Comparative study of colored water samples made up of different humic substances with different properties

Abstract

The influence of the different characteristics of humic substances present in water with was studied in this work in order to observe the treatment performance by coagulation, flocculation and sedimentaion. It was verified that the different molecular weights of the humic substances used to provide the same color (100 HU) in the samples of study waters influenced very much the efficiency of color removal. The removal of apparent color resulted higher for the water study prepared with the fraction of humic substances with biggest molecular weight (> 100 KDa). When comparing the results of color removal with those of nuclear magnetic ressonance and infrared ray, it was observed that the higher the number of groups with the presence of the oxygen in the humic substances, the smaller was the efficiency of color removal for the same conditions of coagulation, flocculation and sedimentation.