Waste Disposal & Sustainable Energy最新文献

Slum dwellers often fail to expend enough on waste disposal to have a healthy life, and remittances provide funds for a household to expend on the betterment of life conditions. This paper examines the impact of remittances on total monthly waste disposal expenditures and the impact of better waste disposal on monthly health expenditures among slum households in Bangladesh. Propensity score matching was adopted as an identification strategy to reduce selection bias. In this study, remittance includes both remittances received from within and outside Bangladesh. Remittance receipt equals 1 if a household receives remittances from within and/or outside of Bangladesh. Our results show that remittances increase expenditures on waste disposal by 28.77% to 32.74% among slum households in Bangladesh. Waste disposal expenditure is considered as an indicator of better waste disposal. Furthermore, we find that better waste disposal reduces total outpatient expenditures. A reduction in outpatient expenditure indicates that waste disposal results in better health conditions for slum dwellers. The findings of this study can be connected to Sustainable Development Goal 11, which targets sustainable cities and communities and suggests that remittances are a bottom-up financial mechanism for improving waste disposal at the micro level to improve health status.

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This paper reviews recent advances in the use of graphite carbon nitride (g-C₃N₄)-based composite photocatalysts for antibiotic and dye degradation and hydrogen production. It also discusses the structure, synthesis, modification, morphology, doping, preparation, and application of a particular subject and evaluates the advantages and disadvantages of different morphologies and preparation processes. The photocatalysts based on g-C₃N₄-based composites have demonstrated great potential. The g-C₃N₄ has been modified and tailored into various novel structures and morphologies to improve its efficiency in the photocatalytic degradation of pollutants. The techniques such as doping, metal deposition, heterojunction formation, and structural tuning enhance the rate of light absorption, charge transfer, and charge separation of g-C₃N₄. This leads to improved photocatalytic performance for antibiotic and dye degradation and hydrogen production.

Chicken manure (CM) is one of the most common animal wastes produced worldwide. The conventional application of CM is as a fertilizer; however, in the present study, we introduce an approach for the straightforward and affordable use of CM for fuel cell applications. It reports the functionalization of carbon nanofibers (CNFs) using CM to confer multiple functionalities. The elements that make up the functionalized CNF are nitrogen (7.40%, atoms ratio, the same below), oxygen (6.22%), phosphorous (0.30%), and sulfur (0.02%), etc., according to energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy studies. It has been verified that following treatment with CM, the morphology of the CNFs remains the same. The CM-modified CNFs exhibit a higher electrocatalytic activity (onset potential: −0.0756 V; limiting current density: 2.69 mA/cm²) for the oxygen reduction reaction (ORR) at the cathode of a fuel cell. The electron transfer number for this sample is 3.68, i.e., the ORR favours a four-electron pathway like Pt/C. The direct method of functionalizing the CNF is more effective; however, treatment of CNFs with Triton X-100 prior to functionalization shields their otherwise exposed open edge sites and in turn affects their ORR activity. A large surface area (99.866 m²/g), the presence of multiple functional elements (oxygen, nitrogen, phosphorous, sulfur, etc.), surface charge redistribution and induced donor–acceptor interactions at the surface of CM-modified CNFs contribute to their enhanced electrochemical activity. This preliminary study reports the suitability of a facile and economical approach for treating CM for the most advanced clean energy applications. Hopefully, this study will pave the way for cutting-edge methods for handling other biowaste materials as well.

