Examination of organic and inorganic xenobiotics in equipped printed circuits

To develop a proper recycling and waste disposal strategy for equipped printed circuit boards a good knowledge of the hazardous residues is required. Following substance groups were selected for investigation: PCBz, PBBz, PCPh, PCB, PBB, PBDPE, PAH and TBBP-A. After sampling in a electronics recycling and disposal company the printed circuits were disassembled and the components were sorted into 34 fractions and gravimetrically registered. The amounts of the organic and inorganic xenobiotics of 22 fractions was determined individually. Unexpectedly, analyses of these fractions have pointed out that PCB could not or only in small quantities be detected (maximum ε PCB = 0.6 mg/kg). Altogether the contamination with chlorinated compounds was smaller than the contamination with brominated ones, while the PBDPE were dominating (average 40.5 mg/kg). The determination of metal contents has shown that the main moiety is due to the elements copper, iron, lead and tin. The total content of nickel in the samples analyzed was clearly higher (5.45 g/kg) than described in literature. The share of single fractions in the total contamination was above average and was depending on substance group. Therefore, it is recommended to reduce the residue amounts of the electronic waste by specific removal of single fractions.