bridging action by the coconut EFB fibre.

A hierarchical cluster analysis of port performance in Malaysia

PurposeThe term competitive has always been used as a comparison to provide a distinction between two or more things. Southeast Asia handles billions of tonnes of global seaborne trade annually. Thus, there is a necessity to look in detail at the performance indicators of port competitiveness on the basis of port performance.Design/methodology/approachThis study has categorized 18 Malaysian bulk terminals into two different classes based on various performance indicators. The distinctions used a hierarchical cluster analysis by arranging the performance indicators. The technique is among the most popular techniques used to form homogeneous groups of entities or objects.FindingsIn this study, it was found that two classes were classified as being competitive from the homogeneous groups created. Based on the performance metrics chosen, Group 1 had the lowest score and Group 2 had the highest score. It was found that the Westport and Northport of Klang Port had the best performance of all.Research limitations/implications A major challenge for the study is the lack of variables relevant to other port competitiveness requirements, and a detailed research study is needed to gather information on the satisfaction of terminal customers, the paperwork involved, the accuracy and consistency of tariffs paid, the level of safety at sea and on land and environmental protection around the facility site.Originality/valueThe study on ports has been given less attention among researchers in this particular area. Therefore, this paper focuses on the port terminals in Malaysia and compares port performance metrics between ports to determine their competitiveness.

Evaluation of physical properties of autoclave aerated concrete (AAC) based glass-gypsum waste into concrete

The world produces billions of tonnes of Municipal Solid Waste (MSW) yearly, with part of it not being properly disposed of. To approach sustainable development and reduce waste in landfills, using waste in material production is proposed. According to the World Green Building Council, construction projects have expanded and demand for green buildings is likely to increase in the next three years. Autoclaved Aerated Concrete (AAC) is considered an environmentally friendly product compared to standard concrete and bricks. This paper aims to investigate the influence of glass waste (GW) and gypsum wastes as additional materials on the physical properties and compressive strength of AAC is to determine the optimum proportion of GW addition to produce AAC based glass-gypsum waste (AAC-GGW) and to compare the properties of AAC-GGW with the reference sample. The materials used were Ordinary Portland Cement (OPC), quartz sand, lime, aluminum paste, GW, and gypsum waste. The ratios of all materials were kept constant except GW with increment of 0%, 5%, 10%, 15%, 20%, 25% and 30%. The density, water absorption, porosity, and average compressive strength of the samples were measured and compared. It was found that increasing GW increased the samples’ density and decreased the samples’ water absorption and porosity. It was also found that the addition of GW from 5% to 25% achieved better average compressive strength than the reference sample with no addition of GW. Maximum compressive strength was achieved at 20% GW addition.

Eco-efficient steel slag concretes: an alternative to achieve circular economy

Abstract Annually billions of tonnes of aggregates are extracted to apply in civil construction generating environmental impacts and energy consumption. So, based on circular economy principles applying residues as aggregates is a good solution to reduce the mining activity and to generate a more efficient destination for the residues. Thus, this research aims to evaluate the technical, economic, and environmental performance of concretes produced entirely with steel slag aggregates. The concretes were characterized through physical properties, as specific gravity, water absorption, compressive and tensile strength. Durability tests (expansibility) were also conducted. The authors analyzed the cost assessment and environmental impact of steel slag concrete production as well. The incorporation of steel slag increases the compressive and tensile strength of concrete, analyzed in different ages. Additionally, the steel slag does not present expansibility when confined in the concrete matrix. The entire replacement of natural aggregates for steel slag allowed to reduce in 31% the cement consumption, a decrease of 140 kg/m3, for the same strength class. The environmental analysis showed that the incorporation of steel slag aggregates reduced the cement intensity of concrete and its impact. Regarding the cost assessment, the mixtures with steel slag presented a lower cost compared to the conventional one. These results indicate that steel slag aggregates could be used in a cleaner production of concrete, replacing natural aggregates with no injury. This research provides the feasibility of using steel slag aggregates in a cleaner and cheaper concrete production and contribute to the promotion of sustainable solutions for the construction sector through the circular economy principles.

