Resources, conservation & recycling advances最新文献

Charcoal is a common woodfuel in sub-Saharan Africa (SSA). Unsustainable wood sourcing and inefficient carbonization result into negative environmental impacts. This action research aimed at building the capacity for sustainable charcoal production including `improving the traditional earth mound kiln (TEK) that is used by 99% of charcoal producers in Kenya. Small stems and branches of the invasive Prosopis juliflora were used and produced quality charcoal with 28 kJ/g which will save trees. Improved earth mound kiln (IEK) increased charcoal yield by 49% per mass of sun dried wood fed into the kiln and reduced emissions of carbon monoxide, carbon dioxide and hydrocarbons by 40%, 49% and 44% respectively. Net charcoal yield by a mass of dry wood in TEK and IEK was 26.4% and 28.4% respectively. Communication and capacity development on sustainable charcoal benefit people and environment. Studies on sustainable charcoal and effects on dryland socio-ecological systems will be needed.

Tobacco industry produces a large amount of tobacco waste every year, and the disposal of tobacco waste become a puzzling problem. Recycling of tobacco waste to reconstituted tobacco sheet (RTS) with suitable strength and low-toxicity was prepared in this paper. RTS with 1wt% compound adhesive that content sodium carboxymethyl cellulose and guar gum has a tensile strength (0.548 kN/m) which meet the requirements of industrial production. Strength enhancement was attributed to the synergistic effect of hydrogen bonding and physical cross-linking network through FTIR and SEM characterization. GC–MS was used to analyze the pyrolysis of RTS. The nicotine release of RTS was lower than commercial cigarettes, which significantly reduces the harmful substance. This work has been preliminarily applied to the industrial production. The production process of RTS is simple, with low water consumption and reuse of tobacco waste. Conforming to the concept of environmental protection, energy conservation, and tobacco resource recycling.

This article seeks to contribute new insights into inclusive recycling environments through universal design. The aim is to develop knowledge on how waste is understood and managed by exploring the practice and design of a recycling environment. Applying a norm-critical view, this is explored in a study with participants from a municipal housing company and waste management company in northern Sweden. Methods used are go-along interviews together with professionals and observations of a recycling environment. The results are discussed as: 1) the “(un)social norm;” where our results show that the waste system is perceived as a social system, contradicting previous approaches where waste systems are treated as technical environments. 2) the “(un)design factor;” where we identify how design in a recycling context that doesn´t emphasise diversity may affect activities of sorting.

This study assessed the contribution of mechanically recycled cotton to reducing environmental impacts of fabric production by blending the recycled cotton with 100% virgin cotton of different types, including the U.S., BCI-Brazilian, Global average, and China. GHG emissions, water footprint, air pollution, and land use were investigated for producing 1 kg fabric, considering a 'cradle-to-gate' approach. A 'Take-Back' system was modeled using the circular economy concept to illustrate potential impact reduction by avoiding virgin cotton. Impact reduction scenarios were created considering varying blending ratios (i.e., virgin/ recycled), focusing on 70% virgin and 30% recycled cotton (target). Results reveal that compared to the baseline impacts, the target scenario could reduce environmental impacts by 2.2–8.6% (GHG emissions), 0.6–24.5% (water footprint), 1.4–11.6% (air pollution), and 3.1–25.2% (land use). In summary, recycled cotton could partially substitute 100% virgin cotton for fabric production. Besides, implementing and scaling up the 'Take-Back' system could reduce environmental impacts and contribute to environmental sustainability.

The consumption of recyclates in open-loop recycling systems raises the question in Life Cycle Assessments of how environmental impacts caused by raw materials and recycling can be allocated to the corresponding products. To solve the multifunctional issue of material flows, this study applies the 50:50 method as well as the cut-off and end-of-life approach using the Circular Footprint Formula across a cascade of three product life cycles. This analysis is based on injection molded products made of virgin and secondary materials, which consist of ABS, PA66GF30, PC and POM from post-industrial waste. The loss of quality due to production and mechanical recycling processes is reflected in the decrease of tensile strength. By quantifying the impact of allocation, this paper highlights the effects on the Product Carbon Footprint according to ISO 14,067 to show that a 50:50 as well as a cut-off allocation is suitable for the assessment of technical plastics.

This study evaluated the economic viability of Sargassum management strategies in southeast Florida. Semi-structured interviews were conducted with key informants, beach managers and potential users. To compare the strategies, a cost and market analysis was conducted to assess the value of Sargassum compost relative to other compost products available in the market. The findings indicate that composting Sargassum is an economically viable option and suggests the potential for recouping some of the costs associated with beach cleaning through the sale of compost. Furthermore, the utilization of Sargassum compost could offer a cost-effective alternative as a soil amendment, especially in the face of rising fertilizer costs. However, it is crucial to address concerns regarding compost quality due to contaminants such as plastics and arsenic before implementing a composting operation. This aspect necessitates thorough investigation and remediation to ensure that the resulting compost meets quality standards and is free from potentially harmful contaminants.

The hydrogen economy is driven by the growing share of renewable energy and electrification of the transportation sector. The essential components of a hydrogen economy are fuel cells and electrolysis systems. The scarcity of the resources to build these components and the negative environmental impact of their mining requires a circular economy. Concerning disassembly, economical, ergonomic, and safety reasons make a higher degree of automation necessary.

Our work outlines the challenges and prospects on automated disassembly of fuel cell stacks. This is carried out by summarizing the state-of-the-art approaches in disassembly and conducting manual non-/destructive disassembly experiments of end-of-life fuel cell stacks. Based on that, a chemical and mechanical analysis of the fuel cell components is performed. From this, an automation potential for the disassembly processes is derived and possible disassembly process routes are modeled. Moreover, recommendations are given regarding disassembly system requirements using a morphological box.

In circular economies, it is imperative to implement effective environmental management solutions to address resource depletion. Over the past few years, there has been a growing recognition of the potential of agricultural crop waste in mitigating greenhouse gas (GHG) emissions and promoting global carbon neutrality. Despite lacking practical management options, open-field burning of crop residue contributes significantly to greenhouse gas emissions and air pollution. This challenge may be addressed by producing biochar through the pyrolysis of agricultural crop residues. A biochar application in agriculture can contribute to reducing global warming through the sequestration of atmospheric carbon and reducing greenhouse gas emissions from the soil. As part of the life cycle assessment of biochar, the yield and greenhouse gas emissions during its production are critical factors, which emphasize the importance of selecting a production method suitable for producing biochar. The objective of this paper is to present a comprehensive overview of the environmental and agronomic advantages associated with biochar, along with a detailed analysis of its life cycle assessment (LCA). Furthermore, it provides an overview of how biochar can facilitate local energy production and contribute to sustainable resource management within the nexus of agroecosystems, environment, and energy.