Recycling Rate Research Articles

Who will pay for the decommissioned photovoltaic modules? Evidence from evolutionary game analysis of China’s photovoltaic industry under dynamic incentives

Following the booming of the PV industry, the tide of photovoltaic modules decommissioning is developing fast to raise environmental concerns. The recycling and conversion of decommissioned photovoltaic modules (DPV) becomes a pressing challenge for the industry to sustain growth with less environmental burdens caused to the society. This study introduces Extended producer responsibility (EPR) and Environmental protection tax (EPT) into the governance framework of DPV recycling. Employing evolutionary game theory, this study develops a tripartite evolutionary game model comprising the government, PV enterprises, and households, based on which the interactions and strategic changes among them are revealed. Moreover, the evolutionary trajectory of DPV recycling industry, as well as the impact of driving factors on their strategic changes are verified through empirical simulations of China’s PV industry. It was found that DPV recycling industry will progress through three stages, namely initial stage, middle stage, mature stage, in which the government plays the role of leader and gradually withdraws its participation as the industry evolves. The dynamic incentives are effective in promoting the adoption of EPR, and the mixed incentives with a baseline of a comprehensive recycling rate of 70 % set by the government work best. The recycling efforts and the conversion benefit value promote DPV recycling through EPR by PV enterprises. Heavy environmental protection tax and heavy landfill costs also drive the implementation of EPR. It is suggested that China should implement regional incentive schemes incorporating regional characteristics to encourage DPV recycling locally. This study has certain reference values for the policy and strategy formulations to promote the development of DPV recycling industry.

The impact of innovative technologies in construction activities on concrete debris recycling in China: a system dynamics-based analysis

As construction activities become more intensive in developing countries, increasing improperly managed construction and demolition waste (CDW) brings serious environmental impacts. Recycling is a beneficial way to dispose of CDW that reduces environmental impact and brings economic benefits, especially for concrete. China is the country that generates the most CDW in the world, but its domestic recycling rate is much lower than that of developed countries. While the efficient technologies in developed regions have helped them to achieve a well-established recycling industry, whether these innovative technologies can be used to improve the concrete debris recycling targets in developing regions is unclear. This study examines whether innovations currently widely used in construction activities and materials can have a positive effect on the recycling of End-of-Life concrete materials in China. Results from modeling system dynamics imply that the introduction of innovative technologies in the recycling system of concrete debris can probably contribute to CO2 reduction (3.6% reduction) and economic benefits (2.6 times increase, but mainly from landfill charges and fines) from 2022 to 2030. Prefabrication and 3D printing significantly impact recycled concrete production and CDW recycling, and they are recommended as a priority for promotion. In contrast, carbonation is not suggested for application due to its minor role. Nevertheless, since the market share of innovative technologies and the basic CDW recycling rates are currently low in China, fluctuations in their usage are hardly to have a substantial positive impact. We suggest that financial support from the government is needed for upcycling by recyclers and technology providers to improve the base recycling rate in order for innovative technologies to make an effective contribution to the sustainable construction industry, creating a win–win situation for both the economy and the environment of the recycling system.

Material Recycling for Manufacturing Aggregates Using Melting Slag of Automobile Shredder Residues

The quantity of waste from end-of-life vehicles is increasing with an increase in the number of scrapped internal combustion engine vehicles owing to international trends such as carbon neutrality and particulate matter reduction. The recycling rate must be ≥95%; however, the average recycling rate remains at approximately 89%. Therefore, the improvement of the recycling of automobile shredder residues (ASR) is gaining attention. In this study, four types of products (interlocking, clay, and lightweight swelled ceramic (LSC) bricks, and asphalt paving aggregate (APA)) were manufactured using ASR melting slag (ASRMS). Environmental performance, quality standards, and technology were evaluated to assess the recyclability of the manufactured bricks. The interlocking brick substituted melting slag for sand and stone powder as an aggregate. As melting slag content increased, absorption decreased and bending strength increased. Clay brick was manufactured by replacing kaolin and feldspar with melting slag that substituted for 20%. The quality of clay bricks mixed with over 15% melting slag was not better than standard. Asphalt paving aggregate was used to investigate the optimum condition of slag content in mixed asphalt; the mixture ratio showed that 61% broken stone of 13 mm, 6% screenings, 10% melting slag, 15% sand and 8% filler was most effective. A lightweight swelled ceramic brick was manufactured by using melting slag, front glass, and so on. Specific gravity and compressive strength ranged from 0.38 to 0.51 and from 339.7 to 373.6 N/cm2. ASRMS exhibited an environmental performance suitable for recycling and the manufactured bricks satisfied the quality standards. The recyclability of ASR was also assessed in terms of waste usage, conformance to quality standards, market size, and demand prediction. APA showed the best results followed by interlocking, clay, and LSC bricks.

