Sustainable Solid Waste Management

Earth’s ability to absorb waste is a major influence on the adaptation of waste-treatment technologies. Landfilling is probably the oldest organized waste-management technology. However, waste management has undergone changes in recent decades, and currently recycling and recovery are a more important focus than landfilling. The organic fraction of municipal solid waste (MSW) is an important consideration, not only because of the quantity generated but also because of its potential negative impacts on environmental and human health. Integrated waste management is a framework for designing and implementing new waste-management systems and for analyzing and optimizing existing systems. Within this framework, both technical and nontechnical components of the management system should be analyzed together. Today a modern integrated waste management that infuses sustainability into all components while considering resource supply and demand is needed.

Waste management is challenging in urban and rural areas. Waste can be classified by its source and by the socioeconomic sector generating the waste. Types of waste include municipal solid waste (MSW), industrial waste, hazardous waste, agricultural waste, medical waste, sludge, chemical waste, biological waste, and e-waste. Testing and analysis of waste are important to understand and determine the type of waste because each kind of waste has unique characteristics and must be treated properly to avoid environmental damage and health impacts. Generation of waste is directly proportional to population growth. Hazardous wastes can be identified by assessing their ignitability, corrosivity, reactivity, and toxicity using standardized methodologies like ASTM or APHA standards. The energy content of waste is determined using bomb calorimeter tests.

This chapter overviews critical issues associated with waste collection and separation systems. Source separation of municipal solid waste (MSW) is an integral component of planning and executing an integrated waste management system. Storing waste at the source of its generation until it is collected is the first essential step of waste management. The factors to consider in the on-site storage of solid wastes include the type of container to use, container location, collection method, and public health and aesthetic aspects. Waste generators require minimally inconvenient waste collection, while collectors must be able to collect waste in a way that is compatible with the planned treatment and processing methods if the waste management system is to be sustainable. Seasonal changes in waste generation will require flexibility in the collection service.

This chapter first discusses key aspects of waste prevention in a multidisciplinary context. It then defines the term “waste prevention” and discusses its importance in relation to sustainability. Next, the chapter presents the policy framework of the European Union (EU), the United States (U.S.), and selected countries that have taken important steps toward promoting waste prevention, presenting an analysis of waste prevention actions and initiatives applicable to production, supply, consumption, and the household for different key waste streams. The chapter specifically tackles food waste, packaging waste, nonpackaging paper waste, waste from electrical and electronic equipment (WEEE), and green waste. Finally, the chapter examines major barriers affecting waste prevention and reviews successful efforts of central and local authorities, businesses, consumers, and social enterprises in mitigating such negative barriers.

In an integrated waste management system, recycling always appears near the top of a hierarchy designed to achieve maximum economic, social, and environmental returns. However, recycling alone is insufficient to completely utilize the waste as a valuable resource. Therefore, resource recovery is another important component and prerequisite. In the EU, resource recovery has been successfully employed on paper and cardboard, bio-waste, glass, plastic, and metals, contributing to substitution of certain raw materials, especially paper and cardboard and iron and steel. Postconsumer rubber tires are the most representative rubber wastes in municipal solid waste (MSW). Through rubber recycling, virgin rubber resources and construction materials can be partially substituted. Rubber recycling technologies include retreading and splitting, pyrolysis, rubber-derived fuel, and rubberized asphalt and concrete. Materials that can be recycled from construction waste include asphalt, bricks, concrete, and masonry.

This chapter describes the meaning and various levels of public participation in environmental matters. Examples of solid waste management from Asia are presented to showcase why public participation is important in waste reduction and recycling activities. These examples also represent possible strategic drivers and methodologies for public engagement. The chapter also deals with the need for reduce, reuse, and recycle (3R) policies that “embed, engage, and empower” the public in waste-management governance, hence sharing the local authorities’ (LA) responsibilities in waste management. With public-private partnerships (PPP), LAs shift from service providers to service facilitators. LAs then focus on planning and management, while a private company or community takes up the day-to-day operations related to waste management. The environmental impact assessment (EIA) sets the public participation in environmental decision making as a fundamental principle.

Thermal treatment can reduce the volume of waste and render it innocuous by destroying pathogens and toxic chemicals. Within the waste-management hierarchy, thermal disposal, especially incineration with energy recovery, is a desirable and viable option often used in industrial nations. Pyrolysis generally takes place at lower temperatures than used for gasification, which results in less volatilization of carbon and certain other pollutants, such as heavy metals and dioxin precursors. The main types of municipal solid waste (MSW) gasifiers include fixed-bed, fluidized-bed, and the rotary kiln bed gasifier. Compared with conventional waste-disposal methods, gasification technology uses energy efficiently, has good environmental properties, and has broad development prospects. Activated carbon adsorption is the simplest and most widely applied dioxin tail gas removal technology, due to its huge surface area and strong adsorption capacity.

