Chemically Induced Phytoextraction of Lead (Pb) Contaminated Soil by Switchgrass (Panicum virgatum L.), assisted with BAP and NTA applications
Date of Award
Master of Science in Integrative Biology (MSIB)
First Committee Member
Second Committee Member
The accumulation of lead (Pb) deposits in soil is a growing global concern. Phytoextraction of Pb-contaminated soil can be enhanced by soil chelation to increase the bioavailability of Pb. In the initial study nitrilotriacetic acid (NTA) 5mM, the alkylpolyglucoside (APG) Triton X-100 (2%), and nano-silica were applied to switchgrass (Panicum virgatum L.) growing in 5L pots of Pb-contaminated soil. The second experiment used 10mM NTA, the alkylpolyglycoside Triton X-100 (2%), foliar application of the plant growth regulator 6-benzylaminopurine (BAP) twice per week, Triple-12® nutrients, and Infuse™ a soil fungicide which were applied to switchgrass Plants were grown in a controlled greenhouse environment in 5L pots with Pb-contaminated soil (5802.5 mg kg-1) collected from a former Superfund site in Cedartown, GA. Following harvest, plant material was dried, acid digested and chemically analyzed for lead (Pb), aluminum (Al) and iron (Fe) using an ICP-OES. Switchgrass treated with 5mM NTA showed an increased average Pb concentration of 858 mg kg-1, but this was further improved with applications of 10mM NTA, with an average concentration of 3196.5 mg kg-1 in plants foliage. Combined applications of NTA and APG and foliar applications of BAP and nutrients resulted in the highest average Pb concentration of 5,355 mg kg-1. The results suggested that soil applications of 10 mM NTA and Triton X-100, Infuse™ and foliar applications of BAP could be a beneficial technique for phytoremediation of Pb contaminated soils.