Optimization of metal-supported solid oxide electrolysis cells with infiltrated catalysts

Metal-supported solid oxide electrolysis cells (MS-SOECs) are being developed for steam-to-hydrogen electrolysis, especially for utilization of dynamic or intermittent electrical power from renewable sources. Various aspects of the electrocatalyst processing and composition, and metal support structure were explored. Catalyst materials, infiltration temperature and infiltration cycles were optimized for high performance and durability. Numerous catalyst materials were screened for both oxygen and steam electrodes. The oxygen catalyst had moderate impact on both initial cell performance and durability. Reducing Ni content in the steam electrode had little effect on durability, but reduced initial performance. Ex-situ XRD analysis and cell assessment of catalyst infiltration temperature revealed that the optimal range is 750–850 °C. The best cell performance and durability was achieved with LSCF-SDC oxygen electrocatalyst and SDC-Ni (60:40 vol%) steam electrocatalyst infiltrated 11 times at 800 °C and operated at 700 °C. At low steam content, a significant mass transport limitation on the steam side results in limiting current behavior. Thinner and more porous metal supports were implemented, and found to improve steam mass transport at low steam content, relevant for SOECs operating under high H2 recycle rate or high steam utilization.

Changes in household recycling behavior: Evidence from panel data

This article uses a longitudinal national U.S. dataset with 232,309 pairs of same-household observations to estimate one-year or two-year changes in recycling behavior. Most households recycled at least one material, as 83% recycle paper, cans, glass, or plastic in the past year, with an average recycling rate of 2.8 materials. Recycling habits are stable, as 68% of households do not change the number of materials recycled from the previous year. Changes in county recycling are reflected in immediate changes in household behavior but at 25% of the change in the county recycling rate. Recycling rates are greater after being newly exposed to deposit laws (+7%), moving to a state with effective recycling laws (+6%), or newly available single-stream recycling (+4%). If market prices for the returned cans doubled, household recycling of cans would increase by 12%, although price responsiveness of recycling other materials is less. Shocks to the household may diminish recycling in the short term, including marriage (−2%), arrival of a newborn (−1%), and either large increase in income (−1%) or large decrease in income (−3%). The estimates for the total number of materials and which particular materials a household recycles follow similar patterns.

Comparative assessment of life cycle impacts of various plastic waste management scenarios in Johannesburg, South Africa

PurposeLandfilling can result in a loss in revenue that would otherwise have been accrued from recycling plastic waste, loss in potential jobs, and groundwater contamination. Plastics in landfills may also eventually find their way into marine environments, where they can be damaging to animals. This work aims to establish the environmental sustainability of current plastic waste management practices in South Africa using the City of Johannesburg (CoJ) as a case study.MethodologyFive scenarios encompassing combinations of landfilling, mechanical recycling, incineration with energy recovery, gasification, and use of plastic waste in a cement kiln were assessed through an environmental Life Cycle Assessment (e-LCA). Scenarios were developed based on an extensive literature review, current practices in South Africa and Europe, and the country’s National Waste Management strategy, which aims to achieve “zero waste to landfill”. SimaPro 9.1.1 software and the Ecoinvent Database were used to assess the life cycle impacts of each scenario over seven impact categories. The ReCiPe endpoint method, Egalitarian version, was employed in determining the impact potentials. A sensitivity analysis was also carried out to evaluate the model’s robustness.Results and discussionOverall, the impact assessment results, including damage assessments and single score results, revealed that moving away from landfilling and combining mechanical recycling, incineration, gasification, and use of plastic waste (PW) as solid refuse fuel in a cement kiln is the least environmentally impactful scenario when managing plastic waste. Landfilling alone was the worst-performing scenario, resulting in adverse effects on human health, ecosystems, and resource depletion. This agrees with the waste hierarchy. On sensitivity analysis, the increase in transportation distances and reduction in market substitution factor in mechanical recycling did not change the ranking of scenarios despite reducing the net benefits to the environment. Including open dumping as an end-of-life scenario significantly increased the negative impact of the current plastic waste management scenario being practised in South Africa, while assuming a 100% mechanical recycling rate had the least environmental impact when compared to the other modelled scenarios.ConclusionsThe current plastic waste management practices in South Africa were found to be environmentally unsustainable based on the modelled scenarios, and a move away from landfilling is encouraged. The outcomes of this study will assist policymakers and other stakeholders in making informed decisions based on scientific evidence when formulating sustainability-related waste management policies.

