The water quality study of the river and tap water in the Watarase, Tone and Edo river system by ion chromatograph

Abstract

In order to understand the behaviors of soluble chemical species at the confluence of the river water and water supply process, the Watarase, Tone, and Edo River System was studied in regard to the inorganic ion. This river system starts from the base of the Ashio copper mine and ends at Tokyo Bay. Along the rivers, there are 14 local municipalities in Gunma, Saitama, Ibaragi and Chiba Prefectures, as well as Tokyo . This area is center of the Kanto plain and includes the main source of water pollution from human activities . Moreover, the water of the river system is the source water for human activities in Kanto area. Also, we analyzed some chemical species to clarify water environmental status and outline the problems of water environment in research area. Water samples from 18 river sites and 42 water faucets at public facilities from Watarase, Tone, and Edo basin which include 14 local municipalities were collected and the degree of contamination was analyzed. The chemical species in river and top wa er were analyzed by ion chromatograph. Overall, it was thought that the Cl- of river water in the Watarase, Tone, Edo Basin contributed more large effect to water pollution than NO₃²- did . It was revealed the present water filtration plant procedures change the mineral balance of water. But, a good correlation in some ion elements between the river and tap water was found . For example, the correlation coefficients of Mg²+ and Ca²+ between them were 0 .912 and 0.969, respec tively. Also, it was confirmed the concentrations of Ca²+ and Na+ showed characteristic changes as the functions of location. These results may be important in the understanding of distribution behaviors of ionic chemical elements in this area.