Municipal Solid Waste Characterization and Landfill Gas Generation in Kakia Landfill, Makkah

Landfill leachate a potential challenge towards sustainable environmental management

The increasing amount of waste globally has led to a rise in the use of landfills, causing more pollutants to be released through landfill leachate. This leachate is a harmful mix formed from various types of waste at a specific site, and careful disposal is crucial to prevent harm to the environment. Understanding the physical and chemical properties, age differences, and types of landfills is essential to grasp how landfill leachate behaves in the environment. The use of Sustainable Development Goals (SDGs) in managing leachate is noticeable, as applying these goals directly is crucial in reducing the negative effects of landfill leachate. This detailed review explores the origin of landfill leachate, its characteristics, global classification by age, composition analysis, consequences of mismanagement, and the important role of SDGs in achieving sustainable landfill leachate management. The aim is to provide a perspective on the various aspects of landfill leachate, covering its origin, key features, global distribution, environmental impacts from poor management, and importance of SDGs which can guide for sustainable mitigation within a concise framework.

Overview of municipal solid waste management in sub-tropical climatic region of North Eastern India

Municipal solid waste management (MSWM) is perceived as a global issue regardless of the place of waste generation. The amount of unmanaged waste is increasing rapidly, along with its impact on the environment and human health. In hilly areas, specifically the North Eastern Region (NER) states of India, due to the unique topography coupled with socio-economic factors, there are inadequate waste management practices marked by insufficient infrastructure, minimal research studies, and limited data availability. This paper comprehensively reviews the existing status of MSWM practices and waste treatment technologies, identifies the challenges, and discusses the prospective approaches for MSWM in NER states of India. NER, is characterized by its hilly terrain and has the most diverse demographic profile in the country. The study highlights the notable increase in waste generation in the urban population in NER. The total amount of waste generated in NER is about 2907 tons per day, with a collection rate of 86.96%, treatment at 31.09%, and landfilling at 33.67%. The biodegradable fraction makes up the majority of waste composition (more than 50%) in NER, followed by recyclables and inert. The existing MSWM consists of waste collection, transportation, and disposal with limited source segregation and treatment. All the states of NER practice open dumping and burning as the primary waste treatment and disposal system. The study discusses the challenges and prospects to ensure effective MSWM in NER. This review is a region-specific study that considers cultural diversity, topography, and socio-economic dynamics. The outcome of this review will be helpful to the researchers and policymakers in making appropriate waste management plans and improve the MSWM system in NER.

Global perspective of municipal solid waste and landfill leachate: generation, composition, eco-toxicity, and sustainable management strategies

Globally, more than 2 billion tonnes of municipal solid waste (MSW) are generated each year, with that amount anticipated to reach around 3.5 billion tonnes by 2050. On a worldwide scale, food and green waste contribute the major proportion of MSW, which accounts for 44% of global waste, followed by recycling waste (38%), which includes plastic, glass, cardboard, and paper, and 18% of other materials. Population growth, urbanization, and industrial expansion are the principal drivers of the ever-increasing production of MSW across the world. Among the different practices employed for the management of waste, landfill disposal has been the most popular and easiest method across the world. Waste management practices differ significantly depending on the income level. In high-income nations, only 2% of waste is dumped, whereas in low-income nations, approximately 93% of waste is burned or dumped. However, the unscientific disposal of waste in landfills causes the generation of gases, heat, and leachate and results in a variety of ecotoxicological problems, including global warming, water pollution, fire hazards, and health effects that are hazardous to both the environment and public health. Therefore, sustainable management of MSW and landfill leachate is critical, necessitating the use of more advanced techniques to lessen waste production and maximize recycling to assure environmental sustainability. The present review provides an updated overview of the global perspective of municipal waste generation, composition, landfill heat and leachate formation, and ecotoxicological effects, and also discusses integrated-waste management approaches for the sustainable management of municipal waste and landfill leachate.

