Concept Of Circular Economy Research Articles

8Rs for circular water and sanitation systems: Leveraging circular economy thinking for safe, resilient and inclusive services

To achieve their normative health, environmental and social objectives, water and sanitation services must be safely managed, inclusive and climate resilient. Meeting these imperatives presents a need and opportunity for innovative thinking about water and sanitation service systems. Circular economy concepts are being applied across a multitude of product and service sectors with the aim to facilitate regenerative flows of resources. Given the dependence on water resources, associated climate risks, and the generation of reusable waste products in water and sanitation service delivery, circular economy concepts can be usefully leveraged to drive sustainability outcomes. This article contributes a heuristic in the form of a conceptual framework for applying circular economy concepts in the design and delivery of water and sanitation services in diverse Global South contexts. The framework seeks to drive multiple outcomes relevant to water and sanitation initiatives: safely managed services, social inclusion, and climate resilience. Co-developed by an international research team applying a theoretical multiplicity approach and collaborative sensemaking, the heuristic takes the form of a suite of eight adapted circular economy ‘R strategies’ for water and sanitation. The R strategies were selected and articulated to reflect theory-based principles of circular economy, climate resilience and inclusion. They are intended to prompt thinking and action in pursuit of safely managed, climate resilient, inclusive water and sanitation services that align with the broader sustainability directions that circular economy narratives aspire to. The heuristic offers a conceptually rigorous, practical tool that can support collaborative, deliberative processes to realise the potential benefits of circularity in water and sanitation service systems.

Implementation of a performance management system for environmental sustainability in an industrial organization

Abstract The paper explores the implementation of process performance management systems in the automotive industry, specifically focusing on improving the assembly line of an organization within this sector thanks to the introduction of cobots in the line of manufacturing electronic modules used in car seat control systems. With an emphasis on environmental sustainability and circular economy (CE) concepts, the study investigates the positive effects of optimizing mechanical and electromechanical systems within the assembly line. Leveraging concepts such as KAIZEN and Gemba Kaizen, along with the guiding principles of Just-In-Time (JIT), Continuous Improvement and Automation with a Human Touch (JIDOKA), the research aims to elucidate the potential benefits of such enhancements. Key performance indicators (KPIs) including Overall Equipment Effectiveness (OEE), First Pass Yield (FPY), and scrap rates were considered. Rejects, primarily stemming from human error in part handling, emerged as the major challenge facing this assembly line. To address this issue, collaborative robots were introduced to automate part handling, replacing manual processes with precise and reliable automation. Before the implementation, the cycle time stood at 13.6 units, which was reduced to 12.5 units post-implementation, resulting in a significant increase in productivity equating to 3000 more parts produced per week. OEE increasing from 80% to 87.74%, FPY rising from 96.42% to 98.48%, and the scrap rate decreasing from 0.06% to 0.02%. By addressing inefficiencies at the assembly line level, organizations can achieve significant improvements in performance metrics while concurrently contributing to a greener and more sustainable future.

Circular Economy in Architecture: Reducing Waste and Promoting Reuse in Construction

This paper explores the concept of circular economy within the Architecture, Engineering, and Construction (AEC) industries. It examines the evolution of the circular economy framework from the traditional 4R model to more expansive 9R and 10R iterations. The study investigates the challenges and opportunities in implementing circular economy principles in Nigeria's AEC sector, considering its significant contribution to the country's GDP and potential for sustainable economic development. By analysing the relationship between construction activities and economic growth, this research aims to provide insights into the transformative potential of circular economy practices in AEC industry and its broader implications for national development.

