Shweta Saraswat

This study examines the prevalence, characteristics, and distribution of microplastics in the Gaula River, Uttarakhand, India. Microplastics collected from surface water samples at four upstream and four downstream locations along the Gaula River in Uttarakhand were analyzed using SEM–EDS and FTIR spectroscopy to assess their concentration and composition. A total of 212 microplastic particles were identified, with higher downstream accumulation (122 particles) than upstream (90 particles). Fibers and fragments were the dominant shapes, primarily composed of polyethylene (PE) and polypropylene (PP). FTIR confirmed polymer-specific functional groups, while SEM–EDS revealed smooth surfaces with minimal heavy metal adsorption, indicating recent contamination. Findings suggest improper waste disposal and urban runoff as primary pollution sources. This study enhances understanding of microplastic pollution in freshwater ecosystems, particularly in urbanized regions, and underscores the urgent need for effective monitoring and mitigation strategies to reduce environmental impacts.

Hydrometallurgy refers to the application of aqueous solutions for metal recovery from ores. The hydrometallurgy and microbial mineral processing of metallic ores is currently a well-established technology. Hydrometallurgy and bioleaching are the methods widely used for metal recovery from solid waste including e-waste. Hydrometallurgy is used in extraction of less electro-positive or less reactive metals like copper, gold, and silver. Hydrometallurgical processes generate various environmental pollutants, such as furans, dioxins, and highly acidic wastewater. However, bioleaching, also referred as biomining, offers various advantages over hydrometallurgical method. These include cost-effectiveness, facilitation of in-situ leaching, zero energy usage, no need for harmful chemical compounds, and less secondary waste production. Bioleaching process exhibits conversion of solid metals into ions in aqueous solution by using a leaching agent produced though the catalysis of microorganisms. Most of the biomining operations have shown their productivity in commercial application of refractory gold concentrates using mesophilic microorganisms followed by the cyanide leaching to recover optimum amount of gold with an environment-friendly method. At present, bioleaching is not limited to high-grade sulfide minerals; instead, it is widely used in metal recovery from solid waste, such as E-waste, sludge, sediment, batteries, catalysts, and low-grade ore. The chapter highlights basics of hydrometallurgy, various metal leaching procedures, their process design, chemistry along with biometallurgical processes involving microbiological principles and potential to be adapted for technical e-waste treatment applications.

Global demand for fossil fuels and the growing environmental concerns linked with them, such as global warming, have shifted global attention toward the production of eco-friendly and inexhaustible bioenergy resources. In recent years, there has been a growing interest in alternative fuel research as a means to lessen our reliance on fossil fuels, especially through the provision of bioenergy sources. This is vital for two primary reasons: first, new fuels are required to augment and eventually replace declining oil sources, and second, carbon-free fuels are required to stop global warming. Bioenergy use falls into two main categories: “traditional” and “modern.” Traditional use refers to the combustion of biomass in such forms as wood, animal waste, and traditional charcoal. Modern bioenergy technologies include liquid biofuels produced from bagasse and other plants, bio-refineries, biogas produced through anaerobic digestion of residues, wood pellet heating systems, etc. This chapter highlights the overview of bioenergy, technologies available for bioenergy production such as microbial fuel cell technology, biohydrogen production, microalgal valorization technology, pelletization, coal-bed methane technology, their environmental implications, challenges, prospects, and future work consideration for the successful transition to bioenergy economy.

The exponential growth of the global population contributes to an increase in waste generation. If not adequately managed, municipal, agricultural, and industrial waste can create an unhealthy and unpleasant environment and potentially spread illness. To be able to establish comprehensive waste management strategies, it is vital to recognize waste sources and types precisely and to have a solid understanding of waste types and their composition. A vast variety of waste valorization methods with different substrates, catalysts, and solvents are well demonstrated in published literature existing in public domain. However, most of these studies are focused on technological advancements for high yield of products without assessing the environmental impacts induced in the production process, which possibly hinders decision makers from evaluating the novel options in a holistic perspective. Thus, to identify and evaluate the environmental impacts of the production process of valorized products and materials from waste biomass, a decision-supporting tool is required. Besides, with growing concerns about waste and the demand for “greener” products, it is vital to conduct life cycle assessments (LCAs) of products, which could assist manufacturers in taking the initial steps toward greener solutions by analyzing the carbon output of their products. An LCA assesses all direct and indirect environmental impacts throughout a product's life cycle, from materials acquisition to manufacturing, usage, and disposal (disposal or reuse) by identifying energy, materials, and emissions produced to the environment. In this context, the objectives of this chapter are to introduce the LCA methodology and outline the procedures for LCA studies that concentrate on waste management. The chapter also covers the case studies for LCAs of particular waste management systems while describing the guiding principles and methodology.

