Sustainable Waste Management Strategy Research Articles

Informing energy justice based decision-making framework for waste-to-energy technologies selection in sustainable waste management: A case of Iran

Due to problems such as limited land area for waste disposal and waste-borne diseases, waste management organizations have increasingly been offering technologies for recovering energy from waste. These technologies can help governments, local authorities, developers and investors for mitigating climate change and building sustainable societies. The suitable waste-to-energy production technology selection is a complex issue in waste supply chain management that must not only be assessed in terms of both socioeconomic and environmental criteria. With the purpose of balance between energy trilemma issues in the context of waste-to-energy generation and develop sustainable waste management strategies in the waste chain, energy justice criteria must also be taken into consideration. The paper considers the application of an integrated multi-criteria decision-making model consisting of fuzzy decision-making trail and evaluation laboratory method, the analytic network process and the simple additive weighting approaches. The integrated method can be applied to select the suitable technology in a sustainable manner, taking into account energy justice criteria. The applicability of proposed model is demonstrated by a case study of the technology selection in the city of Behbahan, Iran. It includes various technologies for waste-to-energy generation and ranks technologies from the most to least preferred as: Anaerobic digestion, Gasification, Pyrolysis, and Incineration.

An analysis of electronic waste management strategies and recycling operations in Malaysia: Challenges and future prospects

The generation of waste electrical and electronic equipment or e-waste has become a significant and current issue in the world, which brings negative environment and health impacts due to the presence of toxic metals and chemical substances. On the other hand, value recovery from e-waste offers significant economic benefits due to the valuable metals in e-waste, such as precious and base metals. Many developed countries have employed effective e-waste management strategies and state-of-art recycling technologies, such as integrated pyrometallurgical and hydrometallurgical smelters to manage this waste stream sustainably and extract the maximum value components from this secondary resource. This has not been the case in most of the developing countries and e-waste management is still in its infancy. The value recovery operations have been informal and semi-formal without incorporating required waste disposal strategies. Addressing this current socio-environmental issue, especially in developing countries, has been significant to achieve some of the United Nation's sustainable development goals (SDGs), such as clean water and sanitation (Goal 6), sustainable cities and communities (Goal 11), responsible production and consumption (Goal 12), and life below water (Goal 14), by 2030 (The United Nations: Sustainable development goals, 2018). This work discusses the current status in Malaysia in terms of both the e-waste management strategies connected to legislative frameworks and e-waste value recovery operations. Key socio-techno-economic challenges that hinder the application of sustainable waste management strategies and value recovery operations were identified and future directions that leads to the sustainable e-waste management in Malaysia will also be discussed.

A novel treatment of waste printed circuit boards by low-temperature near-critical aqueous ammonia: Debromination and preparation of nitrogen-containing fine chemicals

In waste printed circuit boards (PCBs), brominated epoxy resin (BER) and copper are the two types of material that attracts the most attention due to their environmental risk and resource value. In this study, a novel and high-efficiency process for debromination and resource recovery of waste PCBs by low-temperature near-critical aqueous ammonia (NCAA) was successfully developed. A batch reactor was used in experiments with the temperatures ranging from 200 to 350 °C and the reaction times from 30 to 90 min. The ammonia water in near critical conditions can act not only as a medium but also as a reactant. Approximately 100% of the Br in waste PCBs could be removed and trapped by the NCAA at 300 °C. Copper foil could be easily separated and recovered from waste PCBs after the NCAA process. No brominated organic compounds could be detected in the oil phase products after the NCAA treatment of waste PCBs even at low temperature of 200 °C. Two new products (pyrazine and pyridine compounds) with high value-added were obtained for the first time by the treatment of waste PCBs. This study provides a novel and efficient strategy for the debromination, the recovery of copper, and the preparation of high value-added nitrogen-containing fine chemicals from waste PCBs. The low-temperature NCAA processing of waste PCBs could effectively reduce the energy consumption in comparison with traditional thermal decomposition processes, and promote the sustainable waste management strategy for waste electrical and electronic equipment (WEEE).

