Open dumping is a common practice for MSW disposal in most of the Indian cities, apart from the metro-cities. This practice poses significant environmental and health risks due to toxic and greenhouse gases (GHGs) emission through direct combustion and/or decay of wastes. Therefore, integrated solid waste management (ISWM) using different methods viz., incineration, composting, anaerobic digestions, refuse derived fuel, material recovery facility and sanitary landfilling, is much needed. Accordingly, three waste management case scenarios were studied for year 2001-2051 by keeping weightage of sustainable development goals 2030 of India. Case I depicts Indian present scenario of waste management where 164-735 tonnes/year of wastes would be generated for year 2001-2051. Further, 60% of waste can be treated in case II that help in reducing the land requirement up to 40% from estimated conditions of 2031 i.e., 83.8 × 107 m3. The case III is most ideal waste management condition for year 2031 to reduce 80% waste hence landfill requirement would minimize up to 16.76 × 107 m3 where population is at controlled conditions. This article concludes the formal handling and treatment of ISWM would minimize the landfilling, where LCA can be an antidote to achieve sustainable development goals.
Asma Nouira, Mabrouk Ben Hamden, Mouna Sayehi
et al.
The escalating global water crisis, coupled with the unsustainable accumulation of industrial and urban waste, demands innovative solutions that align with circular economy principles. This review explores the transformative potential of waste-derived ceramic membranes as a sustainable strategy for water purification, simultaneously addressing waste valorization and clean water scarcity. Ceramic membranes, traditionally fabricated from high-purity inorganic materials, are renowned for their superior chemical resistance, thermal stability, and durability. Recent advances demonstrate that industrial byproducts, such as red mud, coal fly ash, blast furnace slag, coal gangue, and kiln roller waste, can be effectively repurposed into cost-effective, high-performance filtration materials. This paper critically examines fabrication techniques, material properties, and performance metrics of waste-derived ceramic membranes. By transforming industrial waste into functional filtration materials, this approach not only mitigates environmental pollution but also contributes to sustainable water security.
Khanyisile Lepota, Kasturie Premlall, Major Mabuza
The modern world has brought extensive socioeconomic and ecological changes. Urbanization in developing nations has significantly increased municipal solid waste, necessitating in-depth understanding of waste composition particularly in developing nations for sustainable management practices. This study aimed to classify and characterize waste while evaluating potential waste management methods. Mixed methods were used to examine landfilled waste from Soshanguve and Hatherley sites in Tshwane Metropolitan, South Africa, using techniques such as Fourier transform infrared spectroscopy, X-ray fluorescence, proximate, and ultimate analysis. Seasonal variations in waste components were analysed over two seasons. The study identified that both sites are predominantly composed of organic waste, accounting for over 42 wt.%, with moisture content of ~50 wt.%, and minimal recyclables (<5 wt.%). Seasonal variations in MSW were significant for glass (<4% increase), organic waste (<5% increase), while plastic decreased by ~7% during spring. The biodegradable waste showed high carbon (>50%) and oxygen (>40%) levels, low ash content (<18%), and calorific values of 15–19 MJ/kg. Biodegradables mainly contained oxides of calcium, silicon, iron (III), and potassium with chemical composition indicating functional groups that emphasize composting and energy recovery benefits. The research provides insights into sustainable waste management, revealing waste composition at Tshwane landfills, aiding informed decision-making for resource usage and environmental conservation.
A novel framework is proposed to support the prediction of the plastic waste (PW) collection demand, route optimization, and overall management of PW from individual facilities. Based on electronic manifests from a local recycling company in Fukuoka, Japan, we developed a two-step artificial intelligence (AI)-based approach for predicting the demand for industrial PW (IPW) collection from a hospital. The daily hospital visitor numbers were introduced as a new independent variable in the IPW collection demand prediction. The stability (robustness) of each model was measured by its variance through experiments for two variable groups in four validation months. We found that introducing the visitor variables into IPW collection demand predictions was effective. A high monthly mean accuracy (85.06%) was achieved in predicting the daily IPW collection demand, which exceeded the accuracy of predictions using models without visitor records (84.44%). The stability of the Fine tree model with the highest prediction accuracy for March 2020 was 0.0466 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>∓</mo></mrow></semantics></math></inline-formula> 0.0174. Based on the findings of this study, we propose several strategies for waste management: enhancing prediction models, controlling visitor flows, and analyzing working patterns. This study successfully links AI techniques with a human mobility monitoring system (location data) for waste management using MATLAB.
