Waste Management Applications Research Articles

Efficient CO2 adsorption by deoiled flaxseed hydrochar.

This study optimizes CO2 adsorption using hydrochar from de-oiled flaxseed (FDOP), a waste byproduct of the oil extraction industry, through hydrothermal carbonization (HTC). The aim is to enhance CO2 capture sustainably and cost-effectively. Using Response Surface Methodology (RSM), in optimal conditions achieved 1153.26mg/g CO2 adsorption capacity under 215.15°C synthesis temperature, 3.05h synthesis time, 0.99M acid concentration, 8.997bar pressure, and 25.07°C adsorption temperature. Statistical analysis (F-value: 44.48, R²: 0.9705) confirmed strong model reliability. Kinetic analysis showed both physical and chemical adsorption, while thermodynamic analysis revealed exothermic behavior (ΔH° values: -46.697kJ/mol for M-225, -40.230kJ/mol for MA-203). After 10 regeneration cycles, the adsorption capacity was reduced by only 2.8% and 3.1%, indicating excellent recyclability. This study highlights FDOP-derived hydrochar as a highly efficient, low-cost adsorbent, offering industrial applications for carbon capture and waste management.

Barriers to Reverse Logistics of Construction and Demolition Waste

Objective: This study aims to identify the main barriers to implementing reverse logistics for construction and demolition waste (RCD), focusing on challenges faced by both small and large waste generators. Theoretical Framework: The research is grounded in reverse logistics theories, addressing sustainability and waste management frameworks. These concepts provide a basis for understanding the diverse challenges different generator profiles encounter. Method: A systematic literature review was conducted over nine months (October 2023 to July 2024) following the PRISMA method. Seven databases were consulted—Web of Science, Scopus, MDPI, Emerald, ScienceDirect, Taylor and Francis, and Wiley—resulting in 119 relevant articles. The study identifies and categorizes barriers for small and large generators. Results and Discussion: The results revealed 20 barriers for large generators and 7 for small generators, with 4 common barriers between both groups. These barriers highlight the complexity of RCD management and suggest specific policy and strategy needs. In the discussion, these barriers are analyzed in the context of the theoretical framework, revealing practical implications for improving reverse logistics systems. Research Implications: The findings provide valuable insights for both academic research and practical applications in waste management, contributing to the development of more effective strategies for RCD handling and disposal. This research has the potential to influence public policy and industry practices in waste logistics. Originality/Value: This study fills a gap in the literature by providing a comprehensive overview of barriers specific to different waste generator profiles. It advances theoretical knowledge and offers practical recommendations for improving RCD reverse logistics.

Circular economy for the management of disused tyre waste in Chongón - Guayaquil

Scrap tyres can cause a severe environmental impact on the community. To describe the contribution of the circular economy model to the management of scrap tyre waste in Chongón - Guayaquil. Quantitative, descriptive, correlational study, using a survey of 20 vulcanisers in the parish of Chongón in the city of Guayaquil. A high level of reliability was obtained with a Cronbach's alpha of 0.883, as well as a significant correlation between the variables of waste management of scrap tyres and the circular economy model, with a bilateral sig. of <0.05. The disposal of scrap tyres causes severe environmental impacts in the parish of Chongón-Guayaquil, however, the application of an optimal waste management of these wastes, recycling and reusing them in the manufacture of other products, corresponds to the circular economy model, promoting economic development, sustainability and environmental protection.

Enhancing leachate management with antibacterial nanocomposites incorporating plant-based carbon dots and Satureja Khuzestanica essential oils

Landfill leachate, a complex mixture of pollutants, poses a significant environmental hazard. This study reports the synthesis and characterization of superabsorbent nanocomposites (SANs) designed for enhanced performance in waste management applications. SANs were prepared using carboxymethyl cellulose (CMC) and sodium polyacrylate (SPA) as the main components, carbon dots (CDs) to improve absorption, and Satureja Khuzestanica essential oil (SEO) for antibacterial performance. The results demonstrated that the addition of CDs significantly increased the absorption capacity and liquid retention of the samples, with a water absorption capacity reaching up to 8621 %. Furthermore, the samples exhibited high mechanical strength, with tensile strength improving by over 100 % in the presence of CDs. The inclusion of SEO provided strong antibacterial activity against Escherichia coli and Staphylococcus aureus, with inhibition zones measuring up to 26 mm. These SANs, with their high absorption capacity, mechanical robustness, and antibacterial properties, show great potential for improving waste management practices, particularly in leachate absorption strategies.