Sustainable Exploitation of Wine Lees as Yeast Extract Supplement for Application in Food Industry and Its Effect on the Growth and Fermentative Ability of Lactiplantibacillus plantarum and Saccharomyces cerevisiae

Wine lees, the residue left behind after racking or bottling of wine, are predominantly composed of dead yeast cells, ethanol, phenolic compounds, and tartrates. Yeast extract (i.e., commercial yeast extract), a highly nutritious powder derived from commercially cultivated yeast biomass, is commonly used in nutrient media as a nitrogen source. In the context of by-product valorization, wine lees could potentially be used to produce a substitute for commercial yeast extract (CYE). In our study we investigated the growth and fermentative ability of two major winemaking microorganisms, Lactiplantibacillus plantarum and Saccharomyces cerevisiae, in culture media containing a wine lees yeast extract (WLYE) and a CYE. The effects of yeast extract type, concentration, and initial cell concentration (y0) on key kinetic parameters—maximum specific growth rate (μmax), lag phase duration (λ), and maximum cell concentration (ymax)—were evaluated. For L. plantarum, the results showed that using a WLYE led to similar kinetic parameters to those obtained with a CYE, with λ being unaffected by y0 in samples containing a WLYE. For S. cerevisiae, simultaneous addition of both yeast extracts led to increased μmax values (up to 0.136 h−1) compared to individually added yeast extracts, although this negatively affected λ and ymax. Current research on wine lees is mainly focused on using them as a substrate to produce valuable metabolites through fermentation, overlooking the potential industrial applications of the nutrient-rich autolysate. The findings of this study appear promising for the holistic valorization of wine lees, contributing towards the concepts of sustainability and circular economy.

Aroma enhancement of dealcoholized wines using enzyme treatment and glycosidic aroma precursors

This research has studied the treatment of dealcoholized wines with glycosidic enzymatic preparation and glycosidic aroma precursors extract isolated from aromatic grapes in order to enhance the aroma profile of non-alcoholic white wines. The effect of the addition of the precursors extract and the enzymatic treatment was studied after 15 and 30 d of storage, using dealcoholized wine as control. The analysis of free and bound volatile compounds was carried out by gas chromatography-mass spectrometry (GC-MS) after isolation using solid-phase extraction (SPE). The application of multivariate statistical analysis confirmed differences in the free and bound volatile profile of the studied samples when applicated the different treatments after 15 d and 30 d of storage. The combination of both treatments increased in a significant way the aromatic profile of Verdejo dealcoholized wine, showing high concentrations of terpenic and bencenic compounds due to the addition of precursors extract from an aromatic grape variety. This brings to light that this technique could be considered as a possible way of enhancing the aroma profile of dealcoholized wines in La Mancha region, as well as a way of using by-products from the wine industry, thus contributing to the concept of circular economy.

The Integral Management of the Wastewater Treatment Sector in Mexico Using a Circular Economy Approach

Wastewater treatment must be proactive and sustainable to facilitate an increase in the circularity of water. Therefore, the current approach, based on a linear cycle, must be replaced with a circular economy concept that implements strategies to address the different byproducts in the wastewater treatment sector. In recent years, Nuevo León, Mexico, has encountered high water stress levels, with its main water bodies presenting their lowest levels ever recorded. This study was focused on the wastewater treatment plant Monterrey, which treats the largest volume at the state level. Throughout its operation process, it generates different potential byproducts that are yet to be harnessed to fully. This study developed three proposals using a circular economy approach: the treatment of water for the industrial sector, the use of residual sludge as an organic fertilizer, and the cogeneration of energy from biogas. These proposals can potentially generate benefits regarding the three pillars of sustainability, yielding a closed cycle in the wastewater treatment sector at the national level.

Analysis of the Circular Economy's Implementation at Maggot House Mengger Sub-District Bandung City

