Recycled Content Research Articles

Variability of the declared recycled content by changing allocation methods: A case study on plastic waste recycling

The Chain of Custody (CoC) standard tracks the recycled content (RC) of products, in most cases using the Mass Balance model. This model freely allows the selection of allocation methods and timeframes for the RC evaluation. Our work opens a discussion on the potential effects of this freedom in the RC evaluation. Firstly, we defined the general model representing the viable allocation methods and timeframe, and secondly, we applied the model to a case study. The mass balance model simplifies the monitoring of RC and encourages companies to use recycled materials. However, we outline the need for actions on stricter RC calculation and reporting, for instance, by reducing the timeframe of mass balance calculation or promoting the controlled blending model, which guarantees the physical presence of RC in the product. The results provide a basis for policymakers to set requirements for RC evaluation.

Influence of recycled steel fiber on the properties of self-compacting concrete with high fly ash content


 
 
 The recycled steel fibers from waste steel cables have properties suitable for enhancing the load-bearing capacity, impact resistance, and shrinkage reduction of Self-Compacting Concrete (SCC). The use of a high content of fly ash in SCC reduces production costs and is environment friendly by minimizing the amount of cement in the mix. This article presents the experimental research results on the influence of the content of recycled steel fibers on the properties of high-fly-ash SCC. The research utilized recycled steel fibers from elevator steel cables with volume percentages of 0%, 0.5%, 1% and 1.5% respectively in SCC, with a fly ash content in the SCC mix of 50% by volume of powder. The evaluated properties included workability, plastic shrinkage, drying shrinkage compressive strength, and tensile strength. The results indicate that using recycled steel fibers with a maximum content of 1% enables the production of SCC that meets European standards for workability. In addition, when comparing SCC with 0.5% and 1% recycled steel fiber content to control SCC samples (without steel fibers), the compressive strength of SCC increased by 5.04% and 7.56% respectively, the tensile strength increased by 2.99% and 5.97% respectively, plastic shrinkage decreased by 27.34% and 30.47% respectively, and 28-day drying shrinkage decreased by 3.2% and 4.6% respectively. Using recycled steel fibers combined with high-volume fly ash is a reasonable solution to save production costs and be environmentally friendly. Additionally, this solution not only improves the compressive and tensile strength but also limits plastic and drying shrinkage deformations of SCC. As a result, the durability of SCC is enhanced.
 
 

Macroscopic and Microscopic Investigation of Gypsum Slag Cement-Stabilized Recycled Aggregate Base Layers.

The purpose of this study is to investigate the macro and micro properties of stabilized recycled aggregate base layers using gypsum slag cement (GSC) and compare them with ordinary Portland cement (OPC). To achieve this, four levels of recycled aggregate content (0%, 50%, 60%, 70%) and three levels of binder materials (3.5%, 4.5%, 5.5%) were designed, where the binding materials included OPC and GSC. When GSC is used as the binding material with 0% recycled content, two scenarios for the ratio of slag to activator are considered: 4:1 and 4:2. For recycled content of 50%, 60%, and 70%, only the 4:1 ratio is considered. The macro-mechanical properties of the composite material were studied through compaction tests, unconfined compressive strength tests, and indirect tensile strength tests. Microscopic properties were investigated through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Macroscopic test results indicate that, at an equal binder content, GSC exhibits a higher moisture content and maximum dry density compared to OPC. Moreover, the unconfined compressive strength and indirect tensile strength of GSC are higher than those of OPC. Microscopic test results reveal that the hydration products of both binding materials are essentially similar; however, under identical curing conditions, the hydration products of GSC are more abundant than those of OPC.

Characterization of morphological structures of Fe3O4/SiO2/ZnO composite

The coprecipitation method has been successfully used for the synthesis and characterization of composite Fe3O4/SiO2/ZnO. The purpose of this research was to lower the concentrations of heavy metals in the water in an effort to restore natural functioning of the water. Because of its excellent chemical properties and high biocompatibility, silica is an intriguing and renewable material. The mixing magnetic materials Fe3O4 and ZnO can provide efficient separation effects, increase test sensitivity, and reduce detection time. The modification Fe3O4 with %wt ZnO (5; 10; 15;20) uses rice husk ash as a substitute for SiO2 in the application of heavy metal ion wastewater absorption, the aim is to minimize the composition of recyclable metal ion content which is environmentally friendly. The characterization of composite Fe3O4/SiO2/ZnO using SEM-EDS for morphological analysis and mapping of the elements that make up the sample The composite Fe3O4/SiO2/ZnO has gaps between its particles and a homogeneous shape, as seen by the SEM images.