Browser-Based Object Detection System for Isolating Plastic Bottles using the COCO-SSD Model

Plastic waste, especially in urban environments and water bodies, poses a significant environmental threat. This paper presents a browser-based object detection system for identifying and isolating plastic bottles using state-of-the-art machine learning models. The system leverages TensorFlow.js, ML5.js, and P5.js libraries along with the COCO-SSD model to detect plastic bottles in real time using a mobile camera interface. By employing a browser-based architecture, the system offers cross-platform functionality, eliminating the need for server-based computations or specialised hardware. Experimental evaluation showed high detection accuracy across various environments, underscoring the potential for real-world applications in waste management and recycling efforts.

Standoff Identification of Plastic Waste Using a Low-Cost Compact Laser-Induced Breakdown Spectroscopy (LIBS) Detection System.

We report the standoff/remote identification of post-consumer plastic waste by utilizing a low-cost and compact standoff laser-induced breakdown spectroscopy (ST-LIBS) detection system. A single plano-convex lens is used for collecting the optical emissions from the plasma at a standoff distance of 6.5 m. A compact non-gated Czerny-Turner charge-coupled device (CCD) spectrometer (CT-CCD) is utilized to analyze the optical response. The single lens and CT-CCD combination not only reduces the cost of the detection system by tenfold, but also decreases the collection system size and weight compared to heavy telescopic-based intensified CCD systems. All the samples investigated in this study were collected from a local recycling plant. All the measurements were performed with only a single laser shot which enables rapid identification while probing a large number of samples in real time. Furthermore, principal component analysis has shown excellent separation among the samples and an artificial neural network analysis has revealed that plastic waste can be identified within ∼10 ms only (testing time) with accuracies up to ∼99%. Finally, these results have the potential to build a compact and low-cost ST-LIBS detection system for the rapid identification of plastic waste for real-time waste management applications.

Micro-wave induced pyrolysis of low density polyethylene (LDPE) and biodegradation of resulting wax in soil and by defined microbial consortia is closing the loop towards LDPE upcycling

Plastic has become essential in daily life, replacing traditional materials like glass and wood due to its flexibility, durability, strength, and cost-effectiveness. However, the global plastic production surged to nearly 400 million tons in 2020, causing significant environmental accumulation. Polyethylene (PE), a ubiquitous polymer, poses recycling challenges due to its stability and widespread use in layered products, contributing to long-term pollution. This study focuses on PE degradation challenges, advocating for integrated chemical and biological treatments. Chemical methods like pyrolysis show promise but aren't fully eco-friendly. Microwave-induced pyrolysis emerges as a viable alternative, offering faster, targeted heating with lower energy consumption. Using microwave-absorbent materials such as silicon carbide, this method efficiently breaks down even challenging low-density PE (LDPE), yielding wax products of 68–91 % yield, with reduced molecular weight suitable for further biological degradation. Biodegradation experiments demonstrated over 95 % degradation by defined microbial consortia and considerable degradation in soil without bioaugmentation. The Rhodococcus consortium showed exceptional potential, degrading 90 % of LDPE-wax as a carbon source within 28 days, particularly strain CHBE-144 achieving 98 % degradation in just 14 days. Genomic analysis revealed enzymes crucial for alkane and plastic breakdown, with strains capable of producing biosurfactants, suggesting up-cycling potential for PE-derived materials into value-added products. Integrating microwave-induced pyrolysis with microbial biodegradation offers a promising pathway for managing PE waste sustainably, potentially reducing environmental impact while creating valuable resources from plastic waste. Further research is warranted to optimize these processes and scale them for practical application in waste management and resource recovery efforts globally.