Integrated Waste Management Through Symbiotic Culture, A Holistic Approach

Unsegregated heterogeneous mass of solid waste is a potential threat towards the safe processing and disposal of municipal solid waste [MSW], which is cumbersome and ancillary, elevates the expenditure. The absence of any pertinent technique to handle these bulky mass in an eco-friendly way makes it even more hectic for the MSW processing plants. But, this substantial mass constitutes a huge potential, which can be valorized through the larval digestion of a symbiotic macro culture, to create new economic niches for smallscale entrepreneurship in developing and under-developed nations. The present study incorporates a symbiotic waste reduction system with the efficient functionalism of micro and macro conversion agents which is attributed to the synthesis of waste derived co-products from the same platform. This study is solely a novel approach, which is capable of addressing a wide fraction of solid waste, domestic sewage, and bio-leachate and converts them into value-added coproducts within the magnificent period of time. Multiple experiments have been conducted under the controlled feeding environment with an established symbiosis between the BSF larvae, Wax Moth larvae [Galleria melonella], and effective microorganism culture. An initiation period of 5 days was allocated for the macro conversion agents and during the tenure, the larvae were supplied with synthetic diet to accelerate the body growth index. The entire experiments have been conducted in a newly formulated novel bioreactor namely, Integral Larval Grub Composting Reactor which is capable of performing automated pupal segregation and address solid and liquid waste under a single platform. The system enforces the zero liquid discharge concept and also helps in an indirect suppression of house fly growth. The novel approach only required 14-16 days in order to convert the solid waste into nutrient-rich manure, having significantly high-quality component. The operation has been executed in a number of batch processes and each process valorized a quantity of approx 30 kg. The targeted larval period has been prolonged by means of maintaining higher moisture content with the help of sewage supply and once the maturation period arrives the further addition of moisture has been restricted for 3 days. Overall it’s an ultimate and wholesome biological waste management technique, which is capable of standing solely to strengthen the sustainable waste management strategy. Keywords: Galleria melonella; Hermetia illucens; Larval period; Moisture; Plastic waste;

Upcycling unexplored dregs and biomass fly ash from the paper and pulp industry in the production of eco-friendly geopolymer mortars: A preliminary assessment

Green liquor dregs wastes coming from pulp and paper production are currently disposed in landfills at a huge cost for industry and the environment. In this work, a novel and more sustainable waste management strategy is proposed. Dregs were used for the first time as fine filler in the production of biomass fly ash-based geopolymeric mortars. The influence of the dregs incorporation amount on the fresh (geopolymer kinetics and mortars workability) and hardened-state (mechanical resistance, water absorption and capillary water absorption) properties of the mortars was evaluated. Although dregs incorporation reduce the flow workability (up to 19%), their presence and amount did not significantly alter the geopolymerization kinetics. Additionally dregs-containing mortars exhibited enhanced tensile (up to 71%) and compressive strength (up to 34%), and lower water absorption in comparison with the reference mortar. These results demonstrate the feasibility of using dregs as fine filler in geopolymers production. Moreover the mortars were produced using mainly biomass fly ash waste as aluminosilicate source which further reduces the environmental impact of the pulp and paper industry.

Analysis of Alternative MSW Treatment Technologies with the Aim of Energy Recovery in the Municipality of Vari-Voula-Vouliagmeni

The alternative municipal solid waste (MSW) management is directly linked to the reduction of the biodegradable fraction and total waste mass disposed to landfill sites. Nowadays, the design and implementation of flexible plants with thermal or biological treatment methods are recommended by European and National legislations as an extremely sustainable waste management strategy in terms of this purpose, capable of assuring the protection of the environment and human health as well as the production of renewable energy. This paper focuses on the techno-economic analysis of an integrated mechanical–biological treatment scheme which includes the technology of anaerobic digestion (AD) for combined heat and power (CHP). Additionally, the main design and technical parameters of the biogas to energy project under consideration as well as the local conditions and legal requirements are reviewed. The goal is to investigate the prospects of profitability arisen in the longer term by the integration of a small scale MSW concept and the replacement of the current practice of waste disposal for a suburban municipality of Athens.