Proper waste disposal is still a serious concern worldwide. This book addresses various types of wastes such as industrial, agricultural, and municipal solid and liquid wastes, their generation, and the status of waste management in developed and developing countries. It discusses advanced green technologies used in harnessing energy and bioproducts from wastes such as electricity, biofuel, biopolymers, fertilizers, and chemicals without damaging the quality of the environment but rather creating a source that is an added value to the environment. Through many applications and case studies, this comprehensive book helps readers build a state-of-the-art knowledge on waste utilization and energy generation. FEATURES Provides a comprehensive, state-of-the-art coverage of waste management practices, their challenges, and solutions from a global perspective Discusses conceptual principles and practices of various green technologies that can be used to generate valuable products from waste and improve environmental quality Includes case studies from the United States and Japan, providing detailed explanations of advanced bioremediation technologies Takes a holistic approach to waste management and bioproducts recovery Offers an easy-to-understand and target-oriented approach that helps both students and professionals advance their knowledge in creating wealth from waste Written for undergraduate and graduate students taking courses in environmental biotechnology, environmental microbiology, non-conventional energy sources, waste treatment technologies, environmental waste utilization, energy, and environment taught in universities and colleges. The book can also be used by professionals and researchers at different levels in related fields.

The modern consumerism-based society generates a tremendous amount of waste each day. The world is facing an uncertain future as a result of the ongoing depletion of natural, finite resources. Therefore, sustainable consumption and a comprehensive waste management system would be necessary to stop further depletion of the world's resources. Solid waste is produced by human activities in enormous quantities, and as quality of life demands rise, the quantities typically rise as well. The rising pace of garbage produced in the nation today presents a problem for the government in terms of environmental damage. It is anticipated that methods for trash prevention and garbage treatment will eventually lead to sustainable waste management solutions. The zero waste model is an innovative idea for addressing waste issues in our society. Policymakers have welcomed the zero waste approaches to solid waste management because they promote resource recovery, optimal recycling, and sustainable production and consumption. A nonbiodegradable fraction of solid waste could be used for construction and paving tasks. Overall, the analysis shows how solid waste management concepts have undergone a paradigm shift from linear to circular economies as a result of the “zero waste” concept. The circular economy (CE) is a theoretical framework that can be applied to waste management in order to better utilize resources and reduce waste. The chapter also outlines the policies of the CE for solid waste management, which increases the country's economy and proposes strategies for optimizing local resources.

The pressure to extract more natural resources for the production of new products will increase if the resources embedded in solid waste are not recovered. Solid, liquid, gaseous, and radioactive wastes require various approaches and skills. Industrial ecology, life cycle analysis, material flow analysis, ecological footprint, and other ideas have long shown the need and possibility of reintegrating recyclable materials into production flows, decreasing resource waste, and preserving the environment. Since society's waste streams contain material and energy resources, waste management decision making must be tied inextricably to resource conservation and utilization issues. Changes in the nature of wastes, concern for environmental protection, and the desire to recover resources from the waste stream have stimulated the development of new waste management technologies and processes. Scientific concepts are needed in order to understand how waste management and treatment processes work and the nature of impacts resulting from waste disposal and dispersal in the environment. Academic research is also required to determine the best available technology for treating diverse waste materials and goods derived from them. This chapter highlights the various sources of wastes, their properties, and the possibility of recovery of valued resources for adopting a circular economy and zero waste concept.

The production of solid waste has greatly increased over the world as a result of rising communal living standards, a booming economy, a growing population, and increasing urbanization. The goal of most cities is to change their waste management practices to zero waste (ZW) practices, which are more environmentally friendly. ZW refers to the concept of recovering all resources from waste materials and having a 100% recycling rate. One of the major environmental problems in the world today is solid waste. Besides, the world is facing an uncertain future as a result of the constant depletion of natural, finite resources. Sustainable consumption and a tactical waste management system would be necessary to stop further depletion of the world's resources. The idea of “Zero Waste” is one strategy that has been presented as a way to address these issues. It is still difficult to convert currently wasteful activities to ZW ones. In order to analyze the difficulties and opportunities for transforming conventional waste management toward the ZW vision, this chapter discussed the challenges of solid waste, production and consumption patterns, ZW practices, and ZW strategy to minimize the negative impacts of waste. Moreover, the concept of ZW, its principals, key factors for ZW development, policies, and methods for recycling waste in a sustainable manner have been addressed to achieve ZW goals.