A review of metabolic calorimetric applications in plant stress, waste management, and diagnostics

A review of metabolic calorimetric applications in plant stress, waste management, and diagnostics

Current insights and future prospects of graphene aerogel-enhanced supercapacitors: A systematic review

Supercapacitors present a compelling alternative to conventional batteries, offering rapid energy storage and high power density. Despite their advantages, they typically fall short in energy density compared to traditional batteries, primarily due to limitations in electrode materials. Graphene Aerogels (GA) have emerged as a promising solution to enhance supercapacitor performance because of their unique properties, such as high surface area and excellent conductivity. This systematic review provides a comprehensive analysis of recent advancements in GA technology, focusing on their synthesis methods and applications in supercapacitors. It highlights significant improvements that GA can bring to Electric Double-Layer Capacitors (EDLCs), pseudocapacitors, and hybrid supercapacitors. Additionally, the review explores GA's potential for enhancing electric generators and integrating into flexible, wearable technologies. Future research directions are emphasised, particularly regarding GA’s potential applications in waste management and environmental protection. The review was conducted through a thorough literature search, prioritising peer-reviewed sources related to GA synthesis and supercapacitor applications. Methodological quality and potential biases of the included studies were assessed using principles similar to the Cochrane Risk of Bias tool. Thematic analysis was employed to synthesise findings and identify key trends and challenges. Limitations such as potential biases and methodological variations are discussed. Overall, this review highlights the technological prospects of GA and provides guidance for future research in supercapacitor development and applications.

Preparation and Characterization of Hydroxyapatite Using Precursor Extracted from Cockle Shell Waste

Hydroxyapatite (HAP) is a widely used biomaterial due to its excellent bioactivity, biocompatibility, and structural similarity to the mineral component of human bone and teeth. However, the synthesis of HAP typically relies on expensive and non-renewable precursors, which can limit its widespread applications. This study investigates the extraction and purification of HAP from cockle shells, which are a readily available and renewable source of calcium carbonate. The extraction and purification of hydroxyapatite (HAP) from cockle shells, which are rich in calcium carbonate, is a promising method for producing HAP for biomedical applications due to its bioactivity and biocompatibility. This study investigates the use of a calcination process and wet slurry precipitation technique to produce HAP from seashells, focusing on the effect of reaction time of phosphate source (KH2PO4) and calcium oxide (CaO) on HAP production. EDX reported Ca/P ratio of 1.61 for HAP synthesized by chemical precipitation for 2 hours of reaction. Meanwhile, the XRD results indicate that a 4-hour reaction time produces more crystalline HAP than shorter reaction times, highlighting the importance of reaction time in HAP synthesis. This research demonstrates the potential of utilizing seashell waste as a valuable natural resource for applications in healthcare and waste management.

The Role of Artificial Intelligence in Achieving the United Nations Sustainable Development Goals

The United Nations' 2030 Agenda for Sustainable Development aims to tackle poverty, inequality, and environmental degradation and foster economic growth. This study investigates the transformative potential of artificial intelligence (AI) in achieving these Sustainable Development Goals (SDGs). Analyzing data from 44 sources, the research highlights AI's capacity to address critical challenges in healthcare, education, environmental management, economic growth, and gender equality. AI applications in renewable energy, waste management, disease detection, personalized education, and gender equality are examined. The study also emphasizes the ethical issues associated with AI, such as algorithmic bias, data privacy breaches, and job displacement. To fully leverage AI's potential, it is essential to develop intelligent automation governance systems, foster interdisciplinary research combining AI and sustainability, and promote public-private partnerships. Additionally, enhancing public AI literacy and implementing eco-friendly AI policies are crucial. The study advocates for a holistic ethical framework to maximize AI's benefits while mitigating risks, promoting cross-disciplinary collaboration, and establishing ethical AI standards. By doing so, AI can significantly contribute to a more inclusive, equitable, and sustainable future.