The need for anaerobic digestion (AD) or co-digestion for managing solid waste is increasing in different countries. This chapter describes the principles of AD and co-digestion and how AD evolves into co-digestion. Then, it discusses the types of anaerobic digesters or co-digesters and the major parameters affecting their performance, providing details of the feedstocks required for AD or co-digestion. Next, the chapter talks about substrate pretreatment technologies for AD and co-digestion. It also discusses the design of AD and co-digestion processes; the principles of mass, electron, and energy balance; and evaluation of biogas production. The chapter then presents case studies on anaerobic co-digestion and explains the advantages and disadvantages of anaerobic technology. Finally, the chapter presents the future research required for improving AD processes.

Effective organic-waste management relies on the availability and acceptability of the treatment technology. One such technology is composting. The main objectives of composting are to decompose the organic fraction of waste to a stable condition; reduce its volume, weight, and moisture content; minimize potential odor; destroy pathogens; and increase potential nutrients for agricultural application. Emission of odor is a serious concern during composting of any organic substrate that results from microbial degradation of carbohydrates, proteins, and fats in the substrate. To enhance microbial activities for fast composting, microbial inocula or compost starters may be used, especially for commercial composters. Compost systems can be classified into three broad categories, namely windrows, in-vessel systems, and vermicomposting. Cost-effective and sustainable decentralized composting technology has many advantages, but success depends on the quality of the compost product.

Waste management is inadequate in most cities in developing countries, as a significant portion of the population lacks access to a waste-collection service and only a fraction of the generated waste is actually collected. Biochar is potentially an immediate, economically viable solution for reducing the global impact of bio-waste and wastewater. This chapter discusses biochar and its properties and uses for waste management. Despite widespread interest in applying biochar for soil amelioration and potential mitigation of climate change, substantial uncertainties remain about the impact, capacity, and environmental sustainability of biochar production and its applications, particularly in the long term. Due to the irreversibility of applying biochar to soils, any potential risks should be thoroughly examined before widespread use of biochar is adopted.

This chapter introduces the history and fundamentals of plasma arch gasification of solid waste and its current practical application. Generally, plasmas can be categorized into two types: low-temperature plasmas (LTP) and high-temperature plasmas (HTP). LTP can further be subdivided into thermal LTP and nonthermal or nonequilibrium LTP. The gasification technology provided by Westinghouse is considered one of the most advanced plasma gasification technologies, whereas the plasma torch in Plasco is used for syngas refining and bottom ash melting rather than directly gasifying waste. By converting combustible municipal solid waste (MSW) components into syngas with extremely high temperatures, the pollutants generated from plasma gasification systems are significantly lower than traditional mass burning systems. The pollutants can be removed during cleaning of the syngas or after its combustion.

This chapter introduces newly developed concepts about sustainable hazardous waste management and treatment and describes the key elements of sustainable hazardous waste management in the context of current broader issues (e.g., renewable energy and climate change). It also discusses fundamentals and basic components of sustainable hazardous waste and presents technical options for sustainable hazardous waste treatment and remediation. Microorganisms play an important role in wastewater treatment because of their immense potential for immobilization and bio-accumulative properties. Next, the chapter explains disposal of hazardous waste and reviews adjustments to meet global challenges. The choice of disposal should be based on evaluation of economics and potential pollution risks. Finally, the chapter identifies future trends and challenges for sustainable hazardous waste management/treatment, providing research recommendations to help achieve the broader goals of sustainability.

This chapter reviews the use of biohydrometallurgical technology in the recovery of metals from electronic wastes (e-wastes), specifically focusing on copper extraction. This discussion includes an analysis of bioleaching of copper from printed circuit boards with particular emphasis on the use of chemolithoautotrophic bacteria and heterotrophic fungi, the leaching chemistry, and the secondary reactions and kinetics of the chemical and bioleaching processes. The biggest challenge in reclaiming e-waste is developing a process that can adapt to the complexity, changing compositions, toxicity, and volume of e-waste. Biomining offers a viable option for processing waste electrical and electronic equipment (WEEE) with potential benefits including lower cost and lower-energy options over conventional approaches. Optimizing the recovery of metallic fractions from e-waste requires confirmation that these reactions occur and identification of conditions under which these reactions could be minimized or avoided.

This chapter discusses the current understanding of sludge production, characteristics, legislation, handling and disposal technologies, and recent trends in sludge management. The characteristics of sludge vary globally because the properties of sludge depend upon factors such as population density and habits, the proportion and nature of a community’s industrial base, the composition of wastewater, the age of sludge, and the method of wastewater treatment. The chapter reviews published reports on sludge-management frameworks from around the world and unifies existing data to outline the current sustainable management of sludge, including sludge treatment/disposal options, methods for energy recovery, and production of value-added products from sludge. The disposal of effluent and biosolids is subject to EPA approval and licensing. Finally, the chapter discusses future perspectives of sludge-management issues and specific conditions for different countries.

Antibiotics, cytotoxins (which are toxic to cells and inhibit cell growth and multiplication), corrosive chemicals, and radioactive substances used in modern hospitals and health care institutions ultimately become part of health care wastes (HCW). HCWs include general waste or municipal solid waste, e.g., packaging materials, food scraps, newspapers, bottles, and hazardous HCW. Classification of wastes varies depending on national/local regulations. Waste generation depends on numerous factors such as established waste management methods, type of health care establishment, hospital specializations, proportion of reusable items employed in health care, and proportion of patients treated on a daily basis. The key to minimization and effective management of HCW is segregation (separation) and identification of the waste. Establishment of a sustainable health care waste management system benefits from a national legal framework that regulates and organizes different elements of a health care waste management system.

