A significant challenge the world faces today is rubbish management. Household and industries produce millions of tons of garbage every year. Waste contaminates soil, air and water, posing risks to human and animal health. Recycling is the process in which waste is converted into new materials.

The recycling process commences during rubbish removal. At this stage, the waste is sorted into different classes. For example, household waste is separated into plastic, paper, glass, metal and organic waste. Materials that cannot be recycled are either burnt or buried in landfills.

Recycling solid waste

Waste paper. Waste paper can be in the form of old newspapers or packaging material. In a paper recycling plant, the paper is sorted depending on its surface structure. It is then shredded and pulped. Pulping refers to adding water to form a slurry substance. The substance undergoes various chemical processes to remove ink and bleach the paper. Finally, the paper is mixed with new production materials, dried, and rolled into sheets ready to be reused.

Plastics. Plastics comprise a significant amount of the world's waste. Plastic bottles have found their way into the creative industry. They are used in interior design and various forms of art. At home, plastics bottles can be reused as storage containers, piggy banks or toys. There are special plastic recycling facilities that recycle plastics to make electric wire coating, plastic ropes and plastic bottles.

Metal. Sheet metal can be beaten to form new products. For example, in some countries metal sheets are used to fabricate ovens and grills. During the metal recycling process, the metal is sorted into different types of metal. The metal is then shredded into smaller pieces, melted and purified. Finally, it is solidified ready to produce new products. 

Glass. In a glass recycling facility, the glass is treated and sorted according to its colour. It is then crushed and melted. The molten glass is moulded into new products.

Organic waste. The best way to recycle organic waste is through composting. The organic waste is heaped to allow microorganisms to act on the material to produce manure. Manure is a viable option in crop production as opposed to chemical fertilisers. It improves the soil structure and promotes plant growth. Unlike chemical fertilisers, it does not pollute the soil.

Recycling aims to reduce the amount of solid waste and helps reduce environmental pollution. Some materials such as plastics and organic waste can be recycled at home, while paper waste, glass and metals may require a specialised recycling facility.