Baba urban waste disposal

What are the global statistics on waste generation?

The World Bank estimates that by 2050 global waste will have increased from 2.01 to 3.4 billion tonnes per year.

"The world generates 2.01 billion tonnes of municipal solid waste annually, with at least 33 percent of that—extremely conservatively—not managed in an environmentally safe manner. Worldwide, waste generated per person per day averages 0.74 kilogram but ranges widely, from 0.11 to 4.54 kilograms. Though they only account for 16 percent of the world's population, high-income countries generate about 34 percent, or 683 million tonnes, of the world's waste." World Bank 2018

Main types of waste generated are:

· Food or green waste 44%

· Paper and cardboard 17%

· Plastics 12%

· Glass 5%

· Metals 4%

Most waste is generated in the United States at a rate of 81kg of waste per person per annum, and around half of that ends up in landfill. Colombia produces the least urban waste, at 243kg per person per annum. Chile is the worst country and recycles only 2kg per person, 417kg of waste per person ends up in landfill. The only country not to send waste to landfill is Switzerland and whilst the Swiss produce 706kg of waste per person, 210kg is recycled with 333kg incinerated and the remaining 163kg is compostable waste. Turkey has the least environmentally friendly waste management and most is disposed of illegally each year. In LDEs, over 90% of waste is openly dumped or burned.

What are the sources of urban waste?

Sector Source Examples of Waste

Industry Light and heavy manufacturing, power and chemical plants, fabrication etc. Packaging, food, hazardous wastes, e-waste, ashes, specialist waste, housekeeping wastes etc.

Domestic Single and multifamily housing Food, paper, cardboard, e-waste, textiles, plastic, garden waste, white goods, household hazardous products (paint, aerosols, cleaning products etc.) glass, metals etc.

Commercial Offices, restaurants, markets, shops, hotels etc. Paper, cardboard, plastics, wood, food, glass, metal, special wastes, hazardous wastes, e-wastes etc.

Construction New building sites, road repairs, renovation sites, demolition sites etc. Concrete, steel, hazardous and specialised waste (asbestos, chemical etc.) wood, dirt, bricks, tiles

Municipal/Urban services Landscaping, parks, beaches, leisure areas, water and wastewater treatment plants, street cleaning etc. General public waste, garden waste, tree trimmings, street cleaning etc.

Institutional Hospitals, government buildings, airports, schools, prisons Non-medical waste, paper, cardboard, food etc.

Municipal solid waste (MSW) is classed as domestic waste and municipal refuse is categorised as either hazardous, biological or recyclable waste.

What are waste streams?

Waste streams are flows of specific waste, from origin through recovery, recycling and final disposal. There are two types of streams:

· Material-related streams (including metals; glass; paper and cardboard; plastics; wood; rubber; textiles; bio-waste)

· Product-related streams that need further or specific treatment (including packaging; electronic waste; batteries; end-of-life vehicles; mining, construction and demolition waste) which eventually feed into materials-related streams

Waste streams in HDEs are increasingly managed and regulated. Illegal and environmentally damaging disposal of waste is common in LDEs and EMEs.

Some of the issues include:

· Leachates contaminating land and waterways

· Methane produced through decomposition and particulates from burning waste

· Loss of biodiversity

· Raised health issues - respiratory, skin and other diseases

· Loss of recyclable resources such as glass and metal

· Loss of potential energy from incineration

What economic and lifestyle factors affect waste streams?

Economic: Consumption of goods increases as people become wealthier. HDEs produce more waste than LDEs. Waste components vary depending on level of development - LDEs have higher organic waste production (approx. 64%) whereas HDEs have higher paper and plastic waste. Waste streams vary between countries, but link to wealth is difficult to identify - HDEs recycle a large % of its waste but this also varies between countries (Japan recycles only 9% compared to Germany which recycles 66% of its waste). Most LDEs do not have formal recycling systems in place, but many people collect waste to recycle, repurpose and re-sell to make a living.

Lifestyle: Type and amount of waste varies depending on where people live - higher % of manufactured waste is produced by urbanites, and rural residents produce more organic waste. Placement and number of recycling facilities affect waste streams - encouragement by authorities and accessible facilities increases recycling of waste. Food and diet affects waste components and streams - processed food creates waste and is over packaged; fresh food produces more compostable waste (banana skins, potato peelings etc.) and can be package free. Many people in HDEs have a 'throw-away' culture - clothing worn a few times and thrown away; regular replacement of electronics (smartphone replaced each new release). This generates high levels of complex waste streams, much of which cannot be recycled. High levels of food waste due to people throwing out food near to or just past best before or sell-by dates. People who have concerns over the environmental impacts of waste are more likely to reuse or recycle their waste.

What is the global waste trade and what are the issues associated with it?

The global waste trade is the international trade of waste between countries (usually to EMEs) for further treatment, disposal, or recycling. Every year, thousands of shipping containers filled with 'recyclable waste' are exported by HDEs to EMEs. Toxic or hazardous wastes are often imported by LDEs from HDEs. This is because it is cheaper to export waste rather than develop local recycling infrastructures and reduces landfills. LDEs are not heavily regulated, plus they benefit economically from accepting waste from HDEs. However, many EDEs and LDEs do not have safe recycling or processing facilities, and many workers are exposed to toxic waste through lack of safety equipment. Also, once waste is exported, it is not tracked and rather than being treated, hazardous waste is often incinerated or dumped illegally. Most waste electrical and electronic equipment (WEEE) is shipped to Africa and Asia to be processed and recycled. Heavy metals and toxins leak into waterways and groundwater, poisoning wildlife and people. Animals and birds are harmed by swallowing or getting caught in waste plastic. Workers, children and scavengers on and around the waste dumps, are exposed to excessive and dangerous health risks.