Forecasting the effects of municipal solid plastic waste generation and streaming using system dynamics: A case study in Dubai

To effectively manage municipal solid plastic waste (MSPW), municipalities need to select an appropriate combination of policies and technologies. Numerous policies and technologies are inputs for this selection problem, whereas decision-makers pursue several economic and environmental outcomes. The MSPW flow-controlling variables serve as an intermediary between the inputs and outputs of this selection problem. Examples of the flow-controlling, mediating variables include the source-separated and incinerated MSPW percentages. This study proposes a system dynamics (SD) model that anticipates the influence of these mediating variables on multiple outputs. The outputs include volumes of four MSPW streams and three sustainability-related externalities: GHG emissions reduction, net energy savings, and net profit. Using the SD model, decision-makers can determine the best levels for the mediating variables based on the desired outputs. Consequently, decision-makers can identify the MSPW system stages at which they must choose policies and technologies. Additionally, the values of the mediating variables will help clarify for decision-makers how strict they should be when imposing policies and how much to invest in technologies at the selected MSPW system stages. The SD model is applied to Dubai's MSPW problem. A sensitivity analysis experiment conducted on Dubai's MSPW system demonstrates that the earlier an action is taken, the better the results will be achieved. Consequently, reducing municipal solid waste should take priority, followed by increasing source separation, then post-separation, and finally, incineration with energy recovery. The results of another experiment employing a full factorial design with four mediating variables indicate that recycling would impact GHG emissions and energy reduction values more than incineration with energy recovery. However, these savings are global in nature.

Treatment of landfill leachate using photocatalytic based advanced oxidation process - a critical review

Landfill leachate is a discrete volumetric component of municipal solid waste; hence, researchers and professionals are more concerned about it because of its obscurity. Innovative treatment and emerging technologies are being scrutinized to address the treatment of landfill leachate challenges. The leading target of this review was to examine the possibility of removing recalcitrant organic pollutants from landfill leachate by photocatalytic-based advanced oxidation processes. A summary of the systematic applicability of conventional treatment for landfill leachate is provided, with a focus on physico-chemical and biological processes. The biological treatment, such as aerobic and anaerobic digestion, is an excellent technique for treating highly concentrated organic pollutants in the wastewater. However, Leachate can scarcely be treated using conventional techniques since it is enriched with refractory organics and inorganic ions. It is clear from the literature review that none of the available combinations of physico-chemical and biological treatments are entirely relevant for the removal of recalcitrant organic pollutants from leachate. Recently, the photo-assisted TiO2/ZnO oxidation has shown an excessively potential and feasible way to treat landfill leachate. TiO2/ZnO photocatalysis is currently developing to treat recalcitrant organic pollutants from landfill leachate. The effect of operating parameters reveals that pH and temperature affect the reaction rate. The addition of oxidant H2O2 to the TiO2/ZnO suspension suggests that TiO2 leads to an increase in the rate of reaction when compared to ZnO. Photocatalytic remediation technique of landfill leachate would support the goal of environmental sustainability by greatly enhancing the effectiveness of treated leachate reutilization. In this review, the selection of the best photocatalytic treatment for leachate based on its systematic relevance and potential conditions, characteristics, cost-effectiveness, essential controlling, discharge limit, long-term environmental effects, and its future study perspectives are emphasized and discussed.

Estimation of biogas generation rate and carbon sequestration potential from two landfill sites in southern India

Anaerobic digestion of organic solid waste is one of the mechanisms for sustainable development since it permits both the energy-efficient disposal of solid waste and the use of biogas. As a result, this study provides an assessment of the potential energy and emissions saved by using biogas energy generated from the biodegradation of solid waste. For present study two major cities are selected in south India namely Madurai, Tamil Nādu and Hyderabad, Telangana. The LandGEM 3.03 model is used to estimate the concentration of total landfill gases. The landfill in Madurai produced 2.162 × 106 cu. m per year of methane emissions in the year 2013. The production of biogas has increased over time would continue to increase until 2045, when a production rate of 6.32 × 107 cu. m per year was recorded as the largest concentration of biogas ever generated. For the Hyderabad landfill, methane concentrations during the year 2013 was recorded to be 2.5 × 107 cu. m per year and reached a peak in 2046 with a concentration of 3.7 × 108 cu. m per year, was found to have a potential to generate 2.1 × 106 kWh per year. For the Madurai dump site, the energy potential increases gradually and reaches a peak during the year 2047 with a value of 4.54 × 107 kWh per year. Whereas for Hyderabad dump site was found to have an energy equivalent of 2.1 × 108 kWh per year during 2024 and reaches a peak during 2046 with an energy equivalent of 5.1 × 108 kWh per year.

