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Land degradation. is a human induced or natural process which impairs the capacity of land to function. Soils are the critical component in land degradation when it involves acidification, contamination, desertification, erosion, or salination. Soil acidification.
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Land degradation • is a human induced or natural process which impairs the capacity of land to function. Soils are the critical component in land degradation when it involves acidification, contamination, desertification, erosion, or salination.
Soil acidification • While soil acidification of alkaline soils is beneficial, it degrades land when soil acidity lowers crop productivity and increases soil vulnerability to contamination and erosion. Soil acidification is accelerated by the use of acid-forming nitrogenous fertilizers.
Soil contamination • Soil contamination at low levels is often within soil capacity to treat and assimilate. Many waste treatment processes rely on this treatment capacity. Exceeding treatment capacity can damage soil biota and limit soil function.
Desertification • is an environmental process of ecosystem degradation in arid and semi-arid regions, or as a result of human activity.
Soil erosion • Soil erosional loss is caused by wind, water, ice, movement in response to gravity. Although the processes may be simultaneous, erosion is distinguished from weathering. Erosion is an intrinsic natural process, but in many places it is increased by human land use. Poor land use practices include deforestation, overgrazing and improper construction activity. Improved management can limit erosion using techniques like limiting disturbance during construction, avoiding construction during erosion prone periods, intercepting runoff, terrace -building, use of erosion suppressing cover materials and planting trees or other soil binding plants.
Soil salination • Soil salination is the accumulation of free salts to such an extent that it leads to degradation of soils and vegetation. Consequences include corrosion damage, reduced plant growth, erosion due to loss of plant cover and soil structure, and water quality problems due to sedimentation.
Waste management • Waste can be • solid • liquid • gaseous.
Waste management is the collection, transport, processing (waste treatment), recycling or disposal of waste materials, usually ones produced by human activity, in an effort to reduce their effect on human health or local aesthetics or amenity. A subfocus in recent decades has been to reduce waste materials' effect on the natural world and the environment and to recover resources from them.
The waste hierarchy • reduce • reuse • recycle.
Environment friendly methods of waste management • Composting • Recycling (pre-consumer waste recycling and post- consumer waste recycling)
Recycling • means to recover for other use a material that would otherwise be considered waste. The popular meaning of ‘recycling’ in most developed countries has come to refer to the widespread collection and reuse of various everyday waste materials. They are collected and sorted into common groups, so that the raw materials from these items can be used again (recycled).
Recyclable materials • aluminium • steel • HDPE and PET plastic bottles • glass • paper • cardboard • other types of plastic: PVC, LDPE, PP, PS.
Landfills • Disposing of waste in a landfill is the most traditional method of waste disposal, and it remains a common practice in most countries.
A properly-designed and well-managed landfill can be a hygienic and relatively inexpensive method of disposing of waste materials in a way that minimises their impact on the local environment. Older, poorly-designed or poorly-managed landfills can create a number of adverse environmental impacts such as wind-blown litter, attraction of vermin, and generation of leachate which can pollute groundwater and surface water. Another byproduct of landfills is landfill gas (mostly composed of methane and carbon dioxide), which is produced as organic waste breaks down anaeribically. This gas can create odor problems, kill surface vegetation, and is a greenhouse gas.
Incineration • Incineration is a waste disposal method that involves the combustion of waste at high temperatures.
Composting • Waste materials that are organic in nature, such as plant material, food scraps, and paper products, are increasingly being recycled. These materials are put through a composting and/or digestion system to control the biological process to decompose the organic matter and kill pathogens. The resulting stabilized organic material is then recycled as mulch or compost for agricultural or landscaping purposes.
Mechanical biological treatment • (MBT) is a technology category for combinations of mechanical sorting and biological treatment of the organic fraction of municipal waste. MBT is also sometimes termed BMT- Biological Mechanical Treatment- however this simply refers to the order of processing.
Pyrolysis & gasification • are two related forms of thermal treatment where waste materials are heated to high temperatures with limited oxygen availability. The process typically occurs in a sealed vessel under high pressure. Converting material to energy this way is more efficient than direct incineration, with more energy able to be recovered and used.
Hazardous waste • Paints • Solvents • Heavy metals • Radioactive waste material