In 2023, the city of Bandung faced serious problems because the Sarimukti landfill caught fire and the city of Bandung experienced a "waste emergency". One of the programs launched is the construction of maggot houses in every sub-district in Bandung City with a target of processing 1 ton of organic waste/day. Mengger Sub-district is one of the sub-districts that received assistance to build maggot house. The land area of ​​the maggot house is 150 m2, managed by 4 officers. This study aims to identify various problems that must be resolved first so that the circular economy concept can be implemented at the Mengger Maggot House. The study was carried out by conducting observations, detailed surveys and in-depth interviews with various stakeholders in Mengger Sub-district. Observations were carried out to see the level of compliance of residents in sorting, a detailed survey was carried out on the waste collection and processing system at the maggot house, and in-depth interviews were conducted with assistants from Bandung City Environmental Service Office (DLH), maggot buyers, sub-district officials, maggot house officers, neighbourhood (RT) and hamlet (RW), and waste collector. Based on the results of observations, it was found that only some residents carry out sorting consistently, a collection system already exists in each RT/RW but they have not implemented a segregated waste collection system, and there is no system for transporting waste from the RW to the maggot house so that the amount of organic waste entering the maggot house is still low, no electricity and clean water, no choppers, leaks in the fly cage, and no diversification in maggot products. Through various socialization activities and Focus Group Discussions with all stakeholders, various agreements were obtained to resolve various problems at the Mengger Maggot House.

Recovery of pure PET from wool/PET/elastane textile waste through step-wise enzymatic and chemical processing

Textile waste is mostly incinerated because few recycling processes are available to recover valuable materials. In this work, a feasible chemo-enzymatic recycling process of wool/polyethylene terephthalate (PET)/elastane blends to recover pure PET is for the first time successfully demonstrated. Two novel enzyme formulations were selected for wool hydrolysis, whereas the recovered amino acids were quantified using high-performance liquid chromatography and two assays (Ninhydrin and Folin–Ciocalteu). Kinetic studies on the amino acid formation alongside reaction observations by scanning electron microscopy proved sufficient removal of wool within 8 hours with the new enzyme formulation, marking an acceleration compared to previous studies. Finally, elastane was separated with a non-hazardous solvent to obtain pure PET. Tensile tests on the recovered PET fibres reveal only slight changes through the enzymatic treatment and no changes induced by the applied solvent. The enzyme formulation was successfully tested on five different post-consumer wool/PET textile waste samples. This valorization approach enhances the circular economy concept for textile waste recycling.

A review of the engineered treatment of red mud: Construction materials, metal recovery, and soilization revegetation

Red mud, known as bauxite residue, is an alkaline solid waste generated during alumina production. Globally, the stockpile of red mud is about 3 billion tons and is increasing at a rate of 150 million tons per year. The global production of red mud is mainly distributed in China (28.2 %), Oceania region (22.4 %), South America (14.6 %), Europe (12.9 %), and North America (8.8 %). The increasing stockpile of red mud has posed a huge challenge to safe disposal while restricting the development of the alumina industry. The comprehensive utilization of red mud still needs green, efficient, and massive consumption methods. This work gives a review of the engineered treatment of red mud, including the characteristics and threats, as well as the engineered application through construction materials, metal recovery, and soilization revegetation. For red mud with a high content of metals, resource recovery of valuable metals and rare earth elements is a preferred choice, meeting the circular economy concept. Recovery of valuable metals from red mud can be achieved by magnetic separation, hydrometallurgy, and bioleaching. Hydrometallurgy is promising for recovering valuable metals such as Fe, Al, V, Ti, and rare earth elements, and the recovery is up to 99 %. Construction materials such as cement, geopolymers, and ceramics is an efficient alternative for the massive consumption of red mud, and the high-performance concrete with the compressive strength (129.5 MPa) can be obtained. This strategy is limited by the low price of construction materials, the lowered quality by alkaline components, and potential threats of toxic elements in red mud. Soilization of red mud with ecological restoration is promising for the sustainable management of red mud dam. To accelerate the process of red mud soilization, amendments such as gypsum, organic matter, and microorganisms can be added to neutralize red mud (lowering pH from 10 to 12 to near 7), promote the formation of agglomerates, and provide nutrients, promote the conversion of red mud into soil-like substrate. The phytoremediation of red mud can be realized after effective regulation, finally realizing vegetation establishment of red mud. This work provides technological and practical guidance for the engineered disposal of red mud.