Gas transport in landfill cover system: A critical appraisal

Landfill gas (LFG) emission is gaining more attention from the scientific fraternity and policymakers recently due to its threat to the atmosphere and human health of the populace living in surrounding premises. Though landfill cover (LFC) (viz., daily, intermittent and final cover) is widely used by landfill operators to mitigate or reduce these emissions, their overall performance is still under question. A critical analysis of available literature, primarily pertaining to (i) the composition of the landfill gases and their migration in the LFC system, (ii) experimental and mathematical investigations of the transport mechanism of gas and (iii) the impact of additives to cover soils on transport and fate of gas, has been conducted and presented in this manuscript. Investigation of the efficiency of modified soil was mainly focused on laboratory test. More field tests and application of amended cover soils should be conducted and promoted further. Studies on nitrous oxide and emerging pollutants, including poly-fluoroalkyl substances transport in landfill cover system are limited and need further research. The transport mechanisms of these unconventional contaminants should be considered regarding the selection of LFC materials including geomembrane and geosynthetic clay liners. The existing analytical and numerical models can provide a basic understanding of LFG transport mechanisms and are able to predict the migration behaviour of LFG; however, there are still knowledge gaps concerning the interaction between different species of the gas molecule when modeling multi-component gas transport. Gas transport through fractured cover should also be considered when evaluating LFG emission in the future. Simplified design method for landfill cover system regarding LFG emission based on analytical models should be proposed. Overall, mathematical models combined with experiments can facilitate more visualized and intensive insights, which would be instrumental in devising climate adaptive landfill covers.

IoT-Based Waste Management System in Formal and Informal Public Areas in Mecca

Urban areas worldwide are in the race to become smarter, and the Kingdom of Saudi Arabia (KSA) is no exception. Many of these have envisaged a chance to establish devoted municipal access networks to assist all kinds of city administration and preserve services needing data connectivity. Organizations unanimously concentrate on sustainability issues with key features of general trends, particularly the combination of the 3Rs (reduce waste, reuse and recycle resources). This paper demonstrates how the incorporation of the Internet of Things (IoT) with data access networks, geographic information systems and combinatorial optimization can contribute to enhancing cities' administration systems. A waste-gathering approach based on supplying smart bins is introduced by using an IoT prototype embedded with sensors, which can read and convey bin volume data over the Internet. However, from another perspective, the population and residents' attitudes directly affect the control of the waste management system. The conventional waste collection system does not cover all areas in the city. It works based on a planned scheme that is implemented by the authorized organization focused on specific popular and formal areas. The conventional system cannot observe a real-time update of the bin status to recognize whether the waste level condition is 'full,' 'not full,' or 'empty.' This paper uses IoT in the container and trucks that secure the overflow and separation of waste. Waste source locations and population density influence the volume of waste generation, especially waste food, as it has the highest amount of waste generation. The open public area and the small space location problems are solved by proposing different truck sizes based on the waste type. Each container is used for one type of waste, such as food, plastic and others, and uses the optimization algorithm to calculate and find the optimal route toward the full waste container. In this work, the situations in KSA are evaluated, and relevant aspects are explored. Issues relating to the sustainability of organic waste management are conceptually analyzed. A genetic-based optimization algorithm for waste collection transportation enhances the performance of waste-gathering truck management. The selected routes based on the volume status and free spaces of the smart bins are the most effective through those obtainable towards the urgent smart bin targets. The proposed system outperforms other systems by reducing the number of locations and smart bins that have to be visited by 46% for all waste types, whereas the conventional and existing systems have to visit all locations every day, resulting in high cost and consumption time.

Estimating the methane emissions and energy potential from Trichy and Thanjavur dumpsite by LandGEM model

One major factor, contributing to the emission of greenhouse gas in the environment, is generation of hazardous gases in municipal landfills. Due to these potential negative impacts, it is obligatory to estimate the amount and type of landfill gasses to design and build a gas collecting system. Landfill gas emissions are governed by the type of waste, its biodegradability, its methane emission potential, the degree of separation, and other miscellaneous factors. LandGEM model was used to predict the amount of gases produced in the landfills of Trichy (Ariyamangalam) and Thanjavur (Srinivasapuram). According to the results, the largest amount of landfill gas emissions would be in 1993 for Trichy (Ariyamangalam) landfill and in 2027 for Thanjavur (Srinivasapuram) landfill. The total amount of produced gas, methane, and carbon dioxide would be 16.2E + 10, 8.2E + 10, and 16.2 + 10 cubic meters per year in 1993 for Trichy and 13E + 6, 5E + 6 and 13E + 6 cubic meters per year in 2027 for Thanjavur.

