Acidic Wastes Neutralized Economically with Lime

Lime (calcium hydroxide) is an economical alternative for neutralization of acids in wastewater streams. It is available as a powder or slurried in water.

This table lists the approximate cost of using lime relative to that for other popular alkaline neutralizing agents:

Alkaline                                          relative cost 

Reagent                      

Calcium hydroxide (lime)                            1

Magnesium hydroxide (magnesia)               4

Sodium carbonate (soda ash)                     5

Sodium hydroxide (caustic soda)                7

Potassium Hydroxide                                15

Despite its low cost, the use of lime is often avoided because its successful application presents greater engineering challenges.

ERI offers a bulletin discussing the engineering considerations when using lime to neutralize wastewater.

Engineering Resource, Inc., 19 Edgehill Road, Winchester, MA 01890. Tel: 781-938-1074; Fax: 781-938-1075.