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Uneven heat dissipation will affect the reliability and performance attenuation of tram supercapacitor, and reducing the energy consumption of heat dissipation is also a problem that must be solved in supercapacitor engineering applications. This paper takes the vehicle supercapacitor energy storage power supply as the research object, and uses computational fluid dynamics (CFD) simulation to calculate its internal temperature distribution to solve the problem that the internal heat dissipation of the power supply in the initial design scheme is not uniform, and the maximum temperature of cell capacitors is as high as 67 °C. Filling of heat-conducting silicone film between single cell capacitors inside the module can conduct heat from single cell capacitor in the center of the module to the edge of the module quickly; adding baffles in the cabinet can optimize the air duct, and the temperature between the modules can be uniform; as a result of the combined effect of the two optimization measures, the maximum temperature of the cell capacitors drops to 55.5 °C, which is lower than the allowable operating temperature limit of the capacitor cell 56 °C. For the first time, the scheme of using air-conditioning waste exhaust air to cool supercapacitor energy storage power supply is proposed. Compared with the traditional cooling scheme using special air conditioning units, each energy storage system can save 967.16 kW·h per year using air-conditioning waste exhaust cooling, effectively reducing the overall energy consumption of the vehicle.

Food waste (FW) constitutes a significant portion of municipal solid waste (MSW) and represents an underutilized resource with substantial potential for energy generation. The effective management and recycling of FW are crucial for mitigating environmental issues and minimizing associated health risks. This comprehensive review provides an in-depth overview of current technological applications for converting FW into energy with the dual goals of reducing environmental impact and maximizing resource utilization. It covers various aspects, including pretreatment methods, biological technologies (e.g., anaerobic digestion and fermentation), and thermal technologies (e.g., incineration, pyrolysis, gasification, and hydrothermal carbonization). The analysis includes the scope, advantages and disadvantages of these techniques. Landfilling, composting, and incineration are widely considered the most prevalent methods of FW disposal and have substantial negative impacts on the environment. Advanced technologies such as anaerobic fermentation offer environmental benefits and are suitable for scaling up, reducing greenhouse gas emissions, and producing renewable energy such as biogas, thus reducing carbon emissions. The promotion and adoption of advanced technologies like anaerobic fermentation can contribute to more sustainable FW management practices, reduce environmental impacts, and support the transition to a circular economy. Additionally, this article presents successful case studies, emphasizing the importance of technological integration in FW treatment. Furthermore, this article outlines future directions for FW treatment, including advancements in biological treatment technologies, decentralized treatment systems, and the adoption of digital and data-driven FW management systems. These emerging trends aim to promote sustainable, resource-efficient, and environmentally responsible FW management practices.

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The disposal of bone waste can be effectively addressed utilizing a novel approach involving the synthesis of a bovine bone-derived biochar-based Mg/Al-layered double hydroxide (LDH) nanocomposite (B-Mg/Al-NC). This nanocomposite exhibits exceptional capabilities for removing specific dyes, such as Methylene Blue (MB) and Congo Red (CR), from aqueous media. Extensive characterization using techniques confirmed the successful formation of the B-Mg/Al-NC, which possesses a high surface area, high porosity, and abundant functional groups. The Langmuir monolayer biosorption capacity was 395.56 mg g⁻¹ and 328.25 mg g⁻¹ at 50 °C for MB and CR, respectively, with rapid dye removal achieved within 25 min under alkaline pH conditions. The experimental data fit well with the pseudo-second-order kinetics model for both dyes. The remarkable dye adsorption capacity of the B-Mg/Al-NC can be attributed to the combined basic properties of the bone biochar and Mg/Al-LDH. Proposed mechanisms for enhanced dye removal include hydrogen bonding interactions, anion exchange, surface complexation, electrostatic interactions, and pore filling. Furthermore, the nanocomposite exhibited excellent reusability. In addition to its dye removal capabilities, the B-Mg/Al-NC was found to have a positive effect on seed germination and growth and salient soil health parameters, as demonstrated by a rapid seed germination test using the spent composite. Overall, the facile synthesis of the B-Mg/Al-NC via co-precipitation and ultrasonication is a highly recommended and sustainable approach for producing an eco-friendly bio-sorbent with exceptional dye removal efficiency from wastewater while also addressing the issue of bone waste disposal.

