torage and reuse from earlier years enters the IT equipment waste flow in 2000.4.0 Materials Contained in IT EquipmentThe challenge encountered in diverting computers and peripherals from the waste stream through recycling and refurbishing activity result from the diversity of products and variety of materials contained in each product. For example, each hard drive contains a range of metals and plastics that can be difficult to separate. It is also difficult to identify the different plastics contained in each piece of equipment by resin type. The composition of personal computers and monitors are given in the Table 2 - 7 and the chart below: Precious metals include nickel, manganese, cobalt, barium, tin, silver, antimony, chromium, cadmium, selenium, mercury, gold and arsenic.Many of the materials contained in IT equipment can be potentially hazardous ifimproperly managed. For example, printed circuit boards contain heavy metals such asantimony, silver, chromium, zinc, lead, tin and copper and a CRT in a computer monitorcan contain from 0.7 to 2.7 kg of lead depending on the monitor’s size and year ofmanufacture 10. The production of semiconductors, printed circuit boards, disk drives and monitors use a number of hazardous materials 11. The lead oxide used in the cathode ray tubes (CRT) of computer monitors is of particular concern and it has been estimated that computer monitors represent approximately 15% of the lead found in the municipal waste stream 12.Hazardous materials found in obsolete computer equipment can be released to the environment through the following pathways:- Incineration of computer equipment concentrates heavy metals in ash residue;- Landfill disposal of computer equipment, and;-Recycling and recovery of computer equipment waste. The estimated quantities of materials contained in disposed PC’s and monitors inCanada in 1999 and in 2005 are shown in table and chart below: The hazardous materials co...