Current scenario of solid waste management techniques and challenges in Covid-19 - A review

Annually, world generates 2.01 billion tonnes of solid wastes and it is expected to generate 2.2 billion tonnes of solid waste by 2025. Globally double the amount of waste generation was anticipated by 2050, hence an urgent action is required for this intricate problem in adopting better management techniques and recycling strategies. Unfortunately, poor management of wastes causes vulnerable effects to the society in terms of health. Waste management is the key infrastructure to be developed in society, but so far it is not recognized as much in many developing countries. Significant innovations and improvements are made in the last few decades globally, but still 2 to 3 billion people around the world lack access to waste collection services. The aim of this present study is to give an overview of different types of waste techniques that are effectively followed by different countries and the action plans need to follow. This review focuses on the global current scenario of waste generation, and its management methods with relevant literatures providing the upgrades in the phases of waste management services like collection and transport, various techniques adopted for waste management, policies and legislation, countries investment in waste management process and the impact of solid waste management during Covid-19. Collectively we conclude that Asian countries need to allot more fund for handling solid waste. Also with the available waste management technique, it is not possible to achieve zero waste. Therefore, more new techniques are needed to be adapted.

Integrated Approach to Achieve a Sustainable Organic Waste Management System in Saudi Arabia

Organic waste management (OWM) has always been a fundamental aspect of human populations. Approaches to OWM must be matched to the characteristics of a certain population. In this consideration, the Kingdom of Saudi Arabia (KSA) is no exception. Organizations are being aligned to focus on sustainability matters sharing significant features with universal trends, especially the integration of 3Rs (reducing waste, reusing, and recycling resources). However, the degree and nature of advancement in the direction of sustainability vary depending on the economic level of a state. High-income economies can afford to pay a higher price to integrate 3Rs technologies. Most recent endeavors have focused on achieving ‘Zero Waste’, which is costly for low-income developing countries. The expectations of OWM systems in KSA must be estimated. In this work, the situations in KSA and other countries are analyzed, and pertinent aspects are explored. Matters relating to the sustainability of OWM are conceptually assessed. This study proposes an integrated method for an organic waste management system to achieve sustainable OWM in the context of state policy and appropriate frameworks, suitable technology, institutional order, operational and monetary administration, and people consciousness and involvement. A genetic-based waste collection transportation algorithm that enhances the efficiency of waste collection truck management is presented in line with this technology. The selected routes based on the R_fs and IPv are the most efficient among those available for the examined smart bin destinations. The minimum R_fs of selected routes is less than the maximum R_fs of available routes by 2.63%. Also, the minimum IPv of selected routes is less than the maximum IPv of available routes by 27.08%. The proposed integrated approach, including the waste collection transportation algorithm, would be beneficial across a variety of country-specific layouts.

From carrion-eaters to plastic material plunderers: Toxicological impacts of plastic ingestion on black vultures, Coragyps atratus (Cathartiformes: Cathartidae)

Despite plastic ingestion has already been reported in several bird species, its physiological impacts have been little inspected, especially in representatives of the Cathartidae family. Thus, in this study, we aimed to identify, characterize, and evaluate the effects arising from the ingestion of plastic materials by Coragyps atratus adults, that captured in landfill areas. Herein, a total of 51 individuals were captured, the frequency of plastic intake being higher than 40%. The plastic materials consisted mainly of low-density polyethylene and film-type polystyrene, as well as presenting irregular shapes and diameters between 10 and 30 mm. Biochemically, we observed in animals that contained plastics in the stomach ("plastic" group) high production of reactive oxygen species (ROS), hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) - especially in the intestine, muscle and brain - whose activity of catalase (CAT) and superoxide dismutase (SOD) was not sufficient to counteract the oxidative stress. Moreover, in the liver of these same animals, we observed high production of nitrite and nitrate, suggesting a hepatic nitrosative stress. Plus, we observed a cholinesterase effect in animals from the "plastic" group, marked by increased activity of butyrylcholinesterase (BChE) (in the brain) and muscle and cerebral acetylcholinesterase (AChE). On the other hand, the biochemical changes perceived were not significantly correlated with the identified plastic material concentrations (2.808 ± 0.598 items/g of stomach content and 0.276 ± 0.070 items/g of stomach - fresh weight), body condition of the animals, size, and shape of the identified plastic materials. Hence, our study sheds the light on the toxicity of plastics deposited in landfills and their ingestion by C. atratus, which reinforces the hypothesis that these materials are harming the health of these birds and, consequently, the dynamics of their populations.