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Graphene/semiconductor heterojunction anodes can significantly enhance the output voltage by the photovoltaic effect. However, a significant challenge arises from the high intrinsic work function of heterojunction surfaces, which limits efficient electron emission. In this study, we explored the potential of low work function materials modified by Cs/Cs-O adsorption as anodes for thermionic (TI) converters through first principles calculations. The results demonstrate that the work functions of the graphene/MoS₂ and the graphene/n-type Si surfaces with only Cs coating can decrease to 1.48 eV and 2.46 eV, respectively. The multiple Cs-O atoms co-adsorption enhances the dipole moment, resulting in a further reduction of the work function of the graphene/MoS₂ surface to 1.25 eV. In addition, the impact of work function on the performance of TI converters is revealed by using concentrated solar energy as heat source. The highest conversion efficiency achieves 15.25% for the Cs-4O: Gr/MoS₂ anode. This study establishes a robust foundation for further advancement of the TI converters with graphene/semiconductor heterojunction anodes.

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Biomass-based carbon materials with hierarchical porous structures have attracted attention for their ability to provide more channels and shorten ion transport paths. Here, we developed a simple method based on confined nanospace deposition. During high-temperature treatment, the mesoporous silica layer wrapped around the outside of the crab shells acted as a closed nanospace and effectively suppressed the severe deformation of the crab shell structure by shrinking inward. The prepared carbon material has a layered porous structure with abundant and stable N and O co-doping (N 7.32%, O 3.69%). The specific capacitance of the three-electrode system was 134.3 F/g at a current density of 0.5 A/g in a 6 mol/L KOH electrolyte, and the assembled aqueous symmetric supercapacitors exhibited an excellent cycling stability of 98.81% even after 5000 cycles.

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Infectious waste management is a major environmental and public health challenge worldwide. Household infectious wastes are often mixed with other waste, collected, and disposed of without taking measures to reduce risks. With the emergence of the COVID-19 virus in early December 2019, there have been concerns about the dangers of infectious waste generated in healthcare facilities and homes. Therefore, this review was conducted with the aim of investigating the methods of household infectious waste management in different countries/regions and evaluating the factors affecting the management of household infectious waste. In this study, we conducted a systematic literature search in four electronic databases (PubMed, Web of Science, Scopus, and ProQuest) to answer the research questions. This process was based on the new version of PRISMA guidelines. In total, 52 documents out of 6742 were selected and evaluated. The review of studies based on content analysis led to the emergence of 12 main themes, 36 sub-themes, and 112 codes. The main topics included education and culture, management measures, legal social support, economic support, technology, control and evaluation, waste generation, classification and collection, temporary storage, transportation, processing and recycling, and safe disposal. The factors affecting household infectious waste management identified in this research can serve as a basis for future studies. It is also suitable for providing a comprehensive guide to the management of household infectious waste.

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The energy efficiency enhancement of solar dryers has attracted the attention of researchers worldwide because of the need for energy storage in solar drying applications, which arises primarily from the irregular nature of solar energy that leads to improper drying which will reduce the quality of the products being dried. This work comprehensively reviews the state-of-the-art research carried out on solar dryers for energy efficiency enhancement using various alternative strategies, including hybrid solar dryers that use auxiliary heating sources, such as electric heaters or biomass heaters, solar-assisted heat pump dryer, use of desiccant materials, and heat storage systems that use both sensible and latent heat storage. The advent of phase change materials (PCM), such as thermally and chemically stable PCMs, for long-term storage, bio-degradable and bio-compatible PCM materials to alleviate the negative environmental impact of conventional PCMs is also presented. The performance parameters considered for evaluating dryers include the maximum temperature attained inside the drying chamber, drying time and efficiency, specific moisture extraction rate (SMER), energy and exergy efficiency and CO₂ mitigation effect. The factors considered to analyze the PCMs application in solar dryers include cost and sustainability of PCMs, and both energy and exergy analyses of dryers using PCMs. The gaps in current knowledge and future scope for further improvement of solar dryers are also elucidated.

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