AWWA JAW55360

In water treatment, acid and base addition is a common practice, used primarily to control the pH and alkalinity of the water and thus enhance treatment performance and reliability. Until recently, calculating the exact acid or base dose needed to cause a specific shift in pH required knowledge of the complex chemical reactions involved and the mathematical principles governing them. These calculations were usually made by hand or with the aid of spreadsheet programs. This article introduces a set of easy-to-use carbonate chemistry charts that can help water suppliers calculate the acid or base dose required to adjust the pH or alkalinity of a water. The author explains step by step how to use the charts to add an acid and a base chemical or determine other water parameters. These chart findings are then verified by mathematical calculations. The user-friendly charts eliminate the need for any familiarity with background chemical reactions or their complex mathematical representations. Now water quality engineers and treatment plant operators have only to follow a series of simple steps to arrive at the values they need to help optimize treatment processes. Includes 6 references, table, figures.