Insights into alkali and acid-activated volcanic ash-based materials: A review

This review provides a comprehensive study of the fundamentals of the alkaline and acid activation of volcanic ashes (VA), for mainstreaming their use as a conventional feedstock for developing geopolymers and their applications. The low reactivity in an alkaline environment is driven by the low content of the amorphous phase and the low solubility of iron, calcium and magnesium at pH > 12. Nevertheless, techniques such as mechanochemical activation has significantly improved the reactivity and the properties of the resulting products. In the acid phosphate medium, the high solubility of iron, calcium and magnesium ensures good reactivity and a high reaction rate at room temperature. As a result, the engineering properties of acid-phosphate-activated volcanic ash are superior to those of alkali-activated volcanic ash. The resulting materials have great potential for use as binders in concrete design, for the stabilization of compressed earth bricks and for the rapid repair of deteriorated concrete structures. However, significant research is required to fully understand their durability performances, life cycle and techno-economic viability for large-scale utilisation. Further, the limited availability of phosphate resources makes acid activation not a viable route to activate volcanic ash for building purposes. The acid-activated volcanic ash has potential in waste management applications such as nuclear waste or heavy metal encapsulation. Finally, volcanic ash emerges as a promising raw material for developing sustainable building materials through alkali and acid activation. This holds as its exploitation is non-disruptive, and processing requires less energy compared to calcined clay or fly ash.

Correlating shale geochemistry with metal sorption: influence of kaolinite content

ABSTRACT Argillaceous rocks constituting clay fractions are potential host rock candidates for isolation of radioactive waste in underground repositories. The present study aims at characterization of two argillaceous rocks (shales) from different geological settings (surface and subsurface localities) and investigation of their cesium (Cs) sorption behaviour. The shales were characterized using various analytical techniques to evaluate the textural attributes, mineralogical constituents and surface properties. The major mineralogical constituent of the surface and subsurface shale was quartz (62%) and kaolinite (56%), respectively. The abundance of smectite and illite in both the shales was comparable. Fluorescence and UV-Vis spectra confirmed the presence of polyaromatic hydrocarbons (PAHs) in the subsurface shale. The subsurface shale demonstrated higher Cs retention (17 mg g−1) than the surface shale (12 mg g−1) due to higher kaolinite content. Surface analysis of the shale samples revealed involvement of ion exchange mechanism in Cs uptake. The agreement of experimental results with Freundlich sorption isotherm suggests the heterogenous nature of the shales with multiple sorption sites. The correlation of geochemistry (especially the kaolinite content) for both the shales with Cs sorption is clearly highlighted in the present studies. The present investigation implies the applicability of the studied shales for waste management applications.

AI for Sustainable Development: Applications in Natural Resource Management, Agriculture, and Waste Management

AI for Sustainable Development: Applications in Natural Resource Management, Agriculture, and Waste Management

Investigations on physical, structural, elastic, optical and radiation shielding properties of boro-phosphate glasses for radioactive waste management applications

The effectiveness of nuclear shielding has been investigated on Eu3 doped boro-phosphate glass matrix by altering the extent of modifier addition (CdF and ZnF), for a specific assortment of multicomponent glasses with the following composition; 35B2O3+20P2O5+ 15BaO+9LiO+(20−x)ZnF + xCdF+1Eu2O3 (where x = 0, 5, 10, 15, and 20 in mol%). Various structural deformations are observed in the present batch of glasses, and the sample's irregularity has been verified by examining FTIR and XRD techniques. The structural and elastic features have been estimated from the physical parameters like density and the index of refraction. The influence of the modifiers reveals the existing glass structure's structural integrity, which in turn explains the fact that the samples are a suitable choice for an upgraded shielding procedure. The BPBZC20 glass revealed to be hard and firmly packed by the computed elastic moduli, which is necessary for a superior shielding channel. To ascertain the radiation protection capabilities, the key parameters including the mass attenuation coefficient (MAC), equivalent atomic number, half-value layer (HVL), effective electron density, mean free path (MFP), and buildup factors of the titled glasses are determined. These assessments were conducted using the user-friendly Phy-X software and the robustness of the MAC is validated with FLUKA Monte Carlo stimulation.

