Comparison of Fluoride Concentration between Input and Output Water in Water Treatment Plants No 1 & 2 of Ahvaz in 2010

Background and Objectives: The river is Karoon is the main resource of drinking water in Ahwaz. Fluoride is one of the water soluble ions, both low and high concentrations of which can cause adverse effects on human health and the other animals In this descriptive and analytical study, fluoride  ion level water of input and output in the water from water treatment plants no 1 & 2 of Ahvaz were measured. Subjects and Methods: Monthly, for 9 months, from March to November 2010, 60 samples from input pretreatment and output post-treatment water from water treatment plants no 1 & 2 of Ahvaz were collected in 1 liter polyethylene bottles. Fluoride concentration in water samples was determined by the SPANDS method, using a Spectrophotometer at 580 nm. Descriptive analysis on the data was carried by using SPSS-19 software. Results: Mean fluoride concentration in inputfor water treatment plants no2 was 0.33 mg/L which as higher than input for plant No 1 (0.31mg/L). On the other hand, fluoride concentration in the output water of from both plants was equal (0.26 mg/L). Conclusion: The results showed that the mean fluoride  concentration in  output water of both water treatment plant was lower than is lower than the WHO, EPA, EU and Iran standards. Results also showed that the mean fluoride concentration in drinking water was reduced  compared with  the mean fluoride  concentration in Karoon river. It seems that the precipitating agent, polyaluminum chloride, used in the path of water treatment, may be responsible for reduction of fluoride concentration