•We study the recycling schemes of France, Germany, Portugal, Romania and the UK.•The costs and benefits of recycling are compared for France, Portugal and Romania.•The balance of costs and benefits ...depend on the perspective (strictly financial/economic).•Financial supports to local authorities ought to promote cost-efficiency.
This paper describes and examines the schemes established in five EU countries for the recycling of packaging waste. The changes in packaging waste management were mainly implemented since the Directive 94/62/EC on packaging and packaging waste entered into force. The analysis of the five systems allowed the authors to identify very different approaches to cope with the same problem: meet the recovery and recycling targets imposed by EU law. Packaging waste is a responsibility of the industry. However, local governments are generally in charge of waste management, particularly in countries with Green Dot schemes or similar extended producer responsibility systems. This leads to the need of establishing a system of financial transfers between the industry and the local governments (particularly regarding the extra costs involved with selective collection and sorting). Using the same methodological approach, the authors also compare the costs and benefits of recycling from the perspective of local public authorities for France, Portugal and Romania. Since the purpose of the current paper is to take note of who is paying for the incremental costs of recycling and whether the industry (i.e. the consumer) is paying for the net financial costs of packaging waste management, environmental impacts are not included in the analysis. The work carried out in this paper highlights some aspects that are prone to be improved and raises several questions that will require further research. In the three countries analyzed more closely in this paper the industry is not paying the net financial cost of packaging waste management. In fact, if the savings attained by diverting packaging waste from other treatment (e.g. landfilling) and the public subsidies to the investment on the “recycling system” are not considered, it seems that the industry should increase the financial support to local authorities (by 125% in France, 50% in Portugal and 170% in Romania). However, in France and Portugal the industry is paying local authorities more than just the incremental costs of recycling (full costs of selective collection and sorting minus the avoided costs). To provide a more definitive judgment on the fairness of the systems it will be necessary to assess the cost efficiency of waste management operators (and judge whether operators are claiming costs or eliciting “prices”).
•Reviewed emerging trends in Informal Sector Recycling (ISR) in developing countries.•In some countries we found that ISR is the key factor in the recycling of waste materials.•Overall impact of ISR ...upon the urban economy and environment is positive.•In some instances ISR subsidises large areas of the formal sector.•Ignoring the informal sector could result in unsustainable interventions.
Optimistic estimates suggest that only 30–70% of waste generated in cities of developing countries is collected for disposal. As a result, uncollected waste is often disposed of into open dumps, along the streets or into water bodies. Quite often, this practice induces environmental degradation and public health risks. Notwithstanding, such practices also make waste materials readily available for itinerant waste pickers. These ‘scavengers’ as they are called, therefore perceive waste as a resource, for income generation. Literature suggests that Informal Sector Recycling (ISR) activity can bring other benefits such as, economic growth, litter control and resources conservation. This paper critically reviews trends in ISR activities in selected developing and transition countries. ISR often survives in very hostile social and physical environments largely because of negative Government and public attitude. Rather than being stigmatised, the sector should be recognised as an important element for achievement of sustainable waste management in developing countries. One solution to this problem could be the integration of ISR into the formal waste management system. To achieve ISR integration, this paper highlights six crucial aspects from literature: social acceptance, political will, mobilisation of cooperatives, partnerships with private enterprises, management and technical skills, as well as legal protection measures. It is important to note that not every country will have the wherewithal to achieve social inclusion and so the level of integration must be ‘flexible’. In addition, the structure of the ISR should not be based on a ‘universal’ model but should instead take into account local contexts and conditions.
In this study, we built a green, low-carbon supply chain including one green manufacturer, one green remanufacturer and one retailer in which the manufacturer produces new, green, low-carbon products ...and the remanufacturer recycles and remanufactures the green, low-carbon products. We assumed the manufacturer to be the Stackelberg leader and the remanufacturer and the retailer to be Stackelberg followers. The game model was solved using backward induction. We discuss the optimal operation strategies for green, low-carbon supply-chain members in a centralized decision-making model, decentralized decision-making model, manufacturer-remanufacturer cooperative decision-making model and manufacturer-retailer cooperative decision-making model. Furthermore, we discuss the impacts of the unit cost savings for remanufacturing, the recovery cost coefficient and the green improvement cost coefficient on the green supply-chain members' optimal decision and profits. The results show that increased unit cost savings from remanufacturing can increase the total profit of the supply chain and promote the recycling and remanufacturing of waste products. Moreover, the total profit of the green, low-carbon supply chain is the highest in the centralized decision-making model and lowest in the manufacturer cooperative decision-making model. When there is a cooperation relationship between the manufacturer and the retailer, the optimal recycling effort level and the optimal greenness level for the new product and the remanufactured product are the highest.
