Reflections on COVID-19 pandemic and waste management in developing countries: A case study in São Paulo city, Brazil.

COVID-19 pandemic has changed several aspects in human behaviour, whereas population mobility patterns have been strongly affected by social distancing. In parallel, changes in solid waste generation patterns have been reported worldwide. This work assessed the influence of the COVID-19 pandemic on waste generation and collection in São Paulo city, Brazil, the largest city of Latin America. Data on nine types of wastes collected between 2013 and 2021 were obtained, and the quantities of wastes collected before and during the pandemic were compared. These data were also discussed in light of data on COVID-19 cases and rates of social distancing and mobility. An increase in the amount of recyclables collected during the first wave of COVID-19 (March to September 2020) was observed. Decreases in the quantities of construction, demolition and bulky wastes (first wave of COVID-19) and farmers market wastes (second wave - October 2020 to February 2021) were also evidenced. The quantities of medical wastes collected during the pandemic significantly increased. The amount of residential wastes was lower than the mean for the pre-pandemic period during the first months of COVID-19. Thus, changes in lifestyle and consumption patterns of the population of São Paulo city seem to have affected solid waste generation during the pandemic, which reinforces the need of implementing solid waste management policies based on a diagnostic that characterise and consider these changes.

Spatiotemporal patterns and drivers of carbon emissions from municipal solid waste treatment in China.

Reducing carbon emissions from municipal solid waste (MSW) treatment is non-negligible for China to meet its "carbon peaking and carbon neutrality" targets. It is critical to objectively evaluate the spatiotemporal patterns and drivers of carbon emissions from MSW treatment. This study estimates the carbon emissions from MSW treatment across 30 Chinese provinces from 2011 to 2020. The joint approach LMDI-PDA model is further used to refine the impact of policy on carbon emission changes from technical and efficiency perspectives, while considering the socio-economic factors. The results showed that carbon emissions from MSW treatment grew significantly until peaking at 202.05Mt CO2e in 2017 and then stabilized, finally dropping to 165.10 Mt CO2e in 2020 due to the impact of COVID-19. Compared with the "12th Five-Year Plan" period, the MSW emissions intensity declined significantly during the "13th Five-Year Plan" period, indicating the effective implementation of waste emission control measures. Furthermore, the slowdown in the growth of national emissions was primarily driven by technological advances in waste treatment. Technical efficiency change effect, MSW generation intensity effect, economic scale effect, and population scale effect impeded national emissions decline. Since the performance of various drivers varied greatly in different provinces, a cluster analysis was conducted to provide policy recommendations in provinces with similar characteristics. Both the methods and results of this study can provide better decision-making support for national and provincial carbon emissions control policies targeting MSW treatment.

A cross-jurisdictional comparison on residential waste collection rates during earlier waves of COVID-19.

There is currently a lack of studies on residential waste collection during COVID-19 in North America. SARIMA models were developed to predict residential waste collection rates (RWCR) across four North American jurisdictions before and during the pandemic. Unlike waste disposal rates, RWCR is relatively less sensitive to the changes in COVID-19 regulatory policies and administrative measures, making RWCR more appropriate for cross-jurisdictional comparisons. It is hypothesized that the use of RWCR in forecasting models will help us to better understand the residential waste generation behaviors in North America. Both SARIMA models performed satisfactorily in predicting Regina's RWCR. The SARIMA DCV model's performance is noticeably better during COVID-19, with a 15.7% lower RMSE than that of the benchmark model (SARIMA BCV). The skewness of overprediction ratios was noticeably different between jurisdictions, and modeling errors were generally lower in less populated cities. Conflicting behavioral changes might have altered the residential waste generation characteristics and recycling behaviors differently across the jurisdictions. Overall, SARIMA DCV performed better in the Canadian jurisdiction than in U.S. jurisdictions, likely due to the model's bias on a less variable input dataset. The use of RWCR in forecasting models helps us to better understand the residential waste generation behaviors in North America and better prepare us for a future global pandemic.

