GEOCHEMICAL LEACHING OF ALKALINE BATTERIES: IMPLICATIONS FOR LANDFILL DISPOSAL AND REMEDIATION OF LEAD CONTAMINATED COMPOST

Alkaline batteries containing zinc and manganese oxides are the primary disposable batteries used in North America. Composts from urban sources often exhibit elevated lead levels. Compost amended with these oxide powders might immobilize lead, while the soluble Zn could be taken up as a macronutrient into crops, avoiding landfill disposal risks and reducing Pb exposure. To determine the viability of this method, the oxide powders from AA alkaline batteries from several manufacturers were analyzed using XRF and XRD to determine bulk and trace elemental chemistry and phase identification. The XRD spectra confirmed the presence of the oxides in both new and used batteries. XRF results were consistent with the presence of ZnO and also identified variable amounts of Mn and K. Geochemical correlation analysis suggests distinct relationships between [Mn], voltage, and brand, with the Zn/K ratio serving as a first order proxy for brand. A leaching experiment was then preformed that tested samples in both autoclaved and nonautoclaved water from a brook impacted by suburban developments. ICP results showed that more leaching occurred in the nonautoclaved samples implying that biotic factors increased leaching. Leaching mass balance indicates that while more Zn is leached into solution on a percent basis more Mn is released to the solutions. After a 12 day incubation study at 27°C, municipal compost amended with 10% by weight spent alkaline battery oxide powders resulted in a 30% reduction in soluble lead compared to a control. These preliminary findings suggest that amending municipal compost with alkaline battery oxides does not introduce trace toxic metals and that it may be effective at sorbing soluble fractions of lead in the municipal urban carbon waste stream.