Phosphoric acid also called Mineral acid, has the formula and contains one phosphorous atom, four oxygen atoms, and three hydrogen atoms.
It is used in the removal of rust and in food and beverages.
The Phosphoric acid in its pure form then it can be disposed of directly as it acts as a good fertilizer. It can also be neutralized using Calcium carbonate .
Therefore, in its pure form, it acts as fertilizer, so it can be disposed of directly.