I'd like to know more about some water treatment chemicals(mostly polyphosphates as anti scale and inhibitors) and I'll be glad if someone can help me.
This book goes into decent detail but is still easy to understand about the chemistries available for cooling water treatment, and namely scale and corrosion inhibition.
From what I understand, Poly-PO4 is more of a cathodic corrosion inhibitor than a scale inhibitor. Organic P such as phosphonates and polyacrylamide and polyacrylates are generally seen as better scale inhibitors.
One of the significant drawbacks to any phosphates is that the P will, when it hits water, provide nutrients for algal blooms. Current recommended nutrient levels for P are in the micrograms per liter.
H2SO4 is mostly used as anti scalant increasing solubility of colloidal molecules like silicates, specially for RO, later you have to neutralize its acidity with an alkaline reagent like NaOH