Structure characteristics and development sustainability of municipal solid waste treatment in China

This study aims to analyze the development trend of municipal solid waste (MSW) treatment in China from 2011 to 2020, and provide insights into the challenges and opportunities of sustainable MSW management. Our analysis shows that MSW generation declined in 2020, which could be attributed to a combination of factors, including the low urban population growth rate, the implementation of the garbage classification policy, and the impact of the COVID-19 pandemic. We also found that the shift from landfill to incineration is expected to increase significantly in the coming years, although there are still several structural problems, such as an imbalance in treatment capacity among regions and cities, and uncertainty about whether the increase in incineration treatment capacity can meet overall demand due to the high volume of MSW generation. Our analysis highlights the heavy dependence on government investment for MSW treatment mode change, which is difficult due to the expanding deficit between fiscal revenue and expenditure of local governments. Correlation coefficient analysis shows a significant positive correlation between the proportion of incineration and sanitation investment, and a significant negative correlation between the proportion of landfill treatment and sanitation investment. To address these challenges, we propose technological advancement and management optimization to reduce the cost of MSW treatment, as well as expansion of investment channels through green funds, taxation relief, and other means to promote high-quality and sustainable development of the MSW treatment industry. These changes could accelerate the transformation of China's MSW treatment industry from policy promotion-dependent to market-oriented sustainable operation.

Effect of COVID-19 pandemic on municipal solid waste generation: a case study in Granada city (Spain).

The 2020 coronavirus pandemic has involved a series of political and social measures that have been adapted to the spread of the disease. Apart from the severe effects on health sector, the most effects of the pandemic have been felt in households and day-to-day life. Consequently, COVID-19 has had a significant impact on the generation of not only medical and health care waste but also of municipal solid waste production and composition. In this context, this work studied the implications of COVID-19 for municipal solid waste generation in Granada, Spain. Granada is a city where the economy is based mainly on the services sector, tourism and the University. Therefore, the impact of COVID-19 pandemic has greatly affected the city and it can be analyzed through the municipal solid waste generation. For the study of the incidence of COVID-19 in the generation of waste a period that goes from March 2019 to February 2021 has been chosen. The results show that, in the global calculation, a decrease in the generation of waste in the city is observed in this last year, reaching - 13.8%. Regarding the organic-rest fraction, the decrease in the COVID year represents - 11.7%. However, bulky waste has shown an increase in the COVID year which may be related to higher home furnishings renovation rates than in other years. Finally, glass is the waste flow that best indicates the effect of COVID in the service sector. In leisure areas, a significant reduction in the collection of glass is observed (- 45%). Supplementary Information: The online version contains supplementary material available at 10.1007/s10163-023-01671-2.

Strategic use of thermo-chemical processes for plastic waste valorization

Plastic is one of the most widely used materials in industries including packaging, building, and construction due to its lightweight, low cost, durability, and versatility. However, the mass production of plastics has exacerbated plastic pollution. Globally, plastic waste is predominantly incinerated, landfilled, or released into the environment;only 5-6% is recycled in the United States. Although conventional management protocols such as incineration and landfilling are evidently effective for plastic waste disposal, they are associated with significant environmental and societal challenges. In addition, most recycled plastic is downcycled, and thus does not provide sufficient incentive to use recycled materials instead of virgin materials. This review discusses thermo-chemical upcycling processes such as (catalytic) pyrolysis and heterogeneous catalysis. Furthermore, we present the recent progress in the thermo-chemical upgrading of single-type plastic waste, heterogeneous plastic mixtures, and post-consumer plastic waste obtained from different locations and, finally, suggest future research directions.