TGA-FTIR investigation on the co-combustion characteristics of heavy oil fly ash and municipal sewage sludge

Combustion of heavy oil fly ash (HOFA) blended with municipal sewage sludge (MSS) in existing infrastructures may be a sustainable waste management strategy. In this work, the co-combustion of HOFA and MSS with mass ratios from 80/20 to 60/40 is investigated by TGA-FTIR to identify the thermal behaviors (combustion process, ignition and burnout characteristics) and gaseous emissions. Results indicate that co-combustion of HOFA and MSS is better than mono-combustion. MSS induces lower ignition temperatures of the blends, while HOFA tends to decrease the burnout temperatures. The ignition and comprehensive combustibility indices reach the maximum (1.78 × 10−5 % min−1 K−2, 2.66 × 10−8 %2 min−2 K−3) in the mixture with HOFA/MSS ratio of 80/20. The co-combustion characteristics of blends are synergistically influenced by HOFA and MSS. Moreover, the CaO originated from MSS contributes to the desulfurization effect to retain the SO2 emission.

Introduction to the Concept of Particleboard Production from Mixtures of Sawdust and Dried Food Waste

The promotion of sustainable waste management strategies has been highlighted with the introduction of the Waste Framework Directive, which favors the waste management practices that extend the life-cycle of waste. A significant fraction of municipal solid waste consists from food waste, the treatment of which is done primarily by means of conventional methods like composting and anaerobic digestion. The scope of this manuscript is the production of particleboards from dried food waste, thus reusing the waste and extending significantly their life-cycle. Dried food waste that were gathered from households were mixed with wood on a 1:10 ratio and with an epoxy resin. The mixture was compressed in a hydraulic hot press for the manufacturing of particleboards. The high starch content in the food waste was also an important feature that would assist the adhesion of the particleboards in a concept similar to pelletization. The products had regular structure and compactness, with the density ranging from 645 to 682 kg/m3. The thickness swelling ranged from 18.9 to 19.8% for 24-h experiments, while the water absorption ranged from 65 to 72% for the same time period. Leaching tests, both with deionized water and acetic acid, showed that the leachates had very low concentrations of heavy metals.

“Filthy rich” and “dirt poor:” social and cultural dimensions of solid waste management (SWM) in Lagos

This paper analyses how household solid waste was perceived and handled in traditional Yoruba and contemporary Lagos society in South West Nigeria. It highlights the roles of individuals, households, changing lifestyles and diet, business cycles, residential segregation, and state and non-state actors and institutions in waste management in Lagos. The filthy rich/dirt poor divide in Lagos is epitomised by spatial segregation and social stratification, reflected by contrasting highbrow neighbourhoods and massive dumpsites in the metropolis. Central to this discussion are changing economic dynamics. The boom years were characterised by conspicuous consumption, waste and replacement while economic adversity precipitated destitution, re-use and recycling of waste, and recourse to imported second-hand clothing and household utensils. The paper recommends a multi-pronged sustainable waste management strategy for Lagos.

Spent coffee grounds valorization through pyrolysis for energy and materials production in the concept of circular economy

The aim of the paper is to investigate the recovery of useful material and energy from waste, in the context of circular economy, by studying pyrolysis of spent coffee grounds, for the production of fuels and carbon materials such as biochar, to be further used as fertilizer in arid fields, thus closing loops in agriculture. Pyrolysis was carried out at temperature ranging from 400 to 700 ° C with a heating rate of 50 °C/s, at atmospheric pressure and inert atmosphere. The results have shown that a maximum yield of biooil can be achieved at 540° C (36 wt%) where the gas reached a yield 9 wt% and the char reached the 29 wt%. At 700 ° C, where oxidation reactions mainly take place against of cracking (gasification), gas yield reached 29 wt%, while biooil and char reached 20 wt% and 26 wt%, respectively. These preliminary data can challenge decision making in introducing sustainable food waste management strategies where pyrolysis can be the conversion pathway.

