Anionic speciation in nutrient solutions as a function of pH

In hydroponic plant nutritional research, nutrient solutions are aqueous solutions containing all the essential macro- and micronutrients. In general, nutrient solutions are looked at as static aqueous solutions of inorganic ions. The ions are supposed to be present as free ions. This assumption does not take into account the dissociation, complexation, and precipitation reactions occurring in nutrient solutions and their dynamic equilibrium. All these reactions take place at the same time and interact with each other, affecting elemental speciation and bioavailability. In this research, only speciation calculations are carried out. For a standard nutrient solution, containing Fe(HEDTA) as iron chelate, elemental speciation is calculated for a pH range from 2:0 to 9.0. For all anions present in the nutrient solutions, the formation of precipitates, ion pairs, and soluble complexes as a function of pH are graphically represented.