Titanium alloys are an important material for several industries, despite being very energy intensive to produce. This study aims to maximize chip recyclability by adjusting the milling process and ...subsequent processing steps. The results show that the chip morphology determines the recyclability significantly. Also, a cleaning process is established to reduce chemical contamination. Based on the results a closed-loop material cycle for Ti–6Al–4V powder for additive manufacturing is presented. It is shown that the powder and material properties of printed samples are similar to those of conventional materials, while energy savings of up 77 % can be achieved.
China's paper industry development is rapid, but the recycling rate of China's waste paper has been low all the time. Meanwhile, material flow analysis can help determine the flow of waste paper, and ...life cycle assessment (LCA) is the methodological framework for quantifying greenhouse gas emissions. Therefore, present study integrates these two methods into the model construction of China's waste paper recycling decision system. Present study constructs a benchmark model of China's waste paper recycling decision system in 2017, focusing on the impact of nonstandard waste paper recycling on the economic and environmental benefits of China's domestic waste paper recycling system. This model construction is followed by sensitivity analysis of the relevant parameters affecting the efficiency of the waste paper recycling system. Finally, present study forecasts the system's economic benefits and greenhouse gas (GHG) emissions in the context of integrating and regulating nonstandard recycling vendors. The results show that the economic benefit of China's waste paper recycling in 2017 is approximately 458.3 yuan/t and that the GHG emissions are 901.1 kgCO2eq. The standard recovery rate and nonstandard recovery acceptance rate will both have a significant impact on the system's economic benefits and improve the GHG emissions structure. In the context of integrating nonstandard recycling enterprises and individual recycling vendors, the economic benefits will rise to 3312.5 yuan/t in 2030, while GHG emissions will rise to 942.9 kgCO2eq. Present study can play a certain guiding role for policy makers in formulating waste paper recycling industry specifications and formulating relevant policies.
•Present study constructs the life cycle framework of Chinese paper and paperboard by the combination of MFA and LCA.•Quantitative analysis of the economic benefits and GHG emissions generated by China's waste paper recycling system.•Sensitivity analysis on the main parameters of the economic and environmental benefits of the waste paper recycling system.•Benefits of China’s waste paper recycling from 2018 to 2030 are evaluated by integrating nostandard and standard recycling.
In a circular economy, the use of recycled resources in production is a key performance indicator for management. Yet, academic studies are still unable to inform managers on appropriate recycling ...and pricing policies. We develop an optimal control model integrating a firm's recycling rate, which can use both virgin and recycled resources in the production process. Our model accounts for recycling influence both at the supply- and demand-sides. The positive effect of a firm's use of recycled resources diminishes over time but may increase through investments. Using general formulations for demand and cost, we analytically examine joint dynamic pricing and recycling investment policies in order to determine their optimal interplay over time. We provide numerical experiments to assess the existence of a steady-state and to calculate sensitivity analyses with respect to various model parameters. The analysis shows how to dynamically adapt jointly optimized controls to reach sustainability in the production process. Our results pave the way to sounder sustainable practices for firms operating within a circular economy.
This research provides the analysis of the mill scale and plastic waste properties, as well as ways of their complex recycling. Preliminary experiments on the formation of briquettes were made. The ...results of preliminary experiments on mill scale grinding in a cone inertial crusher and the formation of briquettes together with plastic are presented. This research has revealed the possibility of creating a briquette charge material for further processing in steelmaking processes. The addition of a plasticizer is necessary to improve the formability of the samples during pressing.
