The Effect of Plants on Lead Dissolution

Berm soils at small arms firing ranges (SAFRs) are contaminated with metals as bullets impact the soil and corrode. These berms generally lack vegetation and frequently suffer from erosion that may transport heavy metals (e.g. lead) into surface water and, occasionally, into groundwater. Plants are generally useful for stabilizing metals in SAFR soils by reducing particulate runoff. However, results have shown that plants appear to increase lead solubility in surface runoff and leachate. Studies were conducted to investigate this phenomenon that plants enhance lead solubility and complexation. Hydroponic bermuda plant culture solutions were prepared. Plant culture and soluble lead solutions were reacted to form lead complexes. Ion exchange filtration was performed to separate lead complexes based on relative molecular sizes. Results showed that bermuda cultures increased lead solubility and formed measurable lead complexes for fractionated sizes. Continued research will determine the effect of soluble plant organic compounds on metal dissolution.