GHG Mitigation and Sustainability Co-benefits of Urban Solid Waste Management Strategies: a Case Study of Ahmedabad, India

Driven by rising income and urbanization in India, the urban solid waste generation and associated externalities are rising rapidly. Disposal of municipal solid wastes (MSW) in landfills without adequate treatment and segregation is leading to sizable local environmental impacts including land and water contamination, air pollution and emissions of methane which is a potent greenhouse gas. Continuation of the current waste disposal methods shall add to pressure on increasingly scarce land resources in the urban areas. This paper recognises two distinct spatial dimensions of the environmental impacts of urban waste; first, the local impacts which are typically addressed under the urban sustainability programmes and second, and the global climate change impacts from methane emissions which are implemented locally but are driven by the global climate change policies. The paper proposes a framework to integrate solid waste management strategies in cities to mitigate GHG emissions from land-fills and concurrently maximize sustainability cobenefits. Using the case of Ahmedabad, the paper explores three waste management scenarios. i) Business as Usual scenario ii) INDC Scenario follows the commitments as outlined in India's INDC and iii) sustainable low carbon scenario considers the transition towards the more resource efficient economy through implementation of sustainable waste management strategies The scenarios analysis, spanning till the year 2035 is used to identify the potential greenhouse emission reduction and local co- benefits accrue through waste management strategies.

Short-term greenhouse emission lowering effect of biochars from solid organic municipal wastes

Qatar economy has been growing rapidly during the last two decades during which waste generation and greenhouse gas emissions increased exponentially making them among the main environmental challenges facing the country. Production of biochar from municipal solid organic wastes (SOWs) for soil application may offer a sustainable waste management strategy while improving crop productivity and sequestering carbon. This study was conducted to (1) investigate the physicochemical parameters of biochars for SOW, (2) select the best-performing biochars for soil fertility, and (3) evaluate the potential benefits of these biochars in lowering greenhouse gases (GHGs) during soil incubation. Biochars were produced from SOW at pyrolysis temperatures of 300–750 °C and residence times of 2–6 h. Biochars were characterized before use in soil incubation to select the best-performing treatment and evaluation of potential GHG-lowering effect using CO2 emission as proxy. Here, soil–biochar mixtures (0–2%w/w) were incubated in greenhouse settings for 120 days at 10% soil moisture. Soil properties, such as pH, EC, TC, and WHC, were significantly improved after soil amendment with biochar. Two biochars produced from mixed materials at 300–500 °C for 2 h and used at 0.5–1% application rate performed the best in enhancing soil fertility parameters. A significant decrease in CO2 emission was observed in vials with soil–biochar mixtures, especially for biochars produced at 500 °C compared the corresponding raw materials which exhibited an exponential increase in the CO2 emission. Hence, application of biochar to agricultural soils could be beneficial for simultaneously improving soil fertility/crop productivity while sequestering carbon, thereby reducing anthropogenic emissions of GHGs.

A multi-objective model for sustainable recycling of municipal solid waste.

The efficient management of municipal solid waste is a major problem for large and populated cities. In many countries, the majority of municipal solid waste is landfilled or dumped owing to an inefficient waste management system. Therefore, an optimal and sustainable waste management strategy is needed. This study introduces a recycling and disposal network for sustainable utilisation of municipal solid waste. In order to optimise the network, we develop a multi-objective mixed integer linear programming model in which the economic, environmental and social dimensions of sustainability are concurrently balanced. The model is able to: select the best combination of waste treatment facilities; specify the type, location and capacity of waste treatment facilities; determine the allocation of waste to facilities; consider the transportation of waste and distribution of processed products; maximise the profit of the system; minimise the environmental footprint; maximise the social impacts of the system; and eventually generate an optimal and sustainable configuration for municipal solid waste management. The proposed methodology could be applied to any region around the world. Here, the city of Tehran, Iran, is presented as a real case study to show the applicability of the methodology.

Quantitative Metaproteomics Highlight the Metabolic Contributions of Uncultured Phylotypes in a Thermophilic Anaerobic Digester.

Biogas production through anaerobic digestion of organic waste provides an attractive source of renewable energy and a sustainable waste management strategy. A comprehensive understanding of the microbial community that drives anaerobic digesters is essential to ensure stable and efficient energy production. Here, we characterize the intricate microbial networks and metabolic pathways in a thermophilic biogas reactor. We discuss the impact of frequently encountered microbial populations as well as the metabolism of newly discovered novel phylotypes that seem to play distinct roles within key microbial stages of anaerobic digestion in this stable high-temperature system. In particular, we draft a metabolic scenario whereby multiple uncultured syntrophic acetate-oxidizing bacteria are capable of syntrophically oxidizing acetate as well as longer-chain fatty acids (via the β-oxidation and Wood-Ljundahl pathways) to hydrogen and carbon dioxide, which methanogens subsequently convert to methane.