Screening for Geologic Sequestration of CO2: A Comparison Between SCO2TPRO and the FE/NETL CO2 Saline Storage Cost Model

Meeting greenhouse gas emission reduction targets will likely require identifying and assessing subsurface storage space for sequestering billions of tonnes of CO2 each year. Accomplishing this feat could include estimating the cost and capacity for thousands to hundreds-of-thousands of potential geologic CO2 storage sites with CO2 storage screening tools. In this study, we introduce a screening tool, SCO2TPRO, and compare and contrast it to the FE/NETL CO2 Saline Storage Cost model (CSSC) using publicly available databases of saline reservoir properties in the United States. We find that the two tools use different methodologies to execute site-screening: SCO2TPRO calculates dynamic CO2 injection rates and plume evolution that are used to estimate operationally-realistic well spacing designs and CO2 storage capacities, whereas CSSC combines a volumetric storage estimation approach with geology-engineering well injectivity equations that can lead to an unrealistically high number of wells. These methodological differences translate into CSSC cost estimates that are several times higher than the SCO2TPRO estimates and around double for the capacity estimates. SCO2TPRO can also screen thousands of potential storage sites in seconds, which is thousands of times faster than CSSC. Lastly, we also find there is no single publicly available dataset of saline formation properties that can be used for screening across the United States.

Assessing the carbon capture capacity of South Wales’ legacy iron and steel slag

The industrial revolution was responsible for releasing over 1.5 trillion tonnes of carbon dioxide into the atmosphere resulting in a global temperature increase of ∼1 °C. It also produced billions of tonnes of alkaline materials that have the potential to react with some of that CO2, and this carbon capture potential may be used to help prevent climate change. Here we assess the carbon capture potential of legacy iron (Fe) and steel wastes in South Wales, the United Kingdom, and show that between 0 and 77% of total carbonation potential has been reached in the samples (equating to maximum potential between 40 and 608 kg CO2 /t of slag has been removed from the atmosphere by direct carbonation) across 10 historic works (out of 48 that operated in the region), even after > 140 years. The current work suggests that there is a capture potential of up to 17 Mt CO2 by direct carbonation which represents a potential carbon sink for future emissions. Iron and steel slag contains Ca silicate minerals, often dominated by melilite group phases (gehlenite, Ca2Al2SiO7 and akermanite, Ca2MgSi2O7), but also includes minor phases like olivine (fayalite, (Fe,Mn)2SiO4 and fosterite, Mg2SiO4). The presence of mineral carbonate phases such as calcite, magnesite, ankerite, and kutnohorite in the material demonstrates carbonation reaction has occurred after slag formation. Given that there is still carbonation potential to be realised, and that materials produced in the future from the iron and steel industry could play an important role in meeting our climate targets, then new management strategies are needed to maximise the use of this resource.

Chill in the air

Taking billions of tonnes of carbon dioxide out of the atmosphere looks crucial to limiting global warming – but does anyone really know how to do it, asks Adam Vaughan

Storage of Carbon Dioxide in Saline Aquifers: Physicochemical Processes, Key Constraints, and Scale-Up Potential.

CO2 storage in saline aquifers offers a realistic means of achieving globally significant reductions in greenhouse gas emissions at the scale of billions of tonnes per year. We review insights into the processes involved using well-documented industrial-scale projects, supported by a range of laboratory analyses, field studies, and flow simulations. The main topics we address are (a) the significant physicochemical processes, (b) the factors limiting CO2 storage capacity, and (c) the requirements for global scale-up.Although CO2 capture and storage (CCS) technology can be considered mature and proven, it requires significant and rapid scale-up to meet the objectives of the Paris Climate Agreement. The projected growth in the number of CO2 injection wells required is significantly lower than the historic petroleum industry drill rates, indicating that decarbonization via CCS is a highly credible and affordable ambition for modern human society. Several technology developments are needed to reduce deployment costs and to stimulate widespread adoption of this technology, and these should focus on demonstration of long-term retention and safety of CO2 storage and development of smart ways of handling injection wells and pressure, cost-effective monitoring solutions, and deployment of CCS hubs with associated infrastructure.

A review on ex situ mineral carbonation.

The increased CO2 quantities in the environment have led to many harmful effects. Therefore, it is very important to decrease the CO2 levels in the environment. CO2 capture along with safe and permanent storage using mineral CO2 sequestration method can play an important role to reduce carbon emissions into the environment. Mineral sequestration is a stable storage method that provides long-term storage and an appropriate substitute for the more popular geological storage method. The process is most suited for places where there is a lack of underground cavities for underground geological storage. Minerals rich in Ca and Mg are used predominantly in carbonation reactions. In addition, those alkaline wastes that are rich in Mg and Ca such as cement waste, steel slag and many process ashes can also be employed in CO2 sequestration. Mineral carbonation could be used for the sequestration of billions of tonnes of CO2 every year. However, various drawbacks related to mineral carbonation still need to be addressed, such as resolving the slow rate of reactions, necessity of large amounts of feedstock, decreasing the high overall cost of CO2 sequestration and reducing the huge energy requirements to accelerate the carbonation reaction. This study explores a number of carbonation methods, parameters that control the process and future potential applications of carbonated products.

