Amanda Minke1 and Jean E. McLain2, Joel L. Cuello3, Robert Root4
1Department of Hydrology and Atmospheric Sciences
2Water Resources Research Center
3Agricultural and Bio-Systems Engineering
The University of Arizona, Tucson AZ
Human exposure to lead (Pb) is a global-priority environmental health concern. Lead(Pb) is a known neurotoxin, and has been linked to diminished IQ and serious health problems, affecting the welfare of millions of people worldwide through natural and anthropogenic contamination of drinking water sources. This project will investigate metal-microbe phytoremediation (removal) of Pb from drinking water using common freshwater algae. The preliminary data show that wet algae packed on filter paper can remove nearly 100 µg Pb per gram of algal biomass. Removal of lead increased with algae availability, as 1.0 mg Pb in a 1-liter water sample was reduced to Pb = 0.45, 0.30, 0.26. Furthermore, a kinetic response was observed for increased reaction durations, indicating that control of Pb sequestration in algae is driven by both diffusion and biochemical interactions. Lead removal by algae showed an inverse relation with free-sulfur, possibly indicating that the mechanism of Pb bioremediation by fresh water algae involves sulfur functional groups. This project investigates contact time, algal species, and removal mechanisms under expected water chemistry conditions of drinking water to further characterize Pb removal, information that will be critical to the development of cost effective and sustainable bioremediation strategies.