Analysis of Optimal Solid Waste Recycling Policy: Evidence from U.S. Using Panel Data

Abstract We analyze how implementation of a market-based program of optimal recycling can be pursued and used to promote environmental quality. Presently in the U.S. economy, due to the relatively low private monetary costs of solid waste disposal, households and firms have little or no incentive to undertake recycling. As a result, most current recycling programs are apt to yield less than efficient outcomes. The paper offers a model for achieving an optimal level of recycling, and applies a combination of time-series and cross-sectional data to analyze and verify the potentials of an optimal recycling policy initiative toward an enhanced environmental management. JEL classification numbers: C33, Q24, Q28. Keywords: Recycling rate, Fixed and Random effects, Endogenous variables, Sample selection bias.

Impact of silica nanoparticles architectures on the photosensitization of O2 by immobilized Rose Bengal

Transforming light into chemical energy has been widely studied to design ecofriendly, cost-effective and sustainable synthetic approaches. The heterogenization of organic photocatalysts is a well-known strategy providing efficient solid supported catalysts. One of the most suitable solid as support is silica nanoparticles (NPs). This research note highlights the impact of silica nanoparticles morphology on a representative photochemical process that is the photooxidation of citronellol, involving oxygen sensitization. Three architectures of silica NPs were investigated: Nanospheres (NS), Core-Shell (CS) and Urchins (U). Their surfaces were functionalized with ammonium moieties allowing the immobilization of Rose Bengal (RB) by electrostatic interactions. The heterogenized RB on the various supports displayed different activities in the production of singlet oxygen, CS being the best support in terms of activity, recyclability and dye immobilization rate.

How much can chemical recycling contribute to plastic waste recycling in Europe? An assessment using material flow analysis modeling

Plastic recycling rate in Europe is low, urging developments in recycling technology and strategies to increase circularity. Mechanical recycling (MR) has been the reference recycling technology for years, but in the near future chemical recycling (CR) options are expected to contribute to improve plastic circularity. This study uses a material flow analysis (MFA) at European level to provide quantitative estimates of the contribution of CR technologies to plastic recycling. Ten most used polymer types from five sectors are selected. A status quo 2018 scenario is modelled and compared to five potential future scenarios (in 2030) of plastic waste treatment, including one that only looks at improved waste collection, sorting, and MR technologies and four exploring developments of CR options. The so-called ‘missing plastics’, i.e., plastic waste generated but currently not accounted for in statistics, is considered in one of the future scenarios. The MFA results are compared by calculating four circularity indicators namely end-of-life recycling rate (EoL-RR), plastic-to-plastic rate, plastic-to-chemicals rate, and plastic-to-fuels rate. The results indicate that in the most optimistic scenario the EoL-RR in 2030 is 73–80% (sum of plastic-to-plastic and plastic-to-chemical rates, excluding plastic-to-fuel rate), in which 41–46% is plastic-to-plastic from MR, 15–38% is plastic-to-plastic from CR and 19–35% is plastic-to-chemicals. The highest achievable plastic-to-plastic rate is estimated to be 61% (46% from MR and 15% from CR). In all future scenarios, the plastic-to-fuel rate is estimated to be 3–6%. The MFA results are also used to estimate potential recycled content availability in 2030, which suggest that closed-loop recycling and processing the ‘missing plastics’ will be necessary to achieve the targets.

