Text S1.
Ash leachates were performed following the United States Geological
Survey Field Leach Test, which is a simple and cost-effective method to
simulate leaching by water (Hageman, 2007). Deionised water was added to
ash at a ratio of 20:1. Samples were mixed thoroughly and allowed to
settle for ~10 minutes. Subsamples were collected and
filtered with a 0.45 μm nitrocellulose filter. Filtered samples were
then analysed and quantified using solution Inductively Coupled Plasma
Atomic Emission Spectroscopy and Mass Spectrometry at the Isotope
Tracing in Natural Systems laboratory ANSTO, Australia.