Using Risk Assessment and Management Approaches to Develop Cost-Effective and Sustainable Mine Waste Management Strategies

Soil contamination by mine wastes is an enormous challenge for both mining companies and competent authorities. Mine wastes are usually considered a major source of impacts on human health and the environment. Thus, the prevailing strategy is to reduce or completely remove the contaminants of concern through appropriate in situ or ex situ remediation techniques. Nonetheless, today’s mine waste may become tomorrow’s ore. In order to keep this option open, however, several things need to change in the concept and practice of mine waste management. This paper presents a case study from Greece, where mine waste (mainly metallurgical slags) have been disposed of, posing excess risks to human health and the environment. Complete restoration of the site would not only be cost-prohibitive but would also eliminate any possibility of future exploitation of contained resources. Considering both the protection of human health and the environment and the storage of waste for future use, a risk assessment and management approach was adopted that allowed the selection of cost-effective measures in order to: eliminate health hazards, re-use the site for recreational purposes, and secure the opportunity for resource recovery in the future.

Applying life cycle assessment to support environmentally sustainable waste management strategies in Brazil

This paper aims to investigate sustainable waste management solutions for the city of Rio de Janeiro in Brazil, based on a life cycle approach. The Life Cycle Assessment (LCA) was performed by using the LCA-IWM methodology. The model was adapted to the Brazilian solid waste context and to the local characteristics, including waste composition, electricity mix and regulations. The annual amount of waste generated was the functional unit adopted. Eight municipal solid waste management strategies were evaluated. Scenarios including mixed waste collection and source separated collection as well as materials recovery and energy from waste were investigated. Scenarios were ranked based on the LCA results. Sensitivity analysis was carried out by varying the electricity mix. The results indicate that the current situation of municipal solid waste (MSW) in Rio de Janeiro presents the worst performance in terms of aggregated environmental burdens, indicating the urgency for implement new strategies toward a more environmentally friendly and sustainable MSW management system. It is noted that the better LCA performances were obtained in scenarios with high separately collection rates. Among them, the scenario based on recyclables recovery and anaerobic digestion shows to be a promising strategy to improve environmental sustainability. Sensitivity analysis demonstrates that the ranking of scenarios was not affected by changes in the electricity mix. From the results, the investment in source separated waste collection and materials recovery is the most environmentally friendly MSW strategy for Rio de Janeiro. In addition, scenarios with an emphasis in materials recovery presented higher environmental benefits than the alternatives focused on energy generation.

Development of Landscaped Landfills Using Organic Waste for Sustainable Urban Waste Management

Uncontrolled dumping of waste on open dumps or landfills has become one of the most common methods of disposing waste. Globally, such dumps/landfills have remained as an anomaly in urban landscapes due to its heterogeneous nature and the environmental degradation it causes. This paper considers open dumps/ landfills as specific example cases upgradable to ‘landscaped landfills’ so that landfills transform to be a more sustainable disposal option. Such an approach can be devised only by knowing the quality and quantity of the waste that are disposed in landfills and the background environmental conditions of a particular region. A landfill dominantly of organic/biodegradable character can become a good source of nutrients in developing the soft elements of landscape. In developing a landscaped landfill, the environmental risks associated such as leachate generation, groundwater contamination, greenhouse gas emission and soil stability are major concerns to be addressed. For a long term use of conventional landfills converted into ‘landscaped landfills’ the principles of environmental remediation techniques like phytoremediation, bioremediation and bio reactor landfills have a pivotal role to play.The research work aims at the disposing organic/biodegradable waste on any land or designated open dumps /landfills and simultaneously using the same land for green productive purpose in a cyclic fashion thereby making it a sustainable waste management strategy. The paper discusses the practical issues in converting a landfill into landscaped landfill by doing an onsite experiment using organic kitchen waste considering parameters like the number of households, their expected production of organic waste and suitable worked out land area for dumping, digesting and assimilating waste. In an attempt to streamline the process of planning landscaped landfills, the paper describes a strategy and methodology to convert landfills into a fitting component of typical urban landscapes through enhancing its environmental significance and visual quality for sustainability.