Community composting strategies for biowaste treatment: methodology, bulking agent and compost quality

The European Union’s commitment to increase recycling and recovery rates of municipal solid waste requires significant changes in current waste management. Local governments are developing various strategies for treating the organic fraction of municipal waste (biowaste) via composting. Community composting centres (CCC), green waste collection, treatment points and community gardens are some of these new approaches. Population density and spatial distribution, together with the existence of community green areas, determine the location of the various infrastructures for recycling local biowaste. The composting process consumes high amounts of bulking agent (BA) necessary to provide the structure that allows, amongst other uses, biowaste aeration and microbial surface colonisation. Shredded green waste from parks, gardens and households can be used as BA in community composting and home composting. In this study, a total of 46 compost samples obtained from CCC with two types of handling were analysed: 22 samples treated by vertical flow (VF) and 24 samples treated by horizontal flow (HF). The HF model allowed better use of the volume of modular composting units and the VF model required less effort and time for the CCC operator. Mature, stable and high-nutrient-content composts were obtained with both models. These composts met the legal requirements to be used as an organic amendment, and they can be delivered to the participants or used in community gardens in the municipality.

Human health effects of recycling and reusing food sector consumer plastics: A systematic review and meta-analysis of life cycle assessments

Global transitions to circular economies of plastic could pose both risks and opportunities for human health. Life Cycle Assessment (LCA) can help to quantify possible health effects across plastic life cycles, syntheses of which could inform policy. This systematic review assessed LCA evidence for health effects of increased plastic recycling and reuse in the food sector. Scientific databases including Web of Science, Scopus, MEDLINE, Embase, Global Health, GreenFile and grey literature websites were searched for peer-reviewed LCA of consumer-level food sector plastics that compared virgin or single-use plastics with scenarios of increased recycling and reuse. Data on Human Health impacts and related midpoint impacts were extracted, converted to Disability-Adjusted Life Years (DALYs), and analysed using meta-regression. Forty-nine eligible LCAs were identified, only five of which related to low- and middle-income countries (China: n = 1 and Thailand: n = 4). Meta-regression showed strong evidence for a linear trend in reducing DALYs with increasing percentage recycled content compared to virgin plastic (Coefficient = −1.96E-5; 95% CI = −2.69E-5 to −1.24E-5; p < 0.0001) and increasing end-of-life recycling rate compared to landfill and/or incineration (Coefficient = −2.1E-5; 95% CI = −2.60E-5 to −1.63E-5; p < 0.0001), equating to almost a day of healthy life saved globally per tonne of plastic recycled. On average, reusable plastics reduced climate-related health impacts associated with single-use plastics after 30 uses. Global assessment was limited by data deficits, but meta-analyses suggested that health risks from linear economies of food sector plastics could be reduced by increasing recycling and reuse rates, though some reusable plastics would need to be used many more times than current norms. Encouraging greater geographical coverage in LCA, increasing uptake of health impact assessment methods, and incorporating emerging health data will strengthen future public health evaluations of circular economies.

Elevated physical weathering exceeds chemical weathering of clays during the Paleocene-Eocene Thermal Maximum in the continental Bighorn Basin (Wyoming, USA)

The Paleocene-Eocene Thermal Maximum (PETM) global warming event at ∼56 million years before present changed catchment weathering and erosion. Increased chemical weathering of silicate minerals is thought to be an important process removing CO2 from the atmosphere. However, changes in clay mineralogy can often be explained by enhanced erosion of catchment laterites during the event. Here, we investigate chemical and physical weathering and erosive flux changes through the PETM interval in the Bighorn Basin, Wyoming, a Laramide foreland basin, in a proximal continental-interior alluvial setting. These show an increase of detrital smectite with a lag time of 20-kyr after the main onset the PETM. The smectite increase continued for at least 50-kyr after the event. In-situ, post-depositional pedogenic clay mineral formation is similar between pre-PETM and PETM soil profiles, despite large macroscopic differences between soils that formed before and during the event. Drier, hotter summers during the PETM probably caused decreased vegetation cover that, in concert with more frequent and heavier rainstorms, intensified the erosion of smectite-rich Cretaceous bentonites on the margins of the catchment, which exceeded changes in chemical weathering within the catchment. The lagged response in reaching full PETM clay mineral values can be explained by the time required for upstream sediment to reach the catchment basin floodplain. The prolonged nature of smectite enhancement after the PETM event may again relate to signal propagation times that are now even longer due to lower fluvial recycling rates. Our results indicate that chemical weathering changes were probably superceded by enhanced physical weathering and clay-mineral transport from basin margins at this continental-interior study site.