Great SCO2T! Rapid tool for carbon sequestration science, engineering, and economics

CO2 capture and storage (CCS) technology is likely to be widely deployed in the coming decades in response to major climate and economics drivers: CCS is part of every clean energy pathway that limits global warming to 2 ​°C or less and receives significant CO2 tax credits in the United States. These drivers are likely to stimulate the capture, transport, and storage of hundreds of millions or billions of tonnes of CO2 annually. A key part of the CCS puzzle will be identifying and characterizing suitable storage sites for vast amounts of CO2. We introduce a new software tool called SCO2T (Sequestration of CO2Tool, pronounced “Scott”), a dynamic CO2 injection and storage model, to rapidly characterize saline storage reservoirs. The tool is designed to rapidly screen hundreds of thousands of reservoirs, perform sensitivity and uncertainty analyses, and link sequestration engineering (injection rates, reservoir capacities, plume dimensions) to sequestration economics (costs constructed from around 70 separate economic inputs). We describe the novel science developments supporting SCO2T including a new approach to estimating CO2 injection rates and CO2 plume dimensions as well as key advances linking sequestration engineering with economics. We perform a sensitivity and uncertainty analysis of geology parameter combinations—including formation depth, thickness, permeability, porosity, and temperature—to understand the impact on carbon sequestration. Through the sensitivity analysis, we show that increasing depth and permeability both can lead to increased CO2 injection rates, increased storage potential, and reduced costs, while increasing porosity reduces costs without impacting the injection rate (CO2 is injected at a constant pressure in all cases) by increasing the reservoir capacity. Through uncertainty analysis—where formation thickness, permeability, and porosity are randomly sampled—we show that final sequestration costs are normally distributed with upper bound costs around 50% higher than the lower bound costs. While site selection decisions will ultimately require detailed site characterization and permitting, SCO2T provides an inexpensive dynamic screening tool that can help prioritize projects based on the complex interplay of reservoir, infrastructure (e.g., proximity to pipelines), and other (e.g., land use, legal) constraints on the suitability of certain regions for CCS.

Ambient weathering of magnesium oxide for CO2 removal from air

To avoid dangerous climate change, new technologies must remove billions of tonnes of CO2 from the atmosphere every year by mid-century. Here we detail a land-based enhanced weathering cycle utilizing magnesite (MgCO3) feedstock to repeatedly capture CO2 from the atmosphere. In this process, MgCO3 is calcined, producing caustic magnesia (MgO) and high-purity CO2. This MgO is spread over land to carbonate for a year by reacting with atmospheric CO2. The carbonate minerals are then recollected and re-calcined. The reproduced MgO is spread over land to carbonate again. We show this process could cost approximately $46–159 tCO2−1 net removed from the atmosphere, considering grid and solar electricity without post-processing costs. This technology may achieve lower costs than projections for more extensively engineered Direct Air Capture methods. It has the scalable potential to remove at least 2–3 GtCO2 year−1, and may make a meaningful contribution to mitigating climate change.

Catastrophic tailings dam failures and disaster risk disclosure

The global mining industry produces billions of tonnes of mine tailings each year. This slurry of waste material is often contained in dams, which are among some of the world’s largest engineered structures. Several recent and catastrophic tailings dam disasters bring the complex interaction between a mine and its local operating context into plain sight. The absence of public, timely, multi-scalar information about the multiple dimensions of this interaction is a normalised feature in the management of tailings dams. This article highlights the importance of establishing and sharing diverse knowledge about tailings dam disaster risk. We argue that the assessment and disclosure of “situated” disaster risk ought to be prioritised; that is, the combined risk of a hazard bearing structure situated within a local context with inherent vulnerabilities. We present a method for examining situated disaster risk of tailings dams by utilising Environmental, Social and Governance (ESG) indicators to screen for risk across eight categories: waste, water, biodiversity, land uses, indigenous peoples’ lands, social vulnerability, political fragility, and approval and permitting. Applied to a global sample of operating mines, the method shows disaster risk potential of existing tailings dams globally. Future application could be used to generate a more complete inventory that includes both established and newly constructed facilities.