Advancements in Remote Alpha Radiation Detection: Alpha-Induced Radio-Luminescence Imaging with Enhanced Ambient Light Suppression.

Heavy nuclides like uranium and their decay products are commonly found in nuclear industries and can pose a significant health risk to humans due to their alpha-emitting properties. Traditional alpha detectors require close contact with the contaminated surface, which can be time-consuming, labour-intensive, and put personnel at risk. Remote detection is urgently needed but very challenging. To this end, a candidate detection mechanism is alpha-induced radio-luminescence. This approach uses the emission of photons from radio-ionised excited nitrogen molecules to imply the presence of alpha emitters from a distance. Herein, the use of this phenomenon to remotely image various alpha emitters with unparalleled levels of sensitivity and spatial accuracy is demonstrated. Notably, the system detected a 29 kBq Am-241 source at a distance of 3 m within 10 min. Furthermore, it demonstrated the capability to discern a 29 kBq source positioned 7 cm away from a 3 MBq source at a 2 m distance. Additionally, a 'sandwich' filter structure is described that incorporates an absorptive filter between two interference filters to enhance the ambient light rejection. The testing of the system is described in different lighting environments, including room light and inside a glovebox. This method promises safer and more efficient alpha monitoring, with applications in nuclear forensics, waste management and decommissioning.

In-situ constructing an innovative and versatile nanotraps for incorporation of zero–valent iron nanoparticles into zeolite imidazole framework–8 towards high efficient detoxification and imprisonment of U(VI) and Se(IV) from water via a combination study of capture performance and underlying mechanism aspects

This work reported an in-situ constructing of innovative and versatile nanotraps (NZVI/ZIF–8) namely incorporation of zero–valent iron nanoparticles (NZVI) into zeolite imidazole framework–8 (ZIF–8), and the application of the as-constructed NZVI/ZIF–8 in high efficient detoxification and imprisonment of U(VI) and Se(IV) from wastewater. The results demonstrated that controllable incorporation of NZVI with ZIF–8 used advantages of each component to generate an emphatic boosted interaction in U(VI)/Se(IV) imprisoning. The kinetic adsorption for U(VI)/Se(IV) imprisoned onto NZVI/ZIF–8 was described by pseudo-second-order model well, and the adsorption isotherms followed the Langmuir model better. Thermodynamic analysis (ΔG < 0, ΔS > 0, ΔH > 0) demonstrated that U(VI)/Se(IV) imprisoned onto NZVI/ZIF–8 was endothermic and spontaneous. XPS measurements unveiled that NZVI/ZIF–8 imprisoned U(VI)/Se(IV) by synergistic mechanism of adsorption and reduction. The N–containing functional groups on ZIF–8 was primarily responsible for adsorption, while Fe(0) and surface enriched Fe(II) from NZVI predominantly contributed to reductive conversion of U(VI)/Se(IV) into U(IV)/Se(0). In a word, ZIF-8 played an important role in imprisonment of U(VI)/Se(IV) onto the as-constructed NZVI/ZIF–8 nanotraps with intensified reactivity in comparison with naked NZVI. The findings revealed that the NZVI/ZIF–8 nanotraps would be superb scavengers towards U(VI)/Se(IV), and implied a bright future in potential application in nuclear waste management.

