What is the Initial dose for FeCl2, FeSO4, Al2 (SO4)3) during wastewater coagulation-floculation process?

i want to investigate microplastics removal efficiency through coagulation and flocculation process . i need to know the initial dose of the three mentioned inorganic salts dose for my lab based experiment. what should be the concentration of stock solution and what should be the initial dose during jar test. Thanks