Year Established: 2018 Start Date: 2018-03-01 End Date: 2019-02-28
Total Federal Funds: $9,903 Total Non-Federal Funds: $20,891
Principal Investigators: Robert Root, Amanda Minke, Jon Chorover, Joel Cuello, Jean McLain
Abstract: Human exposure to lead (Pb) is a global-priority environmental health concern. Lead 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. The recently well-documented case of Pb contamination in municipal drinking water in Flint, Michigan has emphasized the critical need for remediation of contaminant Pb from potable water, but recent findings of Pb in Arizona drinking water have brought this problem much closer to home. Because of its environmental abundance, toxicity, and potential for human exposure, Pb has been designated a priority toxin (#2 after arsenic) by the Agency for Toxic Substance and Disease Registry. This undergraduate-driven project will investigate metal-microbe phytoremediation (removal) of Pb from drinking water using common freshwater algae. Our preliminary data show that wet algae packed on filter paper can remove nearly 100 g Pb per gram of algal biomass. Removal of lead increased with algal availability, as 1.0 mg Pb in a 1-liter water sample was reduced to Pb = 0.45, 0.30, 0.26 and 0.15 mg l-1 after passing it through 4, 6, 8, 10, and 16 g of algae. 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. Pb 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 proposal will investigate 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. This work will not only examine the control of a serious water quality problem using renewable natural resources, it will also support the research of a promising University of Arizona undergraduate.