How do I dispose of excess acids?

Most commonly used acids such as Acetic Acid, Hydrochloric Acid and Sulfuric Acid can simply be diluted and then neutralized to be disposed of down the drain with plenty of water. Commonly, sodium bicarbonate (baking soda) is used for the neutralization. However, aqueous sodium hydroxide or another similar base can be used. It should be noted that neutralization of acids with a strongly basic solution will create a tremendous amount of heat and should be added slowly and carefully.

Nitric Acid, being a stong oxidizing agent, needs added care. To dispose of small amounts of nitric acid, dilute the acid first with water, then add a solution of sodium hydroxide to neutralize the solution to an acceptable pH for drain disposal.

Hydroflouric Acid (HF) is especially dangerous and should only be used by individuals aware of its properties and the proper ways in which it should be handled. Disposal can be achieved in one of two ways. First, excess slaked lime can be added to a dilute aqueous solution of HF to form a calcium flouride precipitate. Alternatively, a <1% solution of HF can be cooled in a water bath, while adding dilute aqueous sodium hydroxide to neutralize any acid, and then adding calcium chloride solution to precipitate calcium flouride. In both methods, the calcium flouride can be either washed down the drain (if under 100g) or preferably sent to the landfill.

Questions? Unfamiliar or uncomfortable with above procedures?
Contact Brian @ x1623 or eliasbr@earlham.edu