Water treatment methods in heavy metals removal during photovoltaic modules recycling: a review

Delivering efficient, affordable and sustainable water treatment methods in the removal of heavy metals in wastewater often remains a challenge. This paper seeks to alleviate this challenge by reviewing and assessing the viability and efficiency of different water treatment methods within the realm of end-of-life (EoL) photovoltaic (PV) module recycling. Specifically, this paper evaluates the possible designs, pretreatment requirements, efficiency, relative cost and environmental footprint of adsorption, ion exchange and membrane process, applications of physical-chemical and tertiary treatments, to protect the receiving environment and realise treated water reuse in EoL PV module recycling process respectively. The current results suggest that the membrane process is a promising solution to the various heavy metals removal in EoL PV recycling due to its comparatively good performance in efficiency and environmental footprint. Meanwhile, specifical efforts should be put into the development of cost competitiveness membrane that excels in EoL PV recycling. More importantly, exploring the potential combination of different water treatment methods could also greatly broaden the range of solutions available for addressing the existing water issues in EoL PV recycling.