A novel MADM algorithm for landfill site selection based on q-rung orthopair probabilistic hesitant fuzzy power Muirhead mean operator

With the rapid development of economy and the acceleration of urbanization, the garbage produced by urban residents also increases with the increase of population. In many big cities, the phenomenon of "garbage siege" has seriously affected the development of cities and the lives of residents. Sanitary landfill is an important way of municipal solid waste disposal. However, due to the restriction of social, environmental and economic conditions, landfill site selection has become a very challenging task. In addition, landfill site selection is full of uncertainty and complexity due to the lack of cognitive ability of decision-makers and the existence of uncertain information in the decision-making process. Therefore, a novel multi-attribute decision making method based on q-rung orthopair probabilistic hesitant fuzzy power weight Muirhead mean operator is proposed in this paper, which can solve the problem of landfill site selection well. This method uses probability to represent the hesitance of decision maker and retains decision information more comprehensively. The negative effect of abnormal data on the decision result is eliminated by using the power average operator. Muirhead mean operator is used to describe the correlation between attributes. Then, an example of landfill site selection is given to verify the effectiveness of the proposed method, and the advantages of the proposed method are illustrated by parameter analysis and comparative analysis. The results show that this method has a wider space for information expression, gives the decision maker a great degree of freedom in decision-making, and has robustness.

Beneficial role of biochar addition on the anaerobic digestion of food waste: A systematic and critical review of the operational parameters and mechanisms

The generation of huge amounts of food waste due to the increasing population is a serious global issue. The inadequate management of food waste and lack of proper handling approaches have created adverse negative impacts on the environment and the society. The use of traditional disposal (i.e. landfilling) and treatment (i.e. incineration and composting) methods are not considered to be efficient for managing food waste. Thus, anaerobic digestion (AD) has proven to be promising and cost-effective, as an alternative technology, for digesting and converting food waste into renewable energy and useful chemicals. However, mono-digestion of food waste suffers from process inhibition and instability which limit its efficiency. Adding biochar that has high buffering capacity and ensures optimum nutrient balance was shown to enhance biogas/methane production yields. This review reports on the physicochemical characteristics of food waste, the existing problems of food waste treatment in AD as well as the role of biochar amendments on the optimization of critical process parameters and its action mechanisms in AD, which could be a promising means of improving the AD performance. Also, this review provides insights regarding the selection of the desired/appropriate biochar characteristics, i.e. depending on the source of the feedstock and the pyrolysis temperature, and its role in enhancing biogas production and preventing the problem of process instability in the AD system. Finally, this review paper highlights the economic and environmental challenges as well as the future perspectives concerning the application of biochar amendments in AD.

Assessment of municipal solid waste management system in Lae City, Papua New Guinea in the context of sustainable development

ABSTRACT

Lae City (LC) of Morobe Province is the second-largest city in Papua New Guinea. Due to the abundant natural resources it inherits, the resultant urbanization has led to an influx of the human population. This increase in population as a result of industrialization has led to increased municipal solid waste (MSW) accumulation. To address this exigent issue, which affects the nation's carbon footprint, it is imperative to review socio-economic and geographic factors to establish a feasible approach for managing MSW efficiently and sustainably. In the quest to achieve the same, the present assessment focuses on the 3 core waste management hierarchy systems to support sustainable development for LC by reviewing existing opportunities and challenges associated with the current MSW management system and the associated policies. The result shows that as a sustainable approach to MSW management of LC, a zero-waste campaign for resource recovery engaging all stakeholders can be implemented since the organic content of MSW generated in LC is as high as 70%. Moreover, the dumping of MSW at the dedicated dumpsite site can be minimized if policies are strengthened and the proposed waste avoidance pathway is implemented strictly. In addition to this, to avoid the contamination of groundwater and recovery of methane, the use of the Fukuoka approach in the existing landfills has been suggested to capture leachate without any huge expenditure.