Metals concentration levels in printed circuit boards of discarded cathode ray tube television: trends over the years

The main objective of this study was to investigate the trends of Cu, Pb, Ni, Cr and Cd concentrations present in printed circuit boards of cathode ray televisions over the years. Dismantling, shredding, pulverisation, digestion and chemical analysis were followed for sorting, separation, and analysis of metal concentrations in printed circuit boards of cathode ray televisions. After digestion using EPA SW 846 method 3050B, the extracts were analysed for metal concentrations using atomic absorption spectrophotometric technique. The results obtained showed that the mean metal concentrations in all televisions' printed circuit boards studied were - Cu: 11.73 +/- 2.91%, Pb: 3.30 +/- 0.86%, Ni: 0.106 +/- 0.138%, Cr: 0.00523 +/- 0.00130% and Cd: 0.00291 +/- 0.00148%. There was virtually no regular pattern in the average metal levels from 1975 to 1999; they initially decreased, increased and then decreased. However, an observable decrease in the level of these metals was noticed from 2000 to 2009. Cu, Pb, Ni, Cr and Cd were noticed to have decreased from 2000-2004 to 2004-2009.