Waste management
Waste management or waste disposal includes the processes and actions required to manage waste from its inception to its final disposal. This includes the collection, transport, treatment, and disposal of waste, together with monitoring and regulation of the waste management process and waste-related laws, technologies, and economic mechanisms.
Waste can either be solid, liquid, or gases and each type has different methods of disposal and management. Waste management deals with all types of waste, including industrial, chemical, municipal, organic, biomedical, and radioactive wastes. Waste is produced by human activity, for example, the extraction and processing of raw materials. A big part of waste management deals with municipal solid waste, which is created by industrial, commercial, and household activity.
In some cases, waste can pose a threat to human health. Health issues are associated with the entire process of waste management. Health issues can also arise indirectly or directly: directly through the handling of solid waste, and indirectly through the consumption of water, soil, and food. The aim of waste management is to reduce the adverse effects of waste on human health, the environment, planetary resources, and aesthetics.
Waste management practices are not the same across countries ; regions and residential and industrial sectors can all take different approaches. Proper management of waste is important for building sustainable and liveable cities, but it remains a challenge for many developing countries and cities. A report found that effective waste management is relatively expensive, usually comprising 20%–50% of municipal budgets. Operating this essential municipal service requires integrated systems that are efficient, sustainable, and socially supported.
A large portion of waste management practices deal with municipal solid waste, which is the bulk of the waste that is created by household, industrial, and commercial activity. According to the Intergovernmental Panel on Climate Change, municipal solid waste is expected to reach approximately 3.4 Gt by 2050; however, policies and lawmaking can reduce the amount of waste produced in different areas and cities of the world. Measures of waste management include measures for integrated techno-economic mechanisms of a circular economy, effective disposal facilities, export and import control, and optimal sustainable design of products that are produced.
In the first systematic review of the scientific evidence around global waste, its management, and its impact on human health and life, authors concluded that about a fourth of all the municipal solid terrestrial waste is not collected, and an additional fourth is mismanaged after collection, often being burned in open and uncontrolled fires – or close to one billion tons per year when combined. They also found that broad priority areas each lack a "high-quality research base", partly due to the absence of "substantial research funding", which motivated scientists often require. Electronic waste includes discarded computer monitors, motherboards, mobile phones and chargers, compact discs, headphones, television sets, air conditioners and refrigerators. According to the Global E-waste Monitor 2017, India generates ~ 2 million tonnes of e-waste annually and ranks fifth among the e-waste producing countries, after the United States, the People's Republic of China, Japan and Germany.
Effective 'Waste Management' involves the practice of '7R' - 'R'efuse, 'R'educe', 'R'euse, 'R'epair, 'R'epurpose, 'R'ecycle and 'R'ecover. Amongst these '7R's, the first two relate to the non-creation of waste - by refusing to buy non-essential products and by reducing consumption. The next two refer to increasing the usage of the existing product, with or without the substitution of certain parts of the product. 'Repurpose' and 'Recycle' involve maximum usage of the materials used in the product, and 'Recover' is the least preferred and least efficient waste management practice involving the recovery of embedded energy in the waste material. For example, burning the waste to produce heat.