Mimicking the enzymatic plant cell wall hydrolysis mechanism for the degradation of polyethylene terephthalate

Plastic pollution presents a global challenge, impacting ecosystems, wildlife, and economies. Polyethylene terephthalate (PET), widely used in products like bottles, significantly contributes to this issue due to poor waste collection. In recent years, there has been increasing interest in plant biomass-degrading enzymes for plastic breakdown, due to the structural and physicochemical similarities between natural and synthetic polymers. Filamentous fungi involved in hemicellulose degradation have developed a complex mode of action that includes not only enzymes but also biosurfactants; surface-active molecules that facilitate enzyme-substrate interactions. For this reason, this study aimed to mimic the mechanism of biomass degradation by repurposing plant cell wall degrading enzymes including a cutinase and three esterases to cooperatively contribute to PET degradation. Surfactants of different charge were also introduced in the reactions, as their role is similar to biosurfactants, altering the surface tension of the polymers and thus improving enzymes’ accessibility. Notably, Fusarium oxysporum cutinase combined with anionic surfactant exhibited a 2.3- and 1.6-fold higher efficacy in hydrolyzing amorphous and semi-crystalline PET, respectively. When cutinase was combined with either of two ferulic acid esterases, it resulted in complete conversion of PET intermediate products to TPA, increasing the overall product release up to 1.9– fold in presence of surfactant. The combination of cutinase with a glucuronoyl esterase demonstrated significant potential in plastic depolymerization, increasing degradation yields in semi-crystalline PET by up to 1.4-fold. The approach of incorporating enzyme cocktails and surfactants emerge as an efficient solution for PET degradation in mild reaction conditions, with potential applications in eco-friendly plastic waste management.

Effect of Pesticides on Human Health and Biodiversity: A Comprehensive Insight

Pesticides, whether naturally occurring or chemically synthesized, serve to combat various pests across sectors such as food production, forestry, agriculture, and aquaculture, but they also pose risks of toxicity to ecosystems. The World Health Organization classifies pesticides based on their harmful effects, underscoring the importance of public health considerations. By employing them judiciously and understanding their categorization, their usage can be minimized for the benefit of both human health and the environment. This review examines global perspectives on pesticides, including their distribution and environmental impacts, while literature highlights their potential uses, classification and adverse effects on natural systems, water, plants, human health and food preservation. Additionally, eco-friendly management strategies, like bacterial degradation, myco-remediation, phytoremediation, and microalgae-based bioremediation, are discussed as green solutions to mitigate pesticide pollution. The identification of potent microbes, novel genes and biotechnological applications for pesticide waste management is crucial for fostering a sustainable environment.

CNUCTRAN: A program for computing final nuclide concentrations using a direct simulation approach

It is essential to precisely determine the evolving concentrations of radioactive nuclides within transmutation problems. It is also a crucial aspect of nuclear physics with widespread applications in nuclear waste management and energy production. This paper introduces CNUCTRAN, a novel computer program that employs a probabilistic approach to estimate nuclide concentrations in transmutation problems. CNUCTRAN directly simulates nuclei transformations arising from various nuclear reactions, diverging from the traditional deterministic methods that solve the Bateman equation using matrix exponential approximation. This approach effectively addresses numerical challenges associated with solving the Bateman equations, therefore, circumventing the need for matrix exponential approximations that risk producing nonphysical concentrations. Our sample calculations using CNUCTRAN shows that the concentration predictions of CNUCTRAN have a relative error of less than 0.001% compared to the state-of-the-art method, CRAM, in different test cases. This makes CNUCTRAN a valuable alternative tool for transmutation analysis. Program summaryProgram Title:CNUCTRANCPC Library link to program files:https://doi.org/10.17632/b484w2vx52.1Developer's repository link:https://github.com/rabieomar92/cnuctran/releasesLicensing provisions: MITProgramming language: C++Nature of problem:CNUCTRAN simulates the transmutation of various nuclides such as decays, fissions, and neutron induced reactions using a direct simulation approach. It has the capability of predicting the final concentration of a large system of nuclides altogether after a specified time step, tf.Solution method:CNUCTRAN works based on the novel probabilistic method such that it does not compute the final nuclide concentrations by solving Bateman equations. Instead, it statistically tracks nuclide transformations into one another in a transmutation problem. The technique encapsulates various possible nuclide transformations into a sparse transfer matrix, T, whose elements are made up of various nuclear reaction probabilities. Next, T serves as a matrix operator acting on the initial nuclide concentrations, y(0), producing the final nuclide concentrations, y.