Heavy Metal Mobility in Soil: pH-Driven Sorption Equilibrium

Whether lead, cadmium or zinc contamination in soil turns into a groundwater or crop-uptake hazard depends less on the total amount present than on its chemical speciation — how much sits locked onto clay and organic-matter surfaces versus how much is dissolved and free to move. This simulator renders a 3D block of soil pore space with instanced metal-ion particles that continuously exchange between a sorbed state (bound to colloid surfaces) and a free state (mobile pore-water solution), governed by a real pH-dependent Freundlich-style distribution coefficient. Tune pH and cation-exchange capacity to watch acidification desorb metal back into bioavailable form, switch between lead, cadmium and zinc to see their different binding affinities, and track live readouts of the bound/free split, the current partition coefficient, and a Michaelis–Menten root-uptake flux driven only by the free-ion pool.