WASTE IN CITIES
Waste in cities is becoming a big problem. Cities in Sub-Saharan Africa are growing very quickly. Between 2010 and 2035 the number of people in cities will more than double. By the middle of the century more than 1 billion people will live in urban areas in Africa. Large numbers of people moving to cities is called urbanisation.
Urbanisation causes problems with waste. As a city grows so does the amount of waste that is made. The amount of waste in African cities is expected to grow a lot over the next few years. This will make it harder to manage the waste. If we do not manage waste then this can be bad for our health. We need to improve waste management systems so that we do not have waste in the streets. Waste that is not managed can clog up water systems and breed mosquitoes for example.
TYPES OF WASTE
Solid waste is the main form of waste in cities. Solid waste means any waste that is discarded or abandoned. Other words for solid waste are rubbish or litter. Household waste is the main form of solid waste.
Solid waste is always being generated. It is made every day. This solid waste can be handled in a number of different ways. Solid waste must be managed in a sustainable way to help the environment. Solid waste management reduces some of the bad impacts of waste.
GOOD WASTE MANAGEMENT
There are 5 main steps to a good waste management system:
- Waste generation/storage—people throw waste away. This is mainly in waste bins that are placed on a site. Waste can be thrown in different bins if it can be recycled or not.
- Waste collection and transport—waste bins are collected by lorries. These are moved in large vehicles to another location. All of the waste goes to the same place.
- Process and recovery—waste factories look through the waste and find what can be recycled. This makes it better for the environment.
- Disposal—this is the final stage. It gets rid of the waste. There are a few ways of doing this. These can be landfills and waste-to- energy schemes.
No waste management can cause health problems. Less than half of the waste in African cities is being collected. Accra alone generated 1000 tonnes of waste a day. The existing collection system can only keep up with 55% of this. This means that the city is becoming dirty and full of extra waste.
Unsustainable waste management has poor consequences for the environment. It can breed mosquitos and can spread diseases. It can also lead to the emission of obnoxious odours and methane. This is a gas that is bad for the environment.
These issues are common in African cities. City authorities are seeking easy ways of collecting rubbish.
This graph shows waste management schemes in the world. The ones at the bottom are the worst. Most of the ways of managing waste in Africa are found at the bottom of the graph.
Using waste to energy solutions is a good option in many African cities. Waste can be burned to make heat. This heat then turns water to steam. This is used to make electricity. Any organic waste from cities can be used for this. 66% of waste in Ghana is organic. This is perfect for burning. Waste to energy makes jobs and helps the environment. Most cities in Africa already have trucks that collect rubbish. These trucks could be used for such schemes.