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Waste Utilization for Sustainable Development

Pradeep Kumar

Department of Chemical Engineering, Institute of Engineering & Technology Lucknow (IET Lucknow), Lucknow, Uttar Pradesh, India

“Be part of the solution. Not part of the pollution.”

– Unknown

Abstract

Unwanted and unusable things are termed as waste. The accumulation of waste creates unhealthy and unhygienic conditions in the environment. A prime concern for waste is to manage and utilize it. How to utilize waste is a hot question that must be answered through research or innovative ideas. Many examples are present in nature which are perfect for waste utilization, such as carbon dioxide as a waste respirator being utilized by flora and fauna. Similarly, waste produced by living bodies such as urine and excreta is utilized by soil for enrichment. Industrial development, population growth, and rapid urbanization are the key factors promoting waste generation rates in every corner of the globe. The government, scientists, researchers, and academicians are concerned about environmental pollution due to waste. Apart from implementing laws and regulations, the utilization of waste should be the prime focus for sustainable development.

Keywords: Waste utilization, sustainable development, environment, pollution, zero waste index

1.1 Introduction

Waste utilization is an “end-to-end” process. This means that any material or product formed or produced has a certain lifespan, and whatever is left or undesirable at the end of that product’s use becomes waste. The product becomes waste when it is no useful, resulting in an unused end product. This unused end product creates problems such as space (land area) consumption, degradation, economic losses, and environmental issues. Environmental issues include biodiversity and ecological loss, as well as air, soil, and water pollution. Additionally, resource exploitation, and excessive use of land for landfilling or dumping grounds are the key issues that need to be resolved [1]. The increase in world population growth leads to a higher demand for energy, food, clothing, and shelter. The current world population is around 7.3 billion. With the current growth rate, the global population is expected to reach approximately 11 billion by the end of the 21st century [2]. Rapid urbanization causes the inflow of a growing population from small towns and villages into cities. By the end of this century, it is expected that 80% of the growing population will live in cities. The demand for consumer goods, electricity, energy, items of clothing, construction materials for homes and buildings, food, and agriculture requirements will increase manifold, further draining the planet’s already exhausted natural resources. Apart from the depletion of natural resources, the rate and amount of waste generation have also been increasing manifold. The migration of people to cities led to an increase in urban population. The population explosion in cities generates a large amount and variety of waste that municipal corporations cannot easily handle. The variety of waste includes municipal, factory, farming, hospital, building, mining, plastic, hazardous, and radioactive waste [3]. These wastes are broadly categorized into solid, liquid, and gaseous waste. Managing this waste is essential and a basic human need. It is considered a “basic human right,” alongside providing clean water, shelter, food, energy, transport, and communications. Ensuring proper sanitation and solid waste management is crucial for society and the economy. Despite its significance, waste management often receives less public and political attention compared to other essential services, posing challenges for society and the government. When the government overlooks trash management, it attracts public, political, and media scrutiny, as seen in the 2008 waste crisis in Campania, Italy. People living near landfills, incinerators, and waste management plants protest against government policies due to unsuccessful attempts to solve the waste management crisis. The media worldwide showed pictures of streets filled with uncollected waste, choked drainage channels, ad hoc dumping grounds occupied by waste, and long queues of lorries waiting to unload waste anywhere. This brought an awful situation to the country [4]. The management and handling of waste depend on the economy of the city or country and people’s awareness of waste management. Waste handling varies depending on the city or nation. For instance, in developed nations, the systems and procedures are more intricate and use advanced infrastructure and technologies. In developing nations, procedures are typically more straightforward and informal. Waste is typically disposed of on the outskirts of emerging towns. Figure 1.1 shows waste dumped on the roadside within a city. It clearly shows the variety of waste such as: bagasse, plastic waste (polythene bags, thermocol sheet, plastic bottles), food stuffs, foams, clothing articles and many more. The unhealthy practices of dumping wastes in the cities have resulted in several outbreak of epidemics with high death tolls [3], such as the epidemic in Surat, India, in 1994 [5].

An important question arises in both developing and developed countries: how to effectively utilize and manage the variety of waste. To answer this question, researchers, governments, and the general public must see waste as a potential resource for utilization and energy recovery. Researchers are evaluating the economic benefits of waste [4]. The waste-to-product approach to research is receiving increased attention in poorer nations [6], and people and government are focusing on waste utilization.

Figure 1.1 Dumping of variety of waste on the roadside.

1.2 Waste Utilization

The utilization of the unused end products (waste) is called waste utilization. Utilization means adopting methodologies to use waste in ways that provide economic benefits, environmental remedies, and reduce the burden on landfills. The goal of waste utilization is to reduce the amount of waste sent to landfills and incinerators and find sustainable ways to extract value from resources. The conventional approach to waste management is shown in Figure 1.2, which clearly illustrates the top-to-bottom approach used for waste management.

Figure 1.2 denotes the conventional approach to waste management, which involves reducing raw material at the source, by using “reuse or recycle materials.” The reuse/recycle approach helps reduce the already produced volume of waste, thus lessening the burden on landfills. In most developing countries, like those on Africa or Asia, this top-to-bottom approach has been unsuccessful since segregation and collection of waste is a problem at the source is problematic due to a lack of waste management awareness. The general public is not very much aware of waste management practices. Additionally, landfills are considered the cheapest, easiest, and most viable waste disposal option [7]. The world’s largest landfill by area is the Apex Regional Landfill of Las Vegas, United States, covering 2,200 acres, whereas the largest dumping site by the amount of waste dumped per day is the Guatemala City Dump in Guatemala. In Guatemala City Dump, 500 tons of waste are dumped every day [8]. One major problem with landfills is the emission of methane, which has a high global warming potential. This emission can be controlled by combusting waste material in incinerators to generate and utilize energy. Various methodologies have been adopted to utilize waste.

Figure 1.2 Top-to-bottom approach of waste management.

1.2.1 Methods of Waste Utilization

The first and foremost important thing is to reduce waste, but that is not enough, we must move from waste management in a linear economy to waste utilization in a circular economy. The process of linear economy is described in Figure 1.3: take raw material from the nature, manufacture the product, sell it to the consumers, and after the end life of the product’s life, discard it back to nature.

Figure 1.3 Linear economy.

As discussed in Section 1.1, discarding material as waste to the nature is not sustainable. For a sustainable process, global waste management practices should adopt zero waste practices by implementing waste utilization. Various formal methodologies have been adopted for waste utilization and can be broadly categorized as:

1. Waste Utilization through Energy Conservation
   1. Recycling: The reuse of waste material for the manufacture of new products is known as recycling. Recycling can be used in such a way that either a certain ratio of waste raw material is mixed with new raw material to produce new material, or entirely waste material can be used as raw material for production. Recycling conserves natural resources, reduces energy consumption, and helps lower greenhouse gas emissions. Recycling of waste material has some limitations; initially, it involves the collection, sorting, and processing of waste materials such as paper, plastic, glass, and organic and inorganic waste, which requires a large workforce either manually or mechanically.
   2. Waste-to-Energy (WTE): This method involves converting non-recyclable waste into energy, usually through incineration. The heat generated during...