A novel approach to enhance high optically active L-lactate production from food waste by landfill leachate

The recycling of food waste (FW) through anaerobic fermentation into lactic acid (LA), with two isomers L-LA and D-LA, aligns with the principles of a bio-based circular economy. However, FW fermentation is often limited by competing pathways, acidification inhibition, and trace metals deficiency. This study investigates the introduction of landfill leachate, containing buffering agents (ammonia) and trace metals, into FW fermentation. Various dosages of landfill leachate, ranging from 90 (LN-90) to 450 mg/L (LN-450) based on inclusive ammonia calculation, were employed. Results showed that LA production peaked at 43.65 ± 0.57 g COD/L in LN-180 on day 6, with a high optical activity of L-LA at 92.40 ± 1.15 %. Fermentation pathway analysis revealed that landfill leachate amendment enhances hydrolysis (as evidenced by increased activity of amylase, α-glucosidase, and protease) and glycolysis (resulting in enhanced utilization of carbohydrates and glucose). The inclusive ammonia in leachate plays a crucial role as a buffer, maintaining optimal pH conditions (5–7), thereby reducing volatile fatty acid production and thus intensifying LA orientations. The increased activity of L-lactate dehydrogenase (L-LA generation) and decreased NAD-independent lactate dehydrogenase (LA consumption) in properly dosed leachate further explained the high accumulation of L-LA. Dominance of lactic acid bacteria, including Streptococcus, Enterococcus, Klebsiella, Bifidobacterium, Bavariicoccus, and Lacticaseibacillus, accounted for 91.08% (LN-90), while inhibitory effects were observed in LN-450 (4.45%). Functional gene analysis further supported the enhanced glycolysis, L-lactate dehydrogenase, and nitrogen assimilation. Finally, a network analysis indicates a beneficial effect on the genus Enterococcus and Klebsiella by landfill leachate addition. This study demonstrates the efficiency of utilizing landfill leachate to enhance LA recycling from FW fermentation, aligning with the concept of circular economy by transforming waste into valuable resources.

The Concept of Circular Economy in Wastewater Management along the Slovenian Coast

The Concept of Circular Economy in Wastewater Management along the Slovenian Coast

Innovative applications for civil structures of the Municipality of Finiq using topology optimization and additive manufacturing

The Municipality of Finiq is located in the South of Albania, inside the Vlora’s County and it is just 9 kilometers from the City of Saranda. The village of Finiq is particularly important because of the presence of The Archaeological Park at the top of the hill, which has received this status in 2005. Inside the Municipality there are a lot of attractive sites, such as The Blue Eye, the main lake of the Municipality, the Monastery of St. Nikolla, located in Mesopotam, etc., making the Municipality dominated by nature (e.g. long lots of fields, hills, rivers, and lakes) and monuments that represent the cultural heritage of the municipality. Within this context some villages arise, which are characterized mostly by infrastructures and civil structures in reinforced concrete, this is strictly due to the fact that these buildings were built in the last decades, instead of what can be observed outside the Municipality, e.g. Gjirokaster. The structures of the Municipality’s villages are mostly under construction, some are unfinished, abandoned, or damaged. Despite the trend of reinforced concrete building construction does not tend to decrease, the world of civil engineering is trying to find new solutions, that are also environmentally compatible and sustainable. This necessity is motivated by the fact that the industry of concrete is the most energy-intensive industry in the world. In particular, two main aspects that the research is investigating to address these issues are the use of new manufacturing technologies, e.g. 3D printing, combined also with new computational methodologies, such as topology optimization, and the development of innovative materials, e.g. architected meta-materials. The aim of this paper is to suggest innovative approaches and methodologies in the fields of structural mechanics for civil structures. The proposed approach wants to be applied not only to buildings under construction but also to the existing ones, which could be restored or completed in some specific structural and non-structural parts. In particular, we propose new topology optimization strategies that allow us to obtain an efficient material layout with maximized performance under predefined constraints. This design method is not only used to optimize the structural behavior of the structures but also for the optimization of specific features of the structures, e.g. thermal and acoustic optimization. The interest in this computa- tional method has grown due to the development of innovative techniques of manufacturing, i.e. additive manufacturing. In particular, there are different types of manufacturing that could be used for construction, which differ with respect to the material adopted, e.g. steel, concrete, or stone-like materials. The proposed method will be supported by several examples to under- stand the potentiality of the approach considering the role of additive manufacturing. Indeed, the development of new manufacturing methods has reduced the distance between the Theoretical and practical representation of the optimized layout. In conclusion, the proposed approach allows to obtain novel 3D printable structures characterized by a more efficient use of material, contributing to the realization of the concept of circular economy within the construction industry.

