Sanitary landfill is a solid waste disposal system that uses techniques seeking to minimize the impacts that garbage causes on nature.
The landfill is an area licensed by environmental agencies, intended to receive urban solid waste, basically household garbage, in a planned way, where the garbage is compacted and covered by earth, forming several layers.
The decomposition of garbage produces methane, carbon dioxide and other polluting gases that intensify global warming. A landfill reduces pollution, helps to reduce greenhouse gas emissions, avoids unpleasant odors, generates energy and can be a source of income through credits from carbon.
How does a landfill work
A landfill that meets clean development mechanism standards follows the following process:
1 - The soil is compacted to give firmness to the landfill that will receive a layer of high-density polyethylene, from below and from the sides, which prevents contact between the debris and the subsoil and from above when it is full.
2 – At the base, the layers of geotextile (fabric with bitumen, semi-permeable), gravel and sand, allow drainage of the leachate.
3 – Garbage is deposited in layers in the landfill, periodically interspersed with layers of earth.
4 - The gases produced by the decomposition of waste are captured and taken by pipeline to an energy generating plant
5 – At the plant, the gases combust and move generators, which produce electricity. There is no emission of methane and little carbon dioxide.
6 – The slurry (liquid that runs off the garbage) goes for treatment. After separating the water, solid waste goes back to the landfill.
Disadvantages of landfill
The landfill receives severe criticism because it is not intended to treat or recycle materials present in urban waste. Landfills work as garbage storage on the ground, occupying increasingly scarce spaces, but they are an outlet for the disciplined disposal of solid waste.
Dumping ground
These are places where garbage is deposited in the open, causing serious environmental impacts. The dump is a series of threats to both the environment and society. The main problems generated by garbage are soil and water pollution, the accumulation of non-degradable or toxic material and the proliferation of insects (cockroaches and flies) and rats that can transmit various diseases, such as bubonic plague, dengue etc.
The bacterial decomposition of organic matter, the biodegradable part of garbage, in addition to generating a typical bad smell, produces a dark and acidic broth called leachate, which, in large dumps, infiltrates the soil, contaminating the water table.
Compost
Composting is a biological process in which microorganisms transform organic materials into compost, thus reducing the amount of waste thrown into nature.
Composting can be made from vegetable waste such as vegetable husks and stalks, eggshells, leaves, grass clippings, food waste, paper, manure from vegetarian animals, etc. that are placed for decomposition, and by biochemical processes, carried out by micro-organisms, which use these residues as a source of energy, the degradation of this material occurs.
In composting, the garbage is placed in layers, alternating first with soil and then with organic material. Humus is a great alternative for composting, as a source of micro-organisms, as well as earthworms. In approximately three months, after turning over several times, the fertilizer will be ready for use.
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