Currently, the generation of electricity in most countries around the world primarily relies on fossil fuels, which contribute significantly to environmental degradation and climate change. Municipal solid waste (MSW) presents a promising alternative energy source, as various technologies now exist to treat waste and recover its energy. This shift helps to reduce reliance on non-renewable resources and tackles the growing issue of waste management. This article comprehensively reviews three waste-to-energy technologies: anaerobic digestion, gasification and plasma gasification. It covers the fundamental principles behind each technology, their efficiency in energy recovery, the associated costs and their practical applications. Additionally, the article delves into the technical challenges faced in implementing these technologies, such as their scalability, economic feasibility and environmental impacts. By evaluating these technologies, the article aims to provide insights into their potential for contributing to a more sustainable and circular energy system.
Daniel Mattos, Joaquim C. G. Esteves da Silva, Luis Pinto da Silva
Steel consumption in the construction sector is one of the main contributors to global greenhouse gas emissions. Therefore, developing processes for the reuse of steel-based products with lower environmental impacts is essential for the sustainability of the construction sector. One example is the reuse of metal road guardrail beams on highways. This study investigated the environmental sustainability of a reconditioning process for such beams, instead of using new guardrails. The environmental impacts of the process were studied and compared with the impacts of the traditional production process using a Life Cycle Assessment (LCA) approach. This study revealed that most of the impacts of the reconditioning process derive from the use of electricity. The comparison with the traditional beam production process revealed that when primary raw materials are replaced by reused raw materials, the environmental impacts associated with the production process decrease significantly. Of the 19 impact indicators assessed, 18 were lower, and 17 had a drop of more than 90 percent compared to the traditional production process. The results indicate that the reconditioning process has the potential to significantly reduce environmental impacts by avoiding the consumption and transportation of primary raw materials, which were identified as the main sources of impacts in the traditional production process, as well as minimizing waste generation.
Gertruth Leevhan Tihin, Kim Hung Mo, C. C. Onn
et al.
The global municipal solid waste (MSW) generation rate is 2.01 billion metric tonnes annually with an average of 0.74 kg waste/person/day. Approximately 92 % of the MSW originates from organics composition (e
This study concerns the optimization of an industrial recycling line; in other terms, this paper aims to find the optimal processing parameters that allow for a decrease in the loss of stress crack resistance (SCR) using a notched crack ligament stress (NCLS) test and an increase in the gain of the elongation at break, flexural modulus, and Izod impact strength of a polyethylene (PE) blend before and after recycling. The recycling line is composed mainly of a mono- and twin-screw extruder and a filtration system. Hence, the research question is as follows: How can we optimize the recycling process, without compromising the mechanical properties of recycled polyethylene (PE) blends? To answer the research question, Taguchi’s design of experiment and grey relational analysis (GRA) for multiobjective optimization was applied. Experiments were performed according to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>L</mi></mrow><mrow><mn>16</mn></mrow></msub></mrow></semantics></math></inline-formula> standard orthogonal array based on five process parameters: mono-screw design, screw speed of the mono- and twin-screw extruder, melt pump pressure, and filter mesh size. Based on grey relational analysis (GRA), the optimal setting of process parameters was identified, and a barrier screw and a higher screw speed for both extruders were allowed to have optimal mechanical properties. Furthermore, the analysis of variance (ANOVA) indicated that the mono-screw design and screw speed of the mono- and twin-screw extruder significantly impact the mechanical properties of recycled polyethylene (PE) blends.
Santa Margarida Santos, Margarida Gonçalves, Paulo Brito
et al.
The production of heterogeneous solid waste, such as municipal solid waste (MSW), construction and demolition waste (CDW), and industrial solid waste (ISW), has increased dramatically in recent decades, and its management is one of today’s biggest concerns. Using waste as a resource to produce value-added materials such as char is one of the most promising strategies for successful and sustainable waste management. Virtually any type of waste, through various thermochemical technologies, including torrefaction, pyrolysis, hydrothermal carbonization, and gasification, can produce char with potential material and energy applications. Pyrolysis is the most widespread technology, and there are more studies on producing and applying waste-derived char using this technology. The properties of waste-derived char seem to be influenced by the conversion technology and conditions, as well as by the composition of the source waste. A literature search indicated that the properties of waste-derived char are highly variable with the composition of the raw material, with carbon content in the range 8–77%, a higher heating value of 2.5–28.4 MJ/kg and a specific surface area of 0.7–12 m<sup>2</sup>/g. Depending on the properties of char derived from waste, there are greater or minor difficulties in applying it, with ash content, heavy metals, and polycyclic aromatic hydrocarbon (PAH) concentrations being some of its limiting properties. Therefore, this review attempts to compile relevant knowledge on the production of waste-derived char, focusing on heterogeneous solid waste, applied technologies, and practical application routes in the real world to create a supply chain, marketing, and use of waste-derived char. Some challenges and prospects for waste-derived char are also highlighted in this study.