Modification of the Aeration-Supplied Configuration in the Biodrying Process for Refuse-Derived Fuel (RDF) Production

Biodrying is an essential part of the mechanical–biological treatment process that minimizes moisture content and simultaneously maximizes heating value for refuse-derived fuel (RDF) production. Although the mechanical separation process operates effectively in Thailand's RDF production, high organic content levels and their degradation cause moisture contamination in RDF, producing wet RDF. Aeration is essential for an effective biodrying process, and can reduce RDF's moisture content as well as increase its heating value. To maximize the biodrying effect, aeration should be optimized based on the waste conditions. This study proposes a modified aeration-supplied configuration for wet RDF biodrying. The aeration rate was modified based on the period within the biodrying operation;the first period is from the beginning until day 2.5, and the second period is from day 2.5 to day 5. The optimal aeration supply configuration was 0.5 m3/kg/day in the first period and then 0.3 m3/kg/day until the end of the process;this configuration yielded the greatest moisture content decrease of 35% and increased the low heating value of the biodried product by 11%. The final moisture content and low heating value were 24.07% and 4787 kcal/kg, respectively. Therefore, this optimal aeration-supplied configuration could be applied to meet the moisture content and low heating value requirements of the RDF production standard for Thailand's local cement industry.

Quantitative Evaluation of Municipal Wastewater Disinfection by 280 nm UVC LED

UV-LED irradiation has attracted attention in water and wastewater disinfection applications. However, no studies have quantitatively investigated the impact of light intensity on the UV dosage for the same magnitude of disinfection. This study presents a powerful 280 nm UV-LED photoreactor with adjustable light intensity to disinfect municipal wastewater contaminated with E. coli, SARS-CoV-2 genetic materials and others. The disinfection performance of the 280 nm LED was also compared with 405 nm visible light LEDs, in terms of inactivating E. coli and total coliforms, as well as reducing cATP activities. The results showed that the UV dose needed per log reduction of E. coli and total coliforms, as well as cATP, could be decreased by increasing the light intensity within the investigated range (0–9640 µW/cm2). Higher energy consumption is needed for microbial disinfection using the 405 nm LED when compared to 280 nm LED. The signal of SARS-CoV-2 genetic material in wastewater and the SARS-CoV-2 spike protein in pure water decreased upon 280 nm UV irradiation. © 2023 by the authors.

SARS-CoV-2 surveillance-based on municipal solid waste leachate in Brazil.

Municipal solid waste leachate-based epidemiology is an alternative viral tracking tool that applies fresh truck leachate as an early warning of public health emergencies. This study aimed to investigate the potential of SARS-CoV-2 surveillance based on solid waste fresh truck leachate. Twenty truck leachate samples were ultracentrifugated, nucleic acid extracted, and real-time RT-qPCR SARS-CoV-2 N1/N2 applied. Viral isolation, variant of concern (N1/N2) inference, and whole genome sequencing were also performed. SARS-CoV-2 was detected on 40% (8/20) of samples, with a concentration from 2.89 to 6.96 RNA Log10 100 mL-1. The attempt to isolate SARS-CoV-2 and recover the whole genome was not successful; however, positive samples were characterized as possible pre-variant of concern (pre-VOC), VOC Alpha (B.1.1.7) and variant of interest Zeta (P.2). This approach revealed an alternative tool to infer SARS-CoV-2 in the environment and may help the management of local surveillance, health, and social policies.

Solid Waste Management in Peru's Cities: A Clustering Approach for an Andean District

There is a great deficiency in the collection and disposal of solid waste, with a considerable amount disposed of in dumps instead of in landfills. In this sense, the objective of this research is to propose a solid waste mitigation plan through recovery in the District of Santa Rosa, Ayacucho. For this, a solid waste characterization plan was executed in eight days, and through ANOVA it was shown that there is a significant difference in means between business pairs except between a bakery and a hotel. Through clustering, zones A and B are highly correlated, reflecting that the amount of organic waste was greater than inorganic waste. In the organic waste valorization plan, the results through ANOVA indicate a significant difference for monthly and daily averages, and the clustering shows the different behavior of each month, drawing attention to August, concluding that the valorization pilot plan is viable due to the contribution of a large amount of organic solid waste to the valorization plant.

