Phytoremediation of arsenic contaminated soils
We are working with a community partnership to investigate sustainable arsenic remediation at a field site in south Berkeley. When planning for a community orchard, gardeners discovered arsenic contamination (20-100 mg/kg) in the soil of the Santa Fe Right-of-Way, a former railroad grade now vacant.
We are conducting phytoremediation field trials using the brake fern, Pteris vittata L. Phytoremediation is the use of plants to remediate the soil, in this case by extracting the contaminant from the soil and translocating it to above-ground parts. P. vittata is an arsenic hyperaccumulator; arsenic concentrations in P. vittata fronds can reach 1000-7500 mg/kg. By harvesting the fronds, arsenic is removed from the site while leaving valuable topsoil in place. We are currently investigating use of organic and inorganic slow-release fertilizers to enhance arsenic accumulation in fern fronds. These field trials are a springboard for work quantifying the effects of soil characteristics, climate, and the presence of multiple contaminants on the remediation efficiency of P. vittata. We thus study fundamental biogeochemical cycling of arsenic and metals in soil, through a remediation lens. We hope to contribute to the development of affordable, low-waste, broadly applicable soil remediation methods.
Community partners at the Santa Fe Right-of-Way include Berkeley Partners for Parks, the Berkeley Community Gardening Collaborative, the Ecology Center, and Spiral Gardens Community Food Security Project.