Chlorination and Chloramine

Abstract

The studies reported in this paper are a continuation of those recorded in last year's Journal (vol. 3, 1916, 439-449) and constitute a partial attempt to place water chlorination on a scientific basis. Until comparatively recently the data that we possessed were a disconnected mass of empirically established facts, and it is a regrettable feature that although it is on this continent that the art of chlorination has progressed the most rapidly, it is in Europe, under the stimulus of war, that it is being developed as a science. As chlorination becomes more general it becomes increasingly evident that our stock of information regarding the conditions that tend to successful results is very meagre, and that the dosage is largely determined by the trial and error method. We are also lamentably ignorant as to the reason why some waters have but very small margins between the dose required for satisfactory purification and that which causes complaints as to tastes and odors, while others have much greater ones and can easily absorb slight excesses of the sterilizing agent. Complaints that arise in this way are often ascribed to auto-suggestion by water works and health officials, but they are too often based upon solid fact to be disposed of in this manner, and the time and energy that have been devoted to deluding the public might much better have been spent in improving present methods and so eliminating the cause for complaints. Chlorination is such a cheap and simple process that it is often considered the ultima thule of chemical sterilization, but there is no reason to doubt that the present methods will be modified and considerably improved. A simple modification that has yielded good results with some waters will be described later, but before treating that in detail a few general factors will be considered. In the last paper, the author gave results showing the effect of time, mechanical admixture, temperature, and organic matter upon chlorination by