Life cycle assessment of Tehran Municipal solid waste during the COVID-19 pandemic and environmental impacts prediction using machine learning

Life cycle assessment and machine learning were combined to find the best option for Tehran's waste management for future pandemics. The ReCipe results showed the waste's destructive effects after COVID-19 were greater than before due to waste composition changes. Plastic waste has changed from 7.5 to 11%. Environmental burdens of scenarios were Sc-1 (increase composting to 50%) > Sc-3 > Sc-4 > Sc-b2 > Sc-5 > Sc-2 (increase recycling from 9 to 20%). The artificial neural network and gradient-boosted regression tree could predict environmental impacts with high R2. Based on the results, the environmental burdens of solid waste after COVID-19 should be investigated. © 2023 The Authors

CO2-mediated thermal treatment of disposable plastic food containers

In accordance with global economic prosperity, the frequencies of food delivery and takeout orders have been increasing. The pandemic life, specifically arising from COVID-19, rapidly expanded the food delivery service. Thus, the massive generation of disposable plastic food containers has become significant environmental problems. Establishing a sustainable disposal platform for plastic packaging waste (PPW) of food delivery containers has intrigued particular interest. To comprise this grand challenge, a reliable thermal disposable platform has been suggested in this study. From the pyrolysis process, a heterogeneous plastic mixture of PPW was converted into syngas and value-added hydrocarbons (HCs). PPW collected from five different restaurants consisted of polypropylene (36.9 wt%), polyethylene (10.5 wt%), polyethylene terephthalate (18.1 wt%), polystyrene (13.5 wt%), polyvinyl chloride (4.2 wt%), and other composites (16.8 wt%). Due to these compositional complexities, pyrolysis of PPW led to formations of a variety of benzene derivatives and aliphatic HCs. Adapting multi-stage pyrolysis, the different chemicals were converted into industrial chemicals (benzene, toluene, styrene, etc.). To selectively convert HCs into syngas (H2 and CO), catalytic pyrolysis was adapted using supported Ni catalyst (5 wt% Ni/SiO2). Over Ni catalyst, H2 was produced as a main product due to C[sbnd]H bond scission of HCs. When CO2 was used as a co-reactant, HCs were further transformed to H2 and CO through the chemical reactions of CO2 with gas phase HCs. CO2-assisted catalytic pyrolysis also retarded catalyst deactivation inhibiting coke deposition on Ni catalyst. © 2022 Elsevier B.V.

Effective multipurpose sewage sludge and food waste reduction strategies: A focus on recent advances and future perspectives

Energy crisis and increasing rigorous management standards pose significant challenges for solid waste management worldwide. Several emerging diseases such as COVID-19 aggravated the already complex solid waste management crisis, especially sewage sludge and food waste streams, because of the increasingly large production year by year. As mature waste disposal technologies, landfills, incineration, composting, and some other methods are widespread for solid wastes management. This paper reviews recent advances in key sewage sludge disposal technologies. These include incineration, anaerobic digestion, and valuable products oriented-conversion. Food waste disposal technologies comprised of thermal treatment, fermentation, value-added product conversion, and composting have also been described. The hot topic and dominant research foci of each area are summarized, simultaneously compared with conventional technologies in terms of organic matter degradation or conversion performance, energy generation, and renewable resources production. Future perspectives of each technology that include issues not well understood and predicted challenges are discussed with a positive effect on the full-scale implementation of the discussed disposal methods. © 2022 Elsevier Ltd

Waste management beyond the COVID-19 pandemic: Bibliometric and text mining analyses.

The outbreak of the COVID-19 pandemic has significantly increased the demand for personal protective equipment, in particular face masks, thus leading to a huge amount of healthcare waste generated worldwide. Consequently, such an unprecedented amount of newly emerged waste has posed significant challenges to practitioners, policy-makers, and municipal authorities involved in waste management (WM) systems. This research aims at mapping the COVID-19-related scientific production to date in the field of WM. In this vein, the performance indicators of the target literature were analyzed and discussed through conducting a bibliometric analysis. The conceptual structure of COVID-19-related WM research, including seven main research themes, were uncovered and visualized through a text mining analysis as follows: (1) household and food waste, (2) personnel safety and training for waste handling, (3) sustainability and circular economy, (4) personal protective equipment and plastic waste, (5) healthcare waste management practices, (6) wastewater management, and (7) COVID-19 transmission through infectious waste. Finally, a research agenda for WM practices and activities in the post-COVID-19 era was proposed, focusing on the following three identified research gaps: (i) developing a systemic framework to properly manage the pandemic crisis implications for WM practices as a whole, following a systems thinking approach, (ii) building a circular economy model encompassing all activities from the design stage to the implementation stage, and (iii) proposing incentives to effectively involve informal sectors and local capacity in decentralizing municipal waste management, with a specific focus on developing and less-developed countries.

