The Earth is getting exhausted. Cities are facing an increasing growth in population, and shares in GDP growth, resulting in, among other things, increasing quantities of waste being generated. There is a strong movement in many countries to reduce the volume of wastes to be dumped. Organic fraction of garbage can be converted into a useful and commercial product with a higher value. At home, individually , we can also do our share. Besides a correct waste selection , home composting can be a natural way of recycling.

Urban Solid Waste (USW), commonly known as garbage , is the result of domestic and commercial activity in urban areas. According to the national policy of solid wastes, material, substance, object resulting from human activity in society are solid wastes. Composting and recycling can be  two ways of reusing them.


Composting is nature’s way of recycling. Composting biodegrades organic waste. i.e. food waste, manure, leaves, grass, paper, wood, feathers, crop residue etc., and turns it into a valuable organic fertilizer.

On the composting process we can use some food leftovers (remains, stalks and bark of vegetables and fruits, eggshells, coffee grounds, fresh wastes like grass and leaves that have high nitrogen concentration) and cooked or baked goods (avoiding excess salt and  preservatives in processed foods).

Yet we can´t use  foods like citrus fruits (because their pulp and peels can change the pH of the earth), dairy products, and meat like chicken, fish and beef (because they are too damaging to the compost, smell and attract animals).

Composting has many benefits

Although requiring regular maintenance of the compost pile, to handle factors such as temperature, humidity and aeration, as well as the presence of small animals, composting is a way to eliminate some of  urban solid wastes, avoiding its accumulation in landfills.

Industrial Composting

Approximately 45 – 55% of the waste stream is organic matter, composting can play a significant role in diverting waste from landfills thereby conserving landfill space and reducing the production of  methane gas. In addition, an effective composting program can produce a high quality soil amendment with a variety of end uses (.


Compost can be used in a variety of applications. High quality compost can be used in agriculture, horticulture, landscaping and home gardening. The resulting products can be used to improve the soil structure, returning to the soil the nutrients it needs, increasing its water retention capacity, allowing the control of the erosion and avoiding the use of synthetic fertilizers .

Experts say that 30% of household waste can be used in  composting!


Alunos envolvidos no projeto: Débora Madaleno; Érica Gumbe

Escola: Escola Secundária c/ 3º ciclo de Caneças

Data: 20.03.2018

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