RECYCLING. Recycling is an ancient practice with many modern applications. It refers to the recovery and reuse of materials from spent products. In recent years recycling has become a major part of environmental policy, mainly because of the increased costs of solid- and hazardous-waste disposal, the scarcity of natural resources, and the growing concern over polluted land, water, and air. There are two types of recycling operations: internal and external. Internal recycling is the reuse …showed first 75 words of 498 total…

…showed last 75 words of 498 total…landfills reach their capacity, many municipalities turn to recycling programs as a relatively inexpensive alternative to landfill disposal. Some cities also solve energy-shortage problems and the need to dispose of growing amounts of organic wastes and garbage by converting waste into energy. This is done by pyrolysis, the incineration of refuse with a deficiency of air. While pyrolysis permits recovery of certain fuel gases, chemicals, and heat energy, it can also contribute to air pollution.