Reducing the Environmental Impacts of Plastic Cosmetic Packaging: A Multi-Attribute Life Cycle Assessment

The global packaging industry has been growing significantly, resulting in an increase in waste and emissions. Social responsibilities, regulations and targets are shifting companies’ priorities to various sustainable practices. This study comprised a life cycle assessment (LCA) to quantify and compare key initiatives influencing the sustainability of plastic cosmetic packaging. The life cycle environmental effects of dematerialisation, recycled content, energy-saving initiatives and renewable energy powering the manufacturing processes, and the end-of-life (EoL) recycling rates of various scenarios, were evaluated. Moreover, a variety of fossil-based and bio-based polymers, such as acrylonitrile butadiene styrene (ABS), polypropylene (PP), polyethylene terephthalate (PET), wood–polymer composite (WPC) and polylactic acid (PLA), were considered. The study determined that dematerialisation and recycled content had the most beneficial impacts on packaging sustainability. When 100% recycled materials were used, an overall impact reduction of 42–60% was noted for all the materials considered. Using 100% renewable energy and applying measures to reduce the energy consumption in the manufacturing stage by 50% reduced the total impact by approximately 9–17% and 7–13%, respectively. Furthermore, it was concluded that PP had the lowest environmental impacts in the majority of the case scenarios considered, by an average of 46%.

Effect of Polymer Host on Aggregation-Induced Enhanced Emission of Fluorescent Optical Brighteners.

Fluorophores displaying concentration-dependent luminescence are becoming increasingly valuable in stress-sensing, tagging, and dyeing applications, including the quantification of recycled content in plastic packaging. In this work, we investigate the effects of the polymer matrix, dye structure, and crystallinity on aggregation-induced enhanced emission (AIEE). We demonstrate that the aggregation threshold required for successful quantification can be adjusted through modulation of guest-host (dye-polymer) interactions and monitored using an array of fluorescence characterization. Modification of guest-host interactions is realized through choice of host, change of guest, and tuning of the crystallinity of the host system. Increasing the number of guest-host interactions and solubility between guest and host, loosely predicted through the calculation of the solubility parameter, increases the aggregation threshold relative to other low-polarity and low-interacting systems. We demonstrate that issues, such as loading level and cost, associated with high aggregation thresholds, can be circumvented by increasing system crystallinity, improving spectral intensities, and subsequent quantification. These insights explore the fundamental understanding of supramolecular interactions that govern dye-polymer systems.

Study on the mechanical properties and microstructure of recycled brick aggregate concrete with waste fiber

Abstract Recycled concrete technology can promote the sustainable development of the construction industry, but the insufficient mechanical properties of recycled concrete have become a key constraint on its development. By adding waste fibers, the mechanical properties of recycled concrete can be improved, and the problem of disposing of waste polypropylene fibers can be solved. In this article, the effects of recycled brick aggregate content and waste fiber content on the mechanical properties and microstructures of recycled brick aggregate concrete through macroscopic mechanical experiments and microstructure experiments are investigated. The results show that the addition of recycled brick aggregate reduces the mechanical properties of concrete; when the content of recycled brick aggregate is 100%, the compressive strength and splitting tensile strength decrease by 22.04 and 20.00%, respectively. The addition of waste fibers can improve the mechanical properties of recycled brick aggregate concrete, but it is necessary to control the contents of waste fibers in a certain range. When the content of waste fibers is 0.08%, the best improvement effect on the mechanical properties of concrete is achieved; the compressive strength of concrete with a 50% (100%) recycled aggregate replacement rate increases by 6.06% (8.90%), while the splitting tensile strength of concrete with a 50% (100%) recycled aggregate replacement rate increases by 2.30% (6.16%). Through microstructural analysis, the mechanism by which waste fiber improves the mechanical properties of recycled brick aggregate concrete is revealed. The addition of waste fibers has the effect of strengthening the framework inside the recycled brick aggregate concrete, forming a good structural stress system and allowing the recycled brick aggregate concrete to continue to bear loads after cracking. In this study, waste brick aggregate and waste fiber are effectively utilized, which can not only reduce pollution to the environment but also realize the sustainable utilization of resources.