COVID-19 lockdown and municipal solid waste: evidence from the discarding records of 252 communities in China

This study investigates the impacts of the COVID-19 lockdown on municipal solid waste (MSW). Based on a unique data set of daily discarding records of 252 communities in Beijing, China, we conduct a difference-in-differences estimation and find that the total daily MSW decreased by 134.16 kg in a community, which is equivalent to at least 0.22 kg per household per day, and the average weight of MSW per package decreased by 56.8 per cent after the COVID-19 lockdown. We consider a series of potential mechanisms, such as MSW hoarding, shifts in discarding time, and fear of going out, and find the most support for consumption pattern shifts with reduced consumption. We then discuss the effect of the lockdown on the reduction of MSW generation because of the strict restriction of consumption. We also conduct various heterogeneity analyses. Our results present clear implications for municipal waste management by highlighting the effect of the lockdown on the generation of MSW and the underlying consumption mechanism.

Does the creation of healthy cities promote municipal solid waste management? Empirical research in 284 cities in China.

In the context of the COVID-19 pandemic, the creation of healthy cities has become an important measure to deal with global public diseases and public health emergencies, and has had a profound impact on the management of municipal solid waste (MSW). This study exploits the Healthy Cities pilot (HCP) program established in 2016 as a natural experiment, and evaluates its impact on MSW management using the difference-in-difference (DID) method. The estimates show that the collection amount and harmless treatment capacity of MSW were increased by 15.66 and 10.75%, respectively, after the cities were established as pilot healthy cities. However, the harmless treatment rate was decreased by 3.544. This conclusion remains valid in a series of robustness tests, including parallel trend test, placebo test, propensity score matching (PSM)-DID, eliminating the interference of other policies, and eliminating the non-randomness of the policy. Mechanism analysis shows that the HCP program increased the collection amount and harmless treatment capacity of MSW by increasing the expenditure on MSW treatment. However, after a city was established as a pilot healthy city, the unsustainable high expenditure of local government on municipal sanitation led to the decrease in the harmless treatment rate of MSW. Moreover, heterogeneity analysis shows that the HCP program had a stronger impact on MSW management in cities with higher administrative levels, more obvious location advantages, and a larger size. Therefore, it is advisable to use the creation of healthy cities as an important tool to gradually improve MSW management, so as to realize the coordinated development of city construction and human health.

Prediction of Waste Disposal During Covid-19 Using System Dynamics Modeling

Sound and effective solid waste management practices are important to mitigate health risks and protect the surrounding environment. Proper Municipal Solid Waste (MSW) management practices are especially important during the COVID pandemic. Since the beginning of the COVID pandemic different waste disposal and recycling behaviors are observed in Regina, the capital city of Saskatchewan. It is believed the changes of waste disposal rate at Regina landfill is related to the new hygienic guidelines, more opportunities for work from home, distinct consumer behaviors, and COVID related regulations and recommendations. Waste generation and recycling behaviors are complex and multi-dimensional. The objective of this study is to model waste disposal rate at the City of Regina landfill using a System Dynamics (SD) model. The proposed SD model will help us better manage the City of Regina’s human resources during the pandemic and estimate the demand of additional personal protective equipment required for the waste management workers. In the present work, a total of 7.5 years of waste disposal data is collected, consolidated, and verified. Socio-economical parameters such as GDPs and population at Regina were also collected during the study period from 2013 to 2020. The model is built using stock-flow diagram to illustrate the effects of various inter-related variables on the waste generation behaviors. Construction and demolition (C&D), Grit, Asphalt Shingles Only, Asphalt Shingles Mixed and Treated Biomedical wastes data are used in the SD model. Results show that waste generation has affected by the pandemic and there is a general increase in amount of waste generation. The modeling results are important because it helps us predict the amount of MSW during and after the pandemic. © 2023, Canadian Society for Civil Engineering.