Muyiwa Lawrence Adedara, Ridwan Taiwo, Hans-Rudolf Bork
The annual volume of waste generated in sub-Saharan Africa (SSA) increased from 81 million tonnes to 174 million tonnes per year between 2012 and 2016 and is projected to reach 269 million tonnes in 2030. In 2018, SSA’s municipal solid waste (MSW) collection coverage was estimated at 44%. Concerned that the waste generation rate outweighs the collection pace, we conducted a systematic review of studies on MSW collection to examine the current situation in the region concerning the waste collection and coverage rates and to highlight the impediments to rapid progress in waste collection using the lens of four cities. Findings reveal that, despite the involvement of private waste collectors, collection and coverage rates are still below the desired 100% with backlogs of uncollected waste in public spaces, especially in low-income neighbourhoods where coverage remains abysmally low. This study fortifies the systematic discussion on MSW collection and coverage rates by conducting a meta-analysis. The result of the analysis shows that the waste collection and coverage rates are 65% and 67% in SSA, respectively. Aside from the paucity of data on waste generation rate and characterisation, most available data are incongruent. The review further shows that although several studies have been carried out on waste disposal, waste treatment and recycling in SSA studies directly focused on MSW collection are still few, leaving room for more research in this area. The review offers suggestions on how collection and coverage rates can be increased and equally proposes a strategy for reducing scavenging activities in the region’s unsanitary landfills, given its concomitant health impacts on the scavengers.
W. A. M. A. N. Illankoon, Chiara Milanese, Maria Cristina Collivignarelli
et al.
The quantity of organic waste generated by agricultural sectors is continually increasing due to population growth and rising food demand. Rice is the primary consumable food in Asia. However, many stakeholders follow a linear economic model such as the “take–make–waste” concept. This linear model leads to a substantial environmental burden and the destruction of valuable resources without gaining their actual value. Because these by-products can be converted into energy generating and storage materials, and into bio-based products by cascading transformation processes within the circular economy concept, waste should be considered a central material. This review examines the composition of rice straw, bran, and husks, and the procedures involved in manufacturing value-added goods, from these wastes. Moreover, starting with an extensive literature analysis on the rice value chains, this work systematizes and displays a variety of strategies for using these by-products. The future development of agricultural waste management is desirable to capitalize on the multi-functional product by circulating all the by-products in the economy. According to the analysis of relevant research, rice straw has considerable potential as a renewable energy source. However, there is a significant research gap in using rice bran as an energy storage material. Additionally, modified rice husk has increased its promise as an adsorbent in the bio-based water treatment industry. Furthermore, the case study of Sri Lanka revealed that developing countries have a huge potential to value these by-products in various sectors of the economy. Finally, this paper provides suggestions for researchers and policymakers to improve the current agriculture waste management system with the best option and integrated approach for economic sustainability and eco- and environmental solution, considering some case studies to develop sustainable waste management processes.
Emilio E.X. Guimaraes Filho, Adriano Pinto Mariano, Rubens Maciel Filho
In the past 10 years, Brazil’s government has been investing in alternative sources to decrease the high dependence of the electricity grid on hydropower plants, mainly due to a constant decrease in pluviometry levels. A promising fuel in the context of the circular economy is refuse-derived fuel (RDF), which is the combustible fraction of Municipal Solid Wastes. It has high calorific power, low levels of hazardous components, and is a more homogeneous material. Moreover, RDF is an abundant, secure source of fuel with a market price nearly independent of external currencies. As gasification is a common Waste-To-Power (WTP) technology used worldwide, this work evaluated the electricity generation by this technology on a small scale (200 kW), using air as a gasifying agent and gas turbines, and according to Brazilian legal requirements regarding the composition of RDF. The process was simulated in Aspen Plus v8.6 for an RDF with an LHV of 15.9 MJ/kg. Sensitivity analysis on key operational parameters showed that for the representative composition of RDF in Brazil, an ER between 0.1-0.3 would be suitable for a gasification process, resulting in a net electrical efficiency of 22-27%.
