Journal of Material Cycles and Waste Management最新文献

Solid waste management is a critical issue in India as the country continues to develop. Accurately estimating the types, quantities, and distribution of solid waste is essential for effective waste management. The methods and processes for managing waste in any city, including collection, transportation, treatment, and disposal, rely heavily on accurate estimations of waste quantities. These estimates are in turn influenced by various factors, including socio-cultural, economic, environmental, political, and technological factors. The research aims to identify specific social and spatial factors that influence solid waste generation in municipal cities of the present times through a literature study. It then undertakes the study of a selected area in the city of Cuttack, Orissa, India, as a case study and formulates a model for quantifying solid waste based on the measurements of derived indicators. The research utilizes both primary and secondary data to achieve its objectives. The analysis revealed that factors such as monthly family income, house occupancy, and occupation have a strong positive correlation with the quantity of solid waste. Conversely, factors such as educational qualification and the incentive system provided to citizens exhibit a negative correlation with the amount of solid waste generated. Based on these factors, the model derived will facilitate the accurate estimation of solid waste generated in similar contexts, thereby aiding efficient waste management. By conducting this case study in Cuttack City, we aim to contribute to the existing body of knowledge on solid waste management in India and provide a comprehensive understanding of the factors affecting waste quantity.

Chemical characterization is a crucial step and decision tool before any application of fruit crop residues. This study aims to evaluate the applicability of traditional chemical characterization methods for banana pseudostem, guava seed, and orange bagasse. An analysis of extractives removal time and sugar solubilization during this process was performed. The residues were evaluated based on the cellulose, hemicellulose, lignin, extractives, and ash contents, in addition to the holocellulose and α-cellulose fractions, followed by FTIR spectroscopy. Acid-soluble lignin was evaluated by UV–visible spectrophotometry with different extinction coefficients and wavelengths. The results showed that extractives’ removal for 4 h was sufficient for all materials, and a varied composition was observed among the biomasses. The guava seed had the highest lignin content, 41.66%, banana pseudostem had 33.97% cellulose, and orange bagasse had a high extractive content, 60.78%. The mass balance for all biomasses was above 92%, which suggests the applicability of such chemical characterization methods for fruit residues. A significant influence of different parameters in the determination of soluble lignin was observed. Thus, the present study serves as a basis for future research on the use and application of fruit residues, since there are no specific and complete studies on its characterization; including the evaluation of a greater number of plant varieties to obtain more representative results.

Inefficient waste management poses a significant challenge to solid-waste management at the household level. A comprehensive understanding of current practices and perceptions of solid-waste management at this level is crucial for making informed decisions and establishing an integrated, sustainable waste-management system. Rawalpindi, the fourth most populous city in Pakistan, faces obstacles in infrastructure development and the effective delivery of utility services, including solid-waste management, due to its rapidly growing population and unplanned expansion of peri-urban areas. While limited studies have explored household solid-waste-management practices in urban centers, peri-urban zones have been largely overlooked. This study focuses on comprehensive assessment and comparison of household waste management under both public and private sector systems in the peri-urban areas of Rawalpindi. The data collection was done employing a household survey and cross-sectional questionnaire, utilizing a simple random sampling technique. Analysis involved cross-tabulation and chi-square tests. The results indicate that the private sector outperforms the public sector in waste management operations. However, there is a minimal difference in waste segregation activities between households under public (46%) and private (54%) sector waste-management systems. Residents generally perceive waste, under both waste-management systems, as esthetically unpleasant and harmful to health, with 21.7% considering waste negatively compared to 11.7% who hold a different view. Our findings suggest that socio-demographic characteristics significantly influence household waste practices and perceptions in peri-urban areas of Rawalpindi, particularly under different waste-management systems. There is an opportunity for improvement in waste segregation at the household level through targeted awareness programs, aiming to foster the development of a sustainable waste-management system.

The rapid increase in biogas energy production has led to the accumulation of a significant byproduct, liquid digestate (LD). This study evaluated the effects of various LD dosages on soil CO₂ respiration and microbial biomass through field trials over 1 year and 2 consecutive years. LD was applied to a maize cultivation area at dosages of 10, 30, 50, and 70 t ha⁻¹. The results showed that LD created rapidly diminishing transient effects on soil microbial activity; in long-term applications, microbial stress became apparent at dosages of 30, 50, and 70 t ha⁻¹. Notably, the increase in CO₂ respiration diminished after about 60 days in the 1-year application, while the increase in microbial biomass was sustained for only 30 days. In the 2-year application, the effect on CO₂ respiration disappeared after 30 days, with no significant change in microbial biomass. Initial applications of LD stimulated microbial activity, but high dosages in prolonged applications tended to increase stress factors on microbial communities. These findings indicate that the initial effects of LD on microbial communities can diminish quickly, and soil microorganisms may adapt over time. Additionally, high EC and ammonium concentration in LD may have negatively affected soil microbial communities.

