... Sulphate (PFS)Molecular formula: [Fe2(OH)n(SO4)3-n/2]m (n<2, m=f(n)) Appearance: Light yellow amorphous powder, hygroscopic, ... -soluble, % , ≤0.50.4Applications: As flocculant in purification of municipal water, industrial water, waste water, domestic sewage and sludge ... change after treatment with PFS. 6. Suitable for purification of low-turbidity, low-algae, low-temperature, low-contaminated raw ...