Chemical engineering, Computer engineering. Computer hardware
Eduardo J. P. Martin, Deborah S. B. L. Oliveira, Luiza S. B. L. Oliveira
et al.
The improper disposal of PET bottle waste in Brazil jeopardizes the sustainability goals, impacting the social, economic, and environmental aspects. In order to tackle this issue, this study introduces a framework that was developed using a combination of environmental and social life cycle assessments (LCAs), along with a modified Analytic Hierarchy Process (AHP) methodology. Nine disposal scenarios were evaluated in Bauru, Brazil, including various combinations of landfills, sorting cooperatives, and incineration. Environmental (Env-LCA) and social (S-LCA) assessments followed the ISO 14040 standards, with the S-LCA incorporating the UNEP/SETAC guidelines. Scenario 9 was identified as the most sustainable option from the evaluated scenarios, with 100% of the waste sent to sorting cooperatives, with modified collection schemes. Conversely, Scenario 1, with a high landfill percentage, proved to be the least sustainable.
This article, based on previously unexplored archival documents, examines the recycling of rags in the early Soviet Union, using the Ukrainian Soviet Socialist Republic (SSR) as a case study. Within the context of the early Soviet waste regime, the characteristics of the Ukrainian rag market, its key participants, the challenges they encountered, and the strategies they devised in a republic with limited textile waste are investigated. The article asserts that in the Ukrainian SSR during the 1920s, the paper industry emerged as the primary consumer of rags. Consequently, the secondary utilization of rags in this sector should be regarded as the authorities’ endeavor to extensively utilize substitutes in light of the limited reserves of cellulose and timber in the republic. Rags were also an important export resource, driven more by ideological reasons than purely economic ones. The article demonstrates the specificities of waste management policies during the New Economic Policy period, characterized by the authorities’ directive methods of regulating the market, attributable to the strategic significance of this type of raw material for Soviet enterprises. It contends that the transition to a centralized waste collection model in the early 1930s was a natural outcome of the implementation of the planned economy. However, intense competition for various waste materials, particularly rags, contributed to this transition.
Municipal refuse. Solid wastes, Standardization. Simplification. Waste
This research presents a new solution to use bottle glass wastes together with aluminum hydroxide for porous alumina glass ceramics synthesis. The firing of the samples was conducted at three temperatures: 800, 1000 and 1200 °C. The effect of the bottle waste glass addition on the firing shrinkage, apparent density porosity, chemical stability and compression strength of the sintered samples was investigated. The dimensional stability of the samples, varying between 4.75–11.87% is positively affected by waste glass/alumina substitution ratio. Higher amounts of glass waste lead to higher apparent densities, up to 1.80 g/cm<sup>3</sup> and lower apparent porosities, around 33.74%, depending on the heat treatment temperature. All the studied glass ceramics have very good chemical stability that increase with the glass waste/alumina ratio. The compression strength of the obtained samples, ranging between 4.72–24.20 N/mm<sup>2</sup> is negatively affected by increasing the glass waste amount due to its brittle behavior. The obtained results suggest the viability of the proposed recycling alternative for bottle glass waste together with aluminum hydroxide as porous alumina glass ceramics.
Aluminum dross (AD) is a hazardous waste that contains valuable metallic Al and reactive aluminum nitride (AlN). The intergrowth of Al and AlN presents a challenge to Al recovery and AlN removal. In the current work, a mechanical milling method was developed to separate Al and AlN. Steel bars and balls were used as grinding media. The AD particle size decreased after milling and was distributed in the ranges 0.425–2 mm, 0.15–0.425 mm, 0.08–0.15 mm, and <0.08 mm. The particle size distribution was affected by the ball milling media and grinding time. Steel ball media had a better grinding effect on particles > 2 mm. After ball milling, the Dp0.08–2 mm size fraction accounted for approximately 90%. With changes in particle size, the element content of AD varied: the fraction of metallic Al decreased, while the fraction of Si increased. Metallic Al mainly existed in particles with size > 0.425 mm, accounting for 48.5%. AlN mainly existed in Dp0.15–0.425 mm, accounting for 64.9%. The optimal milling conditions achieved a 65% Al recovery rate and a 90% AlN separation efficiency. This work provides a promising approach for highly efficient pretreatment for AD recovery and AlN elimination in industrial applications.