WATER POLLUTION AND RIVER ALGAE: STUDY IN ZAYANDEH ROOD RIVER – ISFAHAN

Abstract

Introduction: Dischange of domestic, agricultural and industrial waste water into the rivers increase chemical substances such as nitrate and phosphate. These chemical changes increase algal population. High density of algae may cause changes in color, odor and taste of water. Some of the algae such as Oscillatoria, Microcystis and Anabeana produce toxins and in high concentrations may kill fishes. While Zayandehrud river is considered as one of the main water supply sources for drinking water and valuable water resources of Isfahan Province, water quality control of this river is important. The study of algae of the river in relation with the concentration of nitrate and phosphate is the purpose of this research project.
Methods: To perform this projects, seven sampling stations from "Pole Vahid" to .Pole choom. were selected. Grab methods were used for sampling of the river water. 147 water samples were collected in one year of the study.The samples were analyzed for phosphate, nitrate and genera of the algae. Nitrate and phosphate of the water samples were determined using Phenol Disulfonic Acid and Stanous chloride methods, respectively. The genera of the algae were detennined using the keys.
Results and Disccusion:The result of the study showed that the frequency of the algae increased with increasing nitrate and phosphate. Overall.35 genera of algae in the area of the study were observed, which six of them were indicators of water pollution. Minimum frequency of indicators of pollution was observed in the enterance of Isfahan city and maximum frequency was observed after the discharge of municipal water from waste water treatment plant (pole Choom).