Drivers of Solid Waste Segregation and Recycling in Kampala Slums, Uganda: A Qualitative Exploration Using the Behavior Centered Design Model.

Solid-waste management is a challenge in many cities, especially in low-income countries, including Uganda. Simple and inexpensive strategies such as solid-waste segregation and recycling have the potential to reduce risks associated with indiscriminate waste management. Unfortunately, these strategies have not been studied and adopted in slums in low-income countries. This cross-sectional qualitative study, therefore, used the behavioral-centered design model to understand the drivers of recycling in Kampala slums. Data were coded using ATLAS ti version 7.0, and content analysis was used for interpreting the findings. Our findings revealed that the study practices were not yet habitual and were driven by the presence of physical space for segregation containers, and functional social networks in the communities. Additionally, financial rewards and awareness related to the recycling benefits, and available community support were found to be critical drivers. The availability of infrastructure and objects for segregation and recycling and the influence of politics and policies were identified. There is, therefore, need for both the public and private sector to engage in developing and implementing the relevant laws and policies on solid waste recycling, increase community awareness of the critical behavior, and create sustainable markets for waste segregated and recycled products.

Recovery material from a new designed surgical face mask: A complementary approach based on mechanical and thermo-chemical recycling.

The usage of disposable face mask to control the spread of COVID-19 disease has led to the alarming generation of a huge amount of plastic waste in a short span of time. On other hand, face masks are made of high-quality thermoplastic polymers that could be recovered and converted into valuable products. The aim of this study is to investigate a complementary approach for the recycling of face mask in lab-scale plants: the mechanical recycling of the filter in polypropylene (PP) and the chemical recycling of the whole face mask. For this purpose, a new designed surgical face mask was chemically and physically characterized. The results shows that the face mask was composed of 92.3 wt% high grade PP (filter), very similar to virgin PP but with a high melt volume index (MVI, 385 cm3/10 min) due to its non-woven manufacturing. The PP from face mask was mixed with recycled virgin PP in order to obtain a MVI suitable for the extrusion process and recycled as filament for 3D printing. This filament was used to print a specimen with a very similar visual quality of that printed with a commercial PP filament. Simultaneously, the whole face mask underwent a pyrolysis process to produce new feedstocks or fuels. Low-cost catalysts derived from coal fly ash (CFA) were employed to enhance the production of light hydrocarbons. In particular, the synthetized acid X zeolite (HX/CFA) improved the yield of light fractions up to 91 wt% (79 wt% for thermal pyrolysis) and the quality of the light oil with the 85% of C6-C10 (55% for thermal pyrolysis). Furthermore, HX/CFA decreased the degradation temperature of PP to 384 °C versus 458 °C of thermal cracking.

Upcycling face mask wastes generated during COVID-19 into value-added engineering materials: A review.

Billions of disposable face masks (i.e., single-use masks) are used and discarded worldwide monthly due to the COVID-19 outbreak. The immethodical disposal of these polymer-based wastes containing non-biodegradable constituents (e.g., polypropylene) has provoked marked and severe damage to the ecosystem. Meanwhile, their ever-growing usage significantly strains the present-day waste management measures such as landfilling and incineration, resulting in large quantities of used face-covering masks landing in the environment as importunate contaminants. Hence, alternative waste management strategies are crucially demanded to decrease the negative impacts of face mask contamination. In this venue, developing high-yield, effective, and green routes toward recycling or upcycling face mask wastes (FMWs) into value-added materials is of great importance. While existing recycling processes assist the traditional waste management, they typically end up in materials with downgraded physicochemical, structural, mechanical, and thermal characteristics with reduced values. Therefore, pursuing potential economic upcycling processes would be more beneficial than waste disposal and/or recycling processes. This paper reviews recent advances in the FMWs upcycling methods. In particular, we focus on producing value-added materials via various waste conversion methods, including carbonization (i.e., extreme pyrolysis), pyrolysis (i.e., rapid carbonization), catalytic conversion, chemical treatment, and mechanical reprocessing. Generally, the upcycling methods are promising, firming the vital role of managing FMWs' fate and shedding light on the road of state-of-the-art materials design and synthesis.

Deep convolutional neural networks for construction and demolition waste classification: VGGNet structures, cyclical learning rate, and knowledge transfer.