Sustainable Supply Chain Management in Enhancing Circular Economy Performance: Study Case in Indonesia

The concept of circular economy entails the reduction of resource inputs and the reclamation of waste in order to tackle the environmental, economic, and social challenges that sprang from the persistence of the linear economic model. Implementing a circular economy certainly has its own challenges. One of which is to find a sustainable supply chain. Sustainable supply chains are designed and man¬aged by combining practices responsible for the environment and society throughout the life cycle of a product or service. This is possible to achieve through good collaboration between supply chains and having a supply chain design with a sustainable concept. Thus, this research discusses the effect of sustainable supply chain management on circular economy performance mediated by circular economy capability. The objects of this research are 82 courier service companies on Java Island. This research employed quantitative design. The data collection method involved distributing online questionnaires to middle – top managers as respondents. The results show that sustainable supply chain management has a positive effect on environmental performance, then sustainable supply chain management has a positive effect on financial performance. Furthermore, circular economy capability partially mediates the correlation between sustainable supply chain management and environmental performance, and partially mediates the correlation between sustainable supply chain management and financial performance. This research conveys the direction of further research in the same re¬search context.

How Do LCA Studies Support CE? A Systematic Case Study Review

This study explores the integration of Circular Economy (CE) principles within the framework of Life Cycle Assessment (LCA), a foundational methodology in industrial ecology aimed at enhancing product sustainability. With CE offering a roadmap towards ecological sustainability within economic systems, the research examines the extent to which conventional LCA studies align with CE principles across diverse industries classified by the International Standard Industrial Classification (ISIC). Analyzing 282 LCA studies, the investigation identifies a limited incorporation of CE concepts. Most studies inadequately address CE in their goal and scope, lack CE-specific data in inventories, predominantly focus on basic recycling strategies, overlook CE-specific indicators, neglect CE considerations in sensitivity analyses, and omit CE-related recommendations in conclusions. These findings underscore the necessity for a more robust integration of CE principles within LCA methodologies, emphasizing CE measures as pivotal drivers for enhancing product environmental performance across industries.

Pengelolaan limbah rumah kemas sayur melalui produksi pupuk organik cair

Background: The growth of the agricultural sector in Cipanas District, Cianjur Regency, West Java has increased the production of organic waste from vegetable packaging houses. This study aims to explore the method of converting vegetable waste into Liquid Organic Fertilizer (POC) for waste management and sustainable agriculture. Methods: This descriptive study evaluated the process of converting vegetable waste into POC in Cipanas District. The process includes soaking rice grits, mixing ingredients (rice soaking water, brown sugar solution, coconut water, vegetable waste), anaerobic fermentation for three weeks with periodic stirring, and harvesting. Findings: The study resulted in a description of the process of making POC from vegetable waste. POC has the potential to improve soil fertility holistically (physically, chemically, biologically) and has been proven effective in increasing the productivity of various types of vegetables. Conclusion: Utilization of vegetable waste as POC offers a sustainable solution for waste management and environmentally friendly agriculture. Although there are challenges in quality standardization and infrastructure, its economic potential and long-term benefits make this approach worthy of consideration in future agricultural strategies. Novelty: This study highlights the potential use of vegetable waste from packaging houses in Cipanas for POC production, integrating the concept of circular economy in agricultural waste management and the development of sustainable agricultural practices.

Bioremediation of Brilliant Green cationic dye from water using Nutraceutical Industrial Coriander Seed Spent as an adsorbent: adsorption isotherms, kinetic models, and thermodynamic studies.

The article details a feasibility study of removing Brilliant Green (BG), a mutagenic dye from an aqueous solution by adsorption using low-cost coriander seed spent as a by-product in the nutraceutical industry. The study includes an analysis of the parameters that affect the adsorption process. The variables that have been identified include pH, dye concentration, process temperature, adsorbent amount, and particle size of the adsorbent. To obtain information on the adsorption process and to design the mechanism of the adsorption system on experimental equilibrium, 10 isotherm models, namely, Langmuir, Freundlich, Jovanovic, Dubinin-Radushkevich, Sips, Redlich-Peterson, Toth, Vieth-Sladek, Brouers-Sotolongo, and Radke-Prausnitz were applied. It was discovered that the experimental adsorption capacity, qe, was roughly 110mgg-1. The result has a maximum adsorption of 136.17 mgg-1 as predicted by Dubinin-Radushkevich isotherm. Diffusion film models, Dumwald-Wagner and Weber-Morris models, and pseudo-first- and second-order models, were used to determine the adsorption kinetics. It was realized that the adsorption kinetics data fit into a pseudo-second-order model. Thermodynamic analysis with a reduced enthalpy change suggests a physical process. The values of the thermodynamic parameters ΔG0, ΔH0, and ΔS0 demonstrated an endothermic and nearly spontaneous process of adsorption. The small valuation of ΔH0 specifies that the process is physical. FTIR spectroscopy and SEM imaging were used to confirm that the BG dye had been adsorbing on the adsorbent surface. The study concludes that NICSS is an effective adsorbent to extract BG dye from wastewater solutions, offers insights into numerous dye and adsorbent interaction possibilities and indicates that the process can be scaled to fit into the concept of circular economy.

Transforming discarded walnut green husk into a resource of valuable compounds for colored bioactive textiles with a focus on circular economy concept

This study takes a new look at a circular economy concept for discarded walnut green husks. Their ethanol extract was prepared and characterized using RP-HPLC, then diluted with water and employed for dyeing and/or functionalizing different fabrics. A diluted extract can dye wool (WO), cotton (CO), cellulose acetate (CA), and polyamide (PA) at pH 4.5. Extract:water ratio of 10:40, 65 °C and 75 min and extract:water ratio of 15:35, 45 °C, and 60 min were found suitable for dyeing WO and CA, respectively. Dyed WO and CA exhibited color strength values of 29.0 and 9.2, and excellent antioxidant activity (>97 %) before and after washing, and a significant level of efficacy against S. aureus. CA possessed excellent (5) and very good (4) color fastness to rubbing in a dry and wet state, respectively. WO showed very good (4) and good to very good (3–4) color fastness to rubbing in a dry and wet state, respectively. CO and PA displayed excellent antioxidant activity, with CO also exhibiting significant antibacterial activity against S. aureus even after washing. Moreover, the same dyebath can be reused for up to four dyeing cycles, enabling obtaining bioactive WO and CA fabrics in various brown shades suitable for different applications. Cytotoxicity assay confirmed the non-cytotoxic nature of dyed and washed CA, PA, and CO fabrics. Bioactive WO, CO, CA, and PA fabrics can be considered for the production of wound dressing, performance clothes, and tights for people with sensitive skin. Finally, this paper sheds new light on a novel circular economy concept since collected husks’ solid parts that remained after extraction were converted into activated carbon, which was then used for the preparation of supercapacitor having a specific capacitance of 144–275 F/g at current densities 0.1–2.0 A/g.

The hidden concept and the beauty of multiple “R” in the framework of waste strategies development reflecting to circular economy principles

There are numerous unresolved research questions, along with ongoing debates, regarding how to achieve a circular economy and at what level. The forthcoming circular economy standard (ISO 59000 framework, ISO59010) as a result from the ISO/TC 323, from the International Organization for Standardization (ISO) aims to offer global implementation pathways using a unified technical language. The most challenging aspect of circularity, whether viewed scientifically, technically, and/or legislatively, is how to enhance prosperity while reducing reliance on primary materials and energy to achieve climate neutrality by 2050, thereby aiding the EU in achieving a successful and equitable transition towards a sustainable future. Strategies in the framework of waste management and circular economy are essential and needed to reduce the impact of several processes on the environment through product, processes, and corporate policies using green applicable sustainable resources and environmental management systems. In addition, “measuring something that is not there” is very complex and not fully comprehensible, not clear and not tangible from organizations, researchers, policy makers and citizens. The willingness and ability of individuals or organizations to take actions towards a low-carbon society involves grappling with various perspectives, such as social norms and economic viability. Circular economy is considered a tool in combating climate change and implementing climate mitigation (as well as adaptation) measures. Moreover, to date, there has been no common scientific or technical language for the application of the circular economy concept. This paper highlights the multitude of “Rs” beyond the well-known (3Rs) Reduce-Reuse-Recycle pattern, which can be applied in various contexts to assist SMEs (Small and Medium Enterprises), organizations and even citizens successfully adopt circular economy principles. Is also explores how these “Rs” can be utilized to measure intangible aspects (something that is not there). The results indicate that more than 55Rs exist which directly involved in the circular economy framework, also considering waste management strategies. The findings of this study reveal the existence of over 100 “Rs” beyond the well-known principles of “reduce, reuse, recycle,” each playing a distinct role in the development of strategies aimed at addressing waste management issues and advancing circularity towards a low-carbon society. Furthermore, the results could be useful for any policy makers, consultants, engineers, practitioners, urban planners, academics etc., in order to develop, apply, monitor, measure and improve any strategy such as circular economy strategy, waste prevention, zero waste, reuse, reduce, energy recovery etc., in the framework of circular economy principles, solid waste management and beyond.

Investigating the effect of circularity index on a closed loop supply chain with multi-shipment policy

Environmental sustainability has emerged as a crucial aspect for every business, as the wastage of used products greatly contributes to greenhouse gas emissions and environmental hazards. Adopting the circular economy concept is essential to address this problem. This approach prioritizes reliability and re-manufacturability, aiming to simultaneously reduce waste and enhance sustainability and profitability. In this context, the proposed model introduces a sustainable closed-loop supply chain model wherein the manufacturer oversees the production process and delivers requested batches to the retailer under the single order and multi-shipment policy. The model incorporates the notion of circularity, quantified by a circularity index representing the degree to which the product's circularity level. The level of product circularity can be enhanced by material choice, supplier selection, and innovative design while manufacturing. The model being presented aims to maximize the total integrated profit of the closed-loop supply chain system by optimizing the number of shipments as well as the circularity index. It is evident from the analysis that the circularity index significantly influences profits and environmental sustainability by increasing product demand and extending product life cycles. Notably, the numerical example provided in the model illustrates that accounting for the effects of the circularity index results in an optimal profit up to 5% higher compared to scenarios where such effects are not considered.

Plastic waste management in urban areas: Key takeaways from the “Send Plastic Home” project in Bangkok, Thailand

This study evaluates the plastic waste recycling program, named “Send Plastic Home,” tailored for urban areas in Thailand. Thirteen strategically located plastic drop-off points were implemented, and their effectiveness was assessed using the Productivity Index (PI). In-depth interviews and group discussions were conducted to identify key stakeholders and estimate the Social Return on Investment (SROI) associated with the project. Moreover, the environmental impacts of various plastic waste management scenarios were investigated and compared. To improve the PI of drop-off points, pass-through points for smaller amounts of plastic and drive-through points for bulk returns are recommended. Increasing drop-off points in highly populated areas, coupled with effective multi-channel public relations, would be beneficial. The current plastic waste management approach, combining recycling and waste-to-energy methods, yields commendable environmental benefits, particularly in mitigating marine aquatic ecotoxicity. With a collected plastic waste volume of 22,135 kg, greenhouse gas emissions and waste management costs are minimized by 27 tonCO2eq and 1803 USD, respectively. The program operates effectively, as evidenced by an impressive SROI ratio of 8.45. These findings provide a data-driven foundation and actionable insights for the design and implementation of more efficient plastic waste collection infrastructures in urban environments, aligning with the circular economy concept.