Recycling, Material Flow, and Recycled Content Demands of Polyethylene Terephthalate (PET) Bottles towards a Circular Economy in Korea

The recycling and proper management of PET bottles is needed to avoid plastic pollution, as well as to achieve a plastic circular economy. In this study, we examined the recycling system of PET bottles and their material flows by life cycle, from production to recycling and disposal under different scenarios with reduced consumption for PET bottles. In Korea, PET bottle recycling has been managed by the extended producer responsibility system since 2003. As of 2021, annual usage of PET bottles per capita in Korea was estimated to be approximately 6.5 kg. The recycling rate of PET bottles after collection was determined to be 79% in 2021. However, recycled PET (or r-PET) from mechanical recycling is mostly used in low-grade PET applications such as short fibers, bands, and sheets. More than 112 thousand tons of r-PET chips would be needed to meet the 30% recycled content requirement in PET bottles in 2030 by regulation. Thus, there is an urgent need for high-quality secondary raw materials (i.e., food-grade) by adopting advanced sorting and recycling technologies for PET bottles with recycled content. PET bottle-to-bottle recycling practices can ensure the production of high-quality recycled materials and move Korea toward a plastic circular economy.

The Front-Runner Approach—Facilitating Progressive Product Policy by Using Information from EU Product Databases

The European Commission has recently announced two guiding principles for EU product policy: First, product policy shall ensure that the performance of front-runner products in terms of sustainability becomes the norm, and second, the effectiveness of the current Ecodesign legislative framework is going to be significantly improved. Within this paper, already existing front-runner approaches and recent and ongoing product policy-making processes were reviewed. Based on the results, an EU front-runner approach is outlined. The presented approach (i) refers to performance levels of the best products already available on the market, (ii) aggregates information in existing databases, and (iii) works semi-automated. Together, all three attributes have a high potential to facilitate and accelerate the specification of appropriate minimum requirements for products at the EU level. This way, EU policymakers can deliver on the core objectives of the Ecodesign legislative framework much better. The basic mechanism and its legal entrenchment of the approach are illustrated for the energy efficiency of energy-related products. In addition, the Front-Runner Approach can be applied to any product group in the scope of the upcoming Ecodesign for Sustainable Products Regulation and to a wide range of product-related minimum requirements, such as durability, reparability, or recycled content. The study’s objective is to suggest a tailor-made and dynamic approach to keep the EU product legislation up to date using innovative technology based on the investigation of current regulations and identify the gap. Experiences from three international case studies suggest that a front-runner approach to setting energy-performance standards can drive innovation and reduce energy consumption via promoting energy-efficient products; transparency about available products is one of the key factors and can be established by a database. The EU front-runner approach comprises extending the existing energy label database (or making use of the digital product passport) and introducing a legislative procedure that triggers changes in the energy efficiency requirements in the specific EU regulations if the database shows that a certain threshold value is reached. Challenges such as limited EU staff capacities and opportunities such as increased dynamic are discussed.

Life Cycle Assessment of Various Initiatives towards Sustainable Plastic Packaging

The rapid growth of the packaging industry has resulted in a substantial increase in waste and pollution. Regulations, goals and social responsibilities have reoriented businesses’ priorities towards sustainable practices. The life cycle assessment (LCA) carried out in this study measured and compared significant efforts affecting the sustainability of plastic cosmetic packaging. Evaluations were conducted on the life cycle environmental effects of dematerialisation, recycled content, renewable energy share powering the manufacturing processes, energy-saving efforts, and end-of-life (EoL) recycling rates across various scenarios. Consideration was also given to different types of fossil and bio-based polymers (ABS, PP, PET and PLA). Dematerialisation and recycled content were identified as having the most significant positive effects on packaging sustainability. An average net reduction of 52% in the total carbon footprint for all materials assessed was noted when 100% recycling material was applied. The overall impact was reduced by an average of 13% when using 100% solar photovoltaic energy sources in the manufacturing processes. The minimal contribution of the manufacturing stage to the overall impact, compared to the other life cycle stages, was the main attribute causing this comparatively low impact reduction. Furthermore, compared to the other case scenarios, it was determined that polypropylene (PP) was found to have the most favourable environmental impact.

