POSSMs: a parsimonious speciation model for metals in soils

Environmental context Predicting the chemistry of metals is important for understanding their movement and impacts in environment. Metal models are generally complex difficult to apply, but a simpler model, which does not need large amounts input data, can also provide good results. A model be more easily included large-scale metal transport Abstract Mechanistic geochemical useful detailed study speciation well-characterised soils, challenging apply when driving soil compositional data sparse, example, at scales. Empirical models, using minimal have been developed either prediction solid–solution partitioning or computation free ion from total geochemically active metal. This work presents an empirical POSSMs (ParsimOniouS Speciation Metals soils), predicts free, solution-bound sorbed single calculation, set parameters. The has parameterised Ni, Cu, Zn, Cd Pb datasets solution phase composition. used compute was tested by applying it literature on solutions extracts, partitioning. performance comparable other similar complexity. Some test produced biased predictions, particularly underestimation measured circumneutral alkaline pH, where predicted low concentrations. replacement mechanistic tool comprehensive available.