Waste-to-Energy in China: Key Challenges and Opportunities

China—the largest developing country in the world—is experiencing both rapid economic maturation and large-scale urbanization. These situations have led to waste disposal problems, and the need to identify alternative energy sources. Waste-to-energy (WTE) conversion processes, a source of renewable energy, are expected to play an increasingly important role in China’s sustainable management of municipal solid waste (MSW). The purpose of this research is to investigate the key problems and opportunities associated with WTE, to provide recommendations for the government. This paper begins by describing China’s current MSW management situation and analyzing its waste disposal problems. The major challenges associated with China’s WTE incineration are then discussed from economic, environmental and social points of view. These include the high costs associated with constructing necessary facilities, the susceptibility of facilities to corrosion, the lower heating value of China’s MSW, air pollutant emissions and especially public opposition to WTE incineration. Since discarded waste can be used to produce energy for electricity and heat—thus reducing its volume and the production of greenhouse gas (GHG) emissions—with government policies and financial incentives, the use of WTE incineration as a renewable energy source and part of a sustainable waste management strategy will be of increasing importance in the future. The paper concludes by summarizing the management, economic and social benefits that could be derived from developing the country’s domestic capacity for producing the needed incineration equipment, improving source separation capabilities, standardizing regulatory and legal responsibilities and undertaking more effective public consultation processes.

Development of a decision model for the techno-economic assessment of municipal solid waste utilization pathways

Economic competitiveness is one of the key factors in making decisions towards the development of waste conversion facilities and devising a sustainable waste management strategy. The goal of this study is to develop a framework, as well as to develop and demonstrate a comprehensive techno-economic model to help county and municipal decision makers in establishing waste conversion facilities. The user-friendly data-intensive model, called the FUNdamental ENgineering PrinciplEs-based ModeL for Estimation of Cost of Energy and Fuels from MSW (FUNNEL-Cost-MSW), compares nine different waste management scenarios, including landfilling and composting, in terms of economic parameters such as gate fees and return on investment. In addition, a geographic information system (GIS) model was developed to determine suitable locations for waste conversion facilities and landfill sites based on integration of environmental, social, and economic factors. Finally, a case study on Parkland County and its surrounding counties in the province of Alberta, Canada, was conducted and a sensitivity analysis was performed to assess the influence of the key technical and economic parameters on the calculated results.

THE NATURE AND CHALLENGES OF STREET SWEEPING IN ADO-EKITI

This study examined the nature of street sweeping, the composition of litters, the socio-economic and health status of street sweepers and the public perception of the benefits and challenges of street sweeping in Ado-Ekiti. Primary data were obtained through direct personal observation, questionnaire administration and in-depth interview while secondary data were sourced from published and unpublished documents. Purposive and random sampling methods were adopted in the selection of respondents for questionnaire administration. Four types of structured questionnaire were designed and administered separately to: 103 (20%) of the street sweepers along the 21 swept streets; 193 (5%) buildings along the 21 streets; 14 officials of the Ekiti State Waste Management Authority involved in the street sweeping programme, and 42 pedestrians (female and male) along the 21 swept streets. Descriptive statistics were used to analyse the data collected. Findings revealed that all the street sweepers were females and casual workers. Sediments/broken blocks/sand/gravel (18.8%), plastics (16.6%), nylon/polythene (16.6%), leaves/wood/grass (15.0%), food wastes (12.6%), paper (9.9%), aluminum cans/metals/glass (5.3%), and miscellaneous (5.2%) constituted the street litters. The sweepers suffered from joint pain (96.1%), catarrh (91.3%), cough (83.5%) eye infection (70.8%) asthma (46.6%) and malaria (31.1%). Inadequate personnel, insufficient tools and equipment, poor remuneration, stigmatisation, exposure to accidents and harassment were the challenges faced by the sweepers. The benefits created by the street sweeping programme are: city beautification and aesthetics (74.6%); employment opportunity (16.6%); improved urban environmental health (6.2%), and attractiveness of the streets (2.6%).The study concluded that the street sweeping programme has made the streets sanitary and aesthetically pleasing, provided employment and raised public perception of Ado-Ekiti as a clean and healthy city. Employment of more sweepers, provision of adequate equipment, public sensitisation and attitudinal change, enforcement of environmental sanitation laws, and improved remuneration will make street sweeping a sustainable waste management strategy in Ado-Ekiti.