Recovery pathway assessment of recycled HDPE for circular economy: Shorter-life vs longer-life products

High Density Polyethylene (HDPE) is a highly recyclable thermoplastic comprising 17% of all plastic produced. Yet, demand for recycled HDPE (r-HDPE) has outrun availability, partly due to manufacturers’ interest in meeting sustainability goals and recycled content mandates. Given that HDPE has a variety of uses, understanding optimal allocation of the constrained r-HDPE supply across product categories and lifespans will support the challenge of addressing broader sustainability goals and establishing circular economy (CE). By utilizing systems dynamic (SD) and life cycle analysis (LCA) modeling, this work studies whether prioritizing r-HDPE for longer-life products is more environmentally beneficial, compared to shorter-life products (e.g., food-grade packaging). Specifically, this work compares the production of milk containers and drainage pipes using virgin and r-HDPE as examples of HDPE applications through three scenarios. Key findings emerged from this study including the demonstration of a slight advantage to prioritizing allocating the constrained r-HDPE supply to the longer-life product vs the shorter-life product and a distinct challenge in hitting recycled content targets with current recycling rates and 2030 goals for the United States. This highlights a need to expand current recycling infrastructure in tandem with other CE practices to reduce plastic consumption and sustain environmental health for all.

Non-invasive optical property-based strategy to distinguish poly(ethylene terephthalate) containers of different recycled content

For Poly(ethylene terephthalate) (PET), one of the most widely used and re-used plastics, no definitive analytical method has been established to distinguish between the virgin form and its recycled counterpart. Numerous efforts have been made to achieve this purpose by mainly measuring thermal or mechanical properties and in this sense, the challenge arises from the fact that several factors can affect the characteristics of PET, recycled or not. In this study, the optical properties and their correlations for 28 PET containers with different mass, thickness and content of recycled material have been studied, normalized and parameterized to ultimately differentiate between both forms. Diffuse reflectance UV–Vis (DRS) spectra were unique for each sample and, while near-infrared (NIR) and Fourier-transform infrared-attenuated total reflectance (FT-IR-ATR) provided constant overall parameters regardless of the recycled %, fluorescence and Raman results indicated some differences between non-recycled and recycled PET. Furthermore, the Raman identification accuracy of the two groups was 96.4% and the fluorescence intensity could be related to the content of recycled PET. Moreover, water permeability tests were carried out on some samples, concluding that this property was correlated with the thickness of the plastic and not the recycled %. The study was completed by performing a multivariate analysis (PCA, box plot, K-means and hierarchical clustering analysis) to better understand the correlations within the variables studied and finally confirm the selection of those that allowed for a correct and sequential discrimination of the groups, resulting in a fast and non-invasive strategy that allows for an almost complete vPET-rPET distinction.

Influence of Environmental Factors and Aggregates on Concrete Elasticity: Ultrasonic and Strength Testing

This study investigates the effects of recycled aggregates (RAs), temperature, humidity, and freeze–thaw cycles on the modulus of elasticity in concrete, using a comparative approach between ultrasonic pulse velocity (UPV) and compressive strength tests. A range of RA proportions (0%, 25%, 50%, 75%, and 100%) was explored. These mixes were subjected to environmental conditions, including temperatures of 25, 0, and −18°C in both dry and wet states, to assess their impact on the mechanical properties of concrete rigorously. The findings reveal that the modulus of elasticity decreases by up to 35% with higher recycled content and more severe environmental exposure, with significant variations observed under different temperatures (25, 0, and −18°C) and moisture conditions. Notably, samples with 25% recycled content maintained higher elasticity, suggesting an optimal threshold for incorporating recycled materials. The study also validates using UPV as a nondestructive method to efficiently evaluate concrete’s structural integrity. These insights advocate for the tailored use of RA concrete (RAC) in construction, enhancing durability and sustainability in varying climatic conditions. This research contributes to the development of concrete formulations that are both durable and environmentally adaptive, promoting sustainable construction practices.

Assessing the negative impact of the it sector on the environment: a call for sustainable solutions

The article explores the negative impact of the Information and Communication Technology (ICT) sector on the environment and offers recommendations to reduce this impact. The article highlights that while digital and environmental issues are major topics of public debate worldwide, they are rarely discussed together. The article uses a qualitative approach to assess the current impact of the ICT sector on the environment by reviewing relevant literature, analyzing data on the global impact of the sector, and considering measures to prevent the negative effects. The study reveals that while ICT can have positive effects on the environment, it also carries sources of threats, such as excessive consumption of resources for the production of devices, CO2 emissions into the atmosphere, changes in flora and fauna, and growing electronic waste. The article concludes by calling for manufacturers to use environmentally friendly materials and manufacturing processes to create products with high recycled content to reduce the environmental impact of the ICT sector.

