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Composting - Recycling |
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Composting recycles organic household and yard waste into compost, which returns needed organic matter to the soil. While improving the soil for gardens, composting also reduces the amount of waste going into burgeoning landfills. Composting speeds up the process of decompositon by providing an optimal environment for waste to break down and enable it to return to the earth. This requires the correct mix of carbon, nitrogen, oxygen and water.
Decomposition occurs even without some of these ingredients; however, the process can be slow and unpleasant. For example, vegetables in a plastic bag decompose, but the lack of air encourages the growth of anaerobic microbes, which produce disagreeable odors. Degradation with insufficient air is called anaerobic digestion. Materials Different materials contain various nutrients for the composting bacteria. Some materials contain much carbon in the form of cellulose which the bacteria need to produce sugars and heat. Other materials contain nitrogen in the form of protein, which allow the compost bacteria to thrive.
Ingredients with higher carbon content include:
Dry, straw-type material, such as cereal straws
Autumn leaves
Sawdust and wood chips
Some paper and cardboard (such as corrugated cardboard or newsprint with soy-based inks)
Ingredients with higher nitrogen content include:
Green plant material (fresh or wilted) such as crop residues, hay, grass clippings, weeds
Manure of poultry and herbivorous animals such as horses, cows and llamas
Fruit and vegetable trimmings
Seaweeds
Coffee grounds
The most rapid composting occurs in matter containing 25 to 30 times more carbon than nitrogen by dry chemical weight. Grass clippings have an average ratio of 19 to 1 and dry autumn leaves about 55 to 1. Mixing equal parts by volume approximates the ideal range.
Poultry manure provides much nitrogen but little carbon, while horse manure provides both. Sheep and cattle manure compost at a lower temperature and so slower than poultry or horse manure.
Eggshells are a good source of nutrients for the compost pile and the soil, but typically take more than one year to decompose.
Mixing the materials as they are added increases the rate of decomposition, but it can be easier to place the materials in alternating layers, approximately 15 cm (6 in) thick, to help estimate the quantities. Keeping carbon and nitrogen sources separated in the pile can slow down the process, but decomposition will occur.
Some people put special materials and activators into their compost. A light dusting of agricultural lime (not on animal manure layers) can curb excessive acidity. Seaweed meal provides a ready source of trace elements. Finely pulverized rock (rock flour or rock dust) can also provide minerals, while clay and leached rock dust are poor in trace minerals.
Composting also breaks down petroleum hydrocarbons and some toxic compounds for recycling and beneficial reuse. Composting for such purposes is called bioremediation.
Some materials are best left to high-rate, a thermophilic composting system, as they decompose slower, attract vermin and require higher temperatures to kill pathogens than backyard composting provides. These materials include meat, dairy products, eggs, restaurant grease, cooking oil, manure and bedding of non-herbivores, and residuals from the treatment of wastewater and drinking water. Meat and dairy products can be recycled using bokashi, a fermentation method, but milk and oil cannot.
Human waste can be composted by composting toilets, but most composting toilets do not allow for the thermophilic decomposition needed to kill pathogens. If these high temperatures are reached, the resulting compost can be safely used as a fertilizer for food crops and even directly edible crops. Careful filtration of the compost also prevents contamination.
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This site is dedicated to prompting the reduction of an existing homes ecological footprint. The environmental impact of a house (and thus footprint) can be practically reduced through the use of environmentally friendly technologies and common sense ideas. An objective of this site is to find cost effective environmentally friendly solutions / ideas. Other topics include; Alternative energy and Biofuels. Energy conservation, Energy development, Environmental design and Environmental impact assessment. Natural buildings, Recycling and Composting. Renewable energy including solar enery, wind energy and Solar Power Cells. Solid waste treatment, Waste water treatment and Water purification.
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