Waste Management & Research最新文献

In Sri Lanka, the management of Construction & Demolition (C&D) waste poses a major problem, leading to environmental degradation and depletion of resources. This study aims to tackle these issues by examining the implementation of Circular Economy (CE) strategies within the construction industry of Sri Lanka. The focus is on reducing waste generation and maximizing resource utilization during the demolitions and repurpose, as well as material recovery and production stages of the building project life cycle. These stages are crucial in terms of waste generation and resource consumption. A qualitative approach was employed in this research, utilizing the Delphi technique to gather insights through a series of three rounds of expert interviews. In the first round, 17 experts were involved, followed by 15 in the second round, and 12 in the final round. The data collected from these interviews were analysed using manual content analysis methods. Based on the research findings, a total of 14 C&D Waste Management (WM) issues were identified specifically in the Demolitions and Repurpose Stage in Sri Lanka. For each issue, suitable strategies were proposed to overcome them effectively. Furthermore, the study examined the impact of CE strategies on minimizing these issues within the context of the project management iron triangle. Similarly, the Material Recovery and Production Stage of the building presented eight C&D WM issues, each accompanied by corresponding strategies to address them. The research also explored the influence of CE strategies in mitigating these issues, considering the project management iron triangle. During the demolitions and repurpose stage, CE strategies focus on reducing waste generation and optimizing resource utilization. This involves carefully deconstructing buildings to salvage and recover materials that can be reused or repurposed.

Using food and drink disposable containers has heavy environmental and economic consequences. The widespread adoption of reusable containers is a challenge that requires understanding the psychological determinants and barriers of the behaviour. Two studies were conducted: one with a sample from the general public (study 1, N = 302) and one with respondents having access to a reusable container system at work (study 2, N = 737). Online surveys measured self-reported use of single-use and reusable containers for food and drinks takeaway (studies 1 and 2) and for food delivery (study 1). Stages of change and psychological determinants were also measured to provide behavioural levers. Results indicate that in study 1, most of the sample is aware of the issue associated with single-use containers but has not switched to reusable. In study 2, most respondents say they are already using few single-use and are willing to continue, particularly for drinks to go. Thus, accessibility at the workplace to a reusable container system is associated with higher stages of change. However, many respondents are also in the preactional phase for food takeaway, that is, willing to change but have not started yet. In both studies, perception of control on the behaviour and volitional variables are positively associated with stages of change. This suggests that making reusable containers easier to use and helping individuals plan how and when they can do it could encourage behaviour change.

To evaluate the potential of compost based on municipal solid waste (MSW) and 20% legume pruning under a pyrolysis process, generated products, including solids (biochar), liquids (bio-oil), and gases (non-condensable gases), through experimentation in a pilot plant with a fluidized bed reactor at 450°C and gas chromatography/mass spectrometry have been analysed. In addition, the compost kinetic behaviour by thermogravimetric analysis (TGA), using the Flynn-Wall-Ozawa (FWO) method, has been investigated. Four different reaction zones, associated with lignocellulosic materials (hemicellulose, cellulose, and lignin) with a first step for water evaporation, in TGA curve have been observed. A biochar with low stability and aromaticity, considering high and low O/C and H/C ratios, respectively, has been obtained. The obtained pyrolytic liquids contain a high concentration of phenolic compounds because of a significant presence of lignins and other high molecular weight compounds in the original material. Moreover, the generated non-condensable gases consist mainly of short-chain compounds, such as alcohols, aldehydes, and alkenes produced from hemicellulose, cellulose, and proteins.

Healthcare waste (HCW) consists of hazardous material that may be radioactive, toxic or infectious. Inappropriate treatment and disposal of HCW may pose health risks to humans indirectly through the release of pathogens and toxic pollutants into the environment. The biggest problem in HCW management is its handling, which causes anxiety over sorting and categorizing the waste. Hence, the current study identifies and addresses the challenges towards sustainable environmental development by managing infectious HCW in developing countries. Fuzzy Delphi method is used in the present study to carefully examine the barrier drawn from the literature and experts' opinions. The number of barriers taken into consideration for study are 30, which are then grouped into four main categories, that is, social, environmental, technological and economic barriers. Additionally, a hybrid strategy based on the fuzzy decision-making trial and evaluation laboratory is developed in this work to examine the significance and interrelationships of the identified barrier. The research outcome is a hierarchy and classification model based on the relative importance of the barriers. The results of this study indicate that: 'Lack of segregation', 'Inconsistency in waste collection', 'Unregulated disposal site' and 'Inadequate programme for training and awareness' require quick action. The conclusions obtained through the study would facilitate the preparation of check sheets for documenting HCW management procedures by the healthcare administration and Pollution Control Boards. Understanding the priority cause-group barrier would improve the long-term protection of the hospital environment from the spread of infection caused by the HCW.