Other issues with the waste trade: Governments of exporting countries still count exported waste volumes towards their national recycling rates. Waste exports have increased significantly, and since the turn of the century, shipments of recyclable items from the EU rose by more than 70%. There is an attitude of 'out of sight, out of mind' by governments and their policy of the 'waste trade flow'. There are serious environmental impacts such as marine pollution and people are calling for a total ban on waste exports, major improvements to a broken recycling system, along with a significant reduction in single use plastics and packaging.

What was China's role in the global waste trade?

Up until 2017, China was the main destination for global waste, importing 70% of the world's plastic waste. By 2018, China had imposed a ban on most plastics and set limits on recyclable materials under their 'National Sword' policy. By 2020 the EU was shipping less than 4000 tonnes of plastic waste compared to 1.4 million tonnes of 2017. However, waste was still being produced and piling up in the source country, and alternatives were needed. Exports to South East Asia exploded and Turkey became the EU's top destination for waste export (40% of UKs plastic waste was exported to Turkey in 2020). Since China imposed its ban, LDEs have become overwhelmed with waste and in many instances have returned illegally exported contaminated waste back to the country of origin. China finally imposed a total ban on foreign waste imports in January 2021. Despite new regulations, major exporters such as the U.S. continue to ship large volumes of waste.

What are the 3Rs of waste management?

There are many ways to manage urban waste. Ultimately, effective management is essential to reduce the environmental impact of municipal solid waste (MSW).

The most recognisable method are the 3Rs of reduce, reuse and recycle. This encompasses the principle of reducing consumption of products - not using single use plastics, buying only what is needed. Repurposing items - using plastic carrier bags as bin liners or cola bottles as clothes to protect new seedlings. Recycling items such as paper, glass etc.

The benefit is that waste is reprocessed into new products which reduces demand for raw materials and decreases the environmental impact. Also, less energy is used, reducing CO2 emissions. However, recycling does require new infrastructure of collecting and processing facilities, which do add to greenhouse emissions and air pollution.

What is incineration?

Waste is burnt, which reduces the volume of waste to landfill, but the remaining ash needs to be disposed of. Burning waste can generate electricity in a process called energy recovery. This reduces the use of fossil fuels, but can lead to the release of toxic chemicals into the air or water. It involves burning waste at very high temperatures, and the heat released is used to convert water to steam. The steam is sent to a turbine generator to produce electricity. The waste ash is collected and taken to a specialised landfill. But the ash can be contaminated with toxins that can leach out into the environment. Particulates are captured by high-efficient filtering.

Energy recovery incineration is better than simple incineration because:

· It disposes of gas, liquid and solid waste

· It is a practical method of disposing of certain hazardous waste materials (such as biological medical waste)

· Waste ash can be repurposed in roads and concrete (depending on type of ash)

· Waste ash can also be reprocessed to extract recyclable metals and glass

· High-efficiency filters remove many of the emissions

· It reduces the amount of landfill waste

What is landfill?

Landfill is the burial of waste in hollowed out land, where it is left to decompose over time. Waste can also be buried in disused/abandoned mines and quarries. In the past, landfill sites were unmanaged and prevention of environmental damage minimal or non-existent. Modern landfill sites are lined to prevent leachate from running out of the site. Leachate is collected in pipes and transferred to special leachate ponds, where it is treated to reduce environmental damage. Methane is produced as decomposition begins, which is either flared off or collected and used to generate electricity (gas to energy process). Closed landfill sites are landscaped and used as golf courses or housing etc. However, many older landfill sites are still contaminated and releasing methane into the atmosphere. Landfill sites are 'smelly' and attract vermin and rainwater can surface wash chemicals into rivers. In the UK, there is a general lack of space for any new landfill sites.

What are the impacts of the methods of waste disposal?

Waste Disposal Method | Impact |

|---|---|

| Unregulated | Waste is dumped on unofficial sites. Ecosystems are damaged, rivers and groundwater polluted, wildlife can be trapped in waste, unwanted vermin that can transmit diseases |

| Recovery | Waste is re-purposed into new products - concrete crushed to use as base for new roads and buildings. Reduces amount of waste to landfill and demand for natural resources |

| Recycling | Waste is reprocessed to produce a new product - plastic bottles into fleece coats. Reduces demand on raw materials, reduces greenhouse gas emissions, uses less energy. However, does require new infrastructure and collection points |

| Submergence | Waste is dumped at sea - illegal but some countries still do this. Submerged waste is usually toxic and radioactive which leaks into the ocean damaging ocean ecosystems |

| Trade | Waste is bought and sold by countries and shipped around the world. Receiving country may not have regulations in place or have the capacity to safely process waste. Source country still counts exported waste as locally recycled waste in its annual figures |

| Incineration | Waste is burnt at high temperatures. Energy recovery reduces the use of fossil fuel, less waste is sent to landfill. However, toxic chemicals and ash can be released into the atmosphere. Ash waste needs to be disposed of in specialised landfill sites as they are concentrated chemical contaminants |

| Landfill | Waste is buried and allowed to decompose over time. Methane can be used to generate electricity. Smelly and attract vermin. Leachate needs to be collected to prevent waterway contamination |