Sustainability : Waste Management

Sustainability : Waste Management - Key SQA Definitions:

• Reduce - To decrease the amount of waste produced.

• Reuse - To refill or find another use for a product without processing it other than cleaning.

• Recycle - To reprocess materials into new and useful products

Global Waste Production vs Population

As discussed previously, the global Human population has increased massively in recent times. This has put huge pressure on waste management, as the increased population will inevitably produce more waste:-

Reduce, Reuse & Recycle

The key focus of sustainable waste management in Scotland since the 1970s has been the statement - "Reduce, Reuse, Recycle".  

This can be broken down into the following definitions:- 

• Reduce - To decrease the amount of waste produced.

• Reuse - To refill or find another use for a product without processing it other than cleaning.

• Recycle - To reprocess materials into new and useful products.

The video below shows how the University of Aberdeen encourages its students to "Reduce, Reuse & Recycle":-

The Circular Economy 

In traditional production the path taken by a product is known as a "Linear Economy". The product is made from raw materials, sold to a consumer, then becomes waste (usually in a landfill). This method of production is unsustainable and is now being addressed by looking to move towards a much more sustainable path, known as a "Circular Economy". 

In a Circular Economy, all products are designed to be completely reusable, with explicit planning on how the products can be returned to point of origin and then remade, with nothing going to waste. 

Belwo are two examples of the Circular Economy in action within Scotland:-

Waste Management : The Role of SEPA

Waste management activities in Scotland are regulated by SEPA to prevent pollution and to prevent harm to human health. SEPA regulates these activities through a system of licences and permits. If a company wishes to dispose of waste, it has to be done in a regulated way, it cannot just be dumped or released into the environment. 

The videos below show an overview of SEPA, as well as a summary of a multi-agency project on waste management and waste crime that SEPA is a part of:-

You would go to people’s homes and businesses and collect rubbish that can be used for a new purpose rather than just thrown away. Your work would help people and industries re-use resources and reduce their impact on the environment. You would empty recycling boxes and wheelie bins into the collection vehicle, check that the right kind of materials have been put out for recycling. 

You would also use machinery to help you lift and sort items at the waste collection site and the recycling site, work on the conveyor belt at a waste plant, sorting waste and removing non-recyclable items. 

Waste Management : Plastics

When first invented, Plastic was seen as a 'wonder material' something with nearly infinite applications, cheap and easy to produce, durable and long lasting. But it is these very properties that makes Plastic so polluting in our environment. 

The videos below show an overview of the issues of Plastic Pollution:-

As can be seen in other aspects of resource use, Plastic waste is not produced equally across the globe, it can be seen that several key countries create the vast majority:-

However, the data above only shows production, not how the management of waste plastic is dealt with. It is the mismanagment of waste that causes environmental, social economic and political issues. The map below shows how much plastic pollution was released into the world's oceans in 2019:- 

Plastic Production vs Endpoint

The long lasting qualities of Plastics are now causing huge environmental issues. Once plastic enters the environment, it can take 100s of years (if ever) to fully decompose. The diagram below shows some of the average decomposition times from common products in the ocean:-

Plastic Waste : Micro-Plastics

Even once a plastic product has 'decomposed' it still exists in the form of 'Micro-Plastics', fragments of plastic smaller than 5mm in size : 

The potential risks to living organisms due to mirco-plastics is not well understood, and is an area of current research. What is known is that micro-plastic contamination can be found everywhere in the environment : 

The diagram below  further shows the extent of the Plastic Waste issue:-

Reducing Plastic Waste : Recycling

In order to reduce the impact of this huge volume of single use plastic going to landfill, recycling of plastic should be done wherever possible. As can be seen from the previous diagram, this still only makes up a very small proportion of the total plastic volume but is something that is increasing globally. 

The graph below shows how the percentage of household waste being recycled, composted or prepared for re-use has changed in Scotland 2004-2015:-

Plastic recycling is a energy-intesive process. Firstly, the plastic is separated from all other waste materials and then cleaned to remove any other contaminants. This cleaned waste plastic is then shredded into small flakes or melted into pellets, which can then be used to create new plastic products. 

The video below shows the process of recycling plastic waste from homes into a usable raw material:-

A large part of the energy used in  plastic recycling is separating recyclable plastic from non recylable plastic. This can be reduced by being aware of what type of plastic should be put in a plastic recyling bin, and which should be disposed of appropriately elsewhere : 

In the above table, the colour coding shows the ability to be recycled : 

• Green - Recycled through kerbside recycling schemes

• Amber - Recycled a specialist points (e.g. supermarket uplift etc.)