Modelling recycling for the life cycle assessment of perovskite/silicon tandem modules

With the massive growth of the global capacity of photovoltaics (PV) over the last decade, the PV waste is expected to increase dramatically in the near future. Having potential to reduce the use of raw materials and preserve natural resources, PV recycling is attracting more and more attention. This being said, the environmental impacts over the life cycle of PV technologies, including the end-of-life (EoL) stage, should be evaluated carefully. Life cycle assessment (LCA) is currently the most common methodology to assess the potential environmental impacts of a product throughout its entire life cycle. However, the modelling of recycling in LCA has always been a challenge and no consensus has yet been reached, since the treatment of recycling does not only involve an EoL management of waste, but also the production of recycled material. Perovskite on silicon tandem is a widely investigated emerging PV technology having the potential to overcome the power conversion efficiency (PCE) limit of the single-junction crystalline silicon technology. The EoL modelling seems more challenging in the case of emerging technologies for which the EoL is more uncertain than for established technologies. In this article, six common and important approaches of EoL modelling in LCA were applied to future perovskite/silicon tandem modules to analyze the effect of the different EoL modelling approaches on the LCA results. The aim was to identify the most suitable methodological approaches to account for recycling, when modelling the life cycle of PV modules. The environmental performance of perovskite/silicon tandem modules was assessed over their life cycle and expressed in terms of impacts per m2 of module. After testing the six EoL modelling approaches and comparing the LCA results, the EoL modelling choice was found to lead to non-negligible differences. For example, in terms of climate change, the impact of the tandem modules ranges from 45 to 59 kg CO2-eq/m2. Among the six EoL modelling options, the approaches of simple cut-off and cut-off with economic allocation are more oriented towards the promotion of high rates of recycled material integrated as an input to the assessed product among industrial actors, while the approach of closed-loop allocation provides incentives to maximize the ratio of recycling at the EoL, regardless the initial ratio of recycled content within the product. Some approaches such as the circular footprint formula (CFF) tend to provide both incentives to increase the content of recycled input material in the manufacturing of the product and the recycling ratio at the EoL of such product. After applying the different alternatives, a set of recommendations to select the relevant EoL modelling approaches are provided: 1) the CFF is recommended as a representative approach due to its wide applicability, tending to provide an intermediate result and reflecting the characteristics of materials; 2) sensitivity analysis should be applied to check the robustness of the results, 3) the cut-off approach and the closed-loop allocation should be used at least for the sensitivity analysis.

Valorization of Plastic Wastes for the Development of Adsorbent Designed for the Removal of Emerging Contaminants in Wastewater

Plastic waste accrual in the environment has been identified as the topmost significant global issue related to modern civilization. Traditional waste disposal methods, such as open burning, landfilling, and incineration, have increased greenhouse gas emissions in economic and material losses. Unless immediate action is made to curtail demand, prolong product lifespans, enhance waste management, and encourage recyclability, plastic pollution will increase due to an almost threefold increase in plastic use spurred by growing populations and affluence. Plastic production primarily is from crude oil or gas despite more than a fourfold growth from ~6.8 million tonnes in 2000 to ~30 million tonnes in 2019; only ~6% of the world’s total plastics production is made from recycled plastics. The competitiveness and profitability of secondary markets may increase with the establishment of recycled content objectives and advancements in recycling technology. In this review, emerging approaches and the creation of value-added materials from waste plastics such as carbon nanotubes and other carbonaceous nanomaterials production, the environmental impacts of plastic waste, African status concerning plastic waste, the importance of modern techniques in plastic waste management, and the circular economy impact on plastic waste utilization are the high points of this study.

Untargeted screening of NIAS and cyclic oligomers migrating from virgin and recycled polyethylene terephthalate (PET) food trays

Polyethylene terephthalate is considered one of the most used and approved recycled plastic polymer as food contact materials (FCM); however, the fundamental details arising from the recycled content of PET trays in relation to processing conditions or extent of recycling are not well understood. In the present work, the presence and migration of different series of PET cyclic oligomers from industrially recycled trays were investigated using official food simulant D1 at 40 °C for 10 days. The trays were produced in two different facilities, using different extrusion processing technology, namely single and twin-screw extruder. Tested food packaging trays were produced from different ratios of virgin (vPET) and recycled PET (rPET), varying from 0% up to 100% w/w content. Analysis of the trays using MALDI-TOF-MS revealed a decrease in the molecular weight distribution (Mw) in rPET compared to virgin PET plastic. Untargeted screening with UHPLC-QTOF-MS, revealed the presence and migration of several intentionally added substances (IAS) as well as non-intentionally added substances (NIAS). The results demonstrated differences of the cyclic oligomers migration into the selected food simulant, depending on the rPET/vPET ratios as well as among the applied extrusion technology applied. Following multivariate analysis, marker compounds found to be benzyl butyl phthalate (BBP), butyl lactate, dodecenamide, 2-methyl-1,3-dioxolane, PET 2nd series cyclic dimer as well as PET 1st series cyclic dimer can be considered as marker compounds.