Principles of waste management
Waste hierarchy
The waste hierarchy refers to the "3 Rs" Reduce, Reuse and Recycle, which classifies waste management strategies according to their desirability in terms of waste minimisation. The waste hierarchy is the bedrock of most waste minimization strategies. The aim of the waste hierarchy is to extract the maximum practical benefits from products and to generate the minimum amount of end waste; see: resource recovery. The waste hierarchy is represented as a pyramid because the basic premise is that policies should promote measures to prevent the generation of waste. The next step or preferred action is to seek alternative uses for the waste that has been generated, i.e., by reuse. The next is recycling which includes composting. Following this step is material recovery and waste-to-energy. The final action is disposal, in landfills or through incineration without energy recovery. This last step is the final resort for waste that has not been prevented, diverted, or recovered. The waste hierarchy represents the progression of a product or material through the sequential stages of the pyramid of waste management. The hierarchy represents the latter parts of the life-cycle for each product.Product lifecycle
A product lifecycle begins with the design phase and proceeds through manufacture, distribution, and primary use. After these initial stages, the product may be reused, recycled, or disposed of. Designers and manufacturers contribute to waste management through source reduction, such as by selecting materials that have lower environmental impacts and creating products that require less energy and resources to produce.Resource efficiency
reflects the understanding that global economic growth and development can not be sustained at current production and consumption patterns. Globally, humanity extracts more resources to produce goods than the planet can replenish. Resource efficiency is the reduction of the environmental impact from the production and consumption of these goods, from final raw material extraction to the last use and disposal.Polluter-pays principle
The polluter-pays principle mandates that the polluting parties pay for the impact on the environment. With respect to waste management, this generally refers to the requirement for a waste generator to pay for appropriate disposal of the unrecoverable materials.History
Throughout most of history, the amount of waste generated by humans was insignificant due to low levels of population density and exploitation of natural resources. Common waste produced during pre-modern times was mainly ashes and human biodegradable waste, and these were released back into the ground locally, with minimum environmental impact. Tools made out of wood or metal were generally reused or passed down through the generations.However, some civilizations have been more profligate in their waste output than others. In particular, the Maya of Central America had a fixed monthly ritual, in which the people of the village would gather together and burn their rubbish in large dumps.
In the Ashanti Empire by the 19th century, there existed a Public Works Department that was responsible for sanitation in Kumasi and its suburbs. They kept the streets clean daily and commanded civilians to keep their compounds clean and weeded.
United Kingdom
Following the onset of the Industrial Revolution, industrialisation, and the sustained urban growth of large population centres in England, the buildup of waste in the cities caused a rapid deterioration in levels of sanitation and the general quality of urban life. The streets became choked with filth due to the lack of waste clearance regulations. Calls for the establishment of municipal authority with waste removal powers occurred as early as 1751, when Corbyn Morris in London proposed that "... as the preservation of the health of the people is of great importance, it is proposed that the cleaning of this city, should be put under one uniform public management, and all the filth be...conveyed by the Thames to proper distance in the country".However, it was not until the mid-19th century, spurred by increasingly devastating cholera outbreaks and the emergence of a public health debate that the first legislation on the issue emerged. Highly influential in this new focus was the report The Sanitary Condition of the Labouring Population in 1842 of the social reformer, Edwin Chadwick, in which he argued for the importance of adequate waste removal and management facilities to improve the health and wellbeing of the city's population.
In the UK, the Nuisance Removal and Disease Prevention Act of 1846 began what was to be a steadily evolving process of the provision of regulated waste management in London. The Metropolitan Board of Works was the first citywide authority that centralized sanitation regulation for the rapidly expanding city, and the Public Health Act 1875 made it compulsory for every household to deposit their weekly waste in "moveable receptacles" for disposal—the first concept for a dustbin.
File:Manlove, Alliott furnace.jpg|thumb|left|Manlove, Alliott & Co. Ltd. 1894 destructor furnace. The use of incinerators for waste disposal became popular in the late 19th century.
The dramatic increase in waste for disposal led to the creation of the first incineration plants, or, as they were then called, "destructors". In 1874, the first incinerator was built in Nottingham by Manlove, Alliott & Co. Ltd. to the design of Alfred Fryer. However, these were met with opposition on account of the large amounts of ash they produced and which wafted over the neighbouring areas.
Similar municipal systems of waste disposal sprung up at the turn of the 20th century in other large cities of Europe and North America.
Early garbage removal trucks were simply open-bodied dump trucks pulled by a team of horses. They became motorized in the early part of the 20th century and the first closed-body trucks to eliminate odours with a dumping lever mechanism were introduced in the 1920s in Britain. These were soon equipped with 'hopper mechanisms' where the scooper was loaded at floor level and then hoisted mechanically to deposit the waste in the truck. The Garwood Load Packer was the first truck in 1938, to incorporate a hydraulic compactor.