Optimization of Municipal Waste Streams in Achieving Urban Circularity in the City of Curitiba, Brazil

The municipal solid waste (MSW) remains a great challenge in most cities of developing countries, as the majority of the generated waste is either not collected or is dumped in open uncontrolled non-engineered landfill sites, creating significant pollution due to the leakage of landfill leachate in the surrounding environment. In developing countries, a complete transition to a zero-landfill scenario is less likely to happen in the near future due to various socio-economic challenges. Therefore, the existing landfills in developing countries need holistic waste management thinking with more efforts on waste to energy conversions. This study highlights the challenges with existing MSW management practices of Curitiba, Brazil, and suggests some holistic and sustainable landfill management techniques. This is accomplished through the (i) identification of the suitable sites for setting up transfer stations (TSs), (ii) route optimization for MSW transportation, and (iii) analysis of the life expectancy of the existing landfill with waste valorization techniques for enhancing circularity of MSW of the city. The study has identified six potential TSs, making use of various geological criteria and constraints as suggested by the United States Environmental Protection Agency using GIS-based spatial analysis, which could save fuel cost of approximately 1.5 million Brazilian Real (BRL) per year for the solid waste transportation (from the source to the landfill site). This research has also made a value addition in this specific field with the preparation of a digitized road network map of the study region. Further, the sensitivity-based scenario analysis highlights that the lifespan of the existing landfill (until 2030) might be extended to 2058 if the city achieves the targeted recycling rate of 85% compared with the current rate of 23%. The results would be useful for policy-makers to adopt the crucial MSW scenario to achieve a circular economy in the waste management of the city of Curitiba.

Energy transition under mineral constraints and recycling: A low-carbon supply peak

What are the implications of primary mineral constraints for the energy transition? Low-carbon energy production uses green capital, which requires primary minerals. We build on the seminal framework for the transition from a dirty to a clean energy in Golosov et al. (2014) to incorporate the role played by primary minerals and their potential recycling. We characterize the optimal paths of the energy transition under various mineral constraint scenarios. Mineral constraints limit the development of green energy in the long run: Low-carbon energy production eventually reaches a plateau. We run our simulations using copper as the limiting mineral and we allow for its full recycling. Even in the limiting case of a 100% recycling rate, after five to six decades green energy production is 50% lower than in the scenario with unlimited primary copper, and after 30 decades, GDP is 3–8% lower. In extension scenarios, we confirm that a longer life duration of green capital delays copper extraction and the green energy peak, whereas reduced recycling caps moves the peak in green energy production forward.

High-performance and fully recyclable epoxy resins cured by imine-containing hardeners derived from vanillin and syringaldehyde

Increasing concerns about environmental protection have driven the rapid development of recyclable and sustainable thermosetting polymers. Herein, two biobased epoxy hardeners containing imine bonds were prepared from lignin-derived aromatic aldehydes (vanillin and syringaldehyde). The epoxy resins cured by these two hardeners showed comparable mechanical performances in comparison to traditional epoxy resins. Owing to the dynamic feature of incorporated imine bonds, both cured epoxy resins could be repeatedly reprocessed via hot pressing like thermoplastics, and were degradable in the amine solution. It is noteworthy that a closed-cycle chemical recycling process could be realized by utilizing the degradation products to prepare fresh epoxy resins. Notably, the flexural strength and modulus of the chemically recycled and thermally reprocessed epoxy resins were nearly 100% recovered. In addition, both cured epoxy resins showed acceptable glass-transition temperature, thermal stability and chemical resistance. Taken together, our work offered a simple method to develop biobased epoxy resins with versatile recyclability and high performance recovery rates.