The waste polyolefin composition varies regionally due to different sorting technologies, emphasizing the necessity for a robust catalyst capable of selectively converting pyrolysis vapors into ...valuable light olefins while maintaining stability. HZSM-5, a microporous catalyst, efficiently cracks polyethylene (PE) pyrolysis vapors rich in linear aliphatics. However, polypropylene (PP) pyrolysis typically yields branched olefins, potentially hindering effectiveness of HZSM-5 due to mass transfer constraints and coke blockage in micropores. This study modifies HZSM-5 through phosphorus impregnation, mesopore introduction, and steam treatment to evaluate the impact of acidity, pore size, and surface modifications on catalyst stability and light olefin selectivity during PP pyrolysis vapor cracking. Subsequent experiments reveal the superior stability of modified catalysts. Phosphorus-modified (P-HZSM-5ss) and mesoporous phosphorus-modified (P-mesoHZSM-5ss) catalysts retain 72 % and 80 % of their initial activity after 150 runs, respectively, while the parent HZSM-5 experiences a rapid 44 % activity loss. P-mesoHZSM-5ss demonstrates the highest light olefin selectivity (63 wt%) after 150 runs, attributed to improved accessibility of branched olefinic products to active sites within catalyst pores. Further optimization achieves exceptional light olefin selectivity of 84 wt% at 117 ms contact time and 550 °C, surpassing maximum selectivity of the parent catalyst. Comparative analyses of PP, PE, and mixed polyolefinic waste pyrolysis vapor cracking revealed the influence of polyolefin type on optimal operational conditions, stressing the need for flexibility in operating conditions to scale up the proposed polyolefin recycling method. This study highlights the potential of tailored catalyst modifications and process optimization to efficiently convert PP into valuable light olefins, advancing sustainable polyolefin recycling technologies.
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•Chemical recycling of polypropylene through ex-situ catalytic pyrolysis.•Phosphorus-impregnated mesoporous HZSM-5 shows 83 wt% light olefin selectivity.•Polypropylene exhibits a higher tendency to generate coke compared to polyethylene.•Dependence of polyolefin type on optimization for maximum light olefin selectivity.
•The source separated collection and recycling of OFMSW are crucial processes for establishing sustainable waste management strategies.•Odor generation is the most challenging environmental factor ...for the sustainable management of composting plants.•Waste composting should be implemented in conjunction with source-separated collection to ensure the production of high-quality compost.•Quality-based compost classifications are recommended from the perspective of waste material recycling and environmental risk control.
Biodegradable material, primarily composed of food waste, accounts for 40–70wt% of municipal solid waste (MSW) in developing countries. Therefore, to establish a sustainable waste management system, it is essential to separate and recycle biodegradable organic material from the municipal waste stream. Of all the recycling methods, composting is recommended due to its environmental and economic benefits. However, compared with readily recyclable materials (e.g., paper, metals, etc.), recycling/composting biodegradable MSW presents a great challenge to furthering the promotion of waste recycling.
This review provides a systematic analysis of organic waste sorting and recycling/composting practices in several countries: the UK, US, Japan, and China. Compared to the great efforts that have been made in developed countries for the promotion of waste composting, much less has been achieved in developing countries. For example, the MSW composting rate in China decreased from 10% to less than 2% in the past 15 years, and similar trends may exist in other developing countries. Therefore, it is essential to identify the barriers that impede waste composting and predict developing trends. This article emphasizes environmental challenges (i.e., odor, bioaerosols, and heavy metals), focusing on their generation and control strategies, in an effort to identify barriers hindering MSW composting. Successful practices in several European countries suggest that source-separated composting presents many advantages over mechanical-separated composting. This may partially be ascribed to the fact that source separation of organic waste can prevent contact with heavy metal-bearing items, resulting in the production of high-quality compost. Mixed collection MSW normally contains significantly higher concentrations of heavy metals, which could affect the marketing of composting products. Moreover, source separation of organic waste can minimize waste pretreatment operations, leading to lower bioaerosol and malodor generation during composting. Implementing source separation of MSW in more countries would increase the amount of organic waste available for composting. In addition, attention should focus on secondary pollutant production for proper composting management. Finally, setting standards for end product quality control is highly recommended for controlling both marketing and environmental risks.
The protection of human health and the environment (representing the main reason for waste management), as well as the sustainable use of natural resources, requires chemical, biological, physical ...and thermal treatment of wastes. This refers to the conditioning (e.g., drying, washing, comminution, rotting, stabilization, neutralization, agglomeration, homogenization), conversion (e.g., incineration, pyrolysis, gasification, dissolution, evaporation), and separation (classification, direct and indirect (i.e., sensor-based) sorting) of all types of wastes to follow the principles of the waste hierarchy (i.e., prevention (not addressed by this issue), preparation for re-use, recycling, other recovery, and disposal). Longstanding challenges include the increase of yield and purity of recyclable fractions and the sustainable removal or destruction of contaminants from the circular economy.This Special Issue on “Advanced Technology of Waste Treatment” of Processes collects high-quality research studies addressing challenges on the broad area of chemical, biological, physical and thermal treatment of wastes.
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