This article reports on how management approaches influence methane emissions from landfills. The project team created various landfill operational scenarios for different regions of the planet with respect to waste composition, organic waste reduction and landfill gas recovery timing. These scenarios were modelled by applying a basic gas generation model according to the United Nations Intergovernmental Panel on Climate Change (IPCC) recommendations. In general, the IPCC's recommended modelling parameters and default values were used. Based on the modelling undertaken, two options stand out as being the most effective methane mitigation measures in a wide range of conditions throughout the world: (a) early gas recovery and (b) reduction of the amount of biodegradable organic waste accepted in a landfill. It is noted that reduction of organic input to any given landfill can take many years to realize. Moreover, suitable alternative processing or disposal options for the organic waste can be unaffordable for a significant percentage of the planet's population. Although effective, organic waste reduction cannot therefore be the only landfill methane mitigation measure. Early landfill gas recovery can be very effective by applying basic technologies that can be deployed relatively quickly, and at modest cost. Policymakers and regulators from around the globe can significantly reduce adverse environmental impacts from landfill gas emissions by stimulating both the early capture and flaring and/or energy recovery of landfill gas and programmes to reduce the inflow of organic waste into landfills.

Plastic waste has become a major contributor to global environmental pollution. Some of the environmental impacts of plastic waste include littering, the formation of plastic debris in oceans and the contamination of freshwater and terrestrial habitats. Policymakers face great challenges in mitigating plastic waste. Indonesia is considered the second largest contributor of plastic waste in the world. However, existing policies have not addressed this issue. Policies, such as bans on single-use plastic bags and fees on plastic bags, have recently been implemented in some pilot cities, but the results remain unclear. Thus, this study proposes feasible policies to mitigate plastic waste in Indonesia using system dynamics. Specifically, this study seeks to develop a dynamic model of plastic waste mitigation and to propose a policy scenario for plastic waste mitigation. The proposed policies consist of a plastic bag ban, a plastic bag fee, a recycling centre and extended producer responsibility (EPR). The analysis demonstrates that an effective mixed policy instrument for reducing plastic waste depends on the plastic waste type. Regarding plastic bottles, the effective mixed policy is a combination of a recycling centre and EPR. For plastic bags, the effective mixed policies include the following combinations: a plastic bag fee and plastic bag ban, a plastic bag fee and recycling centre and a plastic bag ban and recycling centre.

Electronic waste (e-waste), often dominated by the informal sector, has had adverse effects on recipient developing countries' economies, health and physical environment. Ghana, over the years, has had support from international organisations to manage its e-waste crisis. Until 2016, there was no e-waste specific policy to guide the management of the sector. In 2016, Ghana passed a regulatory policy - Act 917 - to specifically deal with e-waste, supported by other frameworks such as a regulatory instrument (L.I. 2250), a technical guideline for environmentally sound e-waste management and an e-waste-specific policy, which is currently being developed. However, there is dearth of research on how effectively a regulatory policy such as Act 917 can help address an informally dominated sector whose crude recycling approaches have had great environmental and health impacts. Adapting the analytical framework and intervention theory, key stakeholders within the e-waste sector were interviewed on: the effectiveness of the Act, the challenges confronting them and their involvement in the design and implementation processes. The findings showed that stakeholders were represented at various stages of the process. Informal recyclers were provided with training programmes, health centres and an incentive scheme to minimise burning of electrical and electronic equipment. There however exist many challenges to the sound management of the sector, particularly, the lack of end-to-end recycling facilities, registering and formalising the sector and sequencing of the e-waste policy and regulatory framework. The research concludes by recommending areas for future studies.

Discharge from unrestricted tobacco products with filters (TPF) causes environmental damage. To reduce TPF litter quantities, Directive (EU) 2019/904 requires TPF producers to proportionally contribute to the costs of discarding their products in public waste collection systems, including litter waste ones. An appropriate output-based cost model requires assessing TPF quantities in relevant waste streams. Currently, there is no comprehensive data available on TPF quantities in municipal solid waste (MSW). Therefore, a case study was conducted to quantify TPF in MSW. This study aimed to determine TPF quantities (1) in residual waste from four German district types and (2) in waste from public collection systems for three settlement structures within Trier City. Relevant waste streams from public collection systems, namely waste from public waste receptacles, street-cleaning waste and sinkhole residues, were identified. For both sampling campaigns, consideration was given to extrapolating the results to a larger scale. The results showed that the average specific TPF quantities in residual waste were 277.7, 271.8, 193.3 and 204.5 gi^{- 1}a^{- 1} in the selected city district, urban district, densely populated rural district and sparsely populated rural district, respectively. Extrapolation of these results to Germany yielded a specific TPF quantity in residual waste of 250.3 gi^-1a^-1. The average specific TPF quantities in waste from public waste receptacles, street-cleaning waste and sinkhole residues were 12.2, 47.4 and 9.9 gi^-1a^{- 1}, respectively. The results could contribute to cost model development based on Directive (EU) 2019/904.

This study is a critical review of municipal solid waste (MSW) hydraulic conductivity that includes investigation of the influence of vertical stress, dry unit weight and degradation. A total of 56 studies were compiled that included laboratory-, pilot- and landfill-scale hydraulic conductivity experiments. Compacting waste and increasing vertical stress reduce MSW hydraulic conductivity via reshaping the pore networks throughout the waste matrix, reducing the void ratio and increasing tortuosity. However, the magnitude of reduction in hydraulic conductivity is dependent on stress, waste composition and decomposition. Solid waste decomposition can have opposing effects on hydraulic conductivity. Some studies have indicated that an increase in MSW decomposition results in particle size reduction and settlement that reduces the void ratio and decreases hydraulic conductivity. Conversely, some studies indicate that waste decomposition reduces the solid mass, which increases the void ratio and creates larger flow paths that increase hydraulic conductivity. The data compilation, observations and key findings from this study are beneficial for solid waste practitioners to improve design, analysis and operation of MSW landfills.