The Impact of Globalization on the Rate of E-waste Recycling: Evidence From European Countries

The Impact of Globalization on the Rate of E-waste Recycling: Evidence From European Countries

An evaluation of environmental arrangement on recycling and contamination rate on a college campus.

An evaluation of environmental arrangement on recycling and contamination rate on a college campus.

Mass Balance Analysis of Integrated Municipal Solid Waste Management: The Jakarta Recycle Center Program Case Study

With the amount of waste increasing and landfill space becoming critical, the government has undertaken numerous measures to reduce waste, including creation of Integrated Solid Waste Management system through Jakarta Recycle Centre (JRC) Program. An integrated and sustainable waste management system will depend on both the physical and the governance components, with the physical aspect focusing on technical problems. To evaluate the physical aspect of JRC, the flow of the waste needs to be monitored and evaluated to see the success of waste separation and recycling system. This study employs mass balance analysis using data of waste in JRC facilities from January to December 2022. According to the study's findings, JRC system has a significant recycling rate which is around 46,43%. To improve the recycling rate, communication to residents about waste sorting process need to be enhanced. In order to reduce residue from sorting outcomes, it is also crucial to increase the ability and expertise of personnel in waste sorting.

A study on critical associations of media components on enhanced cellulase production from wild Trichoderma viride and cellulase immobilization on iron-oxide magnetic nanoparticles

Aim: The current study is a preliminary step towards enhancing the cellulase productivity in wild Trichoderma viride which will enable robust valorization of non-edible lignocellulosic biomass through co-generative enzymatic saccharification, specifically concentrating on influence of individual media components on biomass growth and cellulase productivity. Further, cellulase immobilization on iron-oxide magnetic nanoparticles was also achieved that can increase the shelf life of the enzyme. Methodology: The cellulase production in the wild Trichoderma viride was enhanced using media design and formulation. EDC {1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide} functionalized iron-oxide nanoparticles were chosen to act as carriers for cellulase immobilization. The binding efficiency and relative activity were measured in addition to optimal pH and temperature for cellulase bound iron-oxide nanoparticles. Further, the hydrolysis efficiency of immobilized cellulases was also measured after which it was subjected to consecutive hydrolytic cycles to calculate the recycle rate. Results: A maximum growth rate of 60 PCV (Packed cell volume) and total cellulase activity of 7.4 U ml-1 was obtained on media design and formulation. 82.5% binding efficiency was achieved on EDC functionalized iron-oxide magnetic nanoparticles which showed good stability at 5pH and 500C. There was 44.4% activity loss after 5 consecutive hydrolytic cycles which showed steady decline with increased cycle number and finally at the end of the 10th hydrolytic cycle, 22.2% of total relative activity was retained. Interpretation: Unprecedented total cellulase activity from a wild strain was obtained through media design. The stability of cellulases was further enhanced using iron-oxide magnetic nanoparticle immobilization. Key words: Cellulases, Immobilization, Iron-oxide magnetic nanoparticles, Submerged fermentation, Trichoderma viride

Portfolio Analysis of Clean Energy Vehicles in Japan Considering Copper Recycling

Several countries are moving toward carbon neutrality to mitigate climate change. The introduction of clean energy vehicles (CEVs) is a measure to offset the adverse effects of global warming. However, each CEV has its strengths and weaknesses. An optimal CEV portfolio must be formulated to create effective policies that promote innovative technologies and introduce them into the market. CEVs also consume more copper than gasoline vehicles. Copper is associated with supply risks, which most previous conventional studies have failed to address. Therefore, this study proposes a novel CEV optimization model for sustainable consumption of copper resources through recycling along with reduction of CO2 emissions. This study aims to analyze the optimal portfolio for domestic passenger vehicles and the assumed effects of copper recycling and usage reduction. For this analysis, this study set up scenarios for the recycling rate of copper contained in end-of-life vehicles and the reduction rate of copper used in newly sold vehicles. Our simulation results showed that increased recycling rates and reduced use of copper are necessary for the diffusion of battery electric vehicles. Furthermore, the simulation results indicated that if these improvements are not implemented, the deployment of fuel cell vehicles needs to be accelerated.