Abstract

Acid and base addition is commonly practiced in drinking water treatment. These chemicals are used primarily to control pH and alkalinity of water in order to enhance treatment performance and reliability. The acid or base dose required to cause a predetermined change in pH is primarily influenced by the starting pH and alkalinity of the water. Calculating the exact acid or base dose needed to cause a specific shift in pH requires knowledge of the basic chemical reactions involved and the mathematical principles that describe them. This article provides an introduction to and validation of user-friendly charts that can be used to answer questions of acid or base addition, as well as the corresponding pH and alkalinity changes. The charts presented do not require any knowledge of the background chemical reactions or their mathematical representations.