Company Perspectives on Circular Economy Management, Assessment and Reporting in the Kymenlaakso Region in Finland

In general, circular economy development is about a system-level change towards significantly enhanced circularity and sustainability encompassing both biological and technical cycles. This study aimed at exploring, identifying, analyzing and synthesizing how companies in the Kymenlaakso region perceive circular economy management, assessment and reporting. This study applied a qualitative research approach using a questionnaire survey as the specific method. The responding companies are of many sizes and represent multiple sectors such as industry, construction and various services. This study addressed a clear gap in research on company-level perspectives. The results indicate that recycling and recovery of materials are perceived as particularly important by companies. In addition, the principles of CE (10Rs) are considered to be important by most companies. Essential management approaches encompass, for example, CE strategy and goals, business ecosystems and development of markets for recycled and recovered products and parts. Companies considered that recycling, recovery, waste minimization and utilization of waste as a raw material, as well as an increase in recycled content in products, reduction in disposable products and prevention of premature obsolescence, are important CE assessment and measurement approaches. For example, continuous reporting of CE as a part of online communication of companies (i.a. sustainability and responsibility), the definition of best practices and best available techniques for CE, and reporting in the whole supply and value chain were perceived as important ways to report CE. However, it is noteworthy that many of the studied aspects of CE were not perceived to be important by companies. Overall, this study contributes to a better understanding of the current state of and future outlook on circular economy development in the studied region and also highlights relevant management, assessment and reporting aspects from the perspective of local companies.

Exploring elastic properties of fly ash recycled aggregate concrete: Insights from multiscale modeling and machine learning

The primary focus of this study is to analyze the impact of different components of fly ash recycled aggregate concrete (FARAC) on its elastic properties, aiming to suggest it as a potential alternative to traditional concrete. For this study, a variety of techniques were employed, such as multiscale modeling, finite element methods, and Mori-Tanaka theory. The study employed supervised machine learning methods to conduct classification and regression analyses, with the goal of investigating the impact of mix proportion on elastic properties. The results obtained from the machine learning models suggest that the XGBoost and K-Nearest Neighbors algorithms have shown exceptional precision when compared to the other algorithms, achieving an accuracy of over 0.9. The current investigation reveals that the elastic characteristics of FARAC are primarily affected by fly ash and calcium silicate hydrate (C-S-H) in comparison to other components. According to the research findings, incorporating recycled aggregate content in the range of 0–100% resulted in a 25% decrease in Young's modulus and an 8% increase in Poisson's ratio of FARAC. In addition, two web-based applications have been developed to calculate the elastic properties of composite materials with spherical inclusions using the Mori-Tanaka theory, and to predict the elastic properties of FARAC through machine learning.

Diffusion control in closed-loop supply chains: Successive product generations

We consider a durable-good producer who optimizes its sales decisions for two successive product generations with refurbishing and recycling potential. Customer arrivals follow a multi-generation diffusion process that takes into account the word-of-mouth feedback spread within each customer population of successive generations as well as the substitution effect among these generations. We investigate whether the producer can profit from partially satisfying the new-generation demand to slow down the product diffusion and improve the refurbishing and recycling volumes in the long run. We derive conditions for optimality of this partial-fulfillment policy. In fast-clockspeed industries, if the producer enters the refurbishing market for both generations, the partial-fulfillment policy is optimal if (i) the profit margin ratio of the early-generation product to the new-generation product is high enough, (ii) the profit margin ratio of the refurbished item to the new item is large enough for the new-generation product, and (iii) the fraction of customers willing to buy the refurbished item is only modestly large for each generation. If the producer uses the recycled content obtained from early-generation returns in new-generation production, the partial-fulfillment policy is optimal if (i) the number of early-generation end-of-life returns and the amount of recyclable material from each such return are large and (ii) the number of customers initially attracted by the early-generation product is high. We also characterize the critical time period beyond which initiating the partial-fulfillment policy provides no improvement in the refurbishing and recycling volumes for the new-generation product.