• Red - Not recyclable, should be disposed of appropriately through other means

Reducing Plastic Waste : Bio-Plastics

When most people think of plastic, they are thinking of plastic made from Crude oil. But the definition of 'Plastic' in chemistry is much wider than that. 

A Plastic is defined as:-

"A synthetic or natural substance that is made from a Polymer (a repeating chain of small molecules)  that can be molded into a new fixed shape." 

Examples of natural polymers (natural plastics)  are:-

• Spider Silk (used for making webs)

• Keratin (makes the structure of nails / horns) 

• Latex (Sap of the Rubber tree) 

• Cellulose (makes the structure of plant material)

By looking to biological sources for plastics, plastic production can be made more sustainable as these plastics will biodegrade in the environment and do not require fossil fuels (as a raw materal at least) to produce. Any 'Plastic' made from a biological source is know as a 'Bio-Plastic'. 

Bio-Plastics can be made from a wide range of natural sources:-

Bio-Plastics support a sustainable 'circular' economy as any waste produced is used as nutrients for the growth of further raw materials:-

The videos below show examples of specific products that are being produced using Bio-Plastics:-

Waste Management : Transport & Air Pollution

Waste in the form of solid object, like plastic or scrap metal, is easily noticed in the environment, but other types of waste are much harder to see, for example air pollution due to emissions from vehicles:-

Air pollution is one of the world’s largest health and environmental problems and is one that is much more common in MEDCs due to the increased Industrial and Transport emissions. 

In the year 2018 alone, 6.67 million deaths globally were caused by air pollution, making it the third highest risk factor to health globally:-

Long-term exposure to air pollution can also have detrimental effects on Health as well, for example some studies have shown a link between air pollution levels and a lowering of cognitive function. 

The videos below show an overview of air pollution, as well as a case study example from India:-

You would make sure that the places where people live, work and go for leisure and sport are safe, healthy and hygienic. You could deal with a wide range of issues including Food safety, Environmental protection, Pollution control, Noise control Health and safety at work or Waste management.

Your work would protect people from dangers like pollution, unsafe food and pests. You might specialise in one of these areas, or you might deal with all environmental health issues in your local area or company. You could work in both the private and public sectors. You would need to understand legislation and procedures and explain the requirements to the business you inspect.

Air Pollution Case Study : Carbon Monoxide

Carbon monoxide is a colourless, odourless toxic gas that is emitted from vehicle exhaust (among other sources). The two images below show the atmospheric carbon monoxide concentration at sea level for East Asia & North America on the 23rd of March 23:-

As can be seen from the images, the areas of high concentration of carbon monoxide are in areas of large population with substantial transport networks and congestion. 

In New York on the 23rd of March 23, the carbon monoxide level was 1.083 ppm (parts per million). This is more than 10 times higher than 'clean air' and is at a level at which the risk of hospitalisation from cardiovascular disease among people over the age of 65 is increased.

Air Pollution Case Study : Particulate Matter (< 2.5 µm)

In waste gas emissions, microscopic particles of whatever is being burnt is released. Of particular concern to health is particles that are smaller than 2.5 micrometers in size (PM2.5). This particulate matter is so small can penetrate deep into the alveoli of the lungs and can cause short-term health effects such as eye, nose, throat and lung irritation, as well as effect lung function and worsen medical conditions such as asthma and heart disease.

The two images below show the atmospheric carbon monoxide concentration at sea level for East Asia & North America on the 23rd of March 23:-

In Northern China on the 23rd of March 23, the PM2.5 particulate level was 84 µg per cubic meter. This is more than 7 times higher than the 'clean air limit' and is at a level at which the risk of aggravation to the heart and lungs of the general public (not just those with sensitivities) is increased. 

Reducing Air Pollution

There are a number of actions that can be taken to help reduce air pollution. The small changes each individual can make will add up to a big change if everyone does their part. 

Changes that can be made to reduce air pollution from transport include:-

• Use vehicles less and use public transport if possible

• Walk or cycle

• Car share whenever possible

• Use a low emission vehicle such as an electric or hybrid car

• Avoid driving during congested peak traffic periods 

• Avoid letting engines 'idle'