Food waste (FW) is a valuable resource for anaerobic digestion (AD) due to its biochemical composition. This study aimed to optimize AD using two widely used optimization methods: Response Surface Methodology with Box–Behnken Design (RSM-BBD) and Taguchi orthogonal array L9. Organic load, oxidation–reduction potential, pH, and hydraulic retention time were evaluated for biogas production and volatile solids removal (VS_r). The Taguchi method assessed responses based on the signal-to-noise ratio, resulting in optimal conditions for AD. After numerical optimization, the predicted biogas production was 440 mL, and VS_r was 19.5%. However, the experimental observations of biogas production were 850  mL, and VS_r was 41%. The RSM-BBD method, calculated based on analysis of variance, resulted in optimal conditions for AD, and after numerical optimization, the predicted biogas production was 852 mL, and VS_r was 43%. However, the experimental observations of biogas production were 906  mL, and VS_r was 44. Despite these results, the study found that Taguchi’s design provided approximate optimization response values and did not allow parameter interaction. In contrast, RSM-BBD provided precise optimal values and details on the impact of individual and combined parameters, making RSM-BBD the preferred choice for optimizing AD systems for better prediction accuracy and reproducibility.

Over the past decades, the mining industry has come to be considered as a material resource for sustainable development programs. Mining wastes are used as raw material in civil construction, minimizing the environmental impacts of waste disposal. However, the addition of these new materials requires in-depth studies on their behavior. This paper aims to study the mechanical behavior, petrography and microstructural analysis of mining waste recycled bricks produced in a full-scale research on sustainability in civil construction. Mechanical tests (compaction, compressive, and tensile strengths) were carried out. A petrographic examination according to international standards was conducted. Complementary scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis were performed. Mechanical tests showed that the addition of red mud can improve compressive strength by over 10% while the addition of fly ash does not show any improvement on the compressive strength. The petrographic characterization showed minerals thermally altered due to the temperatures reached in the brick manufacturing process and isotropic matrix showing glassy materials. The textural homogeneity (well-dispersed grains in a compact matrix) in the thin sections studied could explain the improvement on the geotechnical behavior of the bricks. Similar considerations can be obtained analyzing the geometry and quantity of pores.

In last few decades, there is massive growth in electric and electronics industry which leads to a high rate of obsolesce resulting decline in end of life (EOL) or end of use of the product. Circular economy is a concept used to close the material cycle loop in product ecosystem. The current situation of developing countries like India has a variety of issues in managing the e-waste generated, and only viable answer is to reduce waste output and practice recycling. To change into circular economy, it is necessary to identify the barriers affecting the circular economy for effective e-waste management. The aim of the article is to identify the barriers affecting circular economy of e-waste with previous literature and expert opinion from industries and academia, then analyses of barriers have been done using interpretive structural modeling (ISM) and fuzzy MICMAC technique. The result shows that lack of incentives, lack of customer awareness toward circular economy, and lack of government policies are the key barriers affecting circular economy of e-waste in India. This paper will assist organizations, recycling industries, and policymakers in building a sustainable environment strategy to achieve the effective circular economy of e-waste.

The objective of this study is to investigate the intention of waste pickers to participate in waste picker cooperatives. According to research, cooperatives improve waste pickers' quality of life. However, it is unclear how waste pickers perceive and interpret what is provided to them and if these advantages affect their attitudes and intentions. We provide a unique theoretical model that explains waste pickers’ intentions to join cooperatives by incorporating the theory of planned behavior. A total of 112 waste pickers, consisting of both Turkish individuals and immigrants, were included in the data collection process. The data were analyzed using partial least squares structural equation modeling, utilizing multi-group analysis by including social exclusion and nationality as moderators. One of the most striking findings is that pickers’ feeling of control over their planned action does not affect their intention to join cooperatives without an attitude. To clarify, waste pickers must initially develop a positive attitude towards perceiving the joining behavior as effortless. Our research also shows that socially excluded people trust and value cooperatives more, regardless of their nationality. This pioneering study on waste pickers’ willingness to join cooperatives and other novel findings will benefit scholars and policymakers.

The implementation of life-cycle assessment (LCA) was to quantify the potential environmental impact of activated carbon production from sewage sludge by the molten salt and impregnation methods. Based on the experiments of the molten salt and impregnation methods, a flowchart was developed and the environmental impact was determined. The results showed that the environmental impacts dominated by roasting, followed by grinding or impregnating and finally by washing and drying. The uses of electricity and ZnCl₂ in the production of activated carbon were the main factors causing environmental impact. The energy consumptions of the molten salt and impregnation methods were 56.16 and 73.44 MJ/kg activated carbon, respectively. The global warming potential of the molten salt and impregnation methods was found to be 14.68 and 17.15 kg CO₂ eq/kg activated carbon, respectively. The impregnation method had higher energy consumption and CO₂ emissions than those for the molten salt method. The LCA showed that the molten salt method offered environmental advantages in most impact categories in comparison with the impregnation method.

Photopolymers, which are composed of monomer, oligomer polymer, and their combinations and exhibit photochemical reactions when exposed to light, are now commonly employed in 3D printers, particularly in the flexographic printing industry, and are becoming waste. The utilization of waste solid sheet Photopolymer Plates (PhP) for bitumen modification is an efficient way of disposing of post-consumer items and an alternate method of obtaining new, high-quality modifiers. The consequences of using waste PhP in bitumen modification, both independently and in conjunction with Styrene–Butadiene–Styrene (SBS) were explored. By combining PhP and SBS, it is hoped that savings can be made without sacrificing performance due to the high rate of single SBS modification. The modified binders prepared using PhP and SBS both separately and together were subjected to conventional and rheological tests. The performance of 5% SBS modification could not be achieved at the highest rate that PhP can be used alone without creating a workability problem. The use of 5–7% PhP in combination with 2% SBS outperformed the single 5% SBS modification. This combined binder did not cause workability problems and showed good low and high-temperature behavior and was found to be an economical alternative to SBS modification.