Zinc removal by Chlorella sp. biomass and harvesting with low cost magnetic particles

Remediation of an environment affected by metals based on the use of algae is an important technological breakthrough, where biomass harvesting is the limiting key-point. In this research, iron oxide particles (IOPs) and natural magnetic clay (NMC) coated with polyethilenimine (PEI) were successfully applied in the harvesting of Chlorella sp. coupled to the remediation of zinc ions with harvesting efficiencies >94%. Even though the presence of the metal did not affect the harvesting process, adding IOPs induced a metal displacement which increased zinc concentration upon harvesting. Contrary to that, Clay-PEI functionalized (NMCP) particles increased the amount of removed metal after harvesting. From these results it can be concluded that both tested particles are suitable for harvesting algal biomass and only NMCP are compatible with metal remediation.