Developing countries have practiced reuse and recycling of a portion of construction and demolition waste (C&DW) mainly to reduce construction costs. However, industries are growing more interested in C&DW treatment due to the implementation of green building standards. This chapter discusses the characteristics of CD&W, its sources, and its possible destination. Surveys, past history, country-specific policies, and case studies are the main methodologies for data collection for quantifying C&DW. Conducting surveys (sampling and weighing) at landfills is often used for determining local waste-management system needs with sufficient time and support. The chapter also discusses recycling C&DW with a case study. Recycling is thought to be a vital part of reducing the environmental impact of the construction industry. However, the recycling process uses energy and emits CO₂, which must be balanced against any savings

This chapter describes the characteristics of incineration ashes from municipal solid waste, sewage sludge, and waste biomass with a main focus on their chemical properties. It introduces common ash treatment methods, including separation, solidification/stabilization, and thermal treatment. The purpose of separation for ash materials is to improve the ash quality and thus enhance the utilization potential. Common separation methods include ash washing, leaching procedures, and electrochemical processes. The chapter also reviews nine potential ash applications grouped into four main categories: construction materials (cement and concrete, ceramics, road sub-base, lightweight aggregate); adsorbents for wastewater treatment (hazardous metals, dyes, and other organic compounds); synthesis of zeolites; and agricultural applications. Biomass ashes can be applied in agriculture as a valuable fertilizer without concern about harmful heavy metals and other toxic substances.

This chapter briefly discusses landfill design, construction, and operation. It presents siting considerations, regulations, and other important steps before the design stage. In recent years, the landfill design philosophy has shifted from the dry-storage concept to the bioreactor approach. In the bioreactor approach, the moisture content of the municipal solid waste (MSW) is increased by recirculating leachate to enhance biodegradation. Landfill design involves designing physical elements of the landfill and operational systems. The major design components of a landfill are sub-base, liner, leachate management system, gas management system, final cap, and stormwater management. Monitoring is an important task during landfill construction/operation and after closure. Leachate, possible leakage through the liner system, groundwater quality, landfill gas migration, and stability are among the most commonly monitored aspects.

Landfills are planned and designed to sequester solid waste material by burying it in layers of earth in an effort to decrease human health hazards. Sustainable collection and treatment of landfill leachate is tremendously important to prevent landfill leachate from causing serious environmental problems. This chapter focuses on landfill leachate collection and treatment for sustainable development of human society, including the principles and operations of landfills; leachate production, collection, characterization, and treatments under different operational and environmental conditions; current status of landfill leachate treatment; and future directions. The most commonly used methods of leachate treatment are aerobic biological systems, including aerated lagoons, activated sludge systems, and sequential batch reactors (SBRs). Membrane technologies are also used for leachate treatment, including microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), and forward osmosis (FO).

Reusing a former landfill site is only possible with comprehensive afteruse planning and aftercare management, which is enhanced by increasing the reliability of environmental impact assessments and landfilling technology. Landfill aftercare commences when the site is closed and its surface cover installed. The need to manage leachate and gas continues after landfill closure, which should be an integral component of the total landfill management together with restoration and surveillance. Postclosure landfills are monitored and managed to control landfill-associated factors and to develop endues of the site after closure. Landfill stability, leachate, gas, subsidence, and cover system are the focal points for management. The design, selection of soil type, and quality of final cover material should be geared toward postclosure landfill aftercare and maintenance. Maintenance and rehabilitation of landfills after closure minimize and mitigate the environmental impacts of waste disposal and prevent threats to public safety.

This chapter scrutinizes the solid waste legal and institutional arrangements of several developed and underdeveloped countries. The United States and the European Union (EU) have been chosen to represent the advanced nations, and seven South Asian countries, including Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka, serve as samples for transitional nations. Among the directive provisions for waste management are obligations to develop an integrated waste system among EU countries to reduce cross-boundary waste shipment among member countries and between EU and non-EU members. Member countries develop waste management plans and carry out comprehensive analysis of all waste streams, inventorying waste recycling, recovery, and disposal facilities. In contrast, solid waste management in India is primarily a local affair. State laws lay out the local government duties for keeping the streets clean, supplying garbage containers, and carrying out waste to disposal sites.

This chapter reviews the concept and use of life-cycle assessment (LCA) for environmental performance evaluation of solid waste management and discusses the potential and challenges of such a holistic approach for decision making. According to ISO 14040, conducting an LCA includes four main phases: goal and scope definition, inventory analysis, impact assessment, and interpretation. With regard to waste management, LCA enables evaluation of the environmental impacts of a particular waste management system and trade-offs as compared with waste treatment alternatives. The functional unit under the goal and scope of an LCA is a crucial parameter to define as it provides the basis for the assessment. The development of several LCA computer models has accompanied the increased number of solid waste management LCAs.