Key points are not available for this paper at this time.
In the first article of this series on the nature of organic compounds that cause color in natural waters (BLACK, A. P. & CHRISTMAN, R. F. Characteristics of Colored Surface Waters. Jour. AWWA, 55 :753 Jun. 1963), data was presented concerning the physical and chemical properties of colored raw waters. This article discusses experimental evidence of the chemical properties and structural characteristics of the organic materials responsible for the coloration of water. Because these materials are present in minute quantities in natural streams, concentration of samples was necessary before fractionation and subsequent analysis. Although recovery of the coloring materials was possible by several techniques, only two were used in this study, vacuum distillation and freeze concentration.
Black et al. (1963) studied this question.