COVID-19 AND MUNICIPAL SOLID WASTE MANAGEMENT

The present work analyses the scientific literature available on the impact of the SARS-CoV-2 in the sector of municipal solid waste. After a bibliometric analysis based on data taken from Scopus®, the analysis deals with effects on waste composition, waste quantity, collection, and treatment. As expected, results show that the most productive authors on this topic belong to scientific bodies located in the countries more affected from COVID-19 in the world. Moreover, different strategies of international journals resulted in an unbalanced concentration of papers on this topic. Effects have been observed concerning municipal solid waste composition and amount (mostly for the role of masks and packaging). Impacts on management and circular economy are discussed too. © 2022 WITPress. All rights reserved.

Leading the World: A Review of Household Recycling in Wales

Wales is one of the world leaders in household waste recycling with a steady recent recycling rate of ~65%. The Welsh Assembly Government (WAG) set a statutory target of achieving a 70% recycling rate by 2024/25. We reviewed historical trends in waste management in Wales from 2006 to 2020, with a focus on recycling. Authoritative, official data were obtained from WasteDataFlow, an Internet system for municipal waste data reporting by UK local authorities to government. Data are collected quarterly allowing the generation of time series plots, trendlines and like-for-like comparisons between groupings of various characteristics, such as number of separate kerbside collections, income, political preference, and impact of policy changes. Results showed that the approach taken by the WAG to politically prioritise and encourage participation in household recycling has achieved impressive results that contrast starkly with the recycling performance of other UK countries. In Wales, household waste disposed annually per person via landfill decreased from ~410 kg to <50 kg and household waste recycled increased from to ~150 kg to ~310 kg, with a recent increase in incineration with energy recovery to ~135 kg as infrastructure has come online. Recycling rates show a seasonal variation due to increases in garden waste sent for composting in the summer. There are variations in local authority performance across Wales, mainly caused by variations in the number of separate collections. Co-mingled collections tend to lead to higher contamination of recyclates that are then not able to be sold for recycling. Deprivation, as indicated by differences in income, also influences total waste arisings and recycling rates. A plateau of ~65% recycling rate was reached in 2020, with incineration reaching a rate of >25%. The recycling rate plateaus at exactly the same time as incineration comes on stream. Evidence demonstrates that improvements to recycling rates can become more difficult when incineration becomes available. Whilst further reductions and improvements to recycling in Wales will be more challenging, the WAG’s track record of focused proactive political and policy support shows what can be achieved when there is suitable political will. The WAG has demonstrated that it tends to deliver on its waste-related plans, and it clearly has the best chance of any of the UK’s four countries of achieving its aims.

Hydrogen-rich gas production from disposable COVID-19 mask by steam gasification.

Globally, the demand for masks has increased due to the COVID-19 pandemic, resulting in 490,201 tons of waste masks disposed of per month. Since masks are used in places with a high risk of virus infection, waste masks retain the risk of virus contamination. In this study, a 1 kg/h lab-scale (diameter: 0.114 m, height: 1 m) bubbling fluidized bed gasifier was used for steam gasification (temperature: 800 °C, steam/carbon (S/C) ratio: 1.5) of waste masks. The use of a downstream reactor with activated carbon (AC) for tar cracking and the enhancement of hydrogen production was examined. Steam gasification with AC produces syngas with H2, CO, CH4, and CO2 content of 38.89, 6.40, 21.69, and 7.34 vol%, respectively. The lower heating value of the product gas was 29.66 MJ/Nm3 and the cold gas efficiency was 74.55 %. This study showed that steam gasification can be used for the utilization of waste masks and the production of hydrogen-rich gas for further applications.