The sorting of Construction and Demolition (C&D) waste is a critical step to linking the recycling system and to the macro prediction, which helps to promote the development of the circular economy. Moreover, the effective classification and automated separation process will also help to stop the spreading of pathogenic organisms, such as virus and bacteria, by minimizing human intervention in the sorting process, while also helping to prevent further contamination by COVID-19 virus. This study aims to develop an efficient method to sort C&D waste through deep learning combined with knowledge transfer approach. In this paper, CVGGNet models, that is four VGG structures (VGGNet-11, VGGNet-13, VGGNet-16, and VGGNet-19), based on knowledge transfer combined with the technology of data augmentation and cyclical learning rate, are proposed to classify ten types of C&D waste images. Results show that 2.5 × 10-4, 1.8 × 10-4, 0.8 × 10-4, and 1.0 × 10-4 are the optimum learning rate for CVGGNet-11, CVGGNet-13, CVGGNet-16, and CVGGNet-19, respectively. Knowledge transfer helped shorten the training time from 1039.45 s to 991.05 s, and while it improved the performance of the CVGGNet-11 model in training, validation, and test datasets. The average training time increases as the number of the layers in the CVGGNet architecture rises: CVGGNet-11 (991.05 s) ˂ CVGGNet-13 (1025.76 s) ˂ CVGGNet-16 (1090.48 s) ˂ CVGGNet-19 (1337.81 s). Compared to other CVGGNet models, CVGGNet-16 showed an excellent performance in various C&D waste types, in terms of accuracy (76.6%), weighted average precision (76.8%), weighted average recall (76.6%), weighted average F1-score (76.6%) and micro average ROC (87.0%). In addition, the t-distributed Stochastic Neighbor Embedding (t-SNE) approach can reduce the dataset to a lower dimension and distinctly separate each type of C&D waste. This study demonstrates the good performance of CVGGNet models that can be used to automatically sort most of the C&D waste, paving the way for better C&D waste management.

Circular economy strategy and waste management: a bibliometric analysis in its contribution to sustainable development, toward a post-COVID-19 era.

A descriptive analysis of 416 documents was performed using bibliometric techniques, in order to gather existing knowledge in circular economy focusing on waste management (2007-2020). The results of this study indicate that annual scientific production increased 94% in the last 5 years, highlighting the countries of Italy, Spain, the UK, China, Brazil, and India. Between the most cited documents stand out those related to calorific value of municipal solid waste and waste to energy technologies for achieving circular economy systems. The conceptual analysis indicates strong linkage between circular economy and sustainable production, waste management, and recycling. Emerging research trends evolved from processes and industry-oriented approach (2017) toward waste management, recycling, and circular economy (2019) and sustainable development and urban solid waste (2020). The analysis reveals five dominant circular economy and waste research themes: (1) greenhouse gases; (2) circular economy, waste management, and recycling; (3) life cycle; (4) waste treatment; and (5) anaerobic digestion and recovery; trends research are related to policy interventions, and enforcement of authorities' regulations to foster circular economy transition, increase the use of practices of recycling and reusing, as well as discourage a growing consumption culture. Results found denote the challenge represented by the implementation of comprehensive policies in circular economy. The above being a key alternative for green recovery in response to the current COVID-19 pandemic.

Why is the generation of packaging waste from express deliveries a major problem?

The rapid growth of the express delivery industry resulted in the explosion of packaging waste with a wide range of direct and indirect environmental consequences. Until recently, little attention was given to this topic, but e-commerce and the associated growth of packaging waste exploded with the COVID-19 pandemic. Even though the phenomenon is only little to moderately documented, the waste problems in express delivery are recognized and caused by excessive packaging, lack of recyclability of the packaging material, and the low motivation of consumers to recycle. Key research, policy, and educational actions to reduce the environmental impacts of the fast-growing express delivery industry are discussed in this short discussion article.

Examining challenges and multi-strategic approaches in waste management during the COVID-19 pandemic: A systematic review.

The COVID-19 pandemic has a negative impact on the environment. Waste generation and improper management during the COVID-19 pandemic posed a major threat to human health and the environment. Irregular and improper waste collection, handling, suspension of waste recycling and unsanitary disposal were all important issues in the processing and management of generated waste. This study emphasised a systematic review and content analysis to categorise all types of waste management (WM) during the COVID-19 pandemic to accomplish a well understanding of the relation between the COVID-19 pandemic and its impacts on WM within the literature. In this systematic review, a number of published papers on different aspects of WM during March 2020 to February 2021 were considered in order to identify major challenges in handling WM during the pandemic time and highlight multi-strategic approaches suggested. A content analysis of the 58 relevant papers was carried out by incorporating different types of WM at local as well as global scales. The present review results revealed that the COVID-19 has impacted the quantity and composition of waste, and the crisis caused by the pandemic has also altered the nature of global WM system. A comprehensive analysis on how the systems of WM were affected through the advancement of COVID-19 and what would be the healthier solutions was also highlighted in this systematic review. The results of this systematic review would be beneficial for better policymakers to holistically address potential future pandemics, if any.

Facemasks and ferrous metallurgy: improving gasification reactivity of low-volatile coals using waste COVID-19 facemasks for ironmaking application.

The global pandemic response to COVID-19 has led to the generation of huge volumes of unrecyclable plastic waste from single use disposable face coverings. Rotary hearth furnaces can be used to recover Zn and Fe from non-recyclable steelmaking by-product dusts, and waste plastic material such as facemasks could be utilized as a supplementary reductant for the rotary hearth furnace (RHF), but their fibrous form makes milling and processing to appropriate sizing for RHF application extremely challenging. A scalable method of grinding facemasks to powder by melting and mixing with Welsh coal dust reported herein provides a solution to both environmental challenges. The melt-blended PPE/coal dust shows a dramatically improved CO2 gasification reactivity (Ea = 133-159 kJmol-1) when compared to the untreated coal (Ea = 183-246 kJmol-1), because of improved pore development in the coal during the pyrolysis stage of heating and the catalytic activity of the CaO based ash present in the facemask plastic. The results are promising for the application of waste facemasks in recycling steelmaking by-product dusts in rotary hearth furnaces and may also be suitable for direct injection to the blast furnace subject to further study.

Waste recycling policies and Covid-19 pandemic in an E-DSGE model.

Among the environmental problems of the 21st century, waste production and management are particularly pressing. Despite policy efforts, waste volumes are still increasing worldwide and landfilling remains the main disposal option in several parts of the world. Together with the huge environmental impacts of the large amounts of waste landfilled, it would be possible to save enormous amounts of resources improving reuse and recycle options. The impact of the COVID-19 outbreak has been significant also in the waste cycle, leading to an increase in the amount of non-recyclable consumption in response to sanitary needs, as well as to new consumption practices. On the basis of these considerations this paper aims at analysing: (i) the short run impact on output, consumption and health of appropriate waste policies aimed at reducing non-recyclable waste production, and (ii) to highlight the mechanics triggered by an exogenous pandemic event in terms of waste management, environmental and health impacts. To these ends, we adopt an E-DSGE approach. Our results confirm the relevance of policies and consumers' preferences in driving waste management towards a circular economy transition. More importantly, our (to our knowledge) novel analysis suggests the existence of a trade-off between environmental quality and health in the presence of a pandemic event, suggesting the need to increase preparedness to such events, in order to avoid relying on "emergency approaches", based on resorting to increases in non-recyclable consumption types (e.g. single use plastics).

Impact of COVID-19 lockdown measures on waste production behavior in Lisbon.

The recent restrictions on mobility and economic activities imposed by governments due to the COVID-19 pandemic have significantly affected waste production and recycling patterns in cities worldwide. This effect differed both between cities and within cities as the measures of confinement adopted by governments had diverse impacts in different areas of cities, depending on their characteristics (e.g., touristic, or residential). In the present work, mixed waste collection areas were created, based on waste collection points, that define spatial units in which contextual data such as tourism and residential characteristics were aggregated. The difference in mixed waste collected compared with previous years was analyzed along with the impacts on recycling due to the modification in operations regarding waste collection during the lockdown. The results showed that despite the suspension of the door-to-door recycling system during the lockdown, this did not translate into an increase in the production of mixed waste, and the recycling levels of previous years have not been reached after the lockdown, indicating a possible change in recycling habits in Lisbon. The touristic and non-residential mixed waste circuits presented significantly reduced mixed waste production compared to the non-pandemic context. Also, tourist, mobility, and economic activity were measured to understand which factors contributed to waste production changes during the COVID-19 pandemic. While little evidence of a relationship with these exogenous variables was found at the citywide level, evidence was found at the waste collection circuit level.

Review of hospital plastic waste management strategies for Pakistan.

Healthcare waste management is considered one of the biggest challenges that the world is going to face in the future. This threat is becoming reality owing to the worldwide sharp rise in healthcare waste generation particularly during the current COVID-19 pandemic. Like many other environmental crises, hospital plastic waste management is an area that got very little attention despite being highlighted in the literature, local media, as well as in international electronic and print media. This mini-review was conducted to assess the overall prevailing situation regarding hospital plastic waste management in Pakistan. Several illegal and unethical activities have been observed regarding hospital plastic waste management in Pakistan which includes unhygienic recycling, repacking of used hospital plastic items, open dumping on land, and disposal of hospital plastic waste in the ocean. To improve these conditions, suggestions have been made regarding the better management of hospital plastic waste.

Protective Face Masks: Current Status and Future Trends.

Management of the COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has relied in part on the use of personal protective equipment (PPE). Face masks, as a representative example of PPE, have made a particularly significant contribution. However, most commonly used face masks are made of materials lacking inactivation properties against either SARS-CoV-2 or multidrug-resistant bacteria. Therefore, symptomatic and asymptomatic individuals wearing masks can still infect others due to viable microbial loads escaping from the masks. Moreover, microbial contact transmission can occur by touching the mask, and the discarded masks are an increasing source of contaminated biological waste and a serious environmental threat. For this reason, during the current pandemic, many researchers have worked to develop face masks made of advanced materials with intrinsic antimicrobial, self-cleaning, reusable, and/or biodegradable properties, thereby providing extra protection against pathogens in a sustainable manner. To overview this segment of the remarkable efforts against COVID-19, this review describes the different types of commercialized face masks, their main fabrication methods and treatments, and the progress achieved in face mask development.

The Impact of Carbon Trade on Outsourcing Remanufacturing.

Outsourcing remanufacturing is an important way to achieve resource recycling, green manufacturing and carbon neutrality goals. To analyze the impact of carbon trade on manufacturing/remanufacturing under outsourcing remanufacturing, this article builds a game model between an original equipment manufacturer (OEM) and a remanufacturer under the carbon trade policy. In the outsourcing remanufacturing model, this article compares the impact of the carbon trade policy on the unit retail price, sales volume, revenue, environmental impact, and consumer surplus of new and remanufactured products. The research mainly draws the following conclusions: (1) Carbon trade increases the prices of both new and remanufactured products and the cost of outsourcing. Only when certain conditions are met can increased carbon trade prices increase revenue. (2) The carbon trade policy helps reduce the adverse impact on the environment, but only when the carbon trade price is greater than a certain threshold can it increase consumer surplus. (3) Consumer preferences and carbon emissions of the unit product affect manufacturers' profits. Increased consumer preference for remanufactured products and reduced carbon emissions of remanufactured products contribute to increased sales and revenues.

Plastic waste management: A road map to achieve circular economy and recent innovations in pyrolysis.

The contemporary world is challenged by mounting of plastic waste on the environment due to increase in economy and population. Over 90% of virgin plastics are produced from fossil fuels, hence, recycling is the best solution to reduce extracting and exploiting fossil fuels, and grow towards a circular economy. The type of waste and its hierarchy offers a route to pick up proper waste recycling policies which get the most out of the available resources and its protection. Pyrolysis process offers more valuable ways to turn the plastic waste to useful products for fueling and raw materials for making new plastics, and acts as an environmentally sound alternative to incineration and inefficient landfilling. This study provides a basic insight into plastic pyrolysis technology with recent trends and innovations in various countries, and their path towards the achievement of a circular economy. Plastic manufacturers, waste managers and the public plays a vital role in the development of the recycling sector. Recycling will stay underdeveloped and borderline without specific regulations to increase its effectiveness. Sustainable development in managing the plastic would be possible only through significant policies to instruct the individual and social challenges. The current article also targets the readers without scientific knowledge to get a basic idea of pyrolysis and general awareness of proper plastic waste management in a closed loop system.

Regenerated silica-based RNA purification columns to address the short supply of RNA purification kits for COVID-19 diagnosis.

BACKGROUND: RT-qPCR technique is the current world-wide method used for the early detection of SARS-CoV2 RNA in the suspected clinical samples. Viral RNA extraction is the key pre-analytical step for SARS-CoV2 detection which often achieved using commercial RNA-extraction kits. However, due to the COVID-19 pandemic, bulk production and the supply chains for the commercial RNA-extraction kit have been seriously compromised. The shortage of commercial RNA-extraction kit is even more acute in developing country. Furthermore, use of one-off design RNA-columns can generate plastic wastes that have an environmental pollution effect. METHODS AND RESULTS: To address these issues, in this study, we used warm alkaline solution containing Triton X-100 for the complete removal of the residual SARS-CoV2 RNA from the used RNA-binding silica column. Columns regenerated using the alkaline solution have the viral RNA purification capability that is comparable to the fresh silica columns. We also demonstrated that RNA-binding silica columns can be regenerated and reused for a minimum of five-times. CONCLUSIONS: Therefore, the use of the RNA-column regeneration method may benefits several SARS-CoV2 diagnostic laboratories throughout the world by cutting down the requirement of commercial RNA-purification column.

Optimization of medical waste recycling network considering disposal capacity bottlenecks under a novel coronavirus pneumonia outbreak.

The sudden outbreak and prolonged impact of the global novel coronavirus disease (COVID-19) epidemic has caused an increase in demand for medical products, such as masks and protective clothing, leading to an exponential increase in the generation of medical waste. As medical waste under the epidemic is highly infectious, it poses a great danger to human health. Therefore, with the proliferation of medical waste, it has become crucial to construct a reverse logistics recycling network that can handle medical waste quickly and efficiently. In this study, we construct a multi-period medical waste emergency reverse logistics network siting model with the objectives of minimum cost, minimum safety risk, and minimum time for the safe and quick disposal of medical waste. The model considers disposal capacity bottlenecks of existing facilities. Based on an empirical analysis using the COVID-19 epidemic in New York City, USA, as a case study, we find that the use of a suitable number of synergistic facilities and the establishment of temporary medical waste disposal centers are viable options for handling the dramatic increase in medical waste during the peak of the COVID-19 epidemic.

Circular economy approach in solid waste management system to achieve UN-SDGs: Solutions for post-COVID recovery.

The COVID-19 pandemic and the ensuing socioeconomic crisis has impeded progress towards the UN Sustainable Development Goals (UN-SDGs). This paper investigates the impact of COVID 19 on the progress of the SDGs and provides insight into how green recovery stimulus, driven by circular economy (CE)-based solid waste management (SWM) could assist in attaining the intended targets of UN-SDG. It was understood in this review that the guiding principles of the UN-SDGs such as, public health, environmental concerns, resource value and economic development are similar to those that have driven the growth of waste management activities; thus, in order to achieve the goals of UN-SDG, a circular economy approach in solid waste management system should be prioritized in the post-COVID economic agenda. However, policy, technology and public involvement issues may hinder the shift to the CE model; therefore, niche growth might come from developing distinctive waste management-driven green jobs, formalizing informal waste pickers and by focusing in education and training of informal worker. The review also emphasized in creating green jobs by investing in recycling infrastructure which would enable us to address the climate change related concerns which is one of the key target of UN- SDG. The CE-based product designs and business models would emphasize multifunctional goods, extending the lifespan of products and their parts, and intelligent manufacturing to help the public and private sectors maximise product utility (thus reducing waste generation) while providing long-term economic and environmental benefits. The study also recommended strong policies that prioritized investments in decentralization of solid waste systems, localization of supply chains, recycling and green recovery, information sharing, and international collaboration in order to achieve the UN-SDGs.

Assessing Consumer Preference for Overpackaging Solutions in E-Commerce.

The emergence of e-commerce and express delivery services has significantly transformed business operations and consumer shopping experience. However, the resulting problem of packaging waste, particularly from overpackaging, poses serious challenges to environmental sustainability and human health. Existing research has proposed many solutions from various perspectives, but very few have considered the acceptability and consumer preference for these proposals. Using the value co-creation (VCC) theory, we established a research model to explore consumer preferences for e-commerce overpackaging solutions. A survey of 632 online consumers in Guangzhou and Shenzhen was conducted, and data were analyzed using the SmartPLS software. The results show that establishing a recycling system, government policy, and consumers' environmental awareness have a significant positive impact on consumer preference, while combined packaging has a significant negative impact. We also found that government policy plays an intermediary role in establishing a recycling system and consumer preference. Based on these findings, we recommend that enterprises establish and improve their packaging recycling systems and that e-commerce platforms provide alternative options to combined packaging. Also, the government should play a guiding and coordinating role for enterprises and consumers, and environmental awareness among consumers should actively be promoted.