Evaluation of environmental impacts for non-metallic part in waste printed circuit boards (PCBs) using combined material flow analysis (MFA) and life cycle assessment (LCA)

Abstract

Printed circuit boards (PCBs) have become common components in most electric and electronic equipment. Because of their wide ranges of application, waste PCBs is becoming one of the most rapidly growing wastes. Recycling of waste PCBs is an important subject not only for the protection of the environment but also for the recovery of valuable metals. This study aimed to evaluate the waste PCBs management strategies using the combination of material flow analysis (MFA, STAN v.2.6.801) and life cycle assessment (LCA, SimaPro v.8.3.0.0) methods. The waste management scenario was considered for three different options; disposal of the waste PCBs (Option 1), separation as metallic and non-metallic parts before final disposal of the waste PCBs (Option 2) and recycling non-metallic parts of the waste PCBs (NM-PCBs) as a filler additive in HPDE compounded plastic (Option 3). From MFA results, PCBs can be separated into 71 wt.% of NM-PCBs and 29 wt.%. For climate change impact, the results demonstrated that the least impact value was the recycling the NM-PCBs (Option III) about 21.63 kg CO₂-eq which lower than disposal to landfill and incineration (Option I) about 26.59 kg CO₂-eq. The recycling of NM-PCBs as the substitute material for the production of recycling plastic supported a better environment in terms of climate change (kg CO₂-eq), human toxicity (kg 1,4-DB-eq.), terrestrial ecotoxicity (kg 1,4-DB-eq.) and metal depletion (kg Fe-eq). The ratio of NM-PCBs in virgin HDPE had a linear effect on the environmental impacts. Furthermore, the combination of MFA and LCA